Wheelchair suspension

• US 10,434,019 B2
• Filed: 07/10/2017
• Issued: 10/08/2019
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: Invacare Corporation
• Original Assignee: Invacare Corporation
• Inventors: Bekoscke, Robert, Burns, Kevin
• Primary Examiner(s): To, Toan C
• Application Number:
  US15/645,749
• Publication Number:
  US 20180028379A1
• Time in Patent Office: 820 Days
• Field of Search: 180 651, 180 97, 180907, 280124104, 280755
• CPC Class Codes: A61G 5/043 Mid wheel drive
• CPC Class Codes: A61G 5/045 Rear wheel drive
• CPC Class Codes: A61G 5/06 with obstacle mounting facilities, e.g. for climbing stairs, kerbs or steps
• CPC Class Codes: A61G 5/10 Parts, details or accessories
• 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: B60G 2300/24 Wheelchairs
• CPC Class Codes: B60G 3/207 the arms being essentially parallel to the longitudinal axis of the vehicle

Abstract

A wheelchair suspension includes a frame, a drive assembly pivot arm, a drive assembly, a front caster pivot arm, a front caster, and a spring and shock absorbing assembly. The drive assembly pivot arm is pivotally connected to the frame. The drive assembly includes a drive wheel and is mounted to the drive assembly pivot arm. The front caster pivot arm is pivotally mounted to the frame and coupled to the drive assembly pivot arm. The front caster is coupled to the at least one front caster pivot arm. The spring and shock absorbing assembly is pivotally connected to the drive assembly pivot arm at a first pivotal connection and pivotally connected to the front caster pivot arm at a second pivotal connection. The first and second pivotal connections are positioned such that a majority of the force applied by the spring and shock absorbing assembly is applied to the drive wheel when the suspension is on a flat, horizontal support surface.

Claims

1. A wheelchair suspension comprising:

a frame;

a drive assembly pivot arm pivotally connected to the frame;

a drive assembly including a drive wheel, wherein the drive assembly is mounted to the drive assembly pivot arm;

a front caster pivot arm pivotally mounted to the frame and coupled to the drive assembly pivot arm, the front caster pivot arm having an inner wall and an outer wall;

a front caster coupled to the at least one front caster pivot arm; and

a link pivotally connected to the drive assembly pivot arm and pivotally connected to the front caster pivot arm, wherein the link is positioned between the inner wall and the outer wall of the front caster pivot arm.

2. The wheelchair suspension according to claim 1, wherein the link is positioned between an outer wall of the drive assembly pivot arm and the frame.

3. The wheelchair suspension according to claim 1, wherein the link includes a spring and shock absorber.

4. The wheelchair suspension according to claim 1, wherein the link is rigid.

5. The wheelchair suspension according to claim 1, wherein the link is flexible.

6. The wheelchair suspension according to claim 1, wherein the link is extendible in length.

7. A wheelchair suspension comprising:

a frame;

a drive assembly pivot arm pivotally connected to the frame;

a drive assembly including a drive wheel, wherein the drive assembly is mounted to the drive assembly pivot arm;

a pivot sleeve connected to the drive assembly pivot arm, wherein the drive assembly pivot arm is pivotally connected to the frame by the pivot sleeve;

a front caster pivot arm pivotally mounted to the frame and coupled to the drive assembly pivot arm; and

a front caster coupled to the at least one front caster pivot arm;

wherein the pivot sleeve passes in front of the front caster pivot arm when viewed from the front of the wheelchair suspension and when the wheelchair suspension is on a flat, horizontal support surface.

8. A wheelchair suspension comprising:

a frame;

a drive assembly pivot arm;

a drive assembly including a drive wheel, wherein the drive assembly is mounted to the drive assembly pivot arm;

a pivot sleeve connected to the drive assembly pivot arm, wherein the pivot sleeve has a contact surface that is adjacent to the frame and the pivot sleeve is pivotally connected to the frame;

a front caster pivot arm pivotally connected to the frame, wherein the front caster pivot arm has a contact surface that is adjacent to the frame, and wherein the front caster pivot arm is coupled to the drive assembly pivot arm; and

a front caster coupled to the at least one front caster pivot arm;

wherein the pivot sleeve contact surface and the frame and the front caster pivot arm contact surface are substantially co-planar.