Transportation system with malfunction monitor

• US 3,961,688 A
• Filed: 04/29/1974
• Issued: 06/08/1976
• Est. Priority Date: 04/29/1974
• Status: Expired due to Term

• Current Assignee: Armor Elevator Co., Inc.
• Original Assignee: Armor Elevator Co., Inc.
• Inventors: Maynard, John T.
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Duncanson, Jr., W. E.
• Application Number:
  US05/465,271
• Time in Patent Office: 771 Days
• Field of Search: 187/29
• US Class Current: 187/289
• CPC Class Codes: B66B 1/306 with DC powered elevator drive
• CPC Class Codes: B66B 5/0006 Monitoring devices or performance analysers B66B5/02 takes precedence
• CPC Class Codes: B66B 5/0018 Devices monitoring the operating condition of the elevator system
• CPC Class Codes: B66B 5/02 responsive to abnormal operating conditions

Abstract

A transportation system such as an elevator utilizes a static power converter to directly energize a D.C. drive motor and another static power converter to directly energize a friction type braking element and automatically selects a mode of operation best suited for safe operation from a plurality of modes including a normal operation, a reduced speed operation, an emergency landing operation and an emergency operation in response to certain sensed malfunctions within the system including a decrease in the source voltage to a predetermined magnitude, an increase in the armature current of the D.C. motor to a predetermined magnitude, a decrease in the field current of the D.C. motor below a predetermined magnitude, an increase of an error signal as sensed by an error detector to a predetermined magnitude, a malfunctioning of the error detector, an increase in the velocity of the vehicle as sensed by a velocity detector exceeding certain predetermined magnitudes, the malfunctioning of the velocity detector, a decrease in the source current to a predetermined magnitude, a loss of a phase of source energy as sensed by a phase detector, a failure of a rectifying element within the phase detector, an improper sequential order of the source alternating phases, a predetermined temperature within a gated rectifying circuit, an improper electrical connection by a circuit connector, and the movement of the vehicle to a first position adjacent to a landing at which a stop is being made and a subsequent movement to second position. The system responds to a sensed malfunction by providing a plurality of redundant sequences and fail-safe circuits in selecting the mode best suited for safe operation.

Claims

1. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, braking means selectively permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure, control means connected to a source of energy and cooperating with said motive means and said braking means and controlling movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the movement of said vehicle, means monitoring one or more malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode of operation operating said vehicle and providing normal service between a plurality of landings and a second mode of operation established in response to a malfunction sensed within said transportation system rendering said motive means essentially inoperative for supplying a driving force to said vehicle and automatically operating said braking means as essentially the sole control for guiding said transport vehicle to one of said landings.

2. The transportation system of claim 1, wherein said control means includes first sequence means operatively coupled to said braking means and permitting vehicle movement from one of said landings and second sequence means operatively coupled to said braking means and permitting vehicle movement until arriving at a first position adjacent to a landing at which a stop is to be made, said transfer means operatively removing said first sequence means from effective operation in response to said sensed malfunction.

3. The transportation system of claim 2, wherein said control means includes third sequence means operatively coupled to said braking means in response to said vehicle arriving at a second position with respect to said landing at which said stop is to be made and permitting vehicle movement, said transfer means operatively removing said third sequence means from effective operation in response to said sensed malfunction.

4. The transportation system of claim 1, wherein said control means includes first sequence means operatively coupled to said braking means and permitting vehicle movement until arriving at a first position with respect to a landing at which a stop is to be made and second sequence means operatively coupled to said braking means in response to said vehicle arriving at a second position with respect to said landing at which a stop is to be made and permitting vehicle movement, said transfer means operatively removing said second sequence means from effective operation in response to said sensed malfunction.

5. The transportation system of claim 1, wherein said control means includes sequence means operatively coupled to said braking means and permitting vehicle movement from one of said landings, said transfer means operatively removing said sequence means from effective operation in response to said sensed malfunction.

6. The transportation system of claim 1, wherein said control means includes sequence means operatively coupled to said braking means in response to said vehicle arriving at a first position with respect to said landing at which a stop is to be made and permitting vehicle movement, said transfer means operatively removing said sequence means from effective operation in response to said sensed malfunction.

7. The transportation system of claim 1, wherein said motive means includes an energy dissipating circuit selectively coupled to an armature circuit, said control means includes sequence means operatively coupled to said transfer means and to said dissipating circuit and maintaining said dissipating circuit disconnected from said armature circuit until said vehicle at least arrives at a first position adjacent to said landing at which a stop is to be made in response to said sensed malfunction.

8. The transportation system of claim 1, wherein said motive means includes an energy dissipating circuit selectively coupled to an armature circuit, said control means includes timing means operatively coupled to said dissipating circuit and selectively connecting said dissipating circuit to said armature circuit at a predetermined time after said vehicle has stopped at a landing, said transfer means operatively coupled to said timing means and conditioning said control means to connect said dissipating circuit to said armature circuit substantially at the time said vehicle is stopped at said landing in response to said sensed malfunction.

9. The transportation system of claim 1, wherein said transfer means includes first circuit means rendering said motive means inoperative for supplying a driving force to said vehicle independent of said braking means in response to said sensed malfunction.

10. The transportation system of claim 1, wherein said control means includes a gated rectifying circuit connected to said source and to a gating control circuit and selectively conducting varying amounts of electrical energy between said source and said motive means, said transfer means including a disabling circuit connected to said gating control circuit and conditioning said gated rectifying circuit to terminate the supply of energy between said source and said motive means when operating under said second mode of operation.

11. The transportation system of claim 10, wherein said gating control circuit includes a switching circuit operable between a first and a second condition and selectively supplying a control signal to said gated rectifying circuit and controlling the conduction of electrical energy between said source and said motive means, said disabling circuit supplying a disable signal and transferring said switching circuit from said first condtion to said second condition in response to said sensed malfunction and terminating the condition of energy between said source and said motive means.

12. The transportation system of claim 10, wherin said control means includes a coupling circuit connected to said gated rectifying circuit and said motive means and selectively connecting said rectifying circuit to said motive means, said transfer means including a second disabling circuit operatively connected to said coupling circuit and disconnecting said gated rectifying circuit from said motive means in response to said sensed malfunction.

13. The transportation system of claim 1, wherein said control means includes a gated rectifying circuit connected to said source and selectively connected to said motive means by a coupling circuit, said transfer means including a disabling circuit connected to said coupling circuit and disconnecting said gated rectifying circuit from said motive means in response to said sensed malfunction.

14. The transportation system of claim 1, wherein said control means includes a pattern circuit generating a command signal operatively controlling the condition of energy between said source and said motive means for commanding movement of said vehicle, said transfer means operatively rendering said pattern circuit ineffective to control the conduction of energy between said source and said motive means in response to said sensed malfunction.

15. The transportation system of claim 14, wherein said pattern circuit includes a command circuit selectively supplying a run signal and a stop signal, said transfer means operatively conditioning said command circuit to provide said stop signal in response to said sensed malfunction.

16. The transportation system of claim 14, wherein said pattern circuit includes means providing a signal to establish the maximum velocity limitation for said vehicle, said transfer means operatively conditioning said circuit means to provide a zero maximum velocity limitation in response to said sensed malfunction.

17. The transportation system of claim 14, wherein said pattern circuit includes an integrating amplifier operatively generating said command signal, said transfer means operatively rendering said amplifier ineffective for generating said command signal in response to said sensed malfunction.

18. The transportation system of claim 17, wherein said integrating amplifier provides an output signal commanding a predetermined velocity by said vehicle.

19. The transportation system of claim 17, wherein said integrating amplifier provides an output signal commanding a predetermined acceleration by said vehicle.

20. The transportation system of claim 14, wherein said control means includes an error circuit connected to said pattern circuit through a connector circuit and receiving said command signal and operatively connected to vehicle responsive means and receiving a signal proportional to vehicle movement and providing an error signal operatively controlling the conduction of energy between said source and said motive means and controlling the movement of said vehicle, said transfer means operatively coupled to said connector circuit and disconnecting said pattern circuit from said error circuit in response to said sensed malfunction.

