GB2286368A

GB2286368A - Supermarket trolleys

Info

Publication number: GB2286368A
Application number: GB9506476A
Authority: GB
Inventors: Carlos Jorge Duarte Ribeiro
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-01-19
Filing date: 1992-01-16
Publication date: 1995-08-16
Anticipated expiration: 2012-01-16
Also published as: GB9506476D0; GB2286368B; GB2268136A; GB9314676D0; GB2268136B

Abstract

The trolley is provided with an asymmetrical wheel arrangement whereby the load is supported in use largely by front and rear castors C2, C3 on one side of a trolley and by a fixed-axis control wheel W1 on the other side of the trolley, the control wheel being positioned at a generally mid-position in the length of the trolley. When the trolley is nested (Figure 2), the control wheel W1 is lifted and the trolley is supported by castors C2, C3, C4, C5. An adaptor, (Figure 5) is described for converting a conventional trolley provided with four castors, the adaptor consisting of a bar 42 for connection to front and rear castor mountings and supporting the control wheel 46 at a level below the existing castors. <IMAGE>

Description

TROLLEYS This invention relates to trolleys, particularly, but not exclusively, to trolleys for use in supermarkets.

Supermarket trolleys especially when full are generally difficult to manoeuvre. Some trolleys have been provided with fixed-axes wheels at the front and castors at the rear, whilst others have castors at the front with fixed-axis wheels at the- rear. Neither of these arrangements is satisfactory in practice in that supermarket customers generally find it hard work turning the trolley round corners, or the trolley does not go where intended, especially on sloping car parks or ramps with bends.

I have surprisingly discovered that a trolley having a wheel, the axis of which is at least normally fixed relative to the trolley framework, hereinafter referred to as the 'fixed-axis wheel on one side at a generally intermediate position of the trolley, and two castors on the other side, one castor leading the fixed-axis wheel, and the other castor trailing the fixed-axis wheel, provides good steering characteristics, despite the asymmetric arrangement of the wheel, both when turning to the right and when turning to the left.

The fixed axis wheel is preferably affixed in a mid-position of the trolley for optimum ease of steering but a substantial degree of steerability would still be achieved if the fixed axis wheel were positioned further forward or further rearward of the mid-position.

I am aware that trolleys have been proposed, such as in EP 0,267,817, in which a central wheel or pair of wheels is provided in addition to the usual four castors, but such symmetrical arrangements do not have the steering characteristics of the inventive trolley.

According to a first aspect of my present invention, a trolley comprises a trolley framework and a plurality of ground-engageable wheel means mounted on the trolley framework characterised by an asymmetrical configuration of the wheel means with respect to the longitudinal centre-line of the trolley, the configuration comprising a wheel the axis of which is at least normally fixed relative to the framework, said fixed-axis wheel being provided at an intermediate position in the length of the trolley and towards one side thereof from the centre-line and-first and second castors toward the other side of the framework, the first castor leading the fixed-axis wheel, and being positioned closer to the longitudinal centre-line of the trolley than the second castor, and the second castor trailing the fixed-axis wheel, whereby the weight of the trolley can be supported in use at least substantially by the combination of the fixed-axis wheel and said first and second castors.

The fixed-axis wheel is preferably positioned at substantially midway between the -castors relative to said normal direction of straight-line travel.

One might have expected that such a wheel configuration would have resulted in different trolley steering characteristics when turning the trolley to the right and to the left, but the turning characteristics are found to be substantially the same. The trolley tends to pivot about the fixed-axis wheel when turning in one direction, and about the in-line mid-point between the castors when turning in the opposite direction. In each case, the trolley can be steered in a predictable manner and without the need to exert an excessive sideways force on the trolley.

This steering effect occurs even though the fixed axis wheel is displaced well away from the centre line of the trolley and even though there is no fixed wheel corresponding to such wheel opposite it on the other side of the trolley.

The trolley framework preferably comprises a handle which is gripped during manoeuvring of the trolley, but it may be possible in some cases for the user to grip part of the load-carrying means which then takes the place of a handle.

