EP1605885A1

EP1605885A1 - Wheel coupling

Info

Publication number: EP1605885A1
Application number: EP04723517A
Authority: EP
Inventors: Rainer Grundies
Original assignee: Rolko Scandinavia ApS
Current assignee: Rolko Scandinavia ApS
Priority date: 2003-03-27
Filing date: 2004-03-26
Publication date: 2005-12-21
Also published as: WO2004084787A1; DK200300469A

Abstract

By a wheelchair (4) with detachable wheel/hub (12), typically wheel couplings (2) that are releasably fastened to the wheelchair are used. The retainer elements (6) typically include a bushing (7) through which an axle (8) carrying the hub (12) is passed through and arrested by means of locking means (10) at the opposite side of the retainer element (6). The tolerances between the said bushing (7) and axle (8) are to be very small in order to avoid play, which by dirtying axle/bushing can make difficult the insertion and mounting of hub/wheel and axles. With the purpose of remedying the above problem is indicated a wheel coupling (2) of the kind mentioned in the introduction, which is peculiar in that the axle (8) and the locking means (10) are integrated in the retainer element (6). The bushing (7) in retainer elements may hereby be omitted, and the wheel/hub (12) is fastened directly on the axle (8) and secured thereon by means of the locking means (10).

Description

WHEEL COUPLING

BACKGROUND OF THE INVENTION

The present invention concerns a wheel coupling including a retainer element that can be attached to a light vehicle, preferably a wheelchair, a pram or a hand cart, and for an axle of a wheel hub that may be mounted/dismounted on the vehicle by activation of locking means in the shape of a ball closing mechanism provided on the axle.

Such a wheel coupling is known e.g. from wheelchairs, particularly of the collapsible type, where respective side sections of the wheelchair includes a mounting plate/perforated plate that enable horizontally/vertically oriented movement of the supporting wheels/rear wheels for adjusting e.g. the seat level of the wheelchair, or in connection with changing the axle base between the front wheels and rear wheels of the wheelchair.

The prior art retainer elements are typically constituted by a bushing secured to the said perforated plate and intended for accommodating the wheel-carrying axle which is provided with a snap lock for fastening/releasing the axle with the wheel from the said retainer element.

The said snap lock means may e.g. be constituted by a ball lock which is activat- able/deactivatable by a rod or the like on the axle, disposed at the external side of the wheel hub.

A basic requirement to said wheel couplings of the indicated kind is that mounting and dismounting of the wheels on the vehicle, e.g. a wheelchair, pram or hand cart, are to take place without much effort, and may readily be performed by a person who is disabled.

It is to be noted that when a wheelchair is chosen as terminology in the following de- scription, this is not to be understood as being limiting for that included by the present invention. Thus it is here to be mentioned, that the invention also may find application in many other connections, e.g. together with a pram or a hand car or other light vehi- cle, but the term wheelchair has been chose here for the sake of convenience.

The said known wheel coupling has several inexpediencies, of which the most important is that the tolerances between the bushing and the axle interacting therewith and inserted in it for securing to the sides of the wheelchair are even very small. Too large tolerances between the internal diameter of the bushing and the external diameter of the shaft will imply that play arises in the axle connection which is inconvenient for the user of the wheelchair which in certain cases will have the sensation that the wheels of the wheelchair are about to fall off.

The said required small tolerances between the internal and the external diameters of the bushing and the axle, respectively, implies, however, that mounting of the wheels can be made difficult since the axle is to be inserted approximately perpendicularly in the axle bushing. Mounting of the wheels thus requires that the person doing this work is capable of inserting the axle with the wheel by performing an accurate and directional displacement of the axle into the bushing. A further drawback of the known wheel coupling is that the axle can be dirtied, as well as the bushing in the retainer element for the axle can collect dirt and impurities, causing the insertion of the axle in the bushing to be more difficult.

It is the purpose of the present invention to indicate a wheel coupling that eliminates the above drawbacks, or in any case will reduce them substantially.

This purpose is achieved by a wheel coupling of the kind mentioned in the introduc- tion which is peculiar in that the axle and the ball closing mechanism are connected with the retainer element when mounting/dismounting the wheel hub, and that the ball closing mechanism is arranged for being activated/deactivated from the side of the retainer element facing the vehicle.

