GB2399563A

GB2399563A - Device for transporting a wheeled load

Info

Publication number: GB2399563A
Application number: GB0306249A
Authority: GB
Inventors: Michael Donnelly Fage
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-03-19
Filing date: 2003-03-19
Publication date: 2004-09-22
Anticipated expiration: 2023-03-19
Also published as: GB2399563B; GB0306249D0

Abstract

A device for transporting a wheeled load 22 including: a base 10, a drive means 13 mounted on the base: a steerable wheel 12 mounted for rotation on a first end portion of the base, the steerable wheel being drivable by the drive means; a lifting means 13 mounted generally at the first end portion of the base, comprising a coupling 24 which is movable in a generally vertical plane and is adapted to bear the load, a pivoting steering handle 14 mounted at the second end portion of the base with a pair of wheels 15 for rotation attached to the lower end portion of the handle, the device being constructed such that when the handle is pivoted forward, the pair of wheels raise the second end portion of the base from the ground, and when the handle is lowered the wheels retract into the base.

Description

1 2399563

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r DEVICE FOR TRANSPORTING A WHEELED LOAD This invention relates to a device for transporting wheeled loads particularly in an industrial setting.

Further to the applicants previous invention GB 2279934, where the tractor has a pair of wheels for rotation attached to one end of the base and a steerable drive wheel attached to the other end of the base and where the pair of wheels are smaller than the drive wheel, and where the pair of wheels are lifted from the ground when the coupling is bearing the load, several problems have arisen with this configuration.

Firstly, when pulling a load down a slope onto level ground, the pair of wheels may come into contact with the ground and as a result the drive wheel ceases to be in contact with the ground ( the friction lock of the U shaped coupling described in GB 2279934 inhibits movement in pitch). This then prevents the load from being driven and more importantly also prevents the drive wheel applying a braking force necessary to control the load down the slope.

Secondly, when pulling a load on uneven ground, the pair of wheels may come into contact with the ground reducing the load on the drive wheel causing the latter to spin and shock load the pair of wheels which could cause them or the base to fail or distort.

Thirdly the nature of the device described in GB2279934, means that when the tractor is not supporting the load, the base is inclined back onto the pair of wheels. This means that when the coupling is presented to the load, it is neither vertical nor horizontal, so the coupling has to have a looser fit in order to engage the load prior to the weight being transferred. It is only when the jacking device is activated that the vehicle takes up a vertical stance, however because the coupling has to have a looser fit, the tractor often has to be taken beyond the vertical in order for a firm coupling operation to be completed. This then results in a none horizontal rotation when the device is steered. The pair of wheels can come into contact with the ground inhibiting the full 180 degree rotation that should be possible. This feature detracts from the devices ability to manoeuvre loads in confined spaces.

Fourthly it is understood that in increasing the ground clearance of the pair of wheels when the tractor is vertical only exasperates the problem described in the previous paragraphs.

The invention addresses all of the above problems by making the vertical position of the pair of wheels variable in relation to the base by removing them from the base and attaching them to the lower end portion of the steering handle.

To this end the present invention provides a device as defined in the claims.

riigure 1 shows side views of a device with the handle in the raised and lowered positions.

Figure 2 shows side view of the device attached to a load.

With reference to the accompanying illustration the device for transporting a wheeled load consists of a base 10, a drive means mounted on the base let a steerable wheel 12 mounted for rotation on a first end portion of the base, the steerable wheel being driven by the drive meansl3, a lifting means 11 mounted generally at the first end portion of the base, comprising a coupling 17 which is movable in a generally vertical plane and is adapted to engage and bear the load. The steering handle 14 is attached on a second end portion of the base 10 so it is free to pivot in a vertical plain and where the pivot point 16 is mounted the shorter distance up from the lower end of the steering handle. A pair of wheels for rotation 15 is attached to the lower end portion of the handle.

When the handle is pushed to its fully forward position 18, the pair of wheels 15 are at their most extended, and will lift the base 10 inscribing an arc round the drive wheel 12. The base may be lifted to the horizontal to facilitate coupling 17 to the attachment on the load 19. Conversely when the handle is lowered 14, the base 10 is also lowered as the pair of wheels 15 retracts into the base. If however the device is now coupled to the load the base 10 is inhibited from lowering by virtue of the rigid coupling 17 and when the steering handle l 4 is lowered back into the driving position, the pair of wheels 15 are raised from the ground and retract into the base 10.

The position of the coupling on the tractor 17 can be adjusted with the clamp 24 to a predetermined height from the ground so that when coupling, the base 10 of the device is horizontal to the ground. The lifting means 11 or the handle 18 can than be raised to engage the lip on the trailer coupling 20 into the grove 21 on the devices coupling. The lifting means 11 can than be raised until enough weight has been transferred from the load 22 to the drive wheel 12 to provide sufficient tractive adhesion to move the trailer.

To prevent the device from moving beyond the vertical, the coupling piece attached to the trailer 19 is vertical to the ground and of sufficient length to engage the top of the devices coupling 17 in a friction lock. The pin 23 on the devices coupling engages into a slot on the loads coupling to prevent the coupling twisting apart when turning corners. With the pair of wheels retracted 15 the clearance height of the base above the ground is increased eliminating the problems described earlier. It has been found that a tractor coupled as described may transport on a flat surface a 30 tonne load using a 24 volt electric motor attached to a torque converter.

So that the device may be easily moved when not attached to the load, the handle 14 is partly raised to lower the pair of wheels 15 onto the ground. It is a feature of the invention that the position of the handle pivot point 16 means that there is considerable leverage so that raising and lowering the pair of wheels requires minimal effort.

t is a further feature of the invention that the pair of wheels 15 is mounted just behind the handle so that when the handle is fully raised there is an over centre lock so the handle 18 is stowed in the upright position when not in use.

Claims

1. A device for transporting a wheeled load including: a base: a drive means mounted on the base: a wheel mounted for rotation on a first end portion of the base, the steerable wheel being drivable by the drive means; a lifting means, mounted generally at the first end portion of the base, comprising a coupling which is movable in a generally vertical plane and is adapted to bear thexload, a pivoting steering handle mounted at the second end portion of the base with a pair of wheels for rotation attached to the lower end portion of idle handle, the device being constructed such that when the handle is pivoted forward the pair of wheels raise the second end portion of the base from the ground, and when the handle is lowered the wheels retract into the base.

2. The devise as in claim 1 and further comprising a control means which is operable to permit an operator to control the drive means and direct the tractor.

3. The device as in claims 1 or 2 wherein the wheel is larger than the pair of wheels.

4. The device constructed, arranged and adapted to operate substantially as herein described with reference to the accompanying drawings.