21. The transportation system of claim 14, wherein said control means includes first and second sequence means each rendering said pattern circuit ineffective.

22. The transportation system of claim 14, wherein said pattern circuit includes a leveling circuit operatively providing a leveling command signal and controlling the conduction of energy between said source and said motive means and commanding movement in response to said vehicle approaching one of said landings at which a stop is to be made, said transfer means operatively rendering said leveling circuit ineffective to control the conduction of energy between said source and said motive means in response to said sensed malfunction.

23. The transportation system of claim 22, wherein said leveling circuit includes an integrating amplifier operatively generating said leveling command signal, said transfer means operatively rendering said amplifier ineffective to generate said leveling command signal in response to said sensed malfunction.

24. The transportation system of claim 22, wherein said control circuit includes means sensing the position of said vehicle, and said leveling circuit includes a modifying circuit operatively coupled to said position sensing means and varying said leveling command signal in response to the varying sensed location of said vehicle with respect to said landing, said transfer means operatively disconnecting said position sensing means from said modifying circuit in response to said sensed malfunction.

25. The transportation system of claim 22, wherein said leveling circuit includes circuit means providing a control signal to establish a maximum velocity limitation for said vehicle, said transfer means operatively removing said control signal from effective operation in response to said sensed malfunction.

26. The transportation system of claim 22, wherein said leveling circuit includes means selectively providing a releveling control signal to guide said vehicle to said landing, said transfer means operatively removing said releveling signal from effective operation in response to said sensed malfunction.

27. The transportation system of claim 1, wherein said control means includes a command circuit generating a command signal commanding movement of said vehicle, means operatively sensing the output of said motive means and providing a signal proportional to said motive means output, an error circuit receiving said command signal and said output signal and providing an error signal, and an amplifying circuit operatively connected to said error circuit and providing an amplified error signal operatively controlling the operation of said motive means, said transfer means operatively rendering said amplifying circuit ineffective to control the conduction of energy between said source and said motive means in response to said sensed malfunction.

28. The transportation system of claim 27, wherein said amplifying circuit directly receives said error signal.

29. The transportation system of claim 27, wherein said error circuit includes a first summing circuit and said amplifying circuit is operatively connected to said error circuit through a second summing circuit.

30. The transportation system of claim 29, wherein said second summing circuit directly receives a signal indicative of the energy being conducted between said source and said motive means.

31. The transportation system of claim 27, wherein said control means includes first and second sequence means each rendering said amplifying circuit ineffective.

32. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means providing an output and moving said vehicle relative to the structure, braking means including a friction braking element selectively coupled to said output and permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure, control means connected to a source of energy and cooperating with said motive means and said braking means and controlling movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means including a brake control circuit connected to said source and selectively supplying energizing power and lifting and setting said friction braking element, means monitoring one or more malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and modifying the operation of said brake control circuit in response to a sensed malfunction to selectively lift and set said braking element and operate said vehicle within a predetermined velocity.

33. The transportation system of claim 32, wherein said braking element selectively operates in response to said sensed malfunction and guides said vehicle to one of said landings within said predetermined velocity.

34. The transportation system of claim 33, wherein said motive means is rendered inoperative to supply a driving force to said vehicle in response to said sensed malfunction.

35. The transportation system of claim 32, wherein said brake control circuit includes means selectively varying the braking force exerted by said friction element upon said motive output when in said set condition.

36. The transportation system of claim 32, wherein said brake control circuit includes a gated rectifying circuit connected to said braking element and to said source and selectively supplying energy to said braking element.

37. The transportation system of claim 32, wherein said brake control circuit includes means monitoring the operation of said transportation system, said transfer means operatively connecting said monitoring means to control the operation of said braking element in response to said sensed malfunction.

38. The transportation system of claim 37, wherein said control means includes first and second sequence means operatively coupled to said transfer means ane each operatively and independently connecting said monitoring means to control the operation of said braking element in response to said sensed malfunction.

39. The transportation system of claim 38, wherein said control means includes a third sequence means operatively coupled to said transfer means and operatively coupled to independently connect said monitoring means to control the operation of said braking element in response to said sensed malfunction.

40. The transportation system of claim 32, wherein said transportation means includes speed sensing means providing a signal proportional to the velocity of said vehicle operatively connected to said brake control circuit and maintaining said vehicle speed below said predetermined velocity in response to said sensed malfunction.

41. The transportation system of claim 40, wherein said brake control circuit includes a summing circuit receiving a command signal from a command circuit and said velocity signal and providing a brake control signal selectively setting and lifting said braking element to maintain said vehicle below said predetermined velocity in response to said sensed malfunction.

42. The transportation system of claim 41, wherein said transfer means selectively connects said velocity signal to said summing circuit in response to said sensed malfunction.

43. The transportation system of claim 40, wherein said motive means includes an armature circuit selectively connected to said source and to an energy sensing circuit providing a signal proportional to the energy flowing between said source and said armature circuit, said brake control circuit operatively connected to said energy sensing circuit and to said speed sensing means in response to said sensed malfunction and maintains said vehicle below said predetermined velocity in response to said energy signal and said velocity signal.

44. The transportation system of claim 43, wherein said brake control circuit maintains said vehicle below a second predetermined velocity in response to said velocity signal and the loss of said energy signal.

45. The transportation system of claim 43, wherein said brake control circuit maintains said vehicle below a second predetermined velocity in response to said energy signal and the loss of said velocity signal.

46. The transportation system of claim 43, wherein said brake control circuit includes a first summing circuit selectively receiving said energy signal and said velocity signal and providing a modulating control signal to a second summing circuit, said second summing circuit receiving a command signal from a command circuit and providing a brake control signal to selectively set and lift said braking element and maintain said vehicle below said predetermined velocity in response to said sensed malfunction.

47. The transportation system of claim 46, wherein said transfer means selectively connects said modulating control signal to said second summing circuit in response to said sensed malfunction.

48. The transportation system of claim 46, wherein said brake control circuit includes a unipolar circuit operatively connected between said first and second summing circuits and maintains said modulating control signal at a first electrical polarity.

49. The transportation system of claim 46, wherein said control means includes a brake sensing circuit monitoring the energy supplied to operate said braking element and supplying a signal proportional to the monitored brake energy to said second summing circuit.

50. The transportation system of claim 49, wherein said brake control circuit includes a gated rectifying circuit operatively connected to said second summing circuit and to said source and selectively supplying controlled amounts of electrical energy to said braking element in response to the magnitude of said brake control signal.

51. The transportation system of claim 50, wherein said control means includes a phase sensing circuit connected to said source and providing a phase signal indicative of the electrical phase sequence of said source, and said brake control circuit including a gating control circuit receiving said brake control signal and said phase signal and providing a gating signal to said gated rectifying means to selectively supply controlled amounts of energy to said braking element in response to the magnitude of said brake control signal and the phase sequence of said source.

52. The transportation system of claim 32, wherein said motive means includes an armature circuit selectively connected to said source and an energy sensing circuit providing a signal proportional to the energy conducted between said source and said armature circuit, said brake control circuit operatively receiving said energy signal and maintaining said vehicle below said predetermined speed in response to said sensed malfunction.

53. The transportation system of claim 52, wherein said energy signal is directly proportional to the armature voltage.

54. The transportation system of claim 52, wherein said brake control circuit includes a summing circuit receiving a command signal from a command circuit and operatively receiving said energy signal and providing a brake control signal selectively setting and lifting said braking element and maintaining said vehicle below said predetermined speed in response to said sensed malfunction.

55. The transportation system of claim 54, wherein said transfer means selectively connects said energy signal to said summing circuit in response to said sensed malfunction.

56. The transportation system of claim 32, wherein said control means includes a brake sensing circuit providing a signal proportional to the energy supplied to said braking element, and said brake control circuit includes a summing circuit receiving said brake energy signal and a command signal from a command circuit and providing a brake command signal controlling the amount of energy supplied to said braking element.

152. The transportation system of claim 45, wherein said second malfunction includes said sensed energy decreasing to a predetermined magnitude.

