GB2331495A

GB2331495A - Mounting of control unit for powered wheelchair

Info

Publication number: GB2331495A
Application number: GB9721126A
Authority: GB
Inventors: Donald Brookes
Original assignee: MEDEQUIP SUB 1 Ltd; Sunrise Medical Ltd; Parker Bath Ltd
Current assignee: MEDEQUIP SUB 1 Ltd; Sunrise Medical Ltd; Parker Bath Ltd
Priority date: 1997-10-07
Filing date: 1997-10-07
Publication date: 1999-05-26
Also published as: GB2331495A9; GB9721126D0

Abstract

A control unit for a powered wheelchair is mounted to a mounting member on the wheelchair by a support member (32) which is pivotally connected to both the control unit (26) and a mounting member (31), there further being a link (36) which is pivotally connected to the control unit and the mounting member and which maintains a substantially constant orientation between the control unit and wheelchair when the control unit is moved to a rearwardly-displaced position.

Description

I- - - 2331495 Title: MOUNTING OF CONTROL UNIT FOR POWERED WHEELCHAIR

Description of Invention

This invention relates to powered wheelchairs, and more particularly to the mounting in relation to such a wheelchair of a control unit therefor.

Powered wheelchairs are well known. Typically such a wheelchair has one or more electric driving motors deriving its or their electrical power from a rechargeable electrical storage battery or batteries carried by the wheelchair. The occupant of the wheelchair operates a control device by which he or she is able to control the speed and direction (forwardly or rearwardly) of travel of the wheelchair, and to steer the wheelchair while it is so travelling. Commonly, steering of the wheelchair is achieved by causing respective drive V motors associated with wheels at the left hand side and right hand side of the wheelchair to operate at different speeds. Although there may be other controls, frequently the main control of the wheelchair is of the "joystick" type, i.e. it comprises a member such as a short lever, upstanding from a body of the control unit and which in use is displaced forwardly or rearwardly to a greater or lesser extent from a central position to control the speed and direction of travel of the wheelchair, and also sideways to left or right to control its steering.

Usually such a control unit is disposed at the forward end of an arm rest of the wheelchair so that an occupant of the wheelchair resting his or her arm on the armrest is easily able manually to operate the control. However, such a disposition of a control unit causes a problem in that, in the situation where the wheelchair has closely to approach a table at the front of the 1 2 wheelchair, the control unit or the joystick extending upwardly from a body of the control unit can contact the table to prevent a close approach. It has been proposed that this disadvantage can be overcome if the control unit is mounted to the wheelchair in such a way that it is able to be pivoted sideways until it reaches a position alongside the armrest rather than at the front end thereof, but a simple pivotal mounting of the control unit has a disadvantage in that after it has been pivoted it lies in a different orientation, so the correspondence between the direction of movement of the joystick and the resulting movement of the wheelchair is lost.

It is broadly the object of the present invention to overcome or reduce this problem.

According to one aspect of the present invention, we provide a mounting means for a control unit for a powered wheelchair, comprising a mounting member adapted to be secured to the wheelchair; a support member; a first pivot means providing a pivotal connection between said support member and mounting member; second pivot means spaced from said first pivot means and providing a pivotal connection between said mounting member and control unit; and link means connected between said mounting member and control unit and operable to maintain a substantially constant relative orientation between said mounting member and control unit.

In a mounting means in accordance with the invention, the provision of a support member which is pivotally connected to both the mounting member and the control unit enables the control unit to be moved relative to the mounting member in an arcuate path whose radius is determined by the c distance between the first and second pivot means on the support member. The link. means maintains the orientation of the control unit substantially constant relative to the mounting member, so that when installed on a wheelchair the 3 sense of operation of a joystick control on the control unit relative to the wheelchair is not altered.

According to another aspect of the invention, we provide a powered wheelchair having a control unit, and mounting means in accordance with the first aspect of the invention by which the control unit is mounted relative to the wheelchair.

Preferably the mounting member is secured or adapted to be secured in proximity to an armrest portion of a wheelchair, eg. to a frame part which supports the armrest. Then the path of movement of the control unit can be arranged to be between a position which lies at or adjacent a front end of the armrest and a position alongside the armrest and rearwardly of the front end thereof, The link means preferably comprises a rigid link member pivotally connected to each of the mounting member and the control unit, such pivotal connections being at the same distance as one another from the pivot axes of each from the pivotal connection thereof to the support member.

There may be provided means for causing the control unit to be held in one or more of the positions in which it can be set relative to the mounting member. Such means may comprise detent means.

The invention will now be described by way of example with reference to the accompanying drawings, of which FIGURE 1 is a perspective view of a wheelchair having a control unit mounted thereto in accordance with the invention; FIGURE 2 is an underneath view of the mountina means of the control unit of the wheelchair, with the control unit in a first operative position as it is illustrated in Figure 1; FIGURE 3 is a view as Figure 2, but with the control unit in a second position.

