Obstacle traversing wheelchair

• US 20060255581A1
• Filed: 07/21/2006
• Published: 11/16/2006
• Est. Priority Date: 10/27/2000
• Status: Active Grant

• Current Assignee: Invacare Corporation
• Original Assignee: Invacare Corporation
• Inventors: Goertzen, Gerold, Null, William A. Jr.
• Granted Patent: US 7,597,163 B2
• Time in Patent Office: Days
• US Class Current: 280/755
• CPC Class Codes: A61G 5/04 motor-driven A61G5/06 takes precedence; motor-operated rests A61G5/12; for vehicles with handlebars, equipped with three or more wheels B62K5/003, B62K5/023
• CPC Class Codes: A61G 5/043 Mid wheel drive
• CPC Class Codes: A61G 5/06 with obstacle mounting facilities, e.g. for climbing stairs, kerbs or steps
• CPC Class Codes: A61G 5/061 for climbing stairs
• CPC Class Codes: A61G 5/1075 tilting the whole seat backwards tilting forwards for standing-up or sitting-down aids A61G5/14
• CPC Class Codes: A61G 5/1078 with shock absorbers or other suspension arrangements between wheels and frame
• CPC Class Codes: A61G 5/1089 Anti-tip devices
• CPC Class Codes: A61G 5/128 for feet
• CPC Class Codes: B60G 17/02 Spring characteristics , e.g. mechanical springs and mechanical adjusting meansB60G17/005, B60G17/015 take precedence
• CPC Class Codes: B60G 17/033 characterised by regulating means acting on more than one spring
• CPC Class Codes: B60G 2200/13 with longitudinal arms only
• CPC Class Codes: B60G 2202/42 Electric actuator
• CPC Class Codes: B60G 2300/24 Wheelchairs
• CPC Class Codes: B60G 2300/40 Variable track or wheelbase vehicles
• CPC Class Codes: B60G 7/001 Suspension arms, e.g. constructional features B60G7/006 takes precedence
• CPC Class Codes: Y10S 180/907 Motorized wheelchairs

Abstract

A wheelchair suspension is provided. The wheelchair suspension includes a frame, a pivot arm, a front caster, a drive assembly, and a rear caster. The pivot arm is pivotally coupled to the frame. The front caster is coupled to the pivot arm. Movement of the drive assembly in a first direction causes the pivot arm to substantially remain in a first position. Movement of the drive assembly in a second direction urges the pivot arm away from the first position.

Claims

1. A wheelchair suspension comprising:

a frame;

a pivot arm pivotally coupled to the frame;

a front caster coupled to the pivot arm;

a drive assembly;

a rear caster coupled to the frame; and

wherein movement of the drive assembly in a first direction causes the pivot arm to remain in substantially a first position; and

movement of the drive assembly in a second direction urges the pivot arm away from the first position.

2. The wheelchair suspension of claim 1 wherein movement of the drive assembly in the second direction pushes the pivot arm upward.

3. The wheelchair suspension of claim 1 wherein relative movement between the drive assembly and the pivot arm is dampened.

4. The wheelchair suspension of claim 3 wherein the relative movement between the drive assembly and the pivot arm is dampened by a spring.

5. The wheelchair suspension of claim 1 wherein the movement of the drive assembly in the second direction relative to the frame pushes the pivot arm upward to urge the front caster away from a support surface to traverse an obstacle.

6. The wheelchair suspension of claim 1 wherein the drive assembly is pivotally coupled to the frame.

7. The wheelchair suspension of claim 6 wherein the drive assembly is pivotally coupled to the pivot arm and the pivot arm is pivotally coupled to the frame.

8. The wheelchair suspension of claim 1 wherein movement of the drive assembly in the second direction causes the pivot arm to move upward.

9. The wheelchair suspension of claim 1 wherein movement of the drive assembly in the first direction comprises upward movement of the drive assembly and movement of the drive assembly in the second direction comprises downward movement of the drive assembly.

10. The wheelchair suspension of claim 1 wherein the pivot arm is coupled to the frame at a pivotal connection and force is applied by the drive assembly to the pivot arm between the pivotal connection and the front caster.

11. The wheelchair suspension of claim 10 wherein force applied by the drive assembly to the pivot arm causes the pivot arm to move upward.

