GB2049566A

GB2049566A - Load-tipping devices

Info

Publication number: GB2049566A
Application number: GB7917517A
Authority: GB
Original assignee: LINKTIP Ltd
Current assignee: LINKTIP Ltd
Priority date: 1979-05-19
Filing date: 1979-05-19
Publication date: 1980-12-31

Abstract

A vehicle tipping body 13 is pivotally mounted on a base 12; the base is linked to the body by two pivoted link members 21, 22; a hydraulic ram 30 interconnects the base and the link 21. Thus a small ram can be positioned distant from the body/base pivot 20. <IMAGE>

Description

SPECIFICATION Improvements in or relating to load-tipping devices This invention relates to load-tipping devices, for example load-tipping vehicles and demountabie body systems, and in particular it relates to hydraulically actuated load-tipping devices having a novel link mechanism.

Load-tipping devices actuated by hydraulic means are in common use and have, to a substantial extent, superseded the earlier screw-driven tipping mechanisms. One form of hydraulic tipping device includes a hydraulic ram pivotally connected to the vehicle chassis, the end of the ram piston distant from the ram cylinder being pivotally connected to the body or other load-carrying support ofthe vehicle. However, these vehicles suffer from the following major disadvantage.Since the force required to be provided by the hydraulic ram varies inversely with the distance separating the pivot by which the vehicle body is pivotally mounted to the chassis from the position of the pivotal connection between the ram piston and the vehicle body, it would appear advantageous at first sight to have the pivotal connection between the hydraulic ram piston and the vehicle body as far distant from the vehicle body pivot as possible. But in practice such an arrangement requires the use of ram pistons of considerable length such that the geometry of the mechanism permits the body to be brought into the horizontal position.An alternative arrangement that has been adopted is the use of double or multi-stage pistons but this has the disadvantage that a considerable amount of hydraulic liquid is required and, owing to loss of power in the system, accurate control of the tipping mechanism is not always possible. Although these two disadvantages can be avoided by arrang ingthatthe piston of the hydraulic ram is pivotally connected to the load support at a position nearer the pivot between the load support and the chassis, this arrangement too is not really practicable because of the increased force required. This is a particular disadvantage in tipping vehicles of relatively small size (for example up to 3.5 tonnes) whose power is provided by an electro-hydraulic power pack taking its electrical energy from the vehicle battery.

There is now provided according to the present invention a load-tipping vehicle or other load-tipping device which overcomes this disadvantage referred to above, that is it allows the pivotal connection between the hydraulic ram piston and the vehicle body or other load support to be well spaced apart (for example more than halfway along the length of the load support) from the pivot between the load support and the chassis or sub-frame carrying it.

Accordingly, the present invention provides a load-tipping device comprising a load support mounted for pivotal movement between a substantially horizontal position and a position inclined to the horizontal; a base to which the support is linked by means of a link, said link comprising two link members pivotally interconnected, the first link member being pivotally connected to the base, and the second link member being pivotally connected to said support; and adjustable control means interconnecting the base and said second link member whereby the angle of inclination of the support to the horizontal can be adjusted.

The load-tipping devices of the present invention can be, for example, load-tipping vehicles of upto 3.5 tonnes or of greater weight.

The adjustable control means is conveniently (though not necessarily) a hydraulic means, and it is with particular reference to load-tipping devices provided with hydraulic power means that the following description particularly relates.

The present invention is of particular value in that, where the adjustable control means is a hydraulic means, it can be a single stage hydraulic ram but, if desired, a double or multi-stage hydraulic ram can be used.

The load-tipping support of the present invention can be mounted so as to provide a tipping motion which is forward, backward or sideways, depending on the disposition of the pivot on which it is mounted.

There is now described, by way of example and with reference to the accompanying informal drawings, a load tipping vehicle according to one embodiment of this invention.

In the drawings: Figure 1 is a side elevation of the vehicle; Figure 2 is a side elevation (on an enlarged scale) of the link mechanism of the vehicle; Figure 3 is a second side elevation ofthe link mechanism shown in its retracted position; Figure 4 is a plan view corresponding to the view of Figure 3; and Figures 5 to 8 illustrate the hinge assembly by which the sideboards of the body of the vehicle are pivotally mounted on the body base assembly.