In a preferred embodiment the framework comprises a transverselyextending handle positioned substantially in register with one of the castors relative to said normal direction of straight-line travel, when viewed in plan. Such an- arrangement provides a relatively compact trolley since the handle need not project rearwardly significantly beyond the load-carrying means, as is often necessary with existing trolleys.

A trolley in accordance with the present invention is preferably provided with at least one supplementary ground-engageable wheel means which does not engage the ground in the normal load-carrying condition of the trolley.

Preferably two supplementary wheel means are provided each lying outside the triangle defined by the first, second and third wheel means.

The supplementary wheel means may simply prevent the trolley from turning over if subjected to an abnormal sideways load but preferably the supplementary wheel means can be brought to a condition in which at least the fixed axis wheel on the first or second castor is lifted clear of the ground.

When the supplementary wheel means comprises a pair of spaced-apart supplementary castors, it is preferably arranged that the supplementary castors lift the fixed-axis wheel clear of the ground.

This then means that the trolley can be moved in any direction, being supported entirely on castors, for manoeuvring in nested groups of trolleys by the supermarket staff.

As an alternative to providing such a supplementary wheel means, an axis release means may be provided to release the axis of the fixed axis wheel, to enable the fixed axis wheel to perform as a castor when the trolley is to be manoeuvred without a load, by supermarket staff for example.

In my prior European patent application no. 89306307.3 (publication no. 0,4Q3,702A1), I have disclosed a trolley in which a pivotable load-carrying basket is carried by a pair-of laterally spaced-apart articulated X-frames. The basket is pivotable about a transverse axis of the trolley, that is transverse relative to the normal direction of straight-line travel of the trolley.

The specific embodiment disclosed in that European application was primarily aimed at providing a relatively lightweight trolley which could be stacked with other trolleys to form either a vertical stack or a horizontal nested group. There is currently a need for a larger supermarket trolley than the largest currently available. I have realised that a radical alteration to the design of the trolley disclosed in my European application can provide a trolley of large capacity, but which can nest with like trolleys for manoeuvring by supermarket staff.

In the trolley embodiment of my European application the basket pivoted about the transverse axis of the trolley but, in accordance with a preferred feature of the present invention, I provide a trolley in which a load-carrying basket is pivotable from a normal load-carrying orientation to a nesting orientation about a pivotal axis extending substantially longitudinally of the trolley relative to the normal direction of straight-line travel of the trolley.

The pivotable basket can be relatively elongate in said normal direction of straight-line travel, yet can still be pivoted relatively easily from the normal to the nesting orientation and vice versa.

Control links similar to links 22 in my prior European application can be employed to control the pivotal movement of the basket when the trolley framework comprises a pair of X-frames, the pivotal axis of the X-frames extending parallel to the basket pivotal axis.

According to a second aspect of the present invention I provide an adaptor for providing a supermarket trolley with an additional, control wheel, the adaptor comprising a bar having first and second ends which are adapted to be secured respectively to the castor mounting means at front and rear positions on one side of a supermarket trolley, the bar carrying a control wheel at an intermediate position along the bar, the axis of the wheel being arranged normally to extend transversely of the bar.

A third aspect of the invention is a supermarket trolley fitted with the adaptor.

The bar is conveniently a length of tube of a section such that the bar provides said resilient means for resiliently urging the control wheel downwards relative to the trolley framework. The shape and cross-section of the bar will determine the resilient loading which is exerted on the control wheel when the trolley is sufficiently loaded that all of the castors are resting on a flat floor.

The ends of the bar are preferably in the form of apertured flat plates which can be fitted on the shank of the existing castors, simply by removing the two castors on that side of the trolley, fitting the bar ends over the shank and replacing the castors.

According to a fourth aspect of the present invention a trolley comprises a trolley framework supporting a load-carrying means, the trolley framework having a front and a rear relative to the normal direction of straight-line travel of the trolley when carrying a load, the framework being mounted on five ground-engageable wheel means comprising a pair of laterally spaced-apart front castors, a pair of laterally spaced-apart rear castors, and a steering control wheel mounted to one side of the framework at an intermediate position between the front and rear castors on that side, the axis of rotation of the steering control wheel being normally fixed, as viewed in plan, to extend transversely of the trolley, and resilient means urging the control wheel downwardly relative to-the framework.

