GB2431621A

GB2431621A - Trolley including castor with operator-controlled swivel axis inclination

Info

Publication number: GB2431621A
Application number: GB0521838A
Authority: GB
Inventors: Gordon Creighton
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-10-26
Filing date: 2005-10-26
Publication date: 2007-05-02
Anticipated expiration: 2025-10-26
Also published as: GB2431621B; GB0521838D0

Abstract

A load carrying device, such as a shopping trolley, is equipped with at least one castor wheel. The swivel axis of the castor in normally vertical, but the operator may control the angle of the axis to make it non-vertical. The control mechanism used may act directly on the castor, or indirectly by means of, for instance, a cable. The swivel axis may be biased towards a vertical orientation using a spring, or by means of the weight of the trolley.

Description

DIRECTION CONTROL FOR CASTOR SUPPORTED DEVICES / TROLLEYS

DESCRIPTION

This invention is directed primarily to arresting the frustrating and awkward sideways movement of castor supported trolleys/devices when attempting to push them in a particular direction, such as luggage trolleys or supermarket shopping trolleys. The difficulty in controlling such devices could, apart from being irritating, lead to a compensatory and/or dangerous situation such as the trolley running into and damaging a car or a person.

This invention therefore relates to devices having a plurality of supporting wheels or castors which are in contact with a surface i.e. the ground, and where the device has at least one of the supporting castor wheels having a variable, essentially vertical axis about which the castor swivels/rotates that can be controlled by an operator controlled mechanism, to control the direction of the device.

When the vertical axis of a castor is in its normal essentially vertical position, the castor will freely swivel/rotate about that axis allowing the device to which it is frtted move in a multitude of directions. A castor behaving in this way is typically fitted to supermarket trolleys as shown in figure 1, one of the castors being identified as A. If the vertical axis of the castor about which it rotates is inclined, it prevents the castor from rotating in the normal way. This is diagrammatically shown in figures 2 and 3.

Figure 2 shows a castor B in its normal orientation but mounted on a plate which is hinged at one end H. In this position the castor acts normally just as it would in the situation shown by figure 1. However if the plate on which the castor is mounted is moved about the hinge H it changes the vertical axis of the castor and prevents the castor rotating about its vertical axis in the normal fashion and this is shown in figure 3. With the castor in this position such that it cannot rotate about is normally vertical axis, it prevents the device from moving in a multitude of directions and essentially only allows movement in a direction in line with the inclination of the axis of the castor. This means that in the case of a supermarket trolley depicted in fig 3 that it will essentially only allow the castor to move in the forward direction thus preventing the irritating sideways movement. Clearly the trolley is still controllable as the trolley can pivot around the inclined castor allowing the operator to control the direction of the trolley. This invention is unique as not only will it enable the trolley to be controlled as described but it also will still allow the trolley to move sideways when the device is not being operated. This means that if a trolley is left unattended it can be pushed out of the way in any direction very easily.

In this invention the effect is created and controlled by the operator of the device/trolley as and when necessary. The actuation of the mechanism which changes the inclination of the axis of the castor about which it rotates is effected by a linkage controlled by the operator of the device. This is typically arranged so that when the device mechanism is operated by say a lever, the angle of inclination occurs and when the lever is released the angle of inclination reverts back to the normal vertical position. The reversion of the axis back to its normal position can be effected by several means e.g. by spring/s or bungee elastic suitably placed, or by the weight of the trolley with a suitable geometry of the arrangement. In this situation where the weight of the trolley causes the reversion of the axis about which the castor rotates to the normal vertical position, the horizontal axis about which the wheel rolls should ideally not move behind a vertical line running through the axis about which the vertical axis has been inclined.

One such arrangement of this invention is shown in figure 4. A mounting plate P is attached to the frame/leg of the trolley F. A hinge H connects a castor support plate S to the plate P. The castor support plate S therefore can move about hinge H. Clearly when this plate moves the castor also moves as it is fixed to this plate. In this arrangement the actuation is effected by a sheathed cable K with the inner cable C being attached to the castor support plate S. When the operator pulls cable C via a lever, it pulls the castor support plate S towards the mounting plate P at the point of connection of the cable C to support plate S. The pulling of the lever thus causes the castor support plate S to pivot about hinge H, and in turn it rotates the vertical axis of the castor about hinge H. In this situation if the axis of the rolling motion of the wheel X does not travel beyond a vertical line drawn through H, the weight of the trolley will return the wheel to its normal position when the tension in the cable is released. A screw W can be added to restrict/control the maximum movement of the castor support plate S. The geometry of this mechanism can be changed and springs could be used to return the wheel to its normal position. Clearly the greater the angle of rotation the more effect it will have but small angles of rotation have a significant influence on restricting the sideways movement of the device. An angle of rotation of has been established as being very suitable for this invention. Figure 5 shows the mechanism in the tilted/inclined position.

Another arrangement of this invention is shown in figure 6. Here again the castor is mounted on a support a plate S. This support plate is connected to the frame/leg of the trolley F the via a pivot hinge H. This support plate S can therefore move about H and again as the castor is fixed to this plate it will also pivot about point H. The arrangement shown in the figure, in this instance, is also operated by a cable (K + C) in similar fashion to the previous example. In this arrangement a screw to limit the movement of support plate S is also shown but in addition, a spring G has been included to aid the return of the support plate S to the horizontal position following release of the tension in the cable C. Figure 7 shows the mechanism in the tilted position.

