GB2334498A

GB2334498A - Motorised load mover

Info

Publication number: GB2334498A
Application number: GB9904113A
Authority: GB
Inventors: Michael Neil Keeble Warren
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-02-24
Filing date: 1999-02-24
Publication date: 1999-08-25
Anticipated expiration: 2019-02-24
Also published as: GB2334498B; GB9803675D0; GB9904113D0

Abstract

A motorised load mover includes a frame 20 on which a tow ball 21 is mounted for engagement in a socket of a trailer. A drive wheel 30 is mounted on the frame 20 by means of a parallelogram linkage 26 which permits vertical movement of the axis of rotation of the drive wheel 30 relative to the frame 20.

Description

MOTORISED LOAD MOVERS Field of the Invention This invention relates to motorised load movers.

There are many types of loads which require moving, for example, caravans, trailers and the like, which are provided with an A-frame and a towing socket in which a tow ball can be received.

Previous designs of such load movers are shown in, for example, US Patent Specifications Nos. 5,139,102 and 5,343,969 and are referred to as trailer dollies.

It is an object of the present invention to provide an improved form of motorised load mover or trailer dolly.

Summary of the Invention According to the present invention there is provided a motorised load mover which includes a frame, a tow ball mounted on said frame, which tow ball is designed for engagement with a socket on a trailer, at least one drive wheel mounted on the frame, with the means for mounting the drive wheel on the frame being such as to permit steering movement of the drive wheel and movement of the axis of rotation of the drive wheel vertically relative to the frame.

The means for mounting the drive wheel on the frame preferably includes a parallelogram linkage. The arrangement is preferably such that, after the tow ball has been engaged in the socket of the trailer which is to be moved, the parallelogram linkage can be operated so as to enable the trailer load to be distributed, as required, between the trailer axle(s) and the drive wheel.

Brief DescriPtion of the Drawings Figure 1 of the accompanying drawings is a somewhat diagrammatic view of a motorised load mover or trailer dolly, and Figure 2 is a diagrammatic representation of the front end of a trailer with which the load mover or dolly can be used.

DescriPtion of the Preferred Embodiment The motorised load mover or trailer dolly shown in the drawing is designed for moving a caravan or boat trailer of the kind shown in Figure 2 which includes an A-frame 10 and a downwardly open socket 11 in which a tow ball can be received and then held in position. In its parked condition, the caravan or boat trailer is supported by means of a jockey wheel 12 which is movable up and down relative to the trailer upon rotation of a handle 13 about a substantially vertical axis.

As shown in Figure 1, the motorised load mover or trailer dolly comprises a frame 20 at one end of which an up-standing height-adjustable tow ball 21 is provided, for engagement in the socket 11. The frame 20 includes a pair of longitudinally extending side members 22 and an inverted U-shaped cross member 23 on which wheels 24 are mounted. Clamps 25 are provided on the upper portion of the cross member 23 for engagement with a cross member of the A-frame 10 so that the load mover can be attached positively to the trailer before the jockey wheel 12 is raised.

As an alternative to providing the cross member 23 with two wheels 24, a single wheel may be provided. The cross member 23 and/or the frame 20 as a whole can also be so shaped as to enable the frame 20 to be pushed past a jockey wheel on a trailer.

Figure 1 shows the provision of two clamps 25 on the cross member 23. There could, alternatively, be a single clamp 25 or two or more clamps 25 at different spacings from the ball 21, to facilitate use of the load mover with trailers of different sizes.

The frame 20 is connected by a parallelogram linkage 26 to a support 27 on which a control unit 28 is mounted. The control unit 28 contains a battery and an electronic control system designed to respond to movement of a pivotally mounted handlebar 29. A drive wheel 30 is mounted beneath the support 27, being carried on a support arm 31 which is rotatable relative to the support 27 about a substantially vertical axis, whilst the wheel 30 is rotatable relative to the support arm 31 about a substantially horizontal axis. A generator (not shown) may be contained within the control unit 28 so that power is obtained from both the battery and the generator, as appropriate.

In use, the motorised load mover is moved into a position in which the ball 21 is located immediately below the socket 11 so that, when the arm 13 is turned to raise the jockey wheel 12, the ball 21 will enter the socket 11 and the associate locking mechanism will then be operated, if required, to hold the ball 21 within the socket 11.

The clamps 25 will then be operated to engage the cross member of the A-frame 10 to hold the frame 20 of the load mover securely in engagement with the A-frame 10 of the trailer. The appropriate control will then be actuated to effect operation of the parallelogram linkage 26 such that the wheels 24 are lifted clear of the ground and to tilt the trailer into the required position relative to the horizontal and to obtain a distribution of the load such that effective and controlled steered movement of the trailer can then be obtained. The side members 22 of the frame 20 can be provided with a pair of load-carrying plates 32 on which loads can be placed to obtain the required load distribution. Such loading may be obtained by, for example, the operator standing on the plates 32. It is preferred, however, that the person operating the load mover will stand next to the control unit 28 and effect the required movements of the handlebar 29 from ground level. The plates 32, if provided, will be so mounted on the side members 22 of the frame 20 that they can be folded away when not in use.

The power for effecting rotation of the drive wheel 30 can be obtained by means of an electric motor (not shown) built into the drive wheel 30 which will have a tyre of substantial width so as to enable the load mover to traverse quite soft ground, such as may well be obtained on a caravan park. A pair of drive wheels may alternatively be provided, with such drive wheels mounted on a common axle arranged for controlled steering movement.

The trailer to be moved will typically have a single axle on which wheels are mounted so that, with the embodiment shown in the drawings, three-point engagement with the ground will be obtained enabling the trailer to be turned in substantially its own length. The parallelogram linkage 26 enables the height of the ball 21 above the ground to be varied after the ball has been engaged in the socket 11, thereby enabling the load to be distributed between the trailer axle and the drive wheel 30 so that stable movement of the trailer can be obtained even over uneven ground with minimum risk of tilting of the trailer.

A winch (not shown) may be mounted on the front of the frame 20 so that, if a trailer is to be moved across particularly boggy ground, the winch cable can be attached to a suitable anchorage so that, on operation of the winch, the load mover and the trailer can be pulled over the boggy ground.

Such movement of a trailer over boggy ground may also or alternatively be assisted by placing mats on the ground over which the trailer is to be moved.

Claims

Claims:

1. A motorised load mover which includes a frame, a tow ball mounted on said frame, which tow ball is designed for engagement with a socket on a trailer, at least one drive wheel mounted on the frame, with the means for mounting the drive wheel on the frame being such as to permit steering movement of the drive wheel and movement of the axis of rotation of the drive wheel vertically relative to the frame.

2. A motorised load mover as claimed in Claim 1, in which the means for mounting the drive wheel on the frame includes a parallelogram linkage.

3. A motorised load mover as claimed in Claim 1 or Claim 2, in which clamping means are mounted on the frame for clamping engagement with a part of a frame of a load which is to be moved.

4. A motorised load mover as claimed in any one of the preceding claims, which includes a control unit containing a battery for supplying power to an electric motor for driving the drive wheel, and an electronic control system.

5. A motorised load mover as claimed in Claim 4, in which the electronic control system is designed to respond to movement of a pivotally mounted handlebar.

6. A motorised load mover constructed and arranged to operate substantially as hereinbefore described with reference to and as shown in the accompanying drawings.