The special advantage achieved hereby is that then only the wheel hub is moved in over the axle, after which the locking means are activated. I.e. the mounting itself is considerably facilitated since then we are not speaking of inserting a wheel-carrying axle into a bushing with internal dimensions approximately corresponding to the ex- ternal dimensions of the axle, but instead for just passing the wheel hub in over the axle integrated with the retainer element, after which the locking means integrated therein are activated for retaining the wheel/hub on the axle. It is furthermore advantageous that the ball closing mechanism is activated/deactivated from the side facing the vehicle. As the ends of the pins, which are pressure actuated for performing displacement of the pin in the channel present in the axle and which will cause deactivation of the ball closure, are protected, the ball closing mechanism will not be deactivated inadvertently with consequent danger for the user of the wheelchair.

In a preferred embodiment, the ball closing mechanism is activated/deactivated by a pin seated displacing in the axle.

With the purpose of ensuring that the ball closing mechanism is always activated, and that deactivation thereof is conditioned by active handling, the pin for activa- tion/deactivation of the ball closing mechanism can be seated in a channel oriented in the longitudinal axis of the shaft, and be provided with a spring so that the pin actuating the balls belonging to the ball closing mechanism to an active position partly projecting from the periphery of the axle.

Hereby it is safeguarded that the ball closing mechanism, if not deactivated by a conscious action, is always activated. Deactivation of the ball closing mechanism will only be necessary in the moment of mounting for the wheel hub and in connection with dismounting thereof and will require a consciously performed deactivation of the ball closing mechanism.

With the purpose of facilitating dismounting of the wheels on the wheelchair, the wheel couplings in a particular embodiment can be made so that the ball closing mechanism is provided with means for arresting these in an inactive position. The said measure is an advantage in connection with performing the work of mounting the hub on the axle, since the presence of the arresting means implies that a finger/hand is not used for deactivating the locking means, meaning that the person mounting/dismounting the hub from the axle can use both hands for handling the wheel. After the wheel has been mounted, the arresting means can be actuated for activation of the locking means, whereby the wheels are secured.

In a particular embodiment, in which at least two wheel couplings form a part in a wheelchair for its supporting wheels, the ball closing mechanism in the said wheel couplings can be adapted so that these are activated by an axially oriented displacement towards the centre of the wheelchair by the facing end of the pins. The advantage of this is that there is to be established a definite pull in the said pins in order to release the ball closing mechanism for removing the wheels. Such a pull can hardly occur without authorisation, cf. the previously mentioned spring actuation of the pins. If this arrangement of the wheel coupling is combined with an embodiment, where the mutually facing ends of the pins are mutually connected with a draw wire, it will be possible to release both wheels of the wheelchair by deactivation of the ball closing mechanisms with a single jerk in the said draw wire.

In a further embodiment of the wheel coupling, respective, mutually facing ends of the pins are connected with a wire, the ends of which being connected to a common draw unit with a cable extended to an operating handle on the wheelchair. Hereby it will be possible for the user of the wheelchair by actuation of the operating handle to release both wheels, which can be of vital significance for a disabled wheelchair user. The operating handle can be provided with arresting means so that this can be secured in a position where the ball closing mechanisms are in the deactivated position, meaning that the ball closing mechanism can be left in the deactivated position, until the wheels/wheel hubs are mounted on the axles again, after which the operating handle is displaced so that the ball closing mechanisms are activated.

Advantageously, the arresting means can be established by the mechanism arranged like the one in a ballpoint pen, where an axial displacement of the pin seated in the axle by mutually interacting, sloping faces, on the pin and internally of the axle, respectively, transforms an axial displacement into turning of the pin. This turning movement can advantageously be utilised for securing the locking means/ball closing mechanism in its inactive position, and also it is utilised in connection with activation of the same by simply repeating a pressure on the free end of the pin turned in the axle. DESCRIPTION OF THE DRAWING

The invention is now explained more closely in the following with reference to the drawing, where:

Fig. 1 is a simplified view of a wheelchair; Fig. 2 is a side sectional view of a wheel coupling according to prior art;

Fig. 3 shows a side sectional view of a first embodiment of a wheel coupling according to the invention; Fig. 4 shows a side sectional view of a second embodiment of a wheel coupling according to the invention; Fig. 5 shows a side sectional view of a particular embodiment of the wheel coupling shown in Fig. 3, where two wheel couplings are mutually connected with a , draw wire for releasing the locking means; Fig. 6 , shows the same embodiment as in Fig. 5, however with the difference that the wire is connected to a common draw unit with a cable passed to an operating handle on the wheelchair;

Fig. 7 shows a further embodiment of the wheel coupling according to the invention; and Fig. 8 shows a sectional view through a further embodiment of the wheel coupling according to the invention.

