AU706977B2

AU706977B2 - A wheel

Info

Publication number: AU706977B2
Application number: AU74082/96A
Authority: AU
Inventors: Kenneth Charles Holt
Original assignee: JAKAAR IND 1993 Ltd
Current assignee: JAKAAR INDUSTRIES (1993) Ltd
Priority date: 1995-11-30
Filing date: 1996-11-29
Publication date: 1999-07-01
Anticipated expiration: 2016-11-29
Also published as: AU7408296A

Description

-2- This invention relates to a wheel which has been designed particularly though not necessarily solely for use on a trolley such as a supermarket trolley.

There is a need in some supermarkets to provide a trolley in which at least one but preferably more than one of the wheels can be locked particularly when travelling up or down inclined ramps. Such ramps typically include a travciator having a number of grooves therein. Castors have been proposed and are provided in which a brake ring on the castor or wheel enters the travelacor groove when the trolley is pushed thereonto to operate a mechanism, usually within the wheel hub, to act as a brake. Notwithstanding these constructions there remains a need for wheels of this type which are simple to construct and will work in an effective manner, It is therefore an object of the present invention to provide a wheel and associated apparatus which will go at least some distance toward meeting the foregoing desiderata in a simple yet effective manner or which will at least provide the public with a useful choice.

20 Accordingly in one aspect the invention consists in a wheel having a substantially circumferential space, first part locking means positioned at the outer perimeter of said space, second part locking means engageable with said first part locking means, and a brake ring movable with respect to said wheel and operatively connected to said second, part locking means so that with said brake ring in one position said second part locking means is not engaged with said first part locking means and said wheel may rotate with *respect to said brake ring and with said brake ring in a second position said second part locking means engages said first part locking means to substantially prevent relative rotational movement between said wheel and said brake ring, said brake ring being biased to a position wherein said first part locking means and said second part locking means are engaged one with the other.

Preferably said first part locking means comprises an inwardly directed rack.

Preferably said second part locking means comprises one or more teeth.

Preferably movement of said brake ring is substantially radial of said wheel.

-3- Preferably said brake ring has a larger diameter than said wheel.

Preferably said brake ring is rotatably mounted on a hub, said hub mounting said one or more teeth.

Preferably said hub carries one or more friction reducing members to reduce friction between the brake ring and the hub, Preferably the friction reducing members comprise wheels or bearings between the brake ring and the hub.

Preferably said wheels or bearings are positioned adjacent said teeth.

In a further aspect the invention consists in a wheel and mounting, said wheel being constructed according to any one of the preceding paragraphs and said mounting comprising a bifurcated member, said wheel and said brake ring being mounted for rotational movement relative to said bifurcated member, and restraining means being provided to restrain translational movement of said brake ring to a selected direction in 20 use.

Preferably said selected direction is substantially vertical in use.

Preferably said restraining means comprises a detent on said hub, said detent being positioned in a slot on one arm of said bifurcated member so that said detent moves in said slot.

In a still further aspect the invention consists in a castor comprising a wheel and mounting according to any one of the preceding paragraphs wherein said bifurcated 30 member mounts a member rotatable about an axis substantially normal to a line parallel to the axis of rotation of said wheel.

In a still further aspect the invention consists in a trolley having a front end and a rear end and having a basket into which articles can be put, and a plurality of wheels at least one wheel being a castor according to the preceding paragraph.

In a still further aspect the invention consists in a method of using a trolley according to the preceding paragraphs comprising moving said trolley over a ground surface whereby said brake ring is moved against said bias to allow said wheel or wheels to rotate and allowing one or more said brake rings to enter a groove on said ground surface whereby said bias moves said brake ring to a position wherein said second part locking means engages said first part locking means to thereby substantially lock said wheel in that position until said brake ring is removed from said groove.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the description herein are purely illustrative ad are not intended to be in any sense limiting.

One preferred form of the invention will now be described with reference to the accompanying drawings in which: Figure 1: is a cross sectional view of part of a castor according to one 20 preferred form of the invention, Figure 2: is a side elevation of a hub for use in the castor of figure 1, Figure 3: is a view on line A in figure 2, Figure 4: is a side elevation of a wheel part for use in the castor according to figure 1, Figure 6: is a side elevation of a brake ring for use in the castor of figure 1, Figure 7: is a cross section on B, B in figure 6, Figure 8: is a cross-sectional view as in Figure 1 of an alternative embodiment of the invention, and Figure 9: is a view as in Figure 2 of the alternative embodiment.

