GB2467574A

GB2467574A - Detachable swivel lock for a pair of trolley castors

Info

Publication number: GB2467574A
Application number: GB0902005A
Authority: GB
Inventors: Michael John Blignaut
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-02-06
Filing date: 2009-02-06
Publication date: 2010-08-11
Anticipated expiration: 2029-02-06
Also published as: GB0902005D0; GB2467574B

Abstract

The swivelling of a pair of trolley castors 14 is prevented by the use of a linkage 10 which is detachably secured to the castors 14 to retain them in a fixed alignment relative to one another. The linkage takes the form of a crossbar 12 having a slotted bracket 11 at each end. When it is desired to restrict swivelling of the castors 14, the brackets are slid over the side plates 16 of the castor forks thereby keeping the castors aligned and locked against swivelling. The crossbar 12 of the connecting linkage 10 may be telescopic, and may be secured to the castors by magnets. When use of the trolley is at an end, the user draws the crossbar 12 away to disengage the brackets 11 from the castors. The cross bar can then be telescoped inwards and stowed in, for example, a shopping bag. The linkage 10 can be used with any trolley such as a shopping trolley or a luggage trolley.

Description

IMPROVEMENTS IN OR RELA TING TO TROLLEYS

Field of the Invention

This invention relates to trolleys. That is to say, transport devices for transporting goods and/or people, which transport devices are supported on at least three wheels and in which at least two of the wheels are castors at either end of a common transverse axis. Typical examples of trolleys to which the invention applies are shopping trolleys and luggage trolleys.

Background to the Invention

Many trolleys provided by the operators of supermarkets and travel terminals are supported on four castors -wheels which can freely rotate about their vertical mounting axes. The castors are provided as a front pair and a rear pair, each pair being located at opposite ends of an axis transverse to the longitudinal centreline of the trolley. This arrangement results in difficulties with steering the trolleys, particularly when the trolleys are laden, as the castors inevitably assume aligmnents other than with the desired direction of travel.

It is an object of this invention to provide a method and/or means which will address the aforementioned problem; or which will at least offer a novel and useful alternative.

Summary of the Invention

Accordingly, in one aspect, the invention provides a method of controlling the operation of a trolley supported on at least spaced two castors, said method comprising attaching a linkage to said castors, which linkage retains said castors in fixed alignment with respect to one another.

Preferably said trolley is supported on four castors arranged in two pairs, the castors of each pair being located on a common axis, the two axes being substantially parallel, wherein the method comprises attaching said linkage to only one pair of castors.

Preferably said castor pairs are arranged on said trolley as a front pair and a rear pair, said method comprising attaching said linkage to said rear pair of castors.

In a second aspect the invention comprises a linkage for use in the method set forth above, said linkage having a pair of engagement brackets, each bracket being configured to engage one of said spaced castors; and a linking facility constructed and arranged to link said engagement brackets and to retain said engagement brackets in fixed alignment with respect to one another.

Preferably said linkage is configured to operate in conjunction with castors having a disc wheel rotatably mounted between spaced side plates, said engagement brackets being configured to engage with said side plates.

Preferably each said engagement bracket includes an elongated slot sized to receive the cross-section of one of said side-plates.

Preferably said slot is of a width and length, sufficient to prevent turning movement of said side plate within said slot.

Preferably said linkage further includes a fixing facility to fix said engagement brackets to said castors. Said fixing facility conveniently comprises one or more magnets.

Preferably said linking facility is telescopic.

In a third aspect the invention comprises a trolley supported on at least two castors, the castors being interconnected by a linkage as set forth above.

Many variations in the way the invention may be performed will present themselves to those skilled in the art, upon reading the following description. The description should not be regarded as limiting but rather as an illustration, only, of one manner of performing the invention. Where appropriate any element or component should be taken as including any or all equivalents thereof whether or not specifically mentioned.

Brief Description of the Drawings

One working embodiment of the invention will now be described with reference to the accompanying drawings in which: Fig 1: shows a top view of a linkage according to the invention; Fig 2: shows an underside view of the linkage shown in Fig I; Fig 3: shows the linkage of Figs 1 & 2 in position on a trolley; Fig 4: shows a side view of a typical castor used to support a trolley; and Fig 5: shows detail of engaging the linkage of Figs I & 2 with a castor.

Detailed Description of Working Embodiment

In one aspect, the invention provides a method of controlling the operation of trolley castors such as are typically found on shopping trolleys and baggage trolleys. Such trolleys are generally supported on four castors arranged in two pairs. More typically, there is a front pair of castors mounted on a common transverse axis and a rear pair of castors mounted on the further transverse axis, which further axis is parallel to that on which the front pair are mounted. It should be emphasised that the axes referred to a imaginary axes and simply serve to enable a better description of the wheel geometry of the trolley. In reality each castor can freely rotate about its vertical mounting axis.