1 1 4 Referring firstly to Figure 1 of the drawings, a powered wheelchair comprises a frame indicated generally at 10 which carries a scat cushion 11, backrest 12 and beneath the seat cushion a battery pack 13. The frame carries left hand and right hand rear wheels 14, 15 which are fixed in their orientation relative to the wheelchair and are driveable by respective electric motors 16, 17 by way of suitable gearing arrangements. Left hand and right hand front wheels 18,19 are castor wheels, ic. they are mounted to the frame 10 of the wheelchair by swivel mountings 20,21 which enable the wheels to swivel about substantially vertical swivel axes offset from the axes of rotation of the respective wheels 18, 19. The wheelchair further comprises frame parts 22, 23 which support respective armrests 24, 25 for use by an occupant of the wheelchair.

Electrical power by which the motors 16, 17 are driven is supplied thereto from the battery pack 1 -3) by way of a control unit indicated generally at 26, which as illustrated in Figure 1 is positioned adjacent the front end of armrest 24 where a "joystick" control lever 27 upstanding from a body 28 of the control unit is easily operated manually by an occupant of the wheelchair having his or her arm resting on the armrest 24. The conventional mode of operation for such a joystick control lever 27 is that, from a central position, it is pivotally displaced forwardly or rearwardly to control the speed and forward reverse direction of travel of the wheelchair, upon which movement a displacement to the left or the right can be superimposed to steer the wheelchair by causing the drive motors associated with the wheels 14, 15 to be operated at different speeds.

Referrina now to Ficure 2 and 3 of the drawinas, these show from 0 0 C underneath the means by which the control unit 26 is mounted to the wheelchair. In these figures a part of the frame structure 22 supporting the armrest 24 is visible, and to such frame parts there is fixed, eg. by a bolted connection at 30, a mounting member 3 1. The mounting member 31 is in the form of a metal plate or other member of comparable function, and it is pivotally connected to a support member 32 by a first pivot means which provides for pivoting of the support member relative to the mounting member about an axis 33. Such pivot means is of conventional type, and thus is not described herein in detail. At a position spaced from the first pivot means, a second pivot means provides a pivotal connection between the body 28 of the control unit and the support member 32, for pivotal movement about an axis 34. Such second pivot means includes a member 35 beneath the support member 32, the member 35 being rotationally fast with the body 28 about the axis 34.

The member 35 and the mounting member 31 are further connected by a link member 36 which is pivotally connected to such members at 37, 38 respectively. The distance of the pivotal connection 38 from the axis 33 is the same at the distance of the pivotal connection 37 from the axis 34.

The above described mounting of the control unit enables movement thereof in a generally arcuate path between the positions in which it is illustrated in Figure 2 and 3. In the course of such movement, the link 36 maintains the body 28 of the control unit in a substantially constant orientation relative to the wheelchair.

It will be appreciated that when the control unit of the wheelchair is in the position in which it is shown in Figures 1 and 2, it can prevent the wheelchair from closely approaching a table or like. When the control unit has been moved to the position in which it is shown in Figure 3, the control unit presents no such hindrance and, furthermore, because it remains in the same orientation relative to the wheelchair the sense of operation of its joystick control lever is not changed.

Preferably there is a mechanism for holding the control unit in each of its illustrated positions. Such means conveniently comprises a detent 6 mechanism, the effect of which can be overcome by the application of a force greater than a certain value to the control unit.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

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Claims

1. A mounting means for a control unit for a powered wheelchair, comprising a mounting member adapted to be secured to the wheelchair; a support member; a first pivot means providing a pivotal connection between said support member and mounting member; second pivot means spaced from said first pivot means and providing a pivotal connection between said support member and control unit; and link means connected between said mounting member and control unit and operable to maintain a substantially constant relative orientation between said mounting member and control unit.

2. A mounting means according to Claim 1, wherein the link means comprises a rigid link member pivotally connected to each of the mounting member and the control unit, such pivotal connections being at the same distance as one another from the pivotal connections of each to the support member.

3. A mounting means according to Claim 1 or Claim 2, wherein there is provided means for causing the control unit to be held in one or more of the positions in which it can be set relative to the mounting member.

4. A mounting means according to Claim 3, wherein said means comprises detent means.

5. A powered wheelchair having a control unit, and mounting means in accordance with any one of the preceding claims by which the control unit is mounted relative to the wheelchair.

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6. A wheelchair according to Claim 5, wherein the mounting member is secured in proximity to an arrnrest portion of a wheelchair, eg. to a frame part which supports the armrest.

7. A wheelchair according to Claim 6, wherein the path of movement of the control unit is arranged to be between a position which lies at or adjacent a front end of the armrest and a position alongside the armrest and rearwardly of the front end thereof.

8. A mounting means, or wheelchair having same, substantially as hereinbefore described with reference to the accompanying drawings.

9. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.