Referring to the drawings a wheel, a wheel and a mounting, a castor and a trolley are provided as follows.

The wheel I is constructed of a number of parts hereinafter described.

A wheel part 2 is provided which has a diameter suitable for the use to which the wheel is to be put. Thus for example where the wheel is to be used as a supermarket trolley the diameter could be about l2cms.

The wheel part 2 may be constructed from a number of subassemblies. Thus an outer subassembly 3 may be provided and an inner subassembly 4 imay be manufactured, for example, by injection moulding. The parts may be fixed together by coacting spigots, for example, at 7 and 8 and are also shaped to provide a mounting area 9. The wheel IS thus formed may have a tyre portion 10 mnoulded thereonto or otherwise positioned as required. It will be appreciated that a variety of different wheel constructions could be used but the construction must provide a space 15 on the outer perimeter of which is provided a first part locking means preferably a rack 16. The rack 16 can be seen in figure 4 in which only a number of individual teeth 17 are shown. The rack is therefore *.20 inwardly directed of the space 15. The wheel is able to be mounted on an axle through appropriately positioned apertures and a flanged dust seal 21 may be provided if desired to assist the wheel to have freedom of rotation in use.

A brake ring 26 is provided and this is desirably of a greater diameter than the diameter of the wheel and for example the brake ring 26 could have a diameter about greater than the wheel. The brake ring 26 is capable of translational movement relative to the wheel preferably radial movement. The brake ring 26 is also operatively connected to second part locking means preferably a tooth or teeth, for example, three teeth 27 which are able to engage the rack 17. Thus with the brake ring 26 in one position the teeth 27 engage the rack 17 to prevent relative movement between the teeth 27 and the wheel part 2 and in the other position of the brake ring 26 relative to the wheel part 2 the wheel part 2 is able to rotate relative to the teeth 27.

The operative connection between the brake ring 26 and the teeth 27 may be by means of a hub 30 which in the preferred embodiment is mounted on the same axle 20 as the wheel part 2. The hub 30 may take the form of a wheel with a central slot 31I into which -6is positioned a member 32 able to move in the slot 31. The member 32 is biased into the position shown in figure 2, for example, by spring 33. The hub 30 has an outwardly facing ledge 35 onto which is positioned an inwardly spacing ledge 36 provided on the brake ring 26. The brake ring 26 also has a large central aperture 37 of sufficient diameter to allow the teeth 27 to extend therethrough.

Thus the brake ring 26 may freely rotate on the hub 30, but any translational movement of the brake ring 26 will cause a corresponding translational movement of the hub The construction herein described may be mounted in a bifurcated member 40 which may also mount a swiveling member (not shown) able to receive a spindle to form a castor.

The axis of the castor or spindle is normal to a line parallel to but displaced from the axle 20. The wheel may be kept within the bifurcated member 40, for example, by forming the axle 20 as a bolt threaded at one end to receive a nut 42.

The castors may be used in conjunction with a trolley such as a supermarket trolley or 20 other movable devices and in particular a pair of such castors may be provided at either the front end or the rear end of the trolley or at any other position if desired. As the trolley is moved over the ground the brake ring is forced upwardly against the bias of the spring 33. In such a position the teeth 27 are clear of the rack 17 and the wheel 2 may rotate. When the trolley is pushed onto a travelator with grooves the brake ring 26 is pushed downwardly into the groove partly by the action of the bias 33 and partly by virtue of its own weight. In such a position the teeth 27 engage the rack 17. Thus the hub 30 and the wheel 2 are essentially locked together in terms of rotation.

By providing an outwardly extending detent 43 on the hub 30 which is positioned in a 30 slot 44 on the bifurcated member the hub is prevented from rotation and therefore when the teeth 27 and rack 17 engage the wheel is prevented from rotation. This acts as a brake to the trolley. When the trolley is removed from the travelator the brake ring is g again forced upwardly releasing the engagement between the teeth 27 and the rack 17 to allow the trolley to again be used in the normal manner. The detent 43 constrains transitional movement of the brake ring in the embodiment described to be substantially vertical in use.

-7- In the embodiment of Figures 8 and 9 the hub 30 is modified so that friction reducing members are provided between the hub 30 and the brake ring 26. The friction reducing members are in the described embodiment rollers or wheels 50 arranged about and adjacent the teeth 27. In Figure 9 four such rollers are shown and in use they are positioned towards the bottom of the wheel. Ledge 51 of brake ring 26 thus moves against the rollers or wheels Posts 52 may be provided to carry the rollers or wheels 50 but other support constructions could be used. The member providing ledge 35 is provided with gaps adjacent the posts 52 so that the rollers to wheels 52 protrude a small distance through the gap to allow the brake ring 26 to engage the rollers or wheels 52.

