GB2311970A - Device for converting a chair with castors into a powered disabled wheelchair - Google Patents

Abstract

A device for converting a chair mounted on a central, vertical shaft, attached to a base supported by castors, into a highly manoeuvrable, powered disabled wheelchair comprises a two-part frame 1, 2 which is attached to the central shaft of the chair. The frame carries batteries 8, electric motor, gearbox and wheel assemblies and a pivoted footrest 4. The powered wheels are spring-loaded into contact with the ground, sufficient to give good grip.

Description

DEVICE FOR ENABLING THE CONVERSION OF A CHAIR WITH CASTORS INTO A llIGHLY MANOEUVRABLE, POWERED, DISABLED WHEELCHAIR The invention relates to a device for enabling the conversion of a chair, mounted on a central, vertical shaft attached to a base supported by castors, into a highly manoeuvrable, powered, disabled wheelchair.

Conventional powered wheelchairs, particularly indoor ones, are generally insufficiently manoeuvrable for use in restricted spaces, are not particularly comfortable for prolonged sitting and are very expensive.

According to the present invention, there is provided a frame, platform or other such two-part device, which will attach to the central shaft and to the base of a chair, which is fitted with several castors, typically, but not exclusively, an office chair. This frame, platform or other two-part device will, in turn, provide a base for the attachment of a single, powered, steerable, variable speed wheel or roller, or dual powered wheels or rollers, variable in both speed and in direction of rotation, giving positive driving engagement with the ground, and directional and speed control by means of a controller. By using a standard, ergonomically designed chair of choice, superior support and comfort is obtained at much lower cost and, by virtue of the central disposition of the driving wheel(s), excellent manoeuvrability is also achieved.

A specific embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, in which: Fig.l illustrates how a converted 5-castor wheel chair might look, with the device attached and with standard motors/gearboxes/wheel assemblies, batteries, controller and joy stick, as used for conventional electrically propelled wheelchairs, and also with a footrest, in place.

Fig.2 illustrates a plan of a possible 2-part frame attached to the central shaft of the chair and to the five castor arms, showing the disposition of the main attachments.

Fig.3 illustrates a possible means of mounting the standard electric motor/gearbox/wheel assemblies in such a way that they provide downward pressure on the floor or other surface, in order to give sufficient wheel grip to allow the chair to be propelled.

Fig.4 illustrates a typical, standard, electric motor/gearbox/wheel assembly.

Fig.5 illustrates a possible means of locking the chair seat in a forward-facing orientation, thus preventing it from rotating whilst the chair is in motion and thereby causing danger, and yet still allowing height adjustment of the chair..

Referring to the drawing, the device consists of a two-part frame, 1 and 2, which is attached to the central 5-castor chair shaft and to the five castor arms by means of bolts 3.

To the frame 1 is attached a footrest 4 (the desired seat height is obtained by using the height adjuster) and the electric motor/gearbox/wheel assemblies 5 are slotted into the dually grooved receiving part of the frame, 6, which also provides spring loading 7, to give positive ground pressure..

Batteries 8 and electronic controller 9 are mounted on frame 2 and the related joy stick speed/direction controller 10 is mounted on a chair arm, right or left, to suit the particular need.

The seat lock is shown as 11.

Electrical connections are made and the motorised wheel chair is ready for use.

Claims (7)

1. A device for enabling the conversion of a chair, mounted on a central vertical shaft attached to a base supported by castors, into a highly manoeuvrable, powered, disabled wheelchair.

2. A device, as claimed in Claim 1, wherein a frame, platform, or some such device, encircles and attaches to the central shaft and/or to the chair base, which is supported on castors.

3. A device, as claimed in Claim 1 and Claim 2, wherein the frame, platform, or some such device, means first and second frame, platform or some such device portions, secured together about the said shaft.

4. A device, as claimed in Claim 1, Claim 2 and Claim 3, which provides a frame, platform or other such device, for the easy attachment of all or some of a power source, motor(s), gear box(es), drive wheel(s), drive roller(s), drive speed and direction controller and footrest(s).

5. A device, as claimed in Claim 1, Claim 2, Claim 3 and Claim 4, which provides a means of suspending the drive wheel(s) and or drive roller(s) in such a way that they are under positive downward pressure, in order to give it/them sufficient grip for driving without slip.

6. A device, as claimed in Claim 1, Claim 2, Claim 3, Claim 4 and Claim 5, which mounts the drive wheel(s) and or roller(s) as close as possible in front of the chair shaft, to give maximum manoeuvrability.

7. A development of the device claimed in Claims 1 - 6 which allows a chair conversion to a wheelchair suitable for outdoor use, by incorporating larger castors on the basic chair, a more powerful propulsion system, larger driving wheels and a suspension system with increased freedom of movement in the vertical plane to enable continued positive ground pressure whilst traversing uneven surfaces..