GB2205284A

GB2205284A - A spring loaded attachment for invalid chairs

Info

Publication number: GB2205284A
Application number: GB08713146A
Authority: GB
Inventors: William James Gauden; John Raymond Charlton
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-06-05
Filing date: 1987-06-05
Publication date: 1988-12-07
Anticipated expiration: 2007-06-05
Also published as: GB8713146D0; GB2205284B

Abstract

An attachment for invalid chairs which has the effect of changing the rigid mounting of the rear wheels to a form of independent suspension. The attachment can be adjusted and comprises a spring-loaded pivoting arm which can be attached to the mounting originally occupied by the rear wheels after these have been removed. <IMAGE>

Description

ADAPTABLE AND ADJUSTABLE SPRlNLOADED ATTACHMENT FOR INVALID CHAIRS Patent Specification This invention relates to an adaptable and adjustable attachment for manually propelled invalid chairs, which in effect changes the rigid mounting of rear wheels to a form of spring-loaded independent suspension.

Manually propelled invalid chairs are well known vehicles comprising a seat, two castoring forward wheels and two rear wheels each attached to an axle in a fixed, rigid mounting.

The effect of the rigid mounting is to transmit jarring shocks to the person using the chair when it travels over any uneven surface, or when negotiating sudden changes in the surface, such as steps, kerbs, etc. which can cause considerable discomfort to the person in the chair.

The purpose of the present invention is to prevent the transmission of these shocks to the person seated in the chair.

This is accomplished by the provision of a spring-loaded, pivoting arm to which the axles and the wheels are attached and which in turn is fitted to the position previously occupied by the rear wheel axles. This has the effect of interposing a shock absorbing system between the seat and the wheels.

An adjustment is possible to accomodate different loadings, if this is considered to be necessary for particular applications.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 ......

Figure 2 ......

Referring to the drawing, the attachment comprises an arm ( ) with one end shaped to permit it to be fastened securely by, for example, a bolt or similar means (not shown) to the mounting position originally occupied by the rear wheel axles. The spring-loading assembly ( ) is fitted through the arm and consists of a threaded rod formed to a radius to permit pivoting about the centre line through the original mounting of the wheel axles, to which the arm is now fastened, with a nylon block ( ) on one end for fitting to the lower frame of the chair. The threaded rod above the arm carries the load spring, ( ) the spring retainers ( ), a washer ( ) and self-locking nut ( ).The metal parts of this assembly will be made of stainless, corrosion Patent Specification (cont'd) resistant material, or will be subjected to anti-corrosion treatment, such as plating or suitable coating, dependent upon requirements. The part of the assembly above the arm will be enclosed by a rubber gaiter ( ), or similar component, for additional protection.

Each chair is fitted with two of these attachments, one at each wheel, which ensures a form of independent suspension to provide maximum comfort regardless of the surface being traversed.

When the chair is negotiated down a kerb or step, as the rear wheels drop to the lower level, the seat and frame continue to descend to a small degree, compressing the load-spring and avoiding any sudden shock being transmitted to the person in the chair. As the initial shock load is absorbed, the load-spring returns to its normal position.

Claims

1.

An adaptable and adjustable attachment for manually propelled invalid chairs comprising a pivoting arm fitted with a spring-loaded assembly to provide a shock absorbing system for each rear wheel.

2.

An adaptable and adjustable spring-loaded attachment as claimed in Claim 1 wherein the arm is designed to enable the attachment to be fitted to the rigid mountings occupied by the rear wheels, after the latter have been removed.

3.

An adaptable and adjustable spring-loaded attachment as claimed in Claim 1 or Claim 2 wherein means are provided for the lower part of the chair frame to be fitted to the springloaded assembly which provides the shock absorbing action and for the rear wheels to be fitted to the mountings provided in the arm.

An adaptable and adjustable spring-loaded attachment as claimed in Claim 1 or Claim 2 wherein means are provided to enable various loading requirements to be accomodated.

Alendients to the claims have been filed as follows Claim I.

An adaptable and adjustable attachment for manually propelled invalid chairs comprising a pivoting arm fitted with a spring-loaded assembly to provide a shock absorbing system for each rear wheel. The attachment can be made as a kit, no modification to the chair being required.

2.

3.

An adaptable and adjustable spring-loaded attachment as claimed in Claim 1 or Claim 2 wherein means are provided for the lower part of the chair frame to be fitted to the spring-loaded assembly which provides the shock absorbing action and for the rear wheels to be fitted to the mountings provided in the arm.

Claim 4.

An adaptable and adjustable spring-loaded attachment as claimed in claim I or claim 2 wherein means are provided to enable various loading requirements to be accommodated. The method of loading adjustment can be obtained by either adjusting the nut on the spring loaded assembly, or moving the spring loaded assembly closer or further from the wheel axil point, I.e. by slotting the pivot arm. (and grooving it to keep the asembly in place.) The method of adapting it to various chair designs is by altering the length of the threaded rod.