WO2005105543A1

WO2005105543A1 - Carrier trolley

Info

Publication number: WO2005105543A1
Application number: PCT/GB2005/001591
Authority: WO
Inventors: Anthony R. Laker
Original assignee: Laker Anthony R
Priority date: 2004-04-30
Filing date: 2005-04-28
Publication date: 2005-11-10
Also published as: GB0409698D0; GB2417467A

Abstract

A carrier trolley (1) comprising a wheeled frame (2) having a loading area (3), the frame (2) comprising a pivotally mounted arm (6) inclined downwardly from the underside of the frame (2) to a distal end of which is attached at least one additional wheel (8).

Description

Carrier TroHey

The present invention relates to a carrier trolley.

Conventional carrier trolleys are notoriously difficult to steer because the pushing position at the rear of the trolley, while allowing a person pushing the trolley to control the rear wheels fairly easily, prevents the person from having much control of the front wheels of the trolley. When weight is added to the trolley, especially at the front, the trolley becomes increasingly difficult to steer.

Earlier improvements to conventional four-wheeled shopping trolleys have included the provision of centrally side-positioned wheels at a fixed position relative to the ground. However because the wheel is fixed relative to the ground, multiple trolleys cannot be moved sideways and snaked when moved as a "chain" of trolleys, making collection difficult.

The present invention sets out to alleviate the problems described above by providing a carrier trolley of improved stability that has improved steering performance even when the trolley is substantially weighed down and that allows multiple trolleys to be easily and securely stacked together for storage and movement as a chain of trolleys.

In accordance with a first aspect, the present invention provides a carrier trolley comprising a wheeled frame having a loading area, the frame including a pivotally mounted arm inclined downwardly from the underside of the frame to a distal end of which is attached at least one additional wheel.

In one embodiment the loading area is defined by a container mounted on the wheeled frame wherein the arm is attached to the container and/or the wheeled frame. Preferably the arm is mounted centrally between the lateral sides of the wheeled frame.

In one embodiment, the carrier trolley includes biasing means to resiliently bias the arm downwardly.

Preferably the biasing means comprises a mechanical spring.

Preferably still, the pivoting mechanism of the pivotally mounted arm is spring loaded.

Preferably the force of the arm acting downwards at the ground is between 6 to 8 lbs (25 and 40N).

Preferably the arm is made of steel. Alternatively the arm is made of aluminium, plastic or any other suitable material.

It is envisaged that the material from which the arm is made will be compatible with the trolley to which it is being fitted.

In the case of larger trolleys the spring loading of the pivoting mechanism of the arm ensures that the wheel/s mounted on the arm is/are retained against the ground.

In the case of a small relatively lightweight trolley the weight of the arm may be sufficient to position the or each wheel mounted thereon against the ground and as such, a spring-loaded pivoting mechanism is not required. The fact that the wheel is positioned against the ground improves the steering and stability of the carrier trolley when it is pushed. The frictional force maintained between the wheel and the ground minimises unwanted sideways slip of the trolley. Specifically, the weight or spring force acting on the arm and the pivoting mechanism are such that the wheel is retained against the ground without too much frictional force to resist rotation when the trolley moves or to result in the arm being difficult to lift when the trolley is stacked with other similar or identical trolleys.

Preferably two wheels are mounted on the pivotally mounted arm.

By attaching two wheels to the pivotally mounted arm the sideways grip of the carrier trolley is improved.

In one embodiment, two arms are pivotally mounted each with at least one wheel mounted thereon.

Preferably the length of the pivotally mounted arm is such that the or each wheel mounted thereon is positioned nearer to the front than the rear of the wheeled frame.

In one embodiment the pivotally mounted arm is telescopic.

The length of the pivotally mounted arm can vary depending on the design of the carrier trolley and the likely distribution of weight within the container. For example, the arm could be telescopic.

The arm and its wheel or wheels can be fitted to a wide range of existing trolleys without the need for significant changes to their existing structure.

The angle between the pivotally mounted arm and the ground is preferably as acute as is practicable such that a maximum weight acts between the wheel and the ground whilst the wheel is still easy to lift upwards when necessary. The greater acuteness of the angle the less resistance incurred when raising the arm and wheel when trolleys are stacked together

Preferably, the trolley is designed such that two identical trolleys can be stacked together whereby the pivotally mounted arm of the front trolley is pivoted upwards by engagement with the wheeled frame and/or the arm of the rear trolley.

By "stacking" is meant that two or more neighbouring trolleys facing in the same direction can be fitted one inside the other to form a "chain" of trolleys.

