Obstacle traversing wheelchair

• US 9,149,398 B2
• Filed: 01/24/2014
• Issued: 10/06/2015
• 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.
• Primary Examiner(s): EBNER, KATY MEYER
• Application Number:
  US14/162,955
• Publication Number:
  US 20140138170A1
• Time in Patent Office: 620 Days
• US Class Current: 1/1
• 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 method of climbing an obstacle with a wheelchair that includes a frame, a front caster pivot arm, a front caster coupled to the front caster pivot arm, a drive assembly that includes a motor that drives a drive wheel, and a rear caster, the method comprising:

torquing the drive wheel with the motor in a forward direction;

wherein said torquing causes the drive assembly to pivot about a pivotal connection to the front caster pivot arm;

wherein said pivoting of the drive assembly causes the drive wheel to move forward toward the front caster and causes a distance between a support surface and the pivotal connection of the drive assembly to the front caster pivot arm to increase;

passing over the obstacle with the front caster and the drive wheel.

2. The method of claim 1 wherein the front caster pivot arm is pivots with respect to the frame at a first pivot axis and the drive assembly pivots with respect to the front caster pivot arm at a second pivot axis.

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

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

5. The method of claim 1 further comprising biasing the front caster downward into contact with the support surface.

6. The method of claim 1 further biasing the drive wheel downward into contact with the support surface.

7. The method of claim 6 wherein drive wheel is biased downward by a spring that is interposed between the drive assembly and the front caster pivot arm.

8. The method of claim 1 further comprising biasing the front caster downward into contact with the support surface and biasing the drive wheel downward into contact with the support surface.

9. The method of claim 8 wherein the drive wheel is biased downward by a spring that is interposed between the drive assembly and the front caster pivot arm.