Steering system for crane

• US 7,252,299 B2
• Filed: 02/15/2005
• Issued: 08/07/2007
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: Marine Travelift Incorporated (Marine Travelift, Inc. /Pfeifer & Ashton/)
• Original Assignee: Marine Travelift Incorporated (Marine Travelift, Inc. /Pfeifer & Ashton/)
• Inventors: Wierzba, Jerry J., Minkin, Timothy J.
• Primary Examiner(s): Morris; Lesley D.
• Assistant Examiner(s): Arce-Diaz; Marlon
• Application Number:
  US11/058,738
• Publication Number:
  US 20060180375A1
• Time in Patent Office: 903 Days
• Field of Search: 180/253
• US Class Current: 280/253
• CPC Class Codes: B60K 17/30 the ultimate propulsive elements, e.g. ground wheels, being steerable
• CPC Class Codes: B62D 7/142 specially adapted for particular vehicles, e.g. tractors, carts, earth-moving vehicles, trucks
• CPC Class Codes: B62D 7/1509 with different steering modes, e.g. crab-steering, or steering specially adapted for reversing of the vehicle
• CPC Class Codes: B66C 19/005 Straddle carriers B66C19/007 takes precedence
• CPC Class Codes: B66C 9/04 to facilitate negotiation of curves

Abstract

A steering system (10) for a vehicle, such as a gantry crane (12). The gantry crane (12) generally includes a support structure (14) having a first front wheel (32) and a second opposing front wheel (36) connected proximate a front portion of the crane (12), and a first rear wheel (30) and a second opposing rear wheel (34) connected proximate a rear portion of the crane (12). A control system connected to the crane includes a user interface (111) electronically coupled to a command potentiometer (114) and a programmable controller responsive to the command potentiometer for controlling the angular position of each of the first front wheel (32), the second front wheel (36), the first rear wheel (30) and the second rear wheel (34) to effect a steering mode selected through the user interface (111).

Claims

1. A steering system for a crane comprising:

a first front wheel and a second opposing front wheel connected proximate a front portion of the crane;

a first rear wheel and a second opposing rear wheel connected proximate a rear portion of the crane; and

,

a control system connected to the crane having

a command potentiometer,

a user interface electronically coupled to the command potentiometer, and

a programmable controller responsive to the command potentiometer for controlling the angular position of each of the first front wheel, the second front wheel, the first rear wheel and the second rear wheel to effect one of a carousel mode and a four wheel coordinated steering mode selected through the user interface.

2. The steering system of claim 1 further comprising:

an engine connected to the crane, the engine capable of operation at a variety of different RPMs; and

,

a sensor coupled to the engine and the controller for providing the controller with an operating RPM of the engine, wherein if the operating RPM is lower than a predetermined amount, the controller adjusts the rate of change of the angular position of each wheel.

3. The system of claim 1 further comprising:

a first sensor for monitoring the angular position of the first front wheel;

a second sensor for monitoring the angular position of the second front wheel;

a third sensor for monitoring the angular position of the first rear wheel; and

,

a fourth sensor for monitoring the angular position of the second rear wheel;

the first, second, third and fourth sensors coupled to the controller wherein the controller monitors the angular positions of the wheels and when one of the wheels exceeds a predetermined distance between its sensed position and programmed position, the controller stops angular movement of the remaining wheels.

4. The steering system of claim 1 wherein the controller is programmed to slow down movement of the crane before effecting the carousel steering mode selected through the user interface.

5. The steering system of claim 1 wherein the controller is programmed to move the angular position of each wheel one of clockwise and counter clockwise, to effect the smallest amount of angular movement necessary to position each wheel for the carousel steering mode.

6. The steering system of claim 1 wherein the user interface comprises a proportional device that provides a direction and a magnitude signal.

7. The steering system of claim 6 wherein the proportional device comprises a joystick.

8. A steering system for controlling the steering mode of a crane comprising:

a crane structure having a first front wheel proximate a front portion of a first side of the crane structure, a second front wheel proximate a front portion of a second side of the crane structure, a first rear wheel proximate a rear portion of the first side, and a second rear wheel proximate a rear portion on the second side;

a user interface for selecting one of a carousel steering mode and a four wheel coordinated steering mode; and

,

a controller communicatively coupled to the user interface, the controller configured to monitor the position of the first and second front wheels and the first and second rear wheels, and to control movement of the first and second front wheels and the first and second rear wheels in response to the selected steering mode, the controller further configured to monitor an operating parameter of the crane.

9. The steering system of claim 8 wherein the controller is programmed to disable an engine drive of the crane prior to positioning the wheels in a selected steering mode, and to enable the engine drive after the wheels are in position to effect the selected steering mode.

10. The steering system of claim 9 wherein the selected steering mode is the carousel steering mode and wherein the controller is configured to turn each of the first front wheel, second front wheel, first rear wheel and second rear wheel one of clockwise and counterclockwise in a manner to minimize the amount of turning required by each respective wheel.