Thus, the trolley framework is supported on four castors but has an additional control wheel which is urged resiliently downwards.

With this arrangement the control wheel will always engage the floor to exert a steering control action, as described previously, and at least two of the castors will engage with the ground.

The vertical travel of the control wheel and the resilient loading provided by said resilient means are preferably arranged such that the control wheel always maintains contact with the ground, even on undulating floors. That is, when the castors happen to be on high spots, and the control wheel is sitting on a low spot, the control wheel should still make firm contact with the ground, both in the laden and unladen conditions of the trolley.

It may be the case that when the trolley is unladen, the two castors on the same side of the trolley as the control wheel are lifted clear of the ground by the resilient reaction on the trolley provided by the resilient means. The trolley will then be supported by the control wheel and by the two castors on the opposite side of the trolley. Then, when a load is put into the trolley, all four castors will engage the floor if the surface is perfectly flat.

According to a fifth aspect of the present invention a trolley comprises a trolley framework and a plurality of ground-engageable wheel means mounted on the trolley framework, characterised by an asymmetrical configuration of the wheel means with respect to the longitudinal centre-line of the trolley, the configuration comprising a wheel, the axis of which is at least normally fixed relative to the framework, said fixed-axis wheel being provided at an intermediate position in the length of the trolley and towards one side thereof from the centre-line first and second castors toward the other side of the framework, the first castor leading the fixed-axis wheel, and the second castor trailing the fixed-axis wheel, whereby the weight of the trolley can be supported in use at least substantially by the combination of the fixed-axis wheel and said first and second castors, and by at least one supplementary ground-engageable wheel means mounted on the trolley framework and which does not engage with level ground in the normal load-carrying condition of the trolley, except possibly when the trolley is heavily laden, the supplementary wheel means, in plan view of the trolley, lying outside the triangle defined by the fixed-axis wheel and the first and second castors.

The castors constituting the second and third wheel means may be positioned substantially in-line with each other relative to said normal direction of straight-line travel, but some offsetting of the second and third wheel means is generally required to enable trolleys to nest together.

Some embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which: Figure 1 is a rear view of a trolley in accordance with the invention with the basket in its normal, load-carrying orientation, Figure 2 is a rear view of the trolley of Figure 1 with the basket in its nesting orientation, Figure 3 is a side elevation of the trolley looking from the right in Figure 1, Figure 4 is a side elevation of the lower part of a conventional trolley fitted with an adaptor in accordance with the invention, and Figure 5 is a plan view of the adaptor shown in Figure 4.

The general construction of the trolley of Figures 1 to 3 resembles that of the trolley shown in the drawings of my prior European application publication no. 0,403,702A1, and for convenience parts corresponding to those of the trolley of that prior application are given corresponding reference numerals in the accompanying drawings.

The general articulation of the X-frames, and the control of the pivoting of the basket from the load-carrying orientation of Figure 1 to the stacking orientation of Figure 2 are essentially the same as in the prior European application and will not be repeated here.

Only the principal differences will now be described.

In the present embodiment the trolley is intended to be pushed, or pulled, when loaded in a direction at 90" to that of the illustrated trolley of my prior European application. The configuration of the wheels is quite different, in that the X-frame members 3 each carry at their lower free ends a respective castor wheel C2, C3, the said free ends being in-line as viewed in the normal, load-carrying direction of travel (as viewed in Figure 1). The midpoint of the longitudinal frame member 8 which is integral with the lower ends of the X-frame members 4 carries a fixed-axis wheel W1.

Wheels W1, C2 and C3 constitute the aforementioned first, second and third wheel means respectively.

The aligned longitudinal pivots of the X-frames 1 are indicated at the the support rod 5 for the basket 2 in the normal orientation being separated from the pivots 51 in this construction, rod 5 being secured at its ends to frame members 3.

The upper portion 31 of each frame member 3 is generally horizontal and extends transversely of the trolley to provide a handle, -conveniently at both ends of the trolley, to enable the trolley to be pushed in opposite directions.

The handle 31 is positioned substantially vertically above the respective castor C2 or C3, and hence does not project significantly from the plan area of the basket 2.