As indicated earlier, this arrangement is again shown as being operated by cable but clearly it is simple to operate it by a mechanical linkage or by an extension to the operator. Figure 8 gives an example of this where an extension E is directly attached to the support plate S reaching up to the operator. The top of this extension V can take the form of a lever adjacent to the handle of the trolley. The extension V can be turned through 900 at the top and made to run parallel to the handle of the trolley and one could use fingers to operate it similar to a bicycle brake. This extension again could be turned through 900 at the top and could act as the handle of the trolley spanning the width of the trolley such that when you push the trolley forward with this handle it would also naturally move forward relative to the trolley and thus automatically operate the mechanism.

As an addition it is clear as shown in figure 9 that if a friction pad L is placed behind the wheel it can also be used to operate as a brake. In this instance operating the lever halfway will control the direction of the trolley as previously described but pulling it fully will cause the castor wheel to hit the friction pad thus stopping the trolley.

The mechanism to change the castor axis can be arranged in many other ways and figures 10, and 11 show some further methods in diagrammatic form.

Figure 10 depicts a mechanical method where Y is the handle of the trolley. An "L" shaped member M pivoted in the region of the bend T forms the operating lever V. To operate the mechanism, the user pulls the lever V towards the handle Y of the trolley. The "L" shaped member M is linked to a bar R which consequently moves in the direction of the arrow D thus operating the mechanism. Figure 12 shows an enlarged view of the handle from figure 10 and includes a spring G to aid retraction positioned between the vertical part of the "L" shaped member M and a member of the trolley/device F. This method similarly could be arranged such that the lever V is also the handle of the trolley/device and this is shown in figure 11.

It can be seen in figure 11 that pushing the handle Y forward (direction N) to push the trolley also moves the handle forward relative to the trolley. The mechanism is therefore operated in similar manner to that in the previous example. In each of the mechanisms represented in figures 10 and 11, J represents a guide for the bar R. Clearly more than one guide can be used and typically located at the centre or ends of bar R. Also in figures 10 and 11 retraction springs could be included to aid return of the castor axis to the vertical position.

There are many other ways to effect change of the vertical axis of the castor by the operator and the method chosen will depend on the design of the chassis of the trolley/device and the preferences of the designer/user.

The control of the vertical axis of the castor could also be provided directly by movement of the lever without any tension spring e.g. pulling the lever back operates the mechanism and pushing the lever forward releases it or vice versa. The lever could also have a means of locking it in either the retracted or deployed position.

Control of one, two or more castors having a variable vertical axis could be operated from a single operating device/lever.

The relevant castor wheels could be of traditional type or be specially selected to have a high friction surface to aid their operation when in contact with the surface.

Additionally they could be "wide" to resemble a roller to further enhance the action.

And similarly to enhance the action the castors could be of a double wheel pattern, which would in effect widen their footprint.

Figure Legend: A = Standard Castor Wheel B = Castor Wheel with Variable Vertical Axis C = Inner Cable D = Direction E = Extension F = Frame / Chassis Member G = Spring H = Hinge / Pivot Point J = Guide K = Cable Sheath L = Friction Pad M = "L" shaped member N = Direction N P = Mounting Plate R = Connecting Bar S = Castor Support Plate I = Pivot V = Lever W= Screw Y = Device Handle X = Wheel Rolling Axis 5;

Claims

CLAIMS

Claim 1 A load carrying device comprising a plurality of supporting wheels that contact the ground of which all or some may be castor wheels such that the device can be moved in a multitude of directions parallel to the ground, with at least one of the castor wheels having its essentially / normally vertical swivel axis about which the castor rotates variable such that it can be controlled to change the angle of the swivel axis by an operator controlled mechanism to control the direction of the device Claim 2 A device as described by the previous claim where inclination of the essentially / : *. normally vertical swivel axis of a castor is controlled by an operator of the device. *1** Clam3

A device as described in previous claims having more than one castor with a controllable essentially/normally vertical swivel axis. a...

Claim 4 : A device as described in any the previous claims where the operator control mechanism comprises a lever connected to the variable castor either directly or : * indirectly by means of a linkage or cable.

Claim 5 * A device as described in previous claims where the lever is moved and continuously held by the operator so as to change the inclination of the essentially/normally vertical swivel axis of a castor, and when released returns said castor to its original position so as to return the inclined axis to its original essentially/normally vertical orientation.

Claim 6 A load carrying device as described in previous claims where the lever is used to fix the inclination of the essentially/normally vertical swivel axis of a castor in vertical or inclined or intermediate positions.

Claim 7 A load carrying device as described in previous claims where the lever also serves as a handle for the device.

Claim 8 A load carrying device as described in any of the previous claims where a tension device such as a spring or bungee elastic is used to return the inclined normally vertical swivel axis of a castor to its essentially/normal vertical position. (0

Claim 9 A load carrying device as described in any of the previous claims where the weight of the device acting on the inclined normally vertical swivel axis of a castor is used to return it to its essentially/normal vertical position.

Claim 10 A load carrying device as described in any of the previous claims where a castor is mounted on a plate or member which can be moved to change the angle of inclination of the essentially/normally vertical axis of said castor.

Claim 11 * A load carrying device as described in any of the previous claims where the castor * -* wheel is relatively narrow in width. S...

Claim 12 A load carrying device as described in any of the previous claims, where the castor "*. wheel comprises a roller element, thus providing a larger contact area with the ground. 55.45 * .

Claim 13 * A load carrying device as described in any of the previous claims, where the castor wheel comprises a double wheel element, thus providing a larger contact area with 55, theground. S...

Claim 14 A device as described in previous claims where the device includes fixed, steerable or castor supporting wheels.

Claim 15 A device as described in previous claims were the angle of inclination of an essentially/normally vertical axis of a castor is moved to such an extent to make the wheel rub against a stop in order to interrupt the rotation of the said wheel.

Claim 16 A device as described in previous claims where one operating lever can control the angle of inclination of the essentially/normally vertical axis of more than one castor.