11. The steering system of claim 8 wherein the controller senses the position of each wheel when implementing the selected steering mode and disables movement of all wheels upon a determination that at least one wheel is not moving to a desired position at a desired rate.

12. The steering system of claim 8 wherein the user interface is mounted to the crane and communicatively coupled to the controller via a wire.

13. The steering system of claim 8 wherein the user interface is mounted to a radio transmitter and is communicatively coupled to the controller via radio frequency transmissions.

14. The steering system of claim 8 wherein the user interface is a joystick.

15. The steering system of claim 8 further comprising a command potentiometer coupled to the user interface and the controller.

16. The steering system of claim 8 wherein the controller is configured to monitor the drive engine RPM rate, and wherein the controller lowers a rate of turning each wheel to a desired position for the selected steering mode upon sensing a low RPM rate.

17. The steering system of claim 8 wherein the controller is configured to cause the first front wheel and the second rear wheel to rotate counterclockwise to move into position for a selected carousel steering mode, and to cause the second front wheel and the first rear wheel to rotate clockwise to move into position for the carousel steering mode.

18. The steering system of claim 17 wherein the controller is configured to reverse the drive direction of the second front wheel and the second rear wheel.

19. A steering system for controlling the steering mode of a large vehicle comprising:

a vehicle having a drive engine mechanically coupled to a plurality of wheels positioned to effect movement of the vehicle;

a controller connected to the vehicle configured to implement a user selected steering command to effect a selected steering mode;

a plurality of first sensors coupled to the controller, each first sensor further coupled to a wheel of the plurality of wheels, wherein for each first sensor a signal from the first sensor to the controller provides an indication of the respective wheel position;

a user interface coupled to the controller for providing a user selected steering command;

a plurality of hydraulic motors coupled to the controller, each motor coupled to one of the plurality of wheels of the vehicle to rotate each respective wheel upon receipt of a wheel position command signal from the controller; and

,

a second sensor coupled to the controller for sensing a parameter of the vehicle relevant to the steering mode, wherein the controller is configured to automatically adjust the parameter as necessary to implement one of a current steering mode and a newly selected steering mode.

20. The system of claim 19 wherein the steering system includes a master potentiometer coupled to the user interface and the controller.

21. A steering system for controlling the steering mode of a crane comprising:

a crane structure having a first front wheel proximate a front portion of a first side of the crane structure, a second front wheel proximate a front portion of a second side of the crane structure, a first rear wheel proximate a rear portion of the first side, and a second rear wheel proximate a rear portion on the second side;

a user interface for selecting a steering mode;

a controller communicatively coupled to the user interface, the controller configured to monitor the position of the first and second front wheels and the first and second rear wheels, and to control movement of the first and second front wheels and the first and second rear wheels in response to a selected steering mode; and

,

a sensor coupled to the controller and an engine connected to the crane for sensing RPMs of the engine, wherein the controller is configured to adjust a rate of movement of each of the wheels based on the sensed engine RPMs.

22. A steering system for controlling the steering mode of a crane comprising:

a crane structure having a first front wheel proximate a front portion of a first side of the crane structure, a second front wheel proximate a front portion of a second side of the crane structure, a first rear wheel proximate a rear portion of the first side, and a second rear wheel proximate a rear portion on the second side;

a user interface for selecting a steering mode; and

,

a controller communicatively coupled to the user interface, the controller configured to monitor the position of the first and second front wheels and the first and second rear wheels, and to control movement of the wheel angle of the first and second front wheels and the first and second rear wheels in response to a selected steering mode, wherein the controller is further configured such that when at least one wheel has a sensed wheel angle position a predetermined distance from its a programmed wheel angle position the controller stops movement of the remaining wheels.

23. A steering system for controlling the steering mode of a crane comprising:

a crane structure having a first front wheel proximate a front portion of a first side of the crane structure, a second front wheel proximate a front portion of a second side of the crane structure, a first rear wheel proximate a rear portion of the first side, and a second rear wheel proximate a rear portion on the second side;

a user interface for selecting a steering mode; and

,

a controller communicatively coupled to the user interface, the controller configured to monitor the position of the first and second front wheels and the first and second rear wheels, and to control movement of the first and second front wheels and the first and second rear wheels in response to a selected steering mode, wherein the controller is further configured to disable an engine drive connected to the crane upon selection of a carousel steering mode until the wheels are in the programmed position for the carousel mode.

24. The system of claim 23 wherein the controller is configured to move the first front wheel and the second rear wheel in a counterclockwise direction and to move the second front wheel and the first rear wheel in the clockwise direction to place each wheel in the programmed position for the carousel mode.

25. A steering control system for controlling steering of a vehicle including a first front wheel and a first rear wheel on a first side of the vehicle, and a second front wheel and a second rear wheel on a second side of the vehicle, the vehicle further including an engine, the steering control system comprising:

a controller configured to receive an input selecting one of a carousal steering mode and a four wheel coordinated steering mode from a user interface, the controller further configured to monitor and control the position of each of the first front wheel, the first rear wheel, the second front wheel, the second rear wheel, and to monitor at least one engine parameter.