153. The transportation system of claim 152, wherein said monitoring means includes a summing circuit connected to receive a first polarity reference signal and a second polarity signal proportional to said sensed energy and providing an output signal operatively coupled to said transfer means and providing said third mode in response to said second signal decreasing to a magnitude having a predetermined relationship with respect to said first signal in response to said energy decreasing to said predetermined magnitude.

154. The transportation system of claim 53, wherein said monitoring means includes a reference circuit supplying a substantially constant magnitude first signal.

57. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, and means monitoring one or more malfunctions within said transportation system., said control means incuding means providing first and second outputs in response to sensed first and second functions of said transportaton system, respectively, and operating said vehicle in response to a sensed malfunction below a first predetermined velocity in response to said first and second outputs and below a second predetermined velocity in response to said first output and the loss of said second output.

58. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means incuding an armature circuit selectively connected to a source of energy and moving said vehicle relative to the structure, means monitoring the energy flowing between said source and said armature circuit and providing an armature energy indicative signal, control means connected to said source and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the movement of said vehicle, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said vehicle and providing normal service between a plurality of landings and a second mode of operation established in response to said armature energy signal exceeding a predetermined magnitude and guiding said vehicle to one of said landings.

59. The transportation system of claim 58, wherein said energy signal is directly proportional to armature current.

60. The transportation system of claim 58, wherein said monitoring means includes a summing circuit receiving said energy signal and a reference signal from a reference circuit and initiating the transfer from said first mode to said second mode in response to said energy signal increasing to a magnitude having a predetermined relationship to said reference signal.

61. The transportation system of claim 60, wherein said control means includes a gated rectifying circuit connected to said source and to a gating control circuit and selectively conducting energy between said source and said armature circuit, said transfer means including a switching transistor connected to said summing circuit and having a first output circuit supplying a first disable signal to said gating control circuit through a connector circuit and a second output circuit including a sample and hold circuit supplying a second disable signal to said gating control circuit through said connector circuit in response to said energy signal increasing to said predetermined magnitude for disabling said rectifying circuit.

62. The transportation system of claim 60, wherein said monitoring means includes a unipolar circuit receiving said energy signal and providing a varying signal having a plurality of repetitive negative polarity portions proportional to armature current and one negative polarity portion increasing to said predetermined magnitude effectively transferring said system operation from said first mode to said second mode.

63. The transportation system of claim 62, wherein said reference circuit provides a constant magnitude positive polarity reference signal.

64. The transportation system of claim 62, wherein said one negative polarity portion occurs within a single electrical cycle of said source frequency.

65. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means including an armature circuit selectively connected to a source of energy and moving said vehicle relative to the structure, means monitoring the energy flowing between said source and said armature circuit and providing an armature energy indicative signal, control means connected to said source and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means including a gated rectifying circuit connected to said source and to a gating control circuit and selectively conducting varying amounts of energy between said source and said armature circuit, and transfer means responsive to the functioning of said monitoring means and disabling said gating control circuit rendering said gated rectifying circuit incapable of conducting energy between said source and said armature circuit in response to said armature energy signal exceeding a predetermined magnitude.

66. The transportation system of claim 65, wherein said transfer means includes a switching circuit connected to said monitoring means and transferring from a first output to a second output in response to said armature energy signal exceeding said predetermined magnitude.

67. The transportation system of claim 66, wherein said transfer means includes a disable circuit operatively receiving said second output and providing a disable signal to said gating control circuit and terminating the conduction of energy between said source and said armature circuit.

68. The transportation system of claim 67, wherein said control means includes a coupling circuit selectively connecting said gated rectifying circuit to said armature circuit, said transfer means including a second disable circuit operatively connected to said coupling circuit and disconnecting said gated rectifying circuit from said armature circuit in response to said second output.

69. The transportation system of claim 67, wherein said transfer means includes a connecting circuit conducting said disable signal to said gating control circuit.

70. The transportation system of claim 65, wherein said transfer means includes a memory means operable from a first condition to a second condition in response to said energy signal exceeding said predetermined mangitude and maintaining said second condition for a predetermined time after said energy signal decreases below said predetermined magnitude.

71. The transportation system of claim 70, wherein said transfer means includes a disable circuit connected to said memory means and to said gating control circuit and disabling said gated rectifying circuit in response to said second condition.

72. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means selectively connected to a source of energy and moving said vehicle relative to the structure, braking means including a selectively operable friction braking element and permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure, means monitoring the energy flowing between said source and said motive means, control means connected to said source and cooperating with said motive means and said braking means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means including a brake control circuit controlling the operation of said braking means, and transfer means responsive to the functioning of said monitoring means and modifying the operation of said brake control circuit and selectively operating said braking element to maintain said vehicle below a predetermined velocity in response to said monitored energy exceeding a predetermined magnitude.

73. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means including an armature circuit selectively connected to a source of energy and moving said vehicle relative to the structure, means monitoring the energy flowing between said source and said armature circuit, control means connected to said source and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the movement of said vehicle including a first mode of operation operating said vehicle and providing normal service between a plurality of landings and a second mode of operation established in response to the operation of said monitoring means and guiding said vehicle to one of said landings, and transfer means including first sequence means operatively conditioning said control means to provide said second mode in response to said energy exceeding a first predetermined magnitude and second sequence means operatively conditioning said control means to provide said second mode in response to said energy exceeding a second predetermined magnitude.

74. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means including an armature circuit and a field circuit separately coupled to a source of energy and moving said vehicle relative to the structure, means monitoring the energy flowing between said source and said field circuit and providing a field energy indicative signal, control means connected to said source and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said vehicle, and transfer means responsive to the functioning of said monitoring means and transferring the control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said vehicle and providing normal service between a plurality of landings and a second mode of operation established in response to said field signal decreasing below a predetermined magnitude and guiding said vehicle to one of said landings.

75. The transportation system of claim 74, wherein said predetermined magnitude of said field signal required for mode transfer remains constant during an acceleration sequence and a maximum velocity sequence of said transportation system.

76. The transportation system of claim 74, wherein said control means includes a brake control circuit connected to said source and selectively supplying energy operating a friction braking element, said brake control circuit operatively connected to said transfer means and selectively operating said braking element and maintaining said vehicle below a predetermined speed when operating within said second mode in guiding said vehicle to one of said landings.

77. The transportation system of claim 74, wherein said energy signal is directly proportional to the field current.

78. The transportation system of claim 74, wherein said monitoring means includes a summing circuit receiving said field energy signal and a reference signal from a reference circuit and initiating the transfer from said first mode to said second mode in response to said field energy signal decreasing in magnitude to a predetermined level with respect to said reference signal.

79. The transportation system of claim 74, wherein said transfer means includes a switching circuit connected to said monitoring means and selectively providing a first output conditioning said control means to provide said first mode and a second output in response to said field energy decreasing below said predetermined magnitude conditioning said control means to provide said second mode.

80. The transportation system of claim 79, wherein said control means includes a gated rectifying circuit connected to said source and to a gating control circuit and selectively conducting energy between said source and said armature circuit, said gating control circuit operatively coupled to said transfer means and terminating the conduction of energy between said source and said armature circuit in response to said second output.

81. The transportation system of claim 80, wherein said transfer means includes a disable circuit receiving said first and second outputs and supplying a disable signal to said gating control circuit in response to said second output.

82. The transportation system of claim 81, wherein said control means includes a coupling circuit selectively connecting said gated rectifying circuit to said armature circuit, said transfer means including a second disable circuit connected to said coupling circuit and disconnecting said gated rectifying circuit from said armature circuit in response to said second output.

83. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means including an armature circuit and a field circuit separately coupled to a source of energy and moving said vehicle relative to the structure, braking means including a braking element selectively operable between a set condition and a lifted condition and permitting vehicle movement and retaining said vehicle in a stopped position with respect to said structure, means monitoring the energy flowing between said source and said field circuit and providing a field energy indicative signal, control means connected to said source and cooperating with said motive means and said braking means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means including first sequence means connecting energy from source to said field circuit and a second sequence means supplying a reference signal to said monitoring means in response to a command for vehicle movement, and transfer means responsive to the functioning of said monitoring means and conditioning said braking means to maintain said braking element in a set condition in response to said field energy signal varying to a magnitude having a predetermined relationship with respect to said reference signal and preventing vehicle movement.