Fig. 1 is a very simplified side view of a light vehicle 4 in the shape of a wheelchair. As it appears from Fig. 2, the wheelchair includes a perforated plate 5 in which is fastened a retainer element 6 including a bushing 7 through which is passed an axle 8 carrying a hub 12. The axle is retained by means of locking means 10 in the form of a ball closing mechanism 10 which is deactivated by pressing a pushbutton 11 disposed at the outer side of the hub 12. The ball closing mechanism 10 is activated by means of a compression spring 13 which is seated in a notch in the axle 8.

Fig. 2 shows a wheel coupling of the prior art type, where the retainer element 6 is anchored to the perforated plate 5 by means of a clamping means 9 which in the shown embodiment is constituted by a bolt fastened by a screw thread 15 interacting with it and cut in the external side 17 of the first part of the retainer element 6 through the perforated plate. As it appears from Fig. 2, the hub 12 is fastened to the retainer element 6 by the axle 8 carrying the hub being passed in through the bushing 7 in the retainer element 6. The ball closing mechanism 10 is of course deactivated during insertion of the axle 8 through the bushing 7, so that the balls 28 are in plane with the periphery 30 of the axle, so that the axle can be passed in through the bushing. The ball closing mechanism 10 is subsequently activated so that the balls 28 are bearing against the side 18 of the retainer element 6 facing the vehicle, whereby the axle 8 is retained in its position. The axle 8 also comprises a collar 19 abutting on the external side of the hub 12, whereby the hub is retained in its position.

As it further appears from Fig. 2 and others, the hub also includes ball/roller bearing

32.

In Fig. 3 is seen a wheel coupling 2 according to the invention. The wheel coupling here again includes a retainer element 6 which is clamped to the perforated plate 5 by a bolt 9 on the interacting screw thread 15 cut at the external side 17 of the first part of the retainer element 6 through the plate. The novel feature of the invention is that the axle 8 is an integrated part of the retainer element 6 as well as the locking means 10 for the hub 12 are an integrated part of the retainer element. The locking means 10 are also here constituted by a ball closing mechanism 10 with balls 28 which in the active position of the ball closing mechanism, cf. item 3, by a pin 16 seated in the axle, is retained in a position so that a part of the balls 28 are projecting outside the external periphery 30 of the axle 8.

The pin 16 in the embodiment shown in Fig. 3 is actuated by a spring 26 that ensure displacement of the pin 16 so that it blocks for pressing in of the balls 28 in their seat holes 29 in the axle 8. Deactivation of the shown ball closing mechanism 10 takes place by axial displacement of the pin 16 seated in a channel 24 in the axle 8 in direction of arrow A, whereby a narrowing in the pin 16 is displaced under the balls 28 that hereby can perform displacement inwards in their seat holes 29 so that the peripheries of the balls do not project outside the external 30 periphery of the axle 8. Hereby it becomes possible to move the hub 12 past the balls 28 and thereby release the former from the axle 8, or reversely to fit the hub on the axle. In the embodiment shown in Fig. 3, the ball closing mechanism is deactivated by a pull in the ring 21 which is fas- tened at the end of the pin 16 on the side 18 of the fastened retainer element 6 facing the vehicle.

In Fig. 4 is shown a further embodiment of the wheel coupling 2 according to the in- vention. The ball closing mechanism 10 is arranged so that the hub 12 is released by a pressure on the pin 16 in direction of arrow B, whereby the axle 16 is displaced along longitudinal axis 22 of the axle in the duct 24 in the axle, so that the narrowing 31 in the axle 16 in disposed under the balls 28, whereby these become displacing inwards towards the centre axis 22 of the axle, whereby they will no longer project outside the periphery of the axle 30, and hereby it will be possible to remove the hub 12 from the axle 8.

In Fig. 5 is shown two of the wheel couplings shown in Fig. 3 disposed closely opposite each other as it will be in practice in connection with a wheelchair 4. As it ap- pears, the pins 16, 16' in the mutually facing ends 34, 34' are mutually connected by a draw wire 36 secured in draw wire 21, 21' in said ends of the pins 16, 16'. By pulling the draw wire 36 in direction of arrow C, simultaneous release of both ball closing mechanisms 10, 10' will occur, whereby the hubs/wheels can be removed in the same way as indicated by the description of the embodiment of the wheel coupling accord- ing to the invention shown in Fig. 3.