The wheel means Wl, C2, C3 are arranged in a triangular configuration, and supplementary castors C4 and C5 are carried by the lower portions of respective members 4 at positions which, as viewed in plan, are outside the area of the triangle defined by W1, C2, C3. In the load-carrying condition of the trolley the castors C4 and C5 are clear of the ground but when the X-frames are articulated to the nesting orientation of Figure 2, the castors C4, C5 take over from wheel W1, so that the trolley is then supported by the four castors C2 to C5.

In the nesting orientation of the basket 2 shown in Figure 2, a plurality of the trolleys can be nested together, with the baskets of adjacent trolleys interfitting with one another. Thus, it will be appreciated that, as distinct from the illustrated trolley of my prior European application, the row of nested trolleys extends in a direction which is transverse to the normal in-line direction of travel of the individual trolleys in their load-carrying condition.

The elongate shape of the basket of the presently illustrated trolley provides a large load-carrying capacity.

Although the wheel configuration provided by wheel means W1, C2 and C3 has been shown on a trolley having an articulated framework, it should be appreciated that a trolley having a fixed framework could also employ the inventive wheel configuration.

In a modification, not shown, the wheel W1 is arranged as a castor but a releasable castor retaining means is provided for locking the castor in an orientation such that the axis of the castor wheel is as shown for the wheel W1. The castor retaining means can be released to enable a nested group of such trolleys to be manoeuvred.

Such an arrangement could be employed with a trolley having a fixed or an articulated framework.

Although the inventive wheel configuration--facilitates the design of trolleys having a large capacity such as 225 and 245 litres, this configuration also has substantial advantages when used with trolleys of smaller capacity, such as 175 and 125 litres.

Figure 4 illustrates an adaptor 35 for converting existing supermarket trolleys provided with four castors to the inventive wheel configuration. The existing trolley is of the kind provided with two transversely spaced front castors 36, and two transversely spaced rear castors 37, the transverse spacing of the front castors 36 being less than that of the rear castors 37 to enable the front castors of one trolley to pass between the rear castors of an adjacent trolley when those trolleys are urged together to bring their baskets (not shown) into a nested condition. The framework of the existing trolley on each side comprises a respective bow-shaped frame member 38 the opposite ends 39, 40 of which are provided with sockets 41 to receive the respective castor 36, 37.

The adaptor 35 comprises a straight tubular bar 42 the ends 43, 44 of which are flattened and provided with respective holes 45, the longitudinal spacing of the holes 45 being chosen to correspond with the spacing of the castor spindles, to enable the adaptor 35 to be secured to the existing trolley framework by re-inserting the shanks of castors 36, 37 into the sockets 41. Adaptor 35 comprises a fixed-axis wheel 46 carried by bar 42 at substantially the midpoint of the length of the bar. As shown in Figure 5, the axis 47 of the wheel 46 is arranged to be transverse to the normal direction of forward movement of the trolley, indicated by the arrow F in Figure 5.As shown in Figure 4, which shows the trolley in an unladen condition, the wheel support 48 is dimensioned such that the wheel 46 projects downwardly below the level of the bottom of wheels 37 whereby the wheel 46 will engage a level floor on that side of the trolley, and wheels 36, 37 will normally be held clear of the floor by wheel 46.

The cross-sectional dimensions of bar 42 can be chosen to provide a desired degree of resilient downward force on wheel 46 when the trolley is loaded sufficiently to bring castors 36 and 37 into contact with the floor. Such resilient loading of wheel 46 will ensure that wheel 46 has a predominant role in controlling the movement of the side of the trolley provided with adaptor 35.

It will be appreciated that no such adaptor is applied to the other side of the trolleys which remains supported by the corresponding pair of front and rear castors 36, 37. Since the thickness of the adaptor ends 43, 44 can be kept small, the trolley will remain in a substantially horizontal attitude after fitting with the adaptor.

The adaptor can be fitted either on the left side or the right side of the trolley, in each case the axis 47 of the wheel 46 is arranged to be transverse to the normal direction of forward movement of the trolley.