84. The transportation system of claim 83, wherein said reference signal includes a first signal portion varying from a zero magnitude to a second predetermined magnitude within a predetermined time and a second signal portion maintaining said second predetermined magnitude.

85. The transportation system of claim 83, wherein said energy signal is directly proportional to the field current.

86. The transportation system of claim 83, wherein said monitoring means includes a summing circuit receiving said field energy signal and said reference signal from a reference circuit in response to the conditioning of said control means to initiate vehicle movement.

87. The transportation system of claim 83, wherein said control means includes a gated rectifying circuit connected to said source and to a gating control circuit and selectively conducting energy between said source and said armature circuit, said transfer means operatively coupled to said gating control circuit and rendering said rectifying circuit inoperative for supplying energy to said armature circuit in response to said field energy signal varying to a magnitude having a predetermined relationship with respect to said reference signal and preventing vehicle movement.

88. The transportation system of claim 87, wherein said transfer means includes a disable circuit operatively supplying a disable signal to said gating control circuit and rendering said rectifying circuit inoperative.

89. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means including an armature circuit and a field circuit separately coupled to a source of energy and moving said vehicle relative to the structure, means monitoring the energy flowing between said source and said field circuit and providing a field energy indicative signal compared with a reference signal, control means connected to said source and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing and providing normal service between a plurality of landings, and transfer means modifying the operation of said control means in response to the difference between said field signal and said reference signal exceeding a predetermined value.

90. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, selectively operable braking means permitting vehicle movement and retaining said vehicle in a stopped position with respect to said structure, control means connected to a source of energy and cooperating with said braking means and including an error circuit operatively receiving a command signal from a pattern circuit and operatively receiving an output proportional signal from means responsive to an output of said motive means and providing an error signal operatively controlling the operation of said motive means and moving said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the movement of said transport vehicle, means monitoring said error signal, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode of operation operating said vehicle and providing normal service between a plurality of landings and a second mode of operation established in response to said error signal increasing to a predetermined magnitude rendering said motive means inoperative for supplying a driving force to said vehicle and operating said braking means and guiding said transport vehicle to one of said landings.

91. The transportation system of claim 90, wherein said output responsive means includes a tachometer operatively coupled to said motive means and providing a signal directly proportional to said vehicle velocity.

92. The transportation system of claim 90, wherein said monitoring means includes summing means receiving said error signal and a reference signal from a reference circuit and providing an output signal operatively conditioning said control means to transfer from said first mode to said second mode in response to said error signal increasing to said predetermined magnitude with respect to said reference signal.

93. The transportation system of claim 90, wherein said error circuit provides a positive polarity error signal commanding a first output by said motive means and a negative polarity error signal commanding a second output by said motive means, said monitoring means including a first circuit operatively receiving said positive polarity error signal and providing a first output in response to said positive polarity error signal reaching a first predetermined magnitude conditioning said control means to transfer from said first mode to said second mode and a second circuit operatively receiving said negative polarity error signal and providing a second output in response to said negative polarity error signal reaching a second predetermined magnitude conditioning said control means to transfer from said first mode to said second mode.

94. The transportation system of claim 93, wherein said error circuit includes a logic OR circuit connecting said first and second circuits to said error circuit.

95. The transportation system of claim 93, wherein said first circuit includes a first summing circuit receiving said positive error signal and a negative polarity reference signal from a first reference circuit and providing said first output in response to said positive error signal increasing to a predetermined magnitude with respect to said negative reference signal and said second circuit includes a second summing circuit receiving said negative error signal and a positive polarity reference signal from a second reference circuit and providing said second output in response to said negative error signal increasing to a predetermined magnitude with respect to said positive reference signal.

96. The transportation system of claim 90, wherein said transfer means includes a switching circuit connected to said monitoring means and selectively providing a first output conditioning said control means to provide said first mode and a second output conditioning said control means to provide said second mode in response to said error signal increasing to a predetermined magnitude.

97. The transportation system of claim 96, wherein said control means includes a gated rectifying circuit connected to said source and to a gating control circuit and selectively conducting energy between said source and said motive means, said gating control circuit operatively responding to said second output and rendering said rectifying circuit inoperative for supplying energy between said source and said motive means.

98. The transportation system of claim 97, wherein said transfer means includes a disable circuit operatively responding to said second output and supplying a disable signal to said gating control circuit.

99. The transportation system of claim 98, wherein said transfer means includes a coupling circuit connected to said gated rectifying circuit and to said motive means and permitting energy to flow between said rectifying circuit and said motive means, said transfer means including a second disable circuit connected to said coupling circuit and disconnecting said gated rectifying circuit from said motive means in response to said second output.

100. The transportation system of claim 90, wherein said braking means includes a friction braking element and said control means includes a brake control circuit connected to said source and selectively supplying energy to said braking means to lift and set said braking element, said brake control circuit operatively connected to said transfer means and selectively operating said braking element and maintaining said vehicle below a predetermined speed when operating within said second mode in response to said error signal increasing to said predetermined magnitude.

101. The transportation system of claim 90, wherein said error signal increases to said predetermined magnitude in response to the loss of said output proportional signal and conditions said control means to provide said second mode.

102. The transportation system of claim 90, wherein said transfer means is coupled to said monitoring means and selectively transfers from a first output to a second output in response to said error signal increasing to a predetermined magnitude and initiating a transfer from said first mode to said second mode, said transfer means providing said second output in response to a malfunction sensed within said monitoring means and conditioning said control means to provide said second mode of operation.

103. The transportation system of claim 102, wherein said transfer means provides said second output in response to the loss of operating power supplied from said source to said monitoring means.

104. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, braking means including a selectively operable braking element and permitting vehicle movement and retaining said vehicle in a stopped position with respect to said structure, control means connected to a source of energy and including a sequence means coupled to said braking means and selectively operating said braking element between a set condition and a lifted condition and permitting vehicle movement from one of said landings and an error circuit operatively receiving a command signal from a pattern circuit and an output proportional signal from means responsive to an output of said motive means and providing an error signal operatively controlling the operation of said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, means monitoring said error signal, and transfer means responsive to the functioning of said monitoring means and transferring from a first output to a second output rendering said motive means essentially inoperative for supplying a driving force to said vehicle and guiding said vehicle to one of said landings in response to said error signal exceeding a predetermined magnitude, said transfer means responsive to a malfunction sensed within said monitoring means and providing said second output modifying the operation of said sequence means and maintaining said braking means in said set condition and preventing movement of said vehicle from one of said landings.

105. The transportation system of claim 104, wherein said transfer means provides said second output in response to the loss of operating power supplied from said source to said monitoring means.

106. The transportation system of claim 104, wherein said first output is operatively coupled to said sequence means and conditions said braking means to lift said braking element and permits vehicle movement from one of said landings.

107. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, braking means including a braking element selectively operable between a set condition and a lifted condition and permitting vehicle movement and retaining said vehicle in a stopped position with respect to said structure, control means connected to a source of energy and cooperating with said motive means and said braking means and moving said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the movement of said transport vehicle, means monitoring the position of said vehicle when approaching a landing at which a stop is to be made, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said transport vehicle and providing normal service between a plurality of landings and a second mode of operation established in response to said vehicle arriving at a first position adjacent to a landing at which a stop is to be made and the subsequent movement of said vehicle to a second position spaced from said first position and having a greater distance from said landing than said first position and operatively transferring said braking element to said set condition and preventing further movement of said vehicle.

108. The transportation system of claim 107, wherein said control means includes first sequence means operatively coupled to said braking means and permitting vehicle movement until arriving at said first position adjacent to a landing at which a stop is to be made and second sequence means operatively coupled to said braking means in response to said vehicle arriving at a third position with respect to said landing at which said stop is to be made and permitting vehicle movement, said transfer means operatively rendering said second sequence means inoperative for permitting vehicle movement in said second mode.

109. The transportation system of claim 108, wherein said third position is spaced from said landing by a greater distance than said first and second positions.