In Fig. 6 there is a further embodiment of the wheel coupling shown in Fig. 3 according to the invention, the pins 16, 16' are by a draw wire 38, 38' which is extended into a common draw unit 40 which via cable 42 is connected with an operating handle 44 which in a known way can be arrested in its extreme positions. Release of the ball closing mechanisms 10, 10' will occur in the same way as described in connection with the embodiment shown in Fig. 3 of the wheel coupling according to the invention. However, there is the difference here that by arresting the operating handle 44, the ball closing mechanisms 10, 10' can be left in non-active position so that hereby it will be significantly easier to perform dismounting of the hubs 12 and subsequent mounting of the same.

In Fig. 7 is shown a further embodiment of the wheel coupling 2 according to the in- vention. As it appears here, the ball closing mechanism 10 is deactivated from the external side 47 of the hub 12 by displacing the pin 16 in direction D of arrow D, whereby the narrowings 31 in the pin 16 are displaced under the balls 28 which hereby become displacing into their seats 29 in the axle 8, whereby the hub 12 can be dis- placed beyond the end of the axle and taken off the latter. With the intention of counteracting inadvertent actuation of the pin 16 in direction of arrow D, which will cause unwanted release of the hub 12 from the shaft 8, this may, as shown in Fig. 7, be covered with a protective cap that is fastened to the hub 12 in a known way.

In Fig. 8 there is shown a wheel coupling 2 essentially corresponding to the wheel coupling shown in Fig. 3. In this embodiment, the retainer element 6 is provided at its outer surface with a screw thread 33 that may interact with a corresponding screw thread in a perforated plate or corresponding fittings on the vehicle. The threaded part of the retainer element may, however, also be mounted in a perforated plate as shown in Fig. 3. Hereby nuts may be screwed onto each their side of the perforated plate. A nut 34 is screwed on the thread 33 and has a central part 35 in abutment with an end face 36 on the retainer element 6. Hereby, the nut 34 is provided a well-defined position corresponding to the position of the flange shown in Fig. 3. The retainer element 6 and the axle 8 may be produced from one item with an external diameter correspond- ing to the outer diameter of the screw thread 33. A plug 37 with external screw thread 37 interacting with a corresponding screw thread 39 inside the retainer element 6 forms abutment for the spring 26. Activation of the wheel coupling occurs by means of the ring 21 as explained above.

Of course, the inventor has realised that the wheel coupling 2 according to the invention may assume other embodiments that those shown in the drawing accompanying the present description and as described previously, but this does not alter the inventive aspect consisting of integrating a retainer element attachable to a light vehicle with an axle and locking means for fastening a releasable attachable wheel hub.

It is also to be mentioned that for fastening the hub on the axle, other types of locking means can be used than the ball closing mechanism used in the embodiments shown in the drawing.

Claims

1. A wheel coupling (2) including a retainer element (6) that can be attached to a light vehicle (4), preferably a wheelchair, a pram or a hand cart, and for an axle (8) of a wheel hub (12) that may be mounted dismounted on the vehicle by activation of locking means in the shape of a ball closing mechanism (10) provided on the axle, characterised in that the axle (8) and the ball closing mechanism (10) are connected with the retainer element (6) when mounting dismounting the wheel hub, and that the ball closing mechanism (14) is arranged for being activated/deactivated from the side (18) of the retainer element (6) facing the vehicle (4).

2. Wheel coupling according to claim 1, characterised in that the ball closing mechanism (14) is activated/deactivated by a pin (16) seated displacing in the shaft

(8).

3. Wheel coupling according to claim 2, characterised in that the pin (16) is seated in a channel (24) oriented in the longitudinal axis (22) of the shaft, and that the pin (16) is provided with a spring (26) acting on/displacing the pin (16) for activation of the balls (28) belonging to the ball closing mechanism (14), whereby the balls are arrested in a position partly projecting from the periphery (30) of the axle.

4. Wheel coupling according to any of claims 1 - 3, characterised in that the locking means (10)/the ball closing mechanism (14) are provided with arresting means for arresting these in an inactive position.

5. Wheel coupling according to any of claims 2 - 4, of which there are at least two for the supporting wheels in a wheelchair (4), characterised in that the ball closing mechanism (14) is adapted so that it is deactivated by axially oriented displacement of the mutually facing ends (34, 34') of the pins (16, 16') towards the centre of the wheelchair.

6. Wheel coupling according to claim 5, characterised in that the mutually facing ends (34, 34') of the pins (16, 16') are mutually connected by a draw wire (36).

7. Wheel coupling according to claim 5, characterised in that respective, mutually facing ends (34, 34') of the pins (16, 16') are connected with a wire (38, 38'), the ends of which being connected to a common draw unit (40) with a cable (42) extended to an operating handle (44) on the wheelchair (4).