GB2115355A

GB2115355A - Goods vehicle that carries an auxiliary fork lift truck

Info

Publication number: GB2115355A
Application number: GB08204160A
Authority: GB
Inventors: Alan Victor Short
Original assignee: FRUEHAUF CRANE Ltd
Current assignee: FRUEHAUF CRANE Ltd
Priority date: 1982-02-12
Filing date: 1982-02-12
Publication date: 1983-09-07
Also published as: GB2115355B

Abstract

A road going goods vehicle has a load platform, a rear axle 16 on which the load platform is supported and a pair of sockets open to the rear end of the vehicle. A detachable fork lift truck carried by the vehicle has a pair of forks 10 engageable with the sockets, a base frame, and means 14 for lowering the forks 10 relative to the base frame 22 so that the base frame 22 is lifted from ground contact. The base frame 22 includes a pair of stabiliser arms each formed in two relatively movable sections 1, 4 that may be longitudinally extended to define a working position and collapsed to permit the fork lift truck to be carried on the load platform 11 without a corresponding wheelbase reduction in the road vehicle. <IMAGE>

Description

SPECIFICATION Goods vehicle that carries an auxiliary fork lift truck The present invention relates to a rigid, draw bar trailer or semi-trailer goods vehicle that carries an auxiliary fork lift truck.

The invention provides, in combination with a road going goods vehicle having a load platform a rear axle on which the load platform is supported and a pair of sockets open to the rear end of the vehicle, a fork lift truck having a pair of forks engageable with the sockets, a base frame and means for lowering the forks relative to the base frame so that the base frame is lifted from ground contact, the base frame including a pair of stabiliser arms each formed in two relatively movable sections that may be longitudinally extended to define a working position and collapsed to permit the fork lift truck to be carried on the load platform without a corresponding wheelbase reduction in the road vehicle.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings, in which like parts are denoted by the same reference numerals, and: Figure 1 is a side view of a road going draw bar trailer goods vehicle that carries an auxiliary fork lift truck of known kind; Figures 2 and 3 are side and plan views of a draw bar trailer goods vehicle with a modified auxiliary fork lift truck according to the invention, and Figures 4 and 5 are enlarged side and plan views of hinged stabiliser arms that form part of the base frame of the auxiliary fork lift truck of Figs. 2 and 3.

It is an accepted practice for delivery of certain goods to carry on the delivery vehicle an auxiliary fork lift truck or other form of handling equipment which can be used for offloading the goods at the point of delivery.

One example of this is in the distribution of beer and other drinks to public houses and the like, where the permanent provision of handling equipment at each point of delivery would not be justified, (in this case of course as well as for offloading it is also required to load the empties onto the vehicle). An established method of carrying the forklift truck is to provide sockets on the rear of the vehicle 11 into which the forks 10 of the truck can engage when partly raised and then to operate the forklift system to bring the forks to the lowest position in relation to the truck structure 1 2 which has the effect of raising the fork lift truck clear of the ground. The fork lift truck is thus loaded or unloaded using its own power unit 1 4 and does not take up any of the platform space provided for goods.The concept is illustrated in Fig. 1.

It has been found that this method of carrying a fork lift truck is applied to a trailer the space required behind the trailer rear axle 1 6 is such as to entail an excessive rear overhang, the centre of gravity of the truck being a considerable distance behind the axle.

This also results in a short trailer wheelbase in order to achieve required load distribution between the axles 16, 1 8. Such a trailer is inherently directionally unstable and in practice has been found to "snake" or "weave".

This instability can only be cured by lengthening the wheelbase and/or reducing the rear overhang of the concentrated weight of the fork lift truck. An object of the invention is to reduce the amount by which the fork lift truck projects behind the rear axle 16, which also permits a significantly longer wheelbase; it then achieves both objectives of avoiding a reduced wheelbase and not having a high weight concentration well behind the rear axle.