110. The transportation system of claim 109, wherein said transfer means operatively renders said first sequence inoperative for permitting vehicle movement in said second mode.

111. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, braking means including a braking element selectively operable between a set condition and a lifted condition and permitting vehicle movement and retaining said vehicle in a stopped position with respect to said structure, means monitoring the velocity of said vehicle, and control means connected to a source of energy and cooperating with said motive means and said braking means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing and including first sequence means operatively coupled to said monitoring means and transferring said braking element from said lifted condition to said set condition in response to a first predetermined velocity and second sequence means operatively coupled to said monitoring means and transferring said braking element from said lifted condition to said set condition in response to a second predetermined velocity and third sequence means operatively coupled to said monitoring means and transferring said braking element from said lifted condition to said set condition in response to a third predetermined velocity.

112. The transportation system of claim 111, wherein said monitoring means includes a tachometer operatively coupled to an output of said motive means and supplying a velocity signal operatively controlling said first sequence means, a governor operatively coupled to said vehicle and providing a selectively operable first switch controlling said second sequence means, and a safety clamp coupled to said vehicle and providing a selectively operable second switch controlling said third sequence means.

113. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means providing a first mode of operation operating said vehicle and providing normal service between a plurality of landings and a second mode of operation rendering said motive means essentially inoperative for supplying a driving force to said vehicle and guiding said vehicle to one of said landings, means monitoring malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and providing a first response corresponding to a sensed first malfunction and a second response corresponding to a sensed second malfunction to initiate a transfer from said first mode to said second mode.

114. The transportation system of claim 113, wherein said first response provides a first sequence pattern and said second response provides a second sequence pattern.

115. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and providing a plurality of modes of operation and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, means monitoring malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from a first mode of operation to a second mode of operation in response to a sensed first malfunction, said control means including coupling means selectively supplying energy to said monitoring means and sequence means responsive to the operation of said transfer means and coupled to said coupling means maintaining the supply of energy to said monitoring means to continually sense a second malfunction when operating within said second mode until said vehicle arrives with a first position adjacent to a landing at which a stop is to be made.

116. The transportation system of claim 115, wherein said control means includes timing means operatively connected to said coupling means and maintains the supply of operating energy to said monitoring means for a predetermined time after said vehicle has stopped at said landing when operating within said first mode, said transfer means operatively rendering said timing means ineffective for maintaining the supply of energy to said monitoring means for said predetermined time when operating within said second mode.

117. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the movement of said vehicle including a first mode of operation operating said transport vehicle and providing normal service between a plurality of landings and a second mode of operation rendering said motive means inoperative for supplying a driving force to said vehicle and guiding said transport vehicle to one of said landings, means monitoring one or more malfunctions within said transportation system, and transfer means coupled to said monitoring means and to said control means and providing a first output conditioning said control means to provide said first mode and a second output in response to a sensed malfunction conditioning said control means to provide said second mode, said control means including an interlock circuit operating in response to said second output and connected to maintain said second output to continually provide said second mode.

118. The transportation system of claim 117, wherein said transfer means automatically switches from said first output to said second output in response to said sensed malfunction.

119. The transportation system of claim 118, wherein said interlock circuit includes means selectively manually operable and permits said transfer means to switch from said second output to said first output in response to the lack of said malfunction.

120. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, and means monitoring one or more malfunctions within said transportation system, said control means including means sensing the registration of demands for service at said landings and stopping said vehicle at a selected landing and means operatively coupled to said demand sensing means and to said monitoring means and simulating a demand for service at a pair of adjacent landings in response to said sensed malfunction.

121. The transportation system of claim 120, wherein said simulating means operates in response to said sensed malfunction and conditions said control means to stop said vehicle at said adjacent landing.

122. The transportation system of claim 120, wherein said control means includes means sensing the position of said vehicle at a predetermined distance from said adjacent landing, said position sensing means operatively initiating a stop of said vehicle when arriving at said predetermined distance in response to said simulated demand.

123. The transportation system of claim 122, wherein said position sensing means includes a leveling sensor.

124. The transportation system of claim 120, wherein said control means includes sequence means operatively coupled to said demand simulating means and maintaining said demand simulation for vehicle service at an adjacent landing in response to said sensed malfunction until arriving at a first position adjacent to said landing at which a stop is to be made.

125. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, braking means including a selectively operable braking element and permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure, control means connected to a source of energy and cooperating with said motive means and said braking means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means including a gated rectifying circuit connected to said source and to a gating control circuit and selectively supplying energy to said braking means and permitting vehicle movement, means monitoring one or more malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and coupled to said gating control circuit and operatively terminating the supply of energy to said braking means and stopping said vehicle in response to a sensed malfunction.

126. The transportation system of claim 125, wherein said gating control circuit includes a switching circuit operable between a first and a second condition and selectively supplying a gating control signal to said gated rectifying circuit and controlling the supply of energy to said braking means, said transfer means including disable means connected to said monitoring means and supplying a disable signal to said gating control circuit and transferring said switching circuit from said first condition to said second condition in response to said sensed malfunction and terminating the supply of energy to said braking means to stop said vehicle.

127. The transportation system of claim 126, wherein said control means includes a coupling circuit connected to said gated rectifying circuit and to said braking means and selectively conducting energy to said braking means, said transfer means including a second disable means operatively connected to said monitoring means and to said coupling circuit and disconnecting said gated rectifying circuit from said braking means in response to said sensed malfunction.

128. The transportation system of claim 125, wherein said gated rectifying circuit is connected to said braking means by a coupling circuit, said transfer means including a disable means operatively connected to said monitoring means and to said coupling circuit and disconnecting gated rectifying circuit from said braking means in response to said sensed malfunction.

129. The transportation system of claim 125, wherein said transfer means operatively modifies said gating control circuit to selectively supply energy to said braking means and permit continued controlled vehicle movement in response to a sensed second malfunction.

130. The transportation system of claim 129, wherein said gating control circuit operates in response to said sensed second malfunction and supplies varied controlled amounts of energy to said braking means.

131. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means including an energy dissipating circuit selectively connected to an armature circuit and moving said vehicle relative to the structure, control means connected to a source of energy and including gated rectifying means directly supplying energy to said armature circuit and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, and means monitoring malfunctions within said transportation system, said control means operatively connected to said monitoring means and selectively connecting said energy dissipating circuit to said armature circuit in response to a selected sensed malfunction.

132. The transportation system of claim 131, wherein said selective connection of said energy dissipating circuit to said armature circuit is effective for providing a dynamic braking of said vehicle.

133. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, braking means permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure, means monitoring the velocity of said vehicle, control means connected to a source of energy and cooperating with said motive means and said braking means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means including a gated rectifying circuit connected to said source and to a gating control circuit and selectively supplying energy to said braking means and permitting vehicle movement, and transfer means responsive to the functioning of said monitoring means and coupled to said gating control circuit and operatively terminating the supply of energy to said braking means to stop said vehicle in response to said vehicle exceeding a predetermined velocity.

134. The transportation system of claim 133, wherein said control means includes a second gated rectifying circuit connected to said source and to a second gating control circuit and selectively conducting energy between said source and said motive means, said transfer means coupled to said second gating control circuit and operatively terminating the flow of energy between said source and said motive means in response to said vehicle exceeding said predetermined velocity.

135. The transportation system of claim 134, wherein said control means includes a first coupling circuit connecting said first gated rectifying circuit to said braking means and a second coupling circuit connecting said second gated rectifying circuit to said motive means, said transfer means operatively coupled to said first and second coupling circuits and disconnecting said first gated rectifying circuit from said braking means and said second gated rectifying circuit from said motive means in response to said vehicle exceeding said predetermined velocity.

136. The transportation system of claim 133, wherein said monitoring means includes a tachometer operatively coupled to an output of said motive means.

137. The transportation system of claim 133, wherein said monitoring means includes a summing circuit operatively receiving a velocity signal from means connected to sense an output of said motive means and a reference signal from a reference circuit and providing an output operatively connected to said transfer means and terminating the supply of energy to said braking means in response to said velocity increasing to a predetermined magnitude with respect to said reference signal.

