Steering system for crane

• US 7,798,274 B2
• Filed: 04/14/2009
• Issued: 09/21/2010
• 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
• Assistant Examiner(s): ARCE, MARLON ALEXANDER
• Application Number:
  US12/423,130
• Publication Number:
  US 20090188740A1
• Time in Patent Office: 525 Days
• Field of Search: None
• US Class Current: 180/253
• 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 controlling the steering mode of a lifting apparatus comprising:

a frame structure having a first front wheel proximate a front portion of a first side of the frame structure, a second front wheel proximate a front portion of a second side of the frame 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 capable of placing the apparatus in a carousel steering mode; and

,

a controller communicatively coupled to the user interface, the controller configured to control movement of the first and second front wheels and the first and second rear wheels in response to placing the apparatus in 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 to place the apparatus in the carousel steering mode, and 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 a sensed position and a programmed position for the wheel, the controller stops angular movement of the remaining wheels.

2. The steering system of claim 1 further comprising a lifting assembly supported by the frame structure and adapted to engage and lift an object.

3. The steering system of claim 1, wherein the controller is configured to move the first front wheel and the second rear wheel counterclockwise and to move the second front wheel and the first rear wheel clockwise to place each wheel in position for the carousel steering mode.

4. The steering system of claim 1, further comprising:

an engine connected to the frame structure, 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.

5. The steering system of claim 1, wherein the controller is programmed to slow down movement of the frame structure before effecting the carousel steering mode.

6. The steering system of claim 1, wherein the controller is configured to reverse a drive direction of the second front wheel and the second rear wheel in response to selection of the carousel steering mode.

7. The steering system of claim 1, wherein at least one of the first front wheel, the second front wheel, the first rear wheel and the second rear wheel is capable of turning 360 degrees to steer the apparatus.

8. The steering system of claim 1, wherein at least one of the first front wheel, the second front wheel, the first rear wheel and the second rear wheel has a gear drive mechanism operably connected thereto for turning the respective wheel to steer the apparatus.

9. The steering system of claim 8, wherein the gear drive mechanism comprises a motor connected to a drive gear, the drive gear being operably connected to the wheel wherein rotation of the drive gear causes turning of the wheel.

10. The steering system of claim 9, wherein the drive gear is a pinion drive gear.

11. A steering system for controlling the steering mode of a boat lifting apparatus comprising:

a frame structure having a first front wheel proximate a front portion of a first side of the frame structure, a second front wheel proximate a front portion of a second side of the frame 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, each wheel having an axle, wherein each wheel is configured to selectively turn about the respective axle in one of a first drive direction and a second, opposed drive direction to move the frame structure;

a user interface for selecting a steering mode; and

a controller communicatively coupled to the user interface, the controller configured 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 in response to selection of a carousel steering mode, the controller is configured to cause the wheels to move to respective programmed angular positions for the carousel steering mode, and is further configured to cause the first front wheel and the first rear wheel to turn in the first drive direction and to cause the second front wheel and the second rear wheel to and turn in the second drive direction to cause the frame structure to turn in a carousel manner,

and 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 a sensed position and a programmed position for the wheel the controller stops angular movement of the remaining wheels.

12. The steering system of claim 11 further comprising a lifting assembly supported by the frame structure and adapted to engage and lift an object.

13. The steering system of claim 11, wherein each wheel has a motor connected thereto to provide power to the respective wheel, wherein in response to selection of a carousel steering mode, the controller is configured to reverse the motor for the second front wheel and the motor for the second rear wheel to cause the second front wheel and the second rear wheel to turn in the second drive direction.

14. The steering system of claim 11, wherein the controller is configured to move the first front wheel and the second rear wheel counterclockwise and to move the second front wheel and the first rear wheel clockwise to move each wheel to the respective programmed angular positions for the carousel steering mode.

15. The steering system of claim 11, further comprising:

an engine connected to the frame structure, 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.

16. The steering system of claim 11, wherein the controller is programmed to slow down movement of the frame structure before effecting the carousel steering mode.

17. 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 a steering mode selected through the user interface,

and 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.

18. The steering system of claim 17 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.

19. The steering system of claim 17 wherein the controller is programmed to slow down movement of the crane before effecting a carousel steering mode selected through the user interface.

20. A steering system for controlling the steering mode of a lifting apparatus comprising:

a frame structure having a first front wheel proximate a front portion of a first side of the frame structure, a second front wheel proximate a front portion of a second side of the frame 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 capable of placing the apparatus in a carousel steering mode; and

, a controller communicatively coupled to the user interface, the controller configured to control movement of the first and second front wheels and the first and second rear wheels in response to placing the apparatus in 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 to place the apparatus in the carousel steering mode,

wherein at least one of the first front wheel, the second front wheel, the first rear wheel and the second rear wheel is capable of turning 360 degrees to steer the apparatus.

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

a frame structure having a first front wheel proximate a front portion of a first side of the frame structure, a second front wheel proximate a front portion of a second side of the frame 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 capable of placing the apparatus in a carousel steering mode; and

,

a controller communicatively coupled to the user interface, the controller configured to control movement of the first and second front wheels and the first and second rear wheels in response to placing the apparatus in 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 to place the apparatus in the carousel steering mode,

wherein at least one of the first front wheel, the second front wheel, the first rear wheel and the second rear wheel has a gear drive mechanism operably connected thereto for turning the respective wheel to steer the apparatus.

22. The steering system of claim 21, wherein the gear drive mechanism comprises a motor connected to a drive gear, the drive gear being operably connected to the wheel wherein rotation of the drive gear causes turning of the wheel.

23. The steering system of claim 22, wherein the drive gear is a pinion drive gear.