The tipping vehicle of Figure 1 comprises a chassis 10, a cab 11, a base or sub-fráme 12, a load-carrying body 13 and a link mechanism 14. The load-carrying body is pivotally mounted in the region of its rear end by means of a pivot 20 on the rear portion of sub-frame 12 so that it can be pivoted between a horizontal position (shown in continuous lines) and a tipping position in which it is inclined to the horizontal (shown in chain lines).

Referring to Figures 1 to 4, the link mechanism 14 includes upper and lower link members 21,22, pivotally inter-connected by pivot pin 23. The upper link member 21 comprises a pair of upper link arms 24, 25 and the lower link member 22 comprises a pair of lower link arms 26, 27. The upper ends of the upper link arms 24, 25 are pivotally connected to the load carrying body 13 by means of upper pivot pin 28, and the lower ends of the lower link arms 26,27 are pivotally connected to the sub-frame by means of lower pivot pin 29. It will be seen that the upper link pin 28 is situated well forward on the load support body, being substantially nearer the forward end of that body than it is to the rearward end.

A hydraulic ram 30 consisting of ram cylinder 31 and co-operating ram piston 32 (said hydraulic ram constituting the adjustable control means of the load-tipping vehicle) is pivotally mounted on pivot pin 33 between the two parallel members 34,35 of the sub-frame 12. The end of the piston distant from the hydraulic cylinder is pivotally connected to the upper link arm by means of pivot pin 36. As shown in Figure 4, when the link mechanism is in its retracted position, the load support body then being horizontal, the hydraulic ram lies between and parallel to the two parallel members of the sub-frame and the two lower link arms also lie parallel to the sub-frame but are disposed outside the respective sub-frame members, the upper link arm being disposed upwardly inclined with respect to the sub-frame.

The location of the pivot pin 36 in the upper link arm is offset substantially to one side of the imaginary line joining link pins 23, 28 to which the respective extremities ofthe upper link arm are connected, the off-set being such that in the retracted position the link pin 36 is above said imaginary line. This offset is designed to facilitate easy movement of the upper link arm from the retracted position under the force exerted by the hydraulic ram piston as it is forced out of its cylinder.

Claims

1. A load-tipping device comprising a load support mounted for pivotal. movement between a substantially horizontal position and a position inclined to the horizontal; a base to which the support is linked by means of a link, said link comprising two link members pivotally inter-connected, the first link member being pivotally connected to the base, and the second link member being pivotally connected to said support; and adjustable control means interconnecting the base and said second link member whereby the angle of inclination of the support to the horizontal can be adjusted.

2. A tipping vehicle including a load tipping device as claimed in Claim 1.

3. A tipping vehicle according to Claim 2, in which said adjustable control means comprises a hydraulic ram.

4. Atipping vehicle according to Claim 3, in which the cylinder of the ram is pivotally connected to said base and the piston of the ram is pivotally connected to said second link.

5. A tipping vehicle according to Claim 3 or 4, in which said adjustable control means is driven by an electro hydraulic power pack taking its electrical energy from a battery of the vehicle or from a power take off from the vehicle gear box powering a hydraulic pump.

6. A tipping vehicle according to any of Claim 2 to 5, in which the load support is pivoted to tip rearwards of the vehicle.

7. A tipping vehicle according to Claim 6, in which said second link is pivotally connected to the load support at a position at least halfway along the length of said support as measured from its pivot with the base.

8. A tipping vehicle according to Claim 7, in which the second link is pivotally connected to the load support at a position at least two-thirds along the length of said support as measured from its pivot with the base.

9. Atipping vehicle according to any of Claim 2 to 8, in which the pivotal link between said support and the second link is offset, in the direction of action of the ram, from the plane containing the pivot between the support member and said second link member and the pivot between said first and second link members.

10. A load-tipping device according to Claim 1, substantially as described herein with reference to the accompanying drawings.

11. A load-tipping device substantially as described herein and substantially as shown in the accompanying drawings.

12. A load-tipping vehicle including a loadtipping device as claimed in Claim 10 or 11.

13. A tipping vehicle according to Claim 2, substantially as described herein with reference to the accompanying drawings.

14. Atipping vehicle substantially as described herein and substantially as shown in Figure 1 of the accompanying drawings.