138. The transportation system of claim 137, wherein said monitoring means includes a unipolar circuit receiving said velocity signal and providing a first polarity velocity proportional signal to said summing circuit, said reference signal including a second polarity signal.

139. The transportation system of claim 137, wherein said transfer means includes a switching circuit selectively transferring from a first output to a second output in response to said velocity signal increasing to a predetermined magnitude with respect to said reference signal.

140. The transportation system of claim 133, wherein said control means provides a plurality of modes of operation controlling the operation of said transport vehicle including a first mode providing normal service between a plurality of landings and a second mode established in response to a first malfunction sensed by said monitoring means guiding said vehicle to one of said landings and a third mode established in response to said vehicle exceeding a predetermined velocity constituting a second malfunction modifying the operation of said gating control circuit and operatively terminating the supply of energy to said braking means and stopping said vehicle, said transfer means including a switching circuit operatively coupled to said monitoring means and selectively providing a first output conditioning said control means to provide said first and second modes and a second output in response to said vehicle exceeding said predetermined velocity conditioning said control means to provide said third mode.

141. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle from a first landing and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said vehicle, means monitoring malfunctions including the velocity of said vehicle within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode providing normal service between a plurality of landings and a second mode established in response to a sensed first malfunction guiding said transport vehicle to one of said landings and a third mode stopping said vehicle, said transfer means substantially operative during said vehicle travel from said first landing to said selected landing and transferring said system from said first mode to said third mode in response to a sensed first predetermined velocity of said vehicle and from said second mode to said third mode in response to a sensed second predetermined velocity of said vehicle.

142. The transportation system of claim 141, wherein said monitoring means includes means coupled to an output of said motive means and sensing the velocity of said vehicle and a first coupling circuit operatively connected to said velocity sensing means and sensing said first predetermined velocity and a second coupling circuit operatively connected to said velocity sensing means and sensing said second predetermined velocity.

143. The transportation system of claim 142, wherein said first coupling circuit selectively senses said motive means output in response to said system operating in said first mode and said second coupling circuit selectively senses said motive means output in response to said system operating in said second mode.

144. The transportation system of claim 143, wherein said monitoring means includes a summing circuit receiving a reference signal from a reference circuit and operatively receiving said motive means output through said first and second coupling circuits.

145. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said vehicle, means monitoring malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said vehicle and providing normal service between a plurality of landings and a second mode established in response to a sensed first malfunction and guiding said vehicle to one of said landings and a third mode established in response to a sensed second malfunction of said energy source and stopping said vehicle.

146. The transportation system of claim 145, and including braking means having a friction braking element selectively operable between a set condition and a lifted condition and permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure, said control means operating in response to said transfer means and selectively operating said braking element between said set condition and said lifted condition and guiding said vehicle to one of said landing in said second mode and transferring said braking element to said set condition and stopping said vehicle in said third mode.

147. The transportation system of claim 145, and including braking means permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure, said control means includes a first gated rectifying circuit connected to said source and to a first gating control circuit and selectively supplying energy to said braking means and a second gated rectifying circuit connected to said source and to a second gating control circuit and selectively conducting energy between said source and said motive means, said transfer means including disable means operatively coupled to said monitoring means and to said first and second gating control circuits and operatively terminating the supply of energy from said source to said braking means and between said source and said motive means and stopping said vehicle in response to said malfunction of said energy source.

148. The transportation system of claim 147, wherein said control means includes a first coupling circuit connecting said first gated rectifying circuit to said braking means and a second coupling circuit connecting said second gated rectifying circuit to said motive means, said transfer means including second disable means operatively disconnecting said first gated rectifying circuit from said braking means and said second gated rectifying circuit from said motive means in response to said sensed malfunction of said energy source.

149. The transportation system of claim 147, wherein said disable means includes a first circuit means supplying a first disable signal and a second circuit means supplying a second disable signal and disabling said first and second gating control circuits in response to said sensed malfunction of said energy source.

150. The transportation system of claim 145, wherein said transfer means includes a switching circuit connected to said monitoring means and selectively providing a first output conditioning said control means to provide said first and second modes and a second output conditioning said control means to provide said third mode in response to said sensed malfunction of said energy source.

151. The transportation system of claim 150, wherein said transfer means includes memory means operable from a first condition to a second condition in response to said second output and maintaining said second output for a predetermined time after said energy source has returned to normal operation.

155. The transportation system of claim 145, wherein said monitoring means includes means operatively coupled to said source and sensing a plurality of alternating phases of said energy, said transfer means operating in response to said monitoring means and conditioning said control means to provide said third mode in response to a sensed loss of one of said phases of energy.

156. The transportation system of claim 155, wherein said monitoring means includes a summing circuit receiving a first polarity reference signal and a second polarity signal responsive to said plurality of alternating phases of energy and providing an output signal operatively coupled to said transfer means to provide said third mode in response to said second signal decreasing to a magnitude having a predetermined relationship with respect to said first signal in response to said loss of one of said phases.

157. The transportation system of claim 156, wherein said monitoring means includes a reference circuit supplying a substantially constant magnitude first signal.

158. The trannsportation system of claim 145, wherein said monitoring means includes means operatively coupled to said source and including a plurality of rectifying elements sensing a plurality of alternating phases of energy, said transfer means operating in response to said monitoring means and conditioning said control means to provide said third mode of operation in response to a sensed failure of one of said rectifying elements.

159. The transportation system of claim 145, wherein said monitoring means includes means operatively coupled to said source sensing the sequential order of a plurality of alternating phases of energy, said transfer means operating in response to said monitoring means and conditioning said control means to provide said third mode of operation in response to a sensed improper phase sequence.

160. The transportation system of claim 159, wherein said monitoring means includes a summing circuit receiving a first reference signal and a second signal responsive to said sequential order of said plurality of alternating phases of energy and providing an output signal operatively coupled to said transfer means to provide said third mode in response to said second signal changing according to said sensed improper phase sequence to a magnitude having a predetermined relationship with respect to said first signal.

161. The transportation system of claim 160, wherein said monitoring means includes a reference circuit supplying a substantially constant magnitude first signal.

162. The transportation system of claim 145, wherein said monitoring means includes a summing circuit receiving a first signal from a reference circuit and a second signal continually responsive to the number of a plurality of alternating phases of energy supplied from said source and a third signal continually responsive to the sequential order to said plurality of alternating phases of energy, said first, second and third signals combining and providing a first output conditioning said control means to operate within said first and second modes and a second output conditioning said control means to operate within said third mode in response to a sensed abnormal condition existing within said alternating phases.

163. The transportation system of claim 162, wherein said summing circuit operatively senses the magnitude of said energy from said source by sensing said second signal.

164. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping the vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said vehicle, means monitoring malfunctions with said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said vehicle and providing normal service between a plurality of landings and a second mode established in response to a sensed first malfunction and guiding said vehicle to one of said landings and a third mode established in response to a second malfunction of a predetermined temperature sensed within said control means and stopping said vehicle.

165. The tranportation system of claim 164, wherein said control means includes a gated rectifying circuit operatively connected to said source and to said motive means and selectively conducting energy between said source and said motive means, said monitoring means operatively sensing said predetermined temperature of said gated rectifying circuit.

166. The transportation system of claim 164, wherein said transfer means includes a switching circuit connected to said monitoring means and selectively providing a first output conditioning said control means to provide said first and second modes and a second output conditioning said control means to provide said third mode in response to the sensed temperature increasing to said predetermined magnitude.

167. The transportation system of claim 166, wherein said control means includes a first gated rectifying circuit connected to said source and to a first gating control circuit and selectively supplying energy to a braking circuit and a second gated rectifying circuit connected to said source and to a second gating control circuit and selectively conducting energy between said source and said motive means, said transfer means including a disable means operatively coupled to said first and second gating control circuits and to said second output and terminating the supply of energy from said source to said braking means and between said source and said motive means in response to the sensed temperature increasing to said predetermined magnitude.