Fork lift trucks of the type usually employed have a base frame 20 with two arms 22 projecting forward parallel to the forks 10 with wheels 24 mounted as far forward as practicable, in order to prevent the truck overbalancing when laden without the need for heavy balance weights at the rear. These arms 22 have to be so spaced as to allow the forks 10 and their load to be lowered to the ground between them. This configuration is such that the arms 22 are in plan view in line with the trailer tyres 24 so that it is impossible to move the truck further forward in relation to the rear axle 1 6. It will be understood that other design considerations prevent a sufficient alteration in the width spacing of the trailer tyres 24. The forks 10 themselves do not present a problem as these are inboard of the tyres. This arrangement is shown in Fig.

3.

The problem can be solved according to the invention by dividing each of the arms 24 of the fork lift truck into two sections, one hinged to the other by means of a hinge pin and so designed that when extended the arm resists the vertical moment imposed by the weight of the fork lift together with its load and the reaction from the supporting wheels, but may be folded into a rearward projection position when the fork lift truck is clear of the ground. Provision is also made to resist side forces on the arm. While the preferred form provides for the outer part of the arm to hinge downwards and under its inner portion, it would also be possible to arrange the hinge pins vertically so that the outer arm swings back alongside the inner portion, remaining in the same horizontal plane. Another alternative would be to make the arms telescopic.

In Figs. 4 and 5, each arm of the base of the fork lift truck comprises an inner member 1 having at its outer end a contact face 2 towards the top and a hinge pin 3 below and an outer member 4 with projecting lugs 5 with holes to receive hinge pin 3 and with a contact face 6 corresponding to face 2. The outer end of the outer member 4 is arranged to support carrying wheel 24.

It will be understood that when the fork lift truck is on the ground the bending forces in the joint between the two members of the arm will be transmitted by compression between the contact faces 2 and 6 and by shear in hinge pin 3. Shear forces in the joint will be taken by hinge pin 3 and by the vertical component of force at contact faces 2 and 6.

However when the truck is lifted off the ground the outer member 4 will swing downwards under the force of gravity pivotting about hinge pin 3. In order to control the pivotting of the outer member 4 coil springs 8 are provided on both sides of the arm connected at one end to inner member 1 and at the other to outer member 4 these being so located that when the outer member 4 is hinged to hang substantially vertically the springs will exert a force to swing outer member 4 further back to the reverse folded position shown in Fig. 2. The springs 8 also exert a tension to retain faces 2 and 6 in contact when on the ground in the event of irregularities of ground surface. Locking pins (not shown) may be provided to retain the outer member 4 in either the working or the folded position.

Claims

1. In combination with a road going goods vehicle having a load platform a rear axle on which the load platform is supported and a pair of sockets open to the rear end of the vehicle, a fork lift truck having a pair of forks engageable with the sockets, a base frame and means for lowering the forks relative to the base frame so that the base frame is lifted from ground contact, the base frame including a pair of stabiliser arms each formed in two relatively movable sections that may be longitudinally extended to define a working position and collapsed to permit the fork lift truck to be carried on the load platform without a corresponding wheelbase reduction in the road vehicle.

2. The combination of claim 1 wherein the arms of the fork lift truck base frame are arranged to telescope.

3. The combination of claim 1 wherein the arms of the fork lift truck base frame are arranged to fold.

4. The combination of claim 3 wherein the working position of each base frame arm is defined by a pair of abutting surfaces.

5. The combination of claim 4 wherein coil springs connected between the hinged sections of each base frame arm are arranged to stabilise the forward section both in its extended working position and in its flexed stowed position.

6. The conzkination of anv preceding claim wherein the goods vehicle is a flat platform draw bar trailer or semi-trailer vehicle.

7. The combination with a road going goods vehicle having a load platform of a fork lift truck substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

8. A fork lift truck adapted to be carried on the back of a road going goods vehicle as set forth in any of claims 1 to 7.