The adaptor 35 will not, in general, prevent the existing trolleys being nested together in the usual way since the wheel 46 is laterally spaced from the castor 36 by an amount which is sufficient to prevent interference during nesting.

Claims

1. An adaptor for a supermarket trolley, the supermarket trolley having four ground-engageable wheel means comprising a pair of laterally spaced-apart front castors and a pair of laterally spaced-apart rear castors, the adaptor comprising a bar which carries an additional wheel at an intermediate position along the bar, the bar having first and second ends which are adapted to be secured respectively to the castor mounting means at front and rear positions towards one side of the supermarket trolley, so as to locate the additional wheel in a position for engaging the ground in order for the additional wheel to function as a steering control wheel, the axis of the wheel being arranged normally to extend generally transversely of the bar.

2. An adaptor as claimed in claim 1 in which the bar is a length of tube which has been flattened at the ends.

3. A supermarket trolley fitted with the adaptor of claim 1 or claim 2.

4. A trolley comprising a trolley framework and a plurality of ground-engageable wheel means mounted on the trolley framework in an asymmetrical configuration of the wheel means with respect to the longitudinal centre-line of the trolley, the configuration comprising a wheel, the axis of which is at least normally fixed relative to the framework, said fixed-axis wheel being provided at an intermediate position in the length of the trolley and towards one side thereof from the centre-line, and first and second castors toward the other side of the framework, the first castor leading the fixed-axis wheel, and being positioned closer to the longitudinal centre-line of the trolley than the second castor, and the second castor trailing the fixed-axis wheel, whereby the weight of the trolley can be supported in use at least substantially by the combination of the fixed-axis wheel and said first and second castors.

5. A trolley as claimed in claim 4 in which the axis of the fixed-axis wheel is parallel to level ground when the weight of the trolley is supported in use on the level ground at least substantially by the combination of the fixed-axis wheel and the first and second castors.

6. A trolley as claimed in claim 4 or claim 5 in which the fixed-axis wheel is positioned at substantially midway between the first and second castors relative to the normal direction of straight-line travel of the trolley.

7. A trolley as claimed in any one of claims 4 to 6 in which at least one supplementary ground-engageable wheel means is mounted on the trolley framework and which does not engage with level ground in the normal load-carrying condition of the trolley, except possibly when the trolley is heavily laden, the supplementary wheel means, in plan view of the trolley, lying outside the triangle defined by the fixed-axis wheel and the first and second castors.

8. A trolley as claimed in claim 7 in which supplementary wheel means comprises two castors mounted on the framework in positions symmetrical, relative to said centre-line to the first and second castors.

9. A trolley as claimed in any one of claims 4 to 8 in which a basket is supported on the trolley framework.

10. A trolley as claimed in claim 9 in which the basket is pivotally mounted on the framework about an axis which is substantially parallel to the normal direction of straight-line travel of the trolley, the basket being pivotable from a normal load-carrying orientation to a nesting orientation in which the trolley is adapted to nest with an identical trolley.

11. A trolley as claimed in claim 10 in which the framework comprises a pair of articulated X-frames, the pivotal axes of the X-frames extending parallel to the basket pivotal axis.

12. A trolley comprising a trolley framework and a plurality of ground-engageable wheel means mounted on the trolley framework in an asymmetrical configuration of the wheel means with respect to the longitudinal centre-line of the trolley, the configuration comprising a wheel, the axis of which is at least normally fixed relative to the framework, said fixed-axis wheel being provided at an intermediate position in the length of the trolley and towards one side thereof from the centre-line, first and second castors toward the other side of the framework, the first castor leading the fixed-axis wheel, and the second castor trailing the fixed-axis wheel, whereby the weight of the trolley can be supported in use at least substantially by the combination of the fixed-axis wheel and said first and second castors, and by at least one supplementary ground-engageable wheel means mounted on the trolley framework and which does not engage with level ground in the normal load-carrying condition of the trolley, except possibly when the trolley is heavily laden, the supplementary wheel means, in plan view of the trolley, lying outside the triangle defined by the fixed-axis wheel and the first and second castors.

13. A trolley as claimed in claim 12 in which the first castor is positioned closer to the longitudinal centre-line of the trolley than the second castor.