The ability of each castor to rotate about a vertical axis leads to steering problems which will be well known to all users of such trolleys. The steering problem tends to be exacerbated as more load is applied to the trolley and when the castors become jammed in positions in which the wheels will not readily align with the intended or desired direction of travel.

The invention addresses this problem by providing a linkage which can be engaged with the castors positioned on a common axis, to lock the castors in alignment. The remaining castors on the trolley are left unrestrained to provide steering. In this way substantially improved control of the trolley results.

Referring now to the figures, a linkage 10 is shown having a pair of engagement brackets 11; and a linking facility or cross-bar 12 constructed and arranged to link the engagement brackets 11 and to retain the engagement brackets 11 in fixed alignment with respect to one another. Thus, when the engagement brackets 11 are engaged with spaced trolley castors 14, the castors are retained in a fixed alignment. The castors no longer freely steer and the trolley can thus be controlled far more effectively.

The particular form of linkage 10 described herein is configured to operate in conjunction with castors 14 of a general type shown in Figs 3 & 4, these castors having a disc wheel 15 rotatably mounted between spaced side plates 16. The side plates 16 may be formed by opposite parts of a cup-like structure which receives the wheel 15. Each castor can, in normal circumstances, rotate about vertical mounting axis 17. This castor arrangement is particularly suited to the present invention in that, as can be seen in Figure 3, the fixing brackets 11 can be easily formed to engage the inner or facing side plates of the two castors to be linked.

As can best be seen in Fig 5, the brackets extend forwardly from the cross-bar 12 and may be profiled to allow the bracket to closely contact the side plate 16. Each engagement bracket 11 preferably includes an elongated slot 18 sized to receive the cross-section of the side plate as can be seen in Fig 5. The slots 18 of the brackets are essentially parallel and are preferably of a width and length, sufficient to prevent turning movement of said side plate within said slot. Thus, when the linkage is engaged between two spaced castors, the wheels 15 forming part of the castors, are also kept parallel.

It will be noted that the side plates of the typical castor shown in Fig 4 have sloping rear edges 20. The rear edge 21 of each slot may have a corresponding taper so that the engagement of the brackets 11 with the side plates is maintained horizontal and the profiled sections of the brackets can be kept in contact with the profiled sections of the castor side plates.

To maintain the linkage in position during use, a fixing facility is provided which conveniently comprises one or more magnets 22.

In order to accommodate trolleys of different track width, the cross bar 12 is preferably telescopic and may be formed from two sections of square-sectioned tube, one of the two sections being a sliding fit within the other as can be seen from Figs I & 2. The telescopic cross bar also allows the size of the linkage to be reduced for storage andlor carrying when the linkage is not in use.

In use, a trolley user simply extends the cross bar sections to the required width so that the slots 18 on the engagement brackets 11 are aligned with the inner side plates 16 on the rear set of trolley castors. The linkage is then simply slid forward to engage the brackets with the castors whereupon the linkage is retained in position by the magnets 22. When use of the trolley is at an end, the user simply draws the cross bar away, overcoming the effect of magnets 22 and dis-engaging the brackets 11 from the castors 14. The cross bar 12 can then be telescoped inwards and stowed in, for example, a shopping bag, for future use.

Claims

Claims 1. A method of controlling the operation of a trolley supported on at least spaced two castors located on a common axis, said method comprising attaching a linkage to said castors, which linkage retains said castors in fixed alignment with respect to one another.
2. A method as claimed in claim I wherein said trolley is supported on four castors arranged in two pairs, the castors of each pair being located on a common axis, the two axes being substantially parallel, wherein the method comprises attaching said linkage to only one pair of castors.
3. A method as claimed in claim 2 wherein said castor pairs are arranged on said trolley as a front pair and a rear pair, said method comprising attaching said linkage to said rear pair of castors.
4. A linkage for use in the method claimed in any one of claims I to 3, said linkage having a pair of engagement brackets, each bracket being configured to engage one of said spaced castors; and a linking facility constructed and arranged to link said engagement brackets and to retain said engagement brackets in fixed alignment with respect to one another.
5. A linkage as claimed in claim 4 when configured to operate in conjunction with castors having a disc wheel rotatably mounted between spaced side plates, said engagement brackets being configured to engage with said side plates.
6. A linkage as claimed in claim 5 wherein each said engagement bracket includes an elongated slot sized to receive the cross-section of one of said side-plates.
7. A linkage as claimed in claim 6 wherein said slot is of a width and length, sufficient to prevent turning movement of said side plate within said slot.
8. A linkage as claimed in any one of claims 4 to 7 further including a fixing facility to fix said engagement brackets to said castors. Said fixing facility conveniently comprises one or more magnets.
9. A linkage as claimed in any one of claims 4 to 8 wherein said linking facility is telescopic.
10. A trolley supported on at least two castors, the castors being interconnected by a linkage as claimed in any one of claims 4 to 9.