GB2106047A - Automatic tipper gate catch - Google Patents

Abstract

The catch is especially intended for lorries and trailers, in which case there is a latch 9 on the container body 2 engaging the tail gate 5, and connecting means 12 extending from the latch to the chassis 3, the connecting means being secured to the chassis at a position offset from the connection between the chassis and body so that relative movement between them causes the latch to disengage from the gate. The connecting means 12 may take the form of a wire rope. <IMAGE>

Description

SPECIFICATION Catch mechanism This invention relates to a catch mechanism, espe cially but not exclusively for use on tipper lorries and trailers.

Catch mechanisms for tipper lorry and trailer tailgates have previously been proposed, both in manual version where bolts are released by hand prior to tipping, and in automatic version where the tailgate is opened by lever arrangements actuated by the tipping movement. Such previously-proposed automatic versions, however, have been bulky and awkward, involving the use of external beams which have substantially increased the overall dimensions of the vehicle.

According to the present invention there is provided a catch mechanism for a gate mounted on one of two relatively movable interconnected members of a tipping arrangement, the mechanism having a latch on one of the members and engaging the gate, and connecting means extending from the latch to the other member, the connecting means being secured to the other member at a position offset from the connection between the members so that relative movement between the members causes the latch to disengage from the gate.

The connecting means may be adjustable in length and is preferably a cable or other flexible connector. Preferably the latch and connecting means do not project outwardly beyond the extreme side edges of the members.

The latch members is preferably spring-biassed into a "lock" position, and may have an angled, or bevelled, surface for contact with the gate as it closes, to allow automatic locking.

The mechanism is especially effective when the members are the chassis and container portions of a vehicle such as a tipper lorry or trailer, the latch being secured to the container portion adjacent the openable gate, and the connecting means extending between the latch and the chassis.

The latch is preferably arranged to move in a linear direction towards and away from the hinge connection of the gate. In this way positive locking of the gate can be achieved, with the gate held tightly in its closed position; this is especially important when the catch mechanism is used on containers of grain or other particulate material which could otherwise escape past the gate edges. This positive locking is enhanced if the face of the latch which engages the gate has its free end contacting the gate, this free end being the first part of the latch to engage the gate as the latch moves into its engagement position. Thus the gate is held tightly closed from first engagement of the latch. In this respect the engagemenu face of the latch may be bulbous at its free end or may be planar and parallel to the portion of the gate which it engages.

The latch may be slidable within a housing for guidance against the gate.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a lower perspective view of a rear portion of a tipper trailer having a catch mechanism of the invention Figure 2 is a partly-cut-away side view of the latch and housing of the catch mechanism of Figure 2; and Figure 3 is a side view of an alternative form of the free end portion of the latch.

Referring to the drawings, a tipper trailer 1 has a container portion 2 mounted on a chassis 3 through a pivotal joint 15. The rear face of the container portion 2 has a central gate 5 of wire mesh extending between steel beams 6. A steel flange 7 is welded to two of the beams 6 at the side of the rear face and projects laterally over a side member 10 of the container portion.

A tubular open-ended housing 8 welded just below the flange 7 houses a latch member 9 which is spring-biassed upwardly to project from the housing 8 and engage the flange 7 as shown, thereby locking the gate 5 closed. The lower end of the latch member 9 is secured to a wire rope 12. The wire rope 12 passes downwardly into one end of a bent guide tube 13 which is welded through a bracket 14tothe side of the container portion 2. The wire rope 2 emerges from the other end of the tube 13 inwardly of the side of the trailer 1 and is secured through a rigging screw 23 to a hook 16 bolted to the chassis 3 forward of and at a lower level than the joint 15.

The latch member 9 is shown in more detail in Figure 2. The member 9 itself is about 4 inches long, its uppermost 1 inch having a flat surface 11 which is parallel to the flange 7 and therefore lies flush against it during engagement. The face 17 of the member 9 remote from the surface 11 is cammed so that the horizontal force exerted on it by the flange 7 will cause the member 9 to be moved downwardly.

A spring 18 extends around a screw-threaded bar 19 between a lock-nut 20 on the bar and a plate 22 (Figure 1) at a lower end of the housing 8. The spring 18 biasses the member 9 upwards, its movement in that direction being limited by engagement of a locknut 21 against the plate 22 on the bar 19.

The flush engagement of the surface 11 with the flange 7 ensures that the gate 5 is held fully closed from first engagement between the latch member 9 and flange 7 as the member 9 moves upwardly. An alternative form of the latch member 9 which also achieves this effect is shown in Figure 3, where an upper portion of the surface 11 is bulbous at 23, projecting towards the flange 7. These arrangements prevent the gate 5 from opening slightly as full engagement of the latch is achieved, and this is important when fluids or small particulate material forms the load on the container 2.

In use, the container portion pivots in the direction of arrow A about the joint 15, and due to the fact that the hook 16 is offset from the joint 15 this pivoting increases the distance from the latch member 9 through the guide tube 13 to the hook 16. The wire rope 12 is therefore tensioned and pulls the latch member 9 downwardly as the angle of pivot increases. When the latch member 9 comes out of engagement with the flange 7 the gate 5 is free to swing about a pivotal axis at its upper edge, under gravity, so as to hang vertically. This allows material in the tipped container portion 2 to fall to the ground past the open gate 5.

When the container portion is empty, the direction of pivot is reversed to lower the container portion 2, reducing the effective distance between the latch member 9 and the hook 16 and causing the latch member 9 to travel upwardly under the effect of its spring bias. As the gate 5 closes, the flange 7 slides over the cammed upper face 17 of the latch member 9, pushing it downwards against the spring, until it springs upwardly into the position shown, again locking the gate.

This embodiment of the invention provides a cheap, simple and unobtrusive mechanism for automatically opening and closing the gate on tipping of the trailer container portion on the chassis.

Modifications and improvements can be made without departing from the scope of the invention.

Claims (14)

1. A catch mechanism for a gate mounted on one of two relatively movable interconnected members of a tipping arrangement, the mechanism having a latch on one of the members and engaging the gate, and connecting means extending from the latch to the other member, the connecting means being secured to the other member at a position offset from the connection between the members so that relative movement between the members causes the latch to disengage from the gate.

2. A catch mechanism according to Claim 1, wherein the latch and connecting means are inboard of the extreme side edges of the members.

3. A catch mechanism according to Claim 1 or 2, wherein the connecting means is flexible.

4. A catch mechanism according to Claim 3, wherein the connecting means comprises a cable.

5. A catch mechanism according to any one of the preceding Claims, wherein the latch moves between engaging and disengaