Obstacle traversing wheelchair

• US 8,636,089 B2
• Filed: 05/07/2012
• Issued: 01/28/2014
• Est. Priority Date: 10/27/2000
• Status: Expired due to Fees

• Current Assignee: Invacare Corporation
• Original Assignee: Invacare Corporation
• Inventors: Goertzen, Gerold, Null, William A.
• Primary Examiner(s): EBNER, KATY MEYER
• Application Number:
  US13/465,404
• Publication Number:
  US 20120217070A1
• Time in Patent Office: 631 Days
• Field of Search: 180/907, 180/65.1, 180/65.51, 180/8.2, 180/6.5
• 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 wheelchair suspension is provided. The wheelchair suspension includes a frame, a front caster pivot arm, a drive assembly, and a rear caster. The front caster pivot arm is pivotally connected to the frame. The front caster is coupled to a front end of the front caster pivot arm. The drive assembly is pivotally connected to the front caster pivot arm. The drive assembly comprises a drive wheel and a motor that drives the drive wheel. Torquing of the drive wheel by the motor in a forward direction causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward toward the front caster and a distance between a support surface and the connection between of the drive assembly and the front caster pivot arm increases.

Claims

1. A wheelchair suspension comprising:

a frame;

a front caster pivot arm pivotally connected to the frame;

a front caster coupled to a front end of the front caster pivot arm;

a drive assembly directly pivotally connected to the front caster pivot arm, wherein the drive assembly comprises a drive wheel and a motor that drives the drive wheel;

wherein torquing of the drive wheel by the motor in a forward direction causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward relatively toward the front caster and a distance between a support surface and said pivotal connection between the drive assembly and the front caster pivot arm increases;

a rear caster coupled to the frame.

2. The wheelchair suspension of claim 1 wherein the front caster pivot arm is pivotally connected to the frame at a first pivot axis and the drive assembly is pivotally connected to the front caster pivot arm at a second pivot axis.

3. The wheelchair suspension of claim 2 wherein the first pivot axis is spaced apart from the second pivot axis.

4. The wheelchair suspension of claim 2 wherein the first pivot axis is not aligned with the second pivot axis.

5. The wheelchair suspension of claim 1 further comprising a spring coupled to the front caster pivot arm, wherein said spring biases the front caster downward into contact with the support surface.

6. The wheelchair suspension of claim 1 further comprising a spring coupled to the drive assembly, wherein said spring biases the drive wheel downward into contact with the support surface.

7. The wheelchair suspension of claim 6 wherein the spring is interposed between the drive assembly and the front caster pivot arm.

8. The wheelchair suspension of claim 1 further comprising a first spring coupled to the front caster pivot arm and a second spring coupled to the drive assembly, wherein said first spring biases the front caster downward into contact with the support surface and said second spring biases the drive wheel downward into contact with the support surface.

9. The wheelchair suspension of claim 8 wherein the second spring is interposed between the drive assembly and the front caster pivot arm.

10. A wheelchair suspension comprising:

a frame;

a front caster pivot arm pivotally connected to the frame;

a front caster coupled to a front end of the front caster pivot arm;

a first spring coupled to the front caster pivot arm, wherein said first spring biases the front caster downward into contact with a support surface;

a drive assembly directly pivotally connected to the front caster pivot arm, wherein the drive assembly comprises a drive wheel and a motor that drives the drive wheel;

a second spring coupled to the drive assembly, wherein said second spring biases the drive wheel downward into contact with the support surface;

a rear caster coupled to the frame.

11. The wheelchair suspension of claim 10 wherein the front caster pivot arm is pivotally connected to the frame at a first pivot axis and the drive assembly is pivotally connected to the front caster pivot arm at a second pivot axis.

12. The wheelchair suspension of claim 11 wherein the first pivot axis is spaced apart from the second pivot axis.

13. The wheelchair suspension of claim 11 wherein the first pivot axis is not aligned with the second pivot axis.

14. The wheelchair suspension of claim 10 wherein the second spring is interposed between the drive assembly and the front caster pivot arm.

15. The wheelchair suspension of claim 10 wherein torquing of the drive wheel by the motor causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward toward the front caster.

16. The wheelchair suspension of claim 10 wherein torquing of the drive wheel by the motor causes the drive assembly to pivot with respect to the front caster pivot arm such that a distance between the support surface and said pivotal connection between of the drive assembly to the front caster pivot arm increases.

17. A wheelchair suspension comprising:

a frame;

a front caster pivot arm pivotally connected to the frame;

a front caster coupled to a front end of the front caster pivot arm;

a first spring coupled to the front caster pivot arm, wherein said first spring biases the front caster downward into contact with a support surface;

a drive assembly directly pivotally connected to the front caster pivot arm, wherein the drive assembly comprises a drive wheel and a motor that drives the drive wheel;

a second spring coupled to the drive assembly, wherein said second spring biases the drive wheel downward into contact with the support surface;

wherein torquing of the drive wheel by the motor causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward relatively toward the front caster and a distance between the support surface and said pivotal connection between the drive assembly to the front caster pivot arm increases;

a rear caster coupled to the frame.

18. The wheelchair suspension of claim 17 wherein the front caster pivot arm is pivotally connected to the frame at a first pivot axis and the drive assembly is pivotally connected to the front caster pivot arm at a second pivot axis.

19. The wheelchair suspension of claim 18 wherein the first pivot axis is spaced apart from the second pivot axis.

20. The wheelchair suspension of claim 18 wherein the first pivot axis is not aligned with the second pivot axis.

21. The wheelchair suspension of claim 17 wherein the second spring is interposed between the drive assembly and the front caster pivot arm.