More preferably when the first carrier trolley is stacked inside the second carrier trolley the pivotally mounted arm of the second carrier trolley lifts over and remains on a front bar of the frame of the first carrier trolley.

In one embodiment the pivotally mounted arm of the trolley is pivoted by a mechanical lever or similar mechanical means.

Alternatively, the pivotally mounted arm of the trolley is pivoted upwards by electronically controlled means.

The pivotally mounted arm of the present invention does not obstruct the stacking of two or more carrier trolleys. The pivotally mounted arm lifts up to allow stacking of the trolleys. The or each further wheel of a first trolley may be pivoted upwards by engagement with the wheeled frame of a second trolley stacked within the first trolley. The or each wheel of the first trolley comes to rest over and remains on the front bar of the wheeled frame of the second trolley. This makes it easier to move the trolleys as a chain. The wheel of the first trolley may also act as a hook member to secure the two trolleys together when stacked.

When the second trolley is removed from the stack the first trolley's pivotally mounted arm will be released back to the ground to improve the steering and stability of the remaining trolleys forming the stack.

Preferably the wheel attached by the pivotally mounted arm is non- castered.

Alternatively the wheel attached to the pivotally mounted arm is castored and the wheel is provided with a locking mechanism.

The invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which : -

Figure 1 is a side view of a carrier trolley constructed in accordance with the present invention;

Figure 2 is a view from above of the base of the wheeled frame of the trolley of Figure 1;

Figure 3 is a view from above of an alternative embodiment of the wheeled frame of the trolley; and

Figure 4 is a side view of two trolleys stacked together.

Referring first to Figures 1 and 2, the trolley 1 comprises a wheeled frame 2 part of which forms a loading area 3. The base of the wheeled frame 2 is generally U-shaped with two front wheels 4 and two rear wheels 5. Each wheel 4, 5 sits at or near to a corner of the U-shaped frame 2 and is castored to allow easier movement of a "chain" of trolleys. A pivotally mounted arm 6 extends from the underside of the loading area 3 of the frame 2. The distal end of the arm 6 has a wheel 8 mounted on the arm 6 and is able to rest on the ground. The length of the arm 6 is such that the wheel 8 is positioned nearer to the front of the trolley than to the rear of the trolley. The arm 6 is resiliently biased by a spring 7 around a bar 9 attached to or formed as part of the arm 6 positioned across the U-shaped frame 2. The lateral bar 9 is mounted on the frame 2 in a position nearer to the rear of the trolley than to the front of the trolley.

Figure 2 shows the pivotal arm 6 in the stacked position. When the trolley is not stacked the wheel 8 moves in an arc touching the ground slightly further forward from the front wheels.

In use, the trolley 1 is steered using a handle 10 attached to the rear of the loading area 3. The spring loaded, pivotally mounted arm 6 retains the wheels 8 against the ground when the trolley 1 is moved.

Whereas all of the above description refers to one wheel 8 mounted on the arm 6, it is clearly envisaged that two or more wheels may be used.

Figure 3 shows an alternative embodiment of a carrier trolley 1. The distal end of the pivotally mounted arm 6 has two wheels 8 mounted either side of the arm 6. Similarly, it is envisaged that two or more pivotal arms 6 may be used.

When the trolley 1 is stored it can be stacked together with other trolleys facing in the same direction. Multiple trolleys can be moved as a stack or chain. Such stacking is now described with reference to Figure 4.

To stack two trolleys 1, 1' together a user pushes the front face 11 of the first trolley 1 into the rear face 12' of a second trolley. The loading area 3 of the first trolley nests inside the loading area 3' of the second trolley and the pivotally mounted arm 6' of the second trolley 1' is pivoted upwards by engagement with the wheeled frame 2 of the first trolley 1. The wheel 8' attached to the pivotally mounted arm 6' is lifted off the ground, which allows sideways movement for steering a stack of trolleys around corners. When lifted, the centreline of the wheel 8' mounted to the pivotally mounted arm 6' comes to rest over and remains on the front bar 13 of the wheeled frame 2. This acts to prevent the user's trolley 1 from rolling backwards out of the stacking position.

To release a trolley 1 from the rear of a stack a user simply pulls the trolley 1 backwards to allow the pivotally mounted arm 6' of the neighbouring trolley 1' to pass over the front bar 9 of the wheeled frame 2 of the trolley 1 that is stacked. When the trolley 1 is released from the stack the wheel 8' of the second trolley 1' will fall to the ground either by its own weight or by spring loading of the pivotally mounted arm 6'. This second trolley 2' is now also available for release from the stack.

