Obstacle traversing wheelchair

• US 6,554,086 B1
• Filed: 10/27/2000
• Issued: 04/29/2003
• Est. Priority Date: 10/27/2000
• Status: Expired due to Term

• Current Assignee: Invacare Corporation
• Original Assignee: Invacare Corporation
• Inventors: Goertzen, Gerold, Null, William A. Jr.
• Primary Examiner(s): Johnson, Brian L.
• Assistant Examiner(s): Bottorff, Christopher
• Application Number:
  US09/698,481
• Time in Patent Office: 914 Days
• Field of Search: 280/124.149, 280/124.152, 280/124.166, 280/47.16, 280/250.1, 280/304.1, 180/65.1, 180/907
• US Class Current: 180/65.1
• 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 curb-climbing wheelchair having pivotal arm assemblies. The pivotal arm assemblies include at least one front caster and have the ability to rotate or pivot. The pivot arms rotate or pivot in response to moments generated by accelerating or decelerating the wheelchair thereby raising or lowering the front caster(s) through the rotational movement of the pivot arms. By raising or lowering the front caster(s) in such a manner, curb-like obstacles can be traversed in a low-impact manner.

Claims

1. A wheelchair for traversing obstacles comprising:

(a) a frame;

(b) a pivoting assembly having at least one pivot arm, said at least one pivot arm comprising

(i) a first portion pivotally coupled to said frame;

(ii) a second portion having at least one front caster attached thereto for contacting a supporting surface of the wheelchair; and

(iii) a torsion bar mounting member comprising a recess configured to at least partially receive a portion of a torsion bar;

(c) a drive assembly coupled to a third portion of said at least one pivot arm;

(d) a rear caster coupled to said frame;

(f) a spring device configured to urge said at least one front caster into contact with a surface lower than said supporting surface of said wheelchair;

wherein said at least one pivot arm pivots in response to a moment generated by the drive assembly thereby raising said at least one front caster from said supporting surface to assist said wheelchair in traversing curb-like obstacles.

2. The wheelchair of claim 1 wherein said first portion pivotally coupling said at least one arm to said frame is in between said second and third portions.

3. The wheelchair of claim 1 wherein said pivot assembly further comprises a resilient member coupled to said at least one pivot arm and said frame.

4. The wheelchair of claim 3 wherein said resilient member is coupled to said at least one pivot arm via said drive assembly.

5. The wheelchair of claim 3 wherein said resilient member comprises a spring.

6. The wheelchair of claim 1 wherein said drive assembly comprises a brushless motor.

7. The wheelchair of claim 1 wherein said drive assembly comprises a motor and a transmission.

8. The wheelchair of claim 1 further comprising a second pivot arm and a tension bar coupled to the pivot arms for limiting the independent movement of each pivot arm.

9. A wheelchair for traversing obstacles comprising:

(a) a frame;

(b) a pivoting assembly having at least one pivot arm, said at least one pivot arm comprising

(i) a first portion pivotally coupled to said frame;

(ii) a second portion having at least one front caster attached thereto for contacting a supporting surface of said wheelchair; and

(iii) a torsion bar mounting member comprising a recess configured to at least partially receive a portion of a torsion bar;

(c) a drive assembly coupled to a third portion of said at least one pivot arm; and

(d) at least one rear caster coupled to said frame; and

(e) a resilient member coupled to said at least one pivot arm and said frame;

wherein said resilient member is coupled to said at least one pivot arm via said drive assembly and configured to urge said at least one front caster into contact with a surface lower than said supporting surface of said wheelchair.

10. The wheelchair of claim 9 wherein said at least one pivot arm pivots in response to the forces generated by said drive assembly.

11. The wheelchair of claim 9 wherein said first portion pivotally coupling said at least one arm to said frame comprises a position between said second and third portions.

12. The wheelchair of claim 9 wherein said resilient member comprises a spring.

13. The wheelchair of claim 9 wherein said drive assembly comprises a motor and a transmission.

14. The wheelchair of claim 9 wherein said at least one pivot arm pivots in response to a moment generated by said drive assembly thereby raising said at least one front caster from said supporting surface to assist said wheelchair in traversing said curb-like obstacles.

15. The wheelchair of claim 9 wherein said resilient member comprises a spring.

16. The wheelchair of claim 9 wherein said resilient force member comprises an elastomeric material.

17. The wheelchair of claim 9 wherein each arm further comprises a base member and an angled member.

18. The wheelchair of claim 17 wherein said base member comprises a drive assembly mount.

19. The wheelchair of claim 9 further comprising a second pivot arm and a tension bar coupled to the pivot arms for limiting the independent movement of each pivot arm.

20. An obstacle traversing wheelchair comprising:

(a) a frame;

(b) a pivoting assembly comprising;

(i) a first portion pivotally coupled to said frame;

(ii) a second portion having at least one front caster attached thereto for contacting a supporting surface of said wheelchair;

(iii) a third portion having a drive assembly coupled thereto; and

(iv) a torsion bar mounting member;

(c) a spring device coupled to said pivoting assembly configured to urge said front caster into contact with said supporting surface of said wheelchair and further configured to urge said front caster into contact with a surface lower than said supporting surface of said wheelchair; and

wherein said pivoting assembly and said drive assembly are configured to raise said at least one front caster from said supporting surface of said wheelchair in response to an acceleration of said wheelchair; and

wherein each torsion bar mounting member comprises a recess configured to at least partially receive a portion of a torsion bar.

21. The wheelchair of claim 20 further comprising a seat assembly longitudinally adjustable on said frame.

22. The wheelchair of claim 20 wherein said spring device is further configured to provide one-way urging of said front castor toward said supporting surface of said wheelchair.

23. The wheelchair of claim 20 wherein said first portion of said pivoting assembly pivotally coupling said pivoting assembly said frame comprises spaced-apart first and second brackets and a sleeve mounted at least partly therebetween.

24. The wheelchair of claim 20 further comprising a second pivoting assembly and a torsion bar coupling portions of each pivoting assembly extending at least partly forward of said frame.

25. The wheelchair of claim 21 wherein said first portion is located proximate said seat assembly.

26. An obstacle traversing wheelchair comprising:

(a) a frame;

(b) a first pivoting assembly comprising;

(i) a first portion pivotally coupled to said frame;

(ii) a second portion having at least one front caster attached thereto for contacting a supporting surface of said wheelchair;

(iii) a third portion having a drive assembly coupled thereto; and

(iv) a torsion bar mounting member;

(c) a spring device coupled to said pivoting assembly configured to urge said front caster into contact with said one of a plurality of wheelchair supporting surface levels including said supporting surface of said wheelchair and a surface level lower than said supporting surface of said wheelchair;

(d) a second pivoting assembly and a torsion bar coupling portions of each pivoting assembly extending at least partly forward of said frame;

wherein said pivoting assembly and said drive assembly are configured to raise said at least one front caster from said supporting surface of said wheelchair in response to an acceleration of said wheelchair; and

wherein each torsion bar mounting member comprises a recess configured to at least partially receive a portion of a torsion bar.

27. The wheelchair of claim 26 further comprising a seat assembly longitudinally adjustable on said frame.

28. The wheelchair of claim 26 wherein said spring device is further configured to provide one-way urging of said front castor toward said supporting surface of said wheelchair.

29. The wheelchair of claim 26 wherein said first portion of said pivoting assembly pivotally coupling said pivoting assembly to said frame comprises spaced-apart first and second brackets and a sleeve mounted at least partly therebetween.

30. The wheelchair of claim 27 wherein said first portion is located proximate said seat assembly.