168. The transportation system of claim 167, wherein said control means includes a first coupling circuit connecting said first gated rectifying circuit to said braking means and a second coupling circuit connecting said second gated rectifying circuit to said motive means, said transfer means including second disable means operatively coupled to said second output and disconnecting said first gated rectifying circuit from said braking means and said gated rectifying circuit from said motive means in response to the sensed temperature increasing to said predetermined magnitude.

169. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, means monitoring malfunctions within said transportation system, said control means having a plurality of modes of operation controlling the operation of said transport vehicle including a first mode operating said vehicle and providing normal service between a plurality of landings and a second mode established in response to a sensed first malfunction and guiding said vehicle to one of said landings and a third mode established in response to a sensed second malfunction and stopping said vehicle, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said transfer means provides a first output in response to a sensed proper electrical connection of a circuit connector within said control means conditioning said control means to provide said first and second modes and a second output in response to a sensed improper electrical connection of said circuit connector conditioning said control means to provide said third mode.

170. The transportation system of claim 169, wherein said circuit connector connects a gated rectifying circuit to a gating control circuit.

171. The transportation system of claim 170, wherein said gated rectifying circuit is selectively connected to an armature circuit within said motive means.

172. The transportation system of claim 169, wherein said transfer means includes a switching circuit connected to said monitoring means and selectively providing said first and second outputs.

173. The transportation system of claim 172, wherein said control means includes a first gated rectifying circuit connected to said source and to a first gating control circuit and selectively supplying energy to a braking means permitting vehicle movement and retarding movement and retaining said vehicle in a stopped position with respect to said structure and a second gated rectifying circuit connected to said source and to a second gating control circuit and selectively conducting energy between said source and said motive means, said transfer means including disable means operatively coupled to said first and second gating control circuits and operatively terminating the supply of energy from said source to said braking means and between said source and said motive means in response to said sensed second output.

174. The transportation system of claim 173, wherein said control means includes a first coupling circuit connecting said first gated rectifying circuit to said braking means and a second coupling circuit connecting said second gated rectifying circuit to said motive means, said transfer means including second disable means operatively disconnecting said first gated rectifying circuit from said braking means and said second gated rectifying circuit from said motive means in response to said second output.

175. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, means monitoring malfunctions within said transportation system including a detector monitoring the velocity of said vehicle, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said vehicle including a first mode operating said vehicle and providing normal service between a plurality of landings and a second mode established in response to a sensed first malfunction and guiding said vehicle to one of said landings and a third mode established in response to a sensed second malfunction and preventing movement of said vehicle, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said transfer means providing a first output in response to a proper operating velocity sensed by said detector conditioning said control means to provide said first and second modes and a second output in response to a improper predetermined velocity sensed by said detector conditioning said control means to provide said third mode, said transfer means responsive to a malfunction within said detector and providing said second output conditioning said control means to provide said third mode.

176. The transportation system of claim 175, wherein said transfer means provides said second output in response to the loss of operating power supplied from said source to said detector.

177. The transportation system of claim 175, wherein said control means includes sequence means coupled to said transfer means, and braking means including a braking element selectively operable between a set condition and a lifted condition and permitting vehicle movement from one of said landings, said sequence means operating in response to said second output and maintaining said braking element in said set condition preventing movement of said vehicle from one of said landings in response to said sensed malfunction within said velocity detector.

178. The transportation system of claim 177, wherein said malfunction within said detector includes a loss of operating power supplied from said source to said velocity detector.

179. The transportation system of claim 177, wherein said sequence means operates in response to said first output and operatively lifts said braking element and permits vehicle movement from one of said landings.

180. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, braking means permitting vehicle movement and retaining said vehicle in a stopped position with respect to said structure, control means connected to a source of energy and cooperating with said motive means and said braking means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means including sequence means operatively coupled to said braking means and permitting vehicle movement until arriving at a first position adjacent to a landing at which a stop is to be made, means monitoring malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and conditioning said sequence means to provide continued operative control in response to a first sensed malfunction and rendering said sequence means inoperative for controlling said braking means in response to a second sensed malfunction.

181. The transportation system of claim 180, wherein said control means includes second sequence means operatively coupled to said braking means and permitting vehicle movement from one of said landings, said transfer means operatively rendering said second sequence means inoperative for controlling said braking means in response to said first malfunction and in response to said second malfunction.

182. The transportation system of claim 181, wherein said control means includes third sequence means operatively coupled to said braking means in response to said vehicle arriving at a second position with respect to said landing at which said stop is to be made and permitting vehicle movement, said transfer means operatively rendering said third sequence means inoperative for controlling said braking means in response to said first malfunction and in response to said second malfunction.

183. The transportation system of claim 180, wherein said control means includes second sequence means operatively coupled to said braking means in response to said vehicle arriving at a second position with respect to said landing at which said stop is to be made and permitting vehicle movement, said transfer means operatively rendering said second sequence means inoperative for controlling said braking means in response to said first malfunction and in response to said second malfunction.

184. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, means monitoring malfunctions within said transportation system, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the movement of said transport vehicle including a first mode operating said transport vehicle and providing normal service between a plurality of landings and a second mode rendering said motive means inoperative for supplying a drivng force to said vehicle and guiding said vehicle to one of said landings and a third mode stopping said vehicle, and transfer means coupled to said monitoring means and to said control means and providing a first output conditioning said control means to provide said first mode and a second output in response to a sensed first malfunction conditioning said control means to provide said second mode and a third output in response to a sensed second malfunction conditioning said control means to provide said third mode, said control means including an interlock circuit operating in response to said third output and establishing said second output.

185. The transportation system of claim 184, wherein said interlock circuit operatively transfers from a first condition to a second condition in response to said second output, said second condition coupled to maintain said second output.

186. The transportation system of claim 185, wherein said interlock circuit automatically transfers from said first condition to said second condition in response to said second output.

187. The transportation system of claim 185, wherein said interlock circuit includes means selectively manually operable and transferring said interlock circuit from said second condition to said first condition in response to the lack of said first and second malfunctions.

188. The transportation system of claim 185, wherein said interlock circuit includes first and second sequence means each operatively responding to said second output and providing said second condition.

189. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means including a gated rectifying circuit selectively conducting energy between a source of energy and said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said transport vehicle including a first mode operating said vehicle under a first predetermined maximum velocity limitation and providng normal service between a plurality of landings and a second mode operating said vehicle under a second predetermined maximum velocity limitation, means monitoring the energy supplied by said source, and transfer means responsive to the functioning of said monitoring means and transferring said control means from said first mode to said second mode in response to said energy decreasing to a predetermined magnitude.

190. The transportation system of claim 189, wherein said gated rectifying circuit directly supplies energy to an armature circuit of said motive means.

191. The transportation system of claim 189, wherein said monitoring means includes means sensing the supply of energy from said source and providing a first output in response to said energy existing above a predetermined magnitude conditioning said control means to provide said first mode and a second output in response to said energy decreasing to said predetermined magnitude conditioning said control means to provide said second mode.

192. The transportation system of claim 191, wherein said sensing means senses the electrical voltage of said energy.

193. The transportation system of claim 189, wherein said transportation system includes a terminal landing, said braking means including a braking element selectively operable between a lifted condition permitting vehicle movement and a set condition restraining vehicle movement, said control means operatively sensing the movement of said vehicle and including first sequence means operatively coupled to said braking means and setting said braking element in response to said vehicle traveling beyond said terminal landing by a first predetermined distance while operating in said first mode and second sequence means operatively coupled to said braking means in response to said source energy decreasing to said predetermined magnitude and setting said braking element in response to said vehicle traveling beyond said terminal landing by a second predetermined distance while operating in said second mode.

194. The transportation system of claim 193, wherein said first sequence means includes a high speed limit switch and said second sequence means includes a reduced speed limit switch.

195. The transportation system of claim 189, wherein said transfer means providing a first output conditioning said control means to provide said first mode and a second output conditioning said control means to provide said second mode in response to said source energy decreasing to said predetermined magnitude, and coupling means operating in response to the operation of said braking means and transferring said transfer means from said second output to said first output in response to said source energy increasing above said predetermined magnitude.

196. The transportation system of claim 195, wherein said coupling means transfers said transfer means from said second mode to said first mode in response to said braking means transferring to a set condition when said vehicle stops at a landing.

