NZ205039A - Wheelchair brake - Google Patents

Description

205039 No.: 205039 Date: 27th July 1983 NZPATBirOFFlfcE NEW ZEALAND PATENTS ACT, 1953 COMPLETE SPECIFICATION 29JUNN84 RECEIVED CHANGE OF NAME OF APPLiC." Ho gxt-nn/ kiM»TTSD _ WHEELCHAIR OR THE LIKE BRAKING ARRANGEMENT" #/ We, LMQMUII-A£B5-fcfMiTEfr (previously named BETSTONE INDUSTRIES LIMITED), of 216 Antigua Street, Christchurch, New Zealand, a New Zealand company, hereby declare the invention for which i / we pray that a patent may be granted to XMX^ue, and the method by which it is to be performed, to be particularly described in and by the following statement:- 205039 The present invention relates to improvements in and/or relating to wheelchairs.

There is always a need for an unobtrusive safe and cheap braking system for wheelchairs.

It is therefore an object of the present invention to provide such a braking system.

Accordingly in one aspect the present invention may broadly be said to consist in a braking system for a wheelchair (or indeed any other vehicle e.g. a trolley or the like), comprising a braking member which is pivotally mounted to swing about an arc so as to bring its distal end or an extension thereof into a braking engagement with the wheel or tyre thereof, a brake actuation member (hereinafter "handle member") which is pivoted about a substantially parallel pivot axis capable of being rotated by hand thereabout over at least a restricted arc, a portion of the handle member extending towards the braking member and being pivotally linked to a rigid linkage which itself is pivotally linked to the braking member between the pivotal mounting of the braking member and its distal end, all of the pivots mentioned being substantially parallel, the construction being characterised that the pivot between the handle member and the linkage is such that when the brake is to be applied and the handle member rotated in the brake applying direction the pivotal connection between the linkage and the handle member locks to thereby bring to bear the braking effect by moving the braking member about its pi vot.^mount|ng. c Preferably the arrangement or at least the mode of action is substantially as hereinafter described.

« Preferably the locking up of the pivotal connection between the linkage and the handle member is as a consequence of a modification to the linkage Itself or an attachment thereto. Preferably the modification is substantially as hereinafter described.

Preferably the brake is a pull-on brake. If however the arrangement is reversed insofar as the locking direction is concerned and the geometry changed slightly the brake can be converted to a push-on locking arrangement.

One preferred form of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 shows the preferred brake in accordance with the present invention on the right hand side of a wheelchair showing the brake in its non-braking condition, the connection between the preferably curved handle and the linkage to the braking element being fully utilised to hold without the action of springs the braking element clear of the tyre, Figure 2 is the same arrangement as shown in Figure 1 showing how the limitation on movement about the pivot between the linkage and the handle allows the forcing of the braking element into braking engagement whereupon the same remains owing to an overlocking situation occurring as a consequence of the geometry of the brake, Figure 3 shows clearly the essential elements of the brake, it 205089 being seen that all the pivotal linkages are substantially Identical and showing the preferred linkage limited by an extension thereof to restrict rotation more in one direction than the other, Figure 4 shows the reversible linkage in Its condition as depicted 1n all of the previous drawings, it being realised however that 1f the same is inverted the brake would turn from the pull-on arrangement as depicted to a push-on arrangement, Figure 5 is an exploded view of another preferred form of present invention showing how the braking system can be made from a number of simple components to manufacture and in particular showing how the overcentre stop for locking up the pivot can be provided by an attachment (indicated by reference 'A') rather than the more difficult to machine modification of the linkage shown by reference to Figure 4 and Figure 6 is an alternative to the overcentre stop attachment of Figure 5.

Referring specifically therefore to Figure 3 it can be seen that the handle 1 is arcuate and is provided with a pivotal mounting about a pivot 2 which is parallel to all of the other pivots.

Preferably for ease of fitting a mounting plate 3 carries the member 4 which provides the pivot mounting of the handle 1 and also a member 5 which provides the pivotal mounting 6 of the braking element 7. As can be seen the braking element 7 includes at its distal end region a portion 8 which engages against the wheel.

Preferably the mounting plate 3 1s provided with a clamp member 9 capable of engaging, for example, about the element 10 shown in Figure 2. 205039 The end of the handle 1 not to be grabbed 11 is pivotally mounted at 12 to one end of the linkage member 13, the other end of which is pivoted at 14 between the pivot 6 and the distal end of the braking element 7. The linkage 13 includes a portion 15 best seen in Figure 4 which locks the pivot 12. When 1n a condition as shown in Figure 3 and the handle member 1 is pulled by an occupant between the conditions shown 1n Figure 1 and Figure 3 1t is quite clear that the braking element will drop from the condition as shown in Figure 1 into the condition almost as shown in Figure 2 and the resiliance of the tyre will allow overlocking to occur which holds the brake using the resiliance of the tyre in its locking condition without the need for springs and other biased means. As can be seen from the geometry and in particular Figure 2. The whole arrangement is such that the locking effect provides a force down along the length of the link 13 to hold the portion 8 against the tyre.

In Figures 5 and 6 there is shown in an exploded view the components that can be employed which are usually manufactured and which can be assembled to provide a braking system in accordance with the present invention. In the arrangement as shown in Figure 5 an over-centre stop indicated by letter (A) is employed rather than the modification 15 shown in Figure 4. This is because of the difficulty in manufacturing the modification 15 of the linkage shown in Figure 4. Figure 6 shows an alternative overcentre stop to that shown in Figure 5. / 205039 It is believed with the use of a brake in accordance with the present invention in either Its push-on or pull-on form great savings and a great reduction in complication occurs in the provision of a brake. Moreover the brake 1s not only light which 1s of importance from a mobility point of view but also aesthetically pleasing and cheap. 2O5039

Claims (4)

WHAT WE CLAIM IS:

1. A braking system suitable for use with a wheelchair comprising: a braking member which is pivotally mounted to swing about an arc so as to bring its distal end or an extension thereof into a braking engagement with the wheel or the tyre of a wheel to be braked, a brake actuation member (hereinafter referred to simply as "handle member") which is pivoted about a substantially parallel pivot axis capable of being rotated by hand thereabout over at least a restricted arc, a portion of the handle member extending towards the braking member and being pivotally linked to a rigid linkage which itself is pivotally linked to the braking member between the pivotal mounting of the braking member and its distal end, all of the pivots mentioned being substantially parallel, the construction being charac-teristed that the pivot between the handle member and the linkage is such that when the brake is to be applied and the handle member rotated in the brake applying direction, the pivotal connection between the linkage and the handle member locks to thereby bring to bear the braking effect by moving the braking member about its pivot mounting wherein the linkage has a stop member substantially as hereinbefore described with reference to the accompanying drawinqs, to prevent the handle' member beinci moved past the locking position. i - 8 - 205J.39

2. IA braking system as claimed in any one of the preceding claims wherein the brake is a pull-on brake.

3. /A braking system substantially as hereinbefore described with reference to any of the accompanying drawings. /

4. A wheelchair including at least one braking system as claimed in any one of the preceding claims. DATED THIS 1 OF 19^3 A. J. PARK & SON per ACPMTC TH£. AP»t K-AMTS 20FEBl987m