The above-described trolley 1 can be steered with ease and even when loaded a user has to make very little effort to steer the trolley. The improvements to the trolley 1 allow a user to achieve directional changes with ease, including U-turns. The improved trolley 1 can be easily steered across surfaces such as concrete and tarmac because the friction between the wheel 8 and such surfaces increases its grip. The spring loading of the pivotally mounted arm 6 retains the attached wheel 8 in contact with the ground even when the ground is an uneven surface.

The improved trolley 1 is also stable when being unloaded and will not move side-ways as the load is reduced. It is envisaged that a braking wheel (not shown), used with some conventional trolleys, could also be incorporated into one of the rear castored wheels 5 of the above- described trolley to act when the trolley is being unloaded. The present invention could be applied to any type of trolley to improve stability. For example, pivotally mounted arms could be fitted to a flat bed trolley where the loading area is a flat platform. Such trolleys are conventionally used for moving building or gardening equipment. A pivotally mounted arm could be fitted on each side of the flat- bed trolley or centrally depending on stacking requirements.

The above described embodiment has been given by way of example only, and the skilled reader will naturally appreciate that many variations could be made thereto without departing from the scope of the present invention.

Claims

1. A carrier trolley comprising a wheeled frame having a loading area, the frame comprising a pivotally mounted arm inclined downwardly from the underside of the frame to a distal end of which is attached at least one additional wheel.

2. A carrier trolley as claimed in claim 1 wherein the loading area is defined by a container mounted on the wheeled frame and the arm is attached to the container and/or the wheeled frame.

3. A carrier trolley as claimed in any preceding claim wherein the arm is mounted centrally between the lateral sides of the wheeled frame.

4. A carrier trolley as claimed in any preceding claim wherein the carrier trolley includes biasing means to resiliently bias the arm downwardly.

5. A carrier trolley as claimed in claim 4 wherein the biasing means comprises a mechanical spring.

6. A carrier trolley as claimed in any preceding claim wherein the pivoting mechanism of the pivotally mounted arm is spring loaded.

7. A carrier trolley as claimed in any preceding claim wherein the force of the arm acting downwards at the ground is between 6 to 8 lbs (25 and 40N).

8. A carrier trolley as claimed in any preceding claim wherein the arm is made of steel.

9. A carrier trolley as claimed in any of claims 1 to 7 wherein the arm is made of aluminium.

10. A carrier trolley as claimed in any of claims 1 to 7 wherein the arm is made of plastic.

11. A carrier trolley as claimed in any preceding claim wherein two wheels are mounted on the pivotally mounted arm.

12. A carrier trolley as claimed in any preceding claims comprising two pivotally mounted arms.

13. A carrier trolley as claimed in claim 12 wherein to a distal end of each pivotally mounted arm is attached at least one wheel.

14. A carrier trolley as claimed in any preceding claim wherein the length of the or each pivotally mounted arm is such that the or each wheel mounted thereon is positioned nearer to the front than to the rear of the wheeled frame.

15. A carrier trolley as claimed in any preceding claim wherein the pivotally mounted arm is telescopic.

16. A carrier trolley as claimed in any preceding claim comprising a pivotally mounted arm and at least one wheel retrofitted to an existing carrier trolley.

17. A carrier trolley as claimed in any preceding claim wherein the carrier trolley is stacked together with a second identical carrier trolley whereby the pivotally mounted arm of the front trolley is pivoted upwards by engagement with the wheeled frame and/or the arm of the rear trolley.

18. A carrier trolley as claimed in claim 17 wherein when the carrier trolley is stacked together with a second carrier trolley the pivotally mounted arm of the rear carrier trolley lifts over and remains on a front bar of the frame of the front carrier trolley.

19. A carrier trolley as claimed in claim 18 wherein the wheel of the rear carrier trolley acts as a hook member to secure the two trolleys together when stacked.

20. A carrier trolley as claimed in any preceding claim wherein the pivotally mounted arm of the trolley is pivoted by a mechanical means such as a lever.

21. A carrier trolley as claimed in any of claims 1 to 19 wherein the pivotally mounted arm of the trolley is pivoted upwards by electronically controlled means.

22. A carrier trolley as claimed in any preceding claim wherein the wheel attached by the pivotally mounted arm is non-castored.

23. A carrier trolley as claimed in any of claims 1 to 21 wherein the wheel attached to the pivotally mounted arm is castored and the wheel further comprises a locking mechanism.

24. A carrier trolley substantially as described herein and with reference to Figures 1 to 4.