197. The transportation system of claim 189, wherein said control means includes a pattern circuit generating a first pattern command signal having said first predetermined maximum velocity limitation for operation in said first mode and a second pattern command signal having said second predetermined maximum velocity limitation for operation in said second mode.

198. The transportation system of claim 189, wherein said control means includes a command circuit operatively coupled to said motive means and providing a signal to command movement of said vehicle from one of said landings to another, said transfer means selectively operable between a first output conditioning said control means to provide said first mode and a second output in response to said source energy decreasing to said predetermined magnitude conditioning said control means to provide said second mode, and coupling means conditioning said transfer means for transfer from said first output to said second output in response to said movement command signal.

199. The transportation system of claim 198, wherein said transfer means includes a latching circuit operable in response to said second output and maintaining said second output after the removal of said movement command signal.

200. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and providing a first maximum speed when moving said vehicle from one landing to an immediately adjacent landing and a second maximum speed when moving said vehicle from one landing to a landing spaced from said immediately adjacent landing, means moitoring a malfunction within said transportation system, and transfer means responsive to the functioning of said monitoring means and conditioning said control means to operate said vehicle at said first maximum speed in response to said sensed malfunction when moving from one landing to a landing spaced from said immediately adjacent landing.

201. The transportation system of claim 200, wherein said sensed malfunction includes a decrease of said source energy to a predetermined magnitude.

202. The transportation system of claim 200, wherein said motive means includes a two-speed D.C. motor.

203. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling movement of said vehicle relative to the structure and including first sequence means initiating a stop of said vehicle in response to said vehicle arriving at a first predetermined distance from said landing at which a stop is to be made and second sequence means including a leveling position monitor stopping said vehicle in response to said vehicle arriving at a second predetermined distance from said landing at which a stop is to be made, means monitoring one or more malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring the operation of said control means from said first sequence means to said second sequence means to initiate a stop in response to a sensed malfunction.

204. The transportation system of claim 203, wherein said sensed malfunction includes a decrease of the energy supplied by said source to a predetermined magnitude.

205. The transportation system of claim 203, wherein said first predetermined distance is greater than said second predetermined distance.

206. The transportation system of claim 203, wherein said second sequence means operates in response to a leveling position sensor sensing the arrival of said vehicle at a position adjacent to said landing at which a stop is to be made.

207. The transportation system of claim 203, wherein said first sequence means includes a speed pattern circuit initiating a stopping sequence and generating a deceleration pattern signal controlling the conduction of energy between said source and said motive means and said second sequence means includes a leveling pattern circuit initiating a stopping sequence and generating a decelerating pattern signal controlling the conduction of energy between said source and said motive means.

208. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said transport vehicle, means monitoring malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said vehicle under a first predetermined maximum velocity limitation and providing normal service between a plurality of landings and a second mode operating said transport vehicle under a second predetermined maximum velocity limitation in response to a sensed first malfunction and a third mode rendering said motive means essentially inoperative for supplying a driving force to said vehicle and guiding said vehicle to one of said landings in response to a sensed second malfunction.

209. The transportation system of claim 208, wherein said first malfunction includes a decrease in the energy supplied by said source to a predetermined magnitude.

210. The transportation system of claim 208, wherein said transfer means selectively operates and conditions said control means to provide said third mode in response to said monitoring means sensing one of a plurality of malfunctions including the energy supplied to an armature circuit of said motive means increasing to a predetermined magnitude, the energy supplied to a field circuit of said motive means decreasing below a predetermined magnitude, the error signal derived as a difference between an output proportional signal of said motive means and a command signal as sensed by an error detector exceeding a predetermined magnitude, and the malfunctioning of said error detector.

211. The transportation system of claim 208, wherein said control means provides a fourth mode of operation and renders said motive means inoperative for supplying a driving force to said vehicle and stopping said vehicle in response to a sensed third malfunction.

212. The transportation system of claim 211, wherein said transfer means selectively operates and conditions said control means to provide said fourth mode in response to said monitoring means sensing one of a plurality of malfunctions including the velocity of said vehicle as sensed by a velocity detector exceeding a predetermined magnitude, the malfunctioning of said velocity detector, the energy supplied form said source decreasing to a predetermined magnitude, the loss of a phase of energy supplied from said source as sensed by a phase detector, the failure of a rectifying element within said phase detector, the improper sequential order of a plurality of alternating phases of energy supplied from said source, a predetermined temperature within a gated rectifying circuit, an improper electrical connection by a circuit connector, and the movement of said vehicle to a first position adjacent to a landing at which a stop is being made and the subsequent movement to a second position.

213. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said transport vehicle, means monitoring malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said vehicle under a first predetermined maximum velocity limitation and providing normal service between a plurality of landings and a second mode operating said vehicle under a second predetermined maximum velocity limitation in response to a sensed first malfunction of a decrease in the energy supplied by said source to a predetermined magnitude and a third mode rendering said motive means inoperative for supplying a driving force to said vehicle and stopping said vehicle in response to a sensed second malfunction.

214. The transportation system of claim 213, wherein said transfer means selectively operates and conditions said control means to provide said third mode in response to said monitoring means sensing one of a plurality of malfunctions including the velocity of said vehicle as sensed by a velocity detector exceeding a predetermined magnitude, the malfunctioning of said velocity detector, the energy supplied from said source decreasing to a second predetermined magnitude, the loss of a phase of energy supplied from said source as sensed by a phase detector, the failure of a rectifying element within said phase detector, the improper sequential order of a plurality of alternating phases of energy supplied from said source, a predetermined temperature within a gated rectifying circuit, an improper electrical connection by a circuit connector, and the movement of said vehicle to a first position adjacent to a landing at which a stop is being made and the subsequent movement to a second position.

215. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means connected to a source of energy and cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means having a plurality of modes of operation controlling the operation of said transport vehicle, means monitoring malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation, said plurality of modes including a first mode operating said vehicle and providing normal service between a plurality of landings and a second mode rendering said motive means inoperative for supplying a driving force to said vehicle and guiding said vehicle to one of said landings in response to sensed first malfunction and a third mode rendering said motive means inoperative for supplying a driving force to said vehicle and stopping said vehicle in response to a sensed second malfunction.

216. The transportation system of claim 215, wherein said transfer means selectively operates and conditions said control means to provide said second mode in response to said monitoring means sensing one of a plurality of malfunctionings including the energy supplied to an armature circuit of said motive means increasing to a predetermined magnitude, the energy supplied to a field circuit of said motive means decreasing below a predetermined magnitude, the error signal derived as a difference between an output proportional signal of said motive means and a command signal as sensed by an error detector exceeding a predetermined magnitude, and the malfunctioning of said error detector.

217. The transportation system of claim 215, wherein said transfer means selectively operates and conditions said control means to provide said third mode in response to said monitoring means sensing one of a plurality of malfunctions including the velocity of said vehicle as sensed by a velocity detector exceeding a predetermined magnitude, the malfunctioning of said velocity detector, the energy supplied from said source decreasing to a predetermined magnitude, the loss of a phase of energy supplied from said source as sensed by a phase detector, the failure of a rectifying element within said phase detector, the improper sequential order of a plurality of alternating phases of energy supplied from said source, a predetermined temperature within a gated rectifying circuit, an improper electrical connection by a circuit connector, and the movement of said vehicle to a first position adjacent to a landing at which a stop is being made and the subsequent movement to a second position.

218. A transportation system for a structure having a plurality of spaced landings comprising a transport vehicle, means mounting said vehicle for movement relative to said structure in a path extending adjacent each of said landings, motive means moving said vehicle relative to the structure, control means cooperating with said motive means and controlling the movement of said vehicle relative to the structure and stopping said vehicle at a selected landing, said control means selectively providing a plurality of modes of operation controlling the operation of said vehicle selected from modes providing a normal operation, a reduced speed operation, an emergency landing operation and an emergency operation, means monitoring one or more malfunctions within said transportation system, and transfer means responsive to the functioning of said monitoring means and transferring said control means from one of said modes of operation to another of said modes of operation in response to a sensed malfunction and selecting the mode best suited for safe operation.