Conversion kit for creating an obstacle-mounting wheelchair

• US 6,357,774 B1
• Filed: 09/14/2000
• Issued: 03/19/2002
• Est. Priority Date: 09/16/1999
• Status: Expired due to Fees

• Current Assignee: Derek Nichols
• Original Assignee: Derek Nichols
• Inventors: Nichols, Derek
• Primary Examiner(s): Lerner, Avraham H.
• Application Number:
  US09/662,393
• Time in Patent Office: 551 Days
• Field of Search: 180/8.2, 180/9.21, 180/9.26, 180/9.28, 180/9.3, 180/9.32, 280/250.1, 280/304.1, 280/DIG.10, 280/47.38, 280/5.2, 280/5.22, 280/5.32, D12/131, 114/194
• US Class Current: 280/250.1
• CPC Class Codes: A61G 5/06 with obstacle mounting facilities, e.g. for climbing stairs, kerbs or steps
• CPC Class Codes: A61G 5/066 with endless belts
• CPC Class Codes: Y10S 280/10 Stair climbing chairs

Abstract

A kit for converting a conventional wheelchair into an obstacle-mounting wheelchair, allowing an occupant to glide over obstacles such as sidewalk curbs. After removal of the large rear wheels and smaller front wheels of a conventional wheelchair, a pair of triangular belted support members are fitted to the frame of the wheelchair such that the frame hangs in a pendulum arrangement from the support members. The support members each have a rubber belt extending around their periphery on bearing mounts, and the wheelchair is propelled by an occupant grasping a portion of the two belts at the front of the support members and moving the belts downward. A pair of guide members are attached through spring-biased axles to a forward position on the wheelchair frame or a forward position on the support members. The guide members extend in an upward forward orientation, and rotate against bias when the front of the wheelchair encounters a curb or other obstacle. As they attempt to return to their unbiased position, the guide members lift the front part of the wheelchair, allowing the wheelchair to glide over obstacles with little reduction in forward speed.

Claims

1. A wheelchair conversion kit for converting into an obstacle-mounting wheelchair a conventional wheelchair having a frame, a main pair of circular wheels each mounted on a respective opposite side of the rear of the frame, and a steerable smaller pair of circular wheels each mounted on a respective opposite side of the frame forward of the main pair of circular wheels, parts in the kit being adapted to be fitted to the frame after removal of the main pair and smaller pair of circular wheels, the parts in the kit comprising:

a pair of belted support members each adapted to be fitted to a respective side of the frame, each of the belted support members comprising;

a frame structure on the periphery of which are mounted a series of load-bearing rotatable members;

an endless belt mounted on the series of load-bearing rotatable members, the rotatable members configuring peripheral movement of the belt around the frame structure into a defined path, a first segment of the defined path being adapted to extend proximate to a surface of ground traversed by the obstacle-mounting wheelchair, the first segment having a shallow convex curvature such that only a portion of the first segment of the defined path of the belt is in contact with the ground at any one time; and

,

a pendulum member having one end pivotally mounted on the frame structure of the belted support member, the pendulum member being adapted to extend downwardly in use from its one end, and having its other end adapted to be attached to the respective side of the wheelchair frame; and

,

a pair of obstacle-mounting guide members, each guide member having a first part adapted to be attached at a forward position on the wheelchair, and having a second part connected by a respective resilient member to the first part and biased so as to normally extend in an upwardly forwardly direction on the wheelchair;

wherein, when the obstacle-mounting wheelchair encounters obstacles of a defined size or less during forward movement, each second part of the guide members initially rotates to compress or retract the respective resilient member after first contact with the obstacle, the resilient members then acting to return the second parts toward their original positions, the action of the second parts in returning toward such original positions lifting a forward end of the first segment of the defined path of each belt and thereby allowing the obstacle-mounting wheelchair to smoothly mount the obstacle.

2. The wheelchair conversion kit of claim 1, wherein each obstacle-mounting guide member is adapted to be attached to the frame structure of a respective belted support member.

3. The wheelchair conversion kit of claim 1, wherein each obstacle-mounting guide member is adapted to be attached to a respective opposite side of the frame of the wheelchair.

4. The wheelchair conversion kit of claim 1, wherein the obstacles of a defined size are sidewalk curbs, steps, or entrance thresholds.

5. The wheelchair conversion kit of claim 1, wherein the frame structure is formed such that the periphery of the frame structure extends immediately adjacent the defined path of the endless belt, a first portion of the periphery of the frame structure extending immediately adjacent the first segment of the defined path of the endless belt.

6. The wheelchair conversion kit of claim 5, wherein the periphery of the frame structure has a series of rotary bearings rotatably secured thereto and extending in parallel, generally-equally-spaced relation therearound, the series of bearings extending between the endless belt and the periphery of the frame structure and allowing low-friction movement of the endless belt around the periphery of the frame structure.

7. The wheelchair conversion kit of claim 6, wherein the periphery of the frame structure has a generally triangular shape.

8. The wheelchair conversion kit of claim 1, wherein the second part of each guide member comprises:

an arm normally extending upwardly forwardly on the wheelchair;

first rotary member means mounted on one end of the arm;

second rotary member means mounted on the other end of the arm; and

,

an endless belt means extending around the first and second rotary member means;

wherein the endless belt means of each guide member is that part of the guide member that contacts the obstacle, and wherein the endless belt means rotates around the first and second rotary member means while maintaining contact with the obstacle as the second part of the guide member initially rotates to compress or retract the respective resilient member and then returns toward its original position.

9. The wheelchair conversion kit of claim 1, wherein the one end of each pendulum member that is pivotally mounted on the frame structure of a respective belted support member has a series of holes extending therethrough, each hole being adapted to receive a pivot pin that extends from the frame structure, each hole being incrementally angularly offset from each other hole such that a plane of the respective belted support member may assume a series of different lateral angles relative to the pendulum member.

10. The wheelchair conversion kit of claim 1, wherein a plate is mounted between the one end of each pendulum member and the respective belted support member, the plate being mounted so as to remain both pivotally fixed on a pivot pin relative to the pendulum member and parallel to a plane of the belted support member, a range of relative pivotal movement between the pendulum member and the respective belted support member being determined by a pair of adjustably-positionable stops on the respective plate.

11. The wheelchair conversion kit of claim 9, wherein a plate is mounted between the one end of each pendulum member and the respective belted support member, the plate being mounted so as to remain both pivotally fixed on the pivot pin relative to the pendulum member and parallel to the plane of the belted support member, a range of relative pivotal movement between the pendulum member and the respective belted support member being determined by a pair of adjustably-positionable stops on the respective plate.