12. The wheelchair suspension of claim 10 wherein movement of the drive assembly in the second direction pushes the front caster upward.

13. A method of traversing an obstacle with a wheelchair comprising:

energizing a drive assembly to cause pivotal movement of a drive assembly relative to a wheelchair frame such that the drive assembly urges a front caster pivot arm upward over the obstacle; and

engaging the obstacle with a drive wheel such that the drive assembly pivots with respect to a front caster pivot arm.

14. The method of claim 13 further comprising dampening relative movement between the drive assembly and the front caster pivot arm.

15. The method of claim 13 wherein energizing the drive assembly causes acceleration of the drive assembly.

16. The method of claim 13 wherein the pivotal movement of the drive assembly pushes front caster pivot arm upward over the obstacle.

17. The method of claim 13 wherein the drive assembly transfers force to the front caster pivot arm at a portion of the front caster pivot arm between the front caster and a pivotal connection of the front caster pivot arm to the frame.

18. A wheelchair suspension comprising:

a frame;

a seat supported by the frame;

a rear caster coupled to the frame;

a pair of suspension assemblies disposed on opposite sides of the frame, each suspension assembly comprising;

a pivot arm coupled to the frame;

a front caster coupled to the pivot arm;

a drive assembly;

wherein the movement of the drive assembly in a first direction causes the pivot arm to remain in substantially a first position; and

movement of the drive assembly in a second direction urges the pivot arm away from the first position.

19. The wheelchair suspension of claim 18 wherein movement of the drive assembly in the second direction pushes the pivot arm upward.

20. The wheelchair suspension of claim 18 wherein relative movement between the drive assembly and the pivot arm is dampened.

21. The wheelchair suspension of claim 20 wherein the relative movement between the drive assembly and the pivot arm is dampened by a spring.

22. The wheelchair suspension of claim 18 wherein the pivotal movement of the drive assembly in the second direction relative to the frame pushes the pivot arm upward to urge the front caster away from a support surface to traverse an obstacle.

23. The wheelchair suspension of claim 18 wherein the drive assembly is pivotally coupled to the frame.

24. The wheelchair suspension of claim 23 wherein the drive assembly is pivotally coupled to the pivot arm and the front caster pivot arm is pivotally coupled to the frame.

25. The wheelchair suspension of claim 18 wherein movement of the drive assembly in the second direction causes the pivot arm to move upward.

26. The wheelchair suspension of claim 18 wherein the movement of the drive assembly in the first direction comprises upward movement of the drive assembly and movement of the drive assembly in the second direction comprises downward movement of the drive assembly.

27. The wheelchair suspension of claim 18 wherein the pivot arm is coupled to the frame at a pivotal connection and force is applied by the drive assembly to the pivot arm between the pivotal connection and the front caster.

28. The wheelchair suspension of claim 27 wherein force applied by the drive assembly to the pivot arm causes the pivot arm to move upward.

29. The wheelchair suspension of claim 27 wherein movement of the drive assembly in the second direction pushes the front caster upward.

30. A wheelchair suspension comprising:

a frame;

a pivot arm pivotally coupled to the frame;

a front caster coupled to the pivot arm;

a drive assembly;

a rear caster coupled to the frame; and

a means for coupling the pivot arm and the front caster such that movement of the drive assembly in a first direction causes the pivot arm to remain in substantially a first position; and

movement of the drive assembly in a second direction urges the pivot arm away from the first position.

31. A wheelchair comprising:

a frame;

a front caster assembly comprising a pivot arm;

a drive assembly comprising a pivot bracket;

wherein the pivot arm and the pivot bracket are pivotally coupled.

32. The wheelchair of claim 31 further comprising a spring interposed between the pivot bracket and the pivot arm.

33. The wheelchair of claim 31 wherein the pivot bracket is directly coupled to the pivot arm.

34. The wheelchair of claim 31 wherein movement of the drive assembly in a first direction causes movement of the drive assembly with respect to the front caster pivot arm and movement of the drive assembly in a second direction causes the front caster pivot arm to move upward.

35. The wheelchair suspension of claim 34 wherein the pivotal movement of the drive assembly in the second direction relative to the frame pushes the front caster pivot arm upward to urge the front caster away from a support surface to traverse an obstacle.