Thus it can be seen that at least in the preferred form of the invention a wheel and associated apparatus are provided which are able to made robust in use with a minimum of parts. The construction enables the trolley to be substantially held on normal travelators in an effective manner.

It is a particular advantage of the construction that the rack and teeth are provided a 20 maximum distance from the axle and this reduces strain between the rack and teeth caused by the weight of the trolley when locked on an inclined ramp. Similarly the outwardly extending detent on the hub is at the maximum distance from the axle thereby reducing strain on the detent.

In the embodiment of Figures 8 and 9 the rollers or wheels 50 carry the pressures between the hub 30 and brake ring 26. As the wheels or roller 50 readily rotate friction between the hub 30 and brake ring 26 is reduced.

-8- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: I. A wheel having a substantially circumferential space, first part locking means positioned at the outer perimeter of said space, second part locking means engageable with said first part locking means, and a brake ring movable with respect to said wheel and operatively connected to said second part locking means so that with said brake ring in one position said second part locking means is not engaged with said first part locking mneans and said wheel may rotate with respect to said brake ring and with said brake ring in a second position said second part locking means engages said first part locking means to substantially prevent relative rotational movement between said wheel and said brake ring, said brake ring being biased to a position wherein said first part locking means and said second part locking means are engaged one with the other.

2. A wheel as claimed in claim I wherein said first part locking means comprises an inwardly directed rack.

3. A wheel as claimed in claim 2 wherein said second part locking means comprises one or more teeth.

4. A wheel as claimed in any one of the preceding claims wherein movement of said brake ring is substantially radial of said wheel.

A wheel as claimed in any one of the preceding claims wherein said brake ring has a larger diameter than said wheel.

A wheel as claimed any one of the preceding claims wherein said brake ring is rotatably mounted on a hub, said hub mounting said one or more teeth.

7. A wheel as claimed in claim 6 wherein said hub carries one or more friction reducing members to reduce friction between the brake ring arnd the hub.

8. A wheel as claimed in claim 7 the friction reducing members comprise wheels or bearings between the brake ring and the hub.

Claims

9. A wheel as claimed in claim 8 wherein said wheels or bearings are positioned adjacent said teeth.
10. A wheel substantially as herein described with reference to the accompanying drawings.
11. A wheel and mounting, said wheel being constructed according to any one of the preceding claims and said mounting comprising a bifurcated member, said wheel and said brake ring being mounted for rotational movement relative to said bifurcated member, and restraining means being provided to restrain translational movement of said brake ring to a selected direction in use.
12. A wheel and mounting member as claimed in claim 11 wherein said selected direction is substantially vertical in use.
13. A wheel and mounting member as claimed in either one of claims 11 and 12 wherein said restraining means comprises a detent on said hub, said detent being positioned in a slot on one arm of said bifurcated member so that said detent 20 moves in said slot.
14. A wheel and mounting member substantially as herein described with reference to the accompanying drawings.
15. A castor comprising a wheel and mounting according to any one of claims 11 to 14 wherein said bifurcated member mounts a member rotatable about an axis substantially normal to a line parallel to the axis of rotation of said wheel.
16. A castor substantially as herein described with reference to the accompanying 30 drawings.
17. A trolley having a front end and a rear end and having a basket into which articles can be put, and a plurality of wheels at least one wheel being a castor according to either one of claims 15 and 16.
18. A method of using a trolley according to claim 17 comprising moving said trolley over a ground surface whereby said brake ring is moved against said bias to allow said wheel or wheels to rotate and allowing one or more said brake rings to enter a groove on said ground surface whereby said bias moves said brake ring to a position wherein said second part locking means engages said first part locking means to thereby substantially lock said wheel in that position until said brake ring is removed from said groove. S :3 ABSTRACT The invention consists in a wheel having a substantially circumferential space, an inwardly directed rack at the outer perimeter of the space, one or more teeth engageable into the rack, and a brake ring movable with respect to the wheel and operatively connected to the one or more teeth. Thus with the brake ring in one position the one or more teeth are not engaged with the rack and the wheel may rotate with respect to the teeth and with the brake ring in a second position the one or more teeth engage the rack to substantially prevent relative rotational movement between them. The brake ring is biased to a position wherein the one or more teeth engage the rack. The invention also claims the wheel in conjunction with a mounting member, a castor, a trolley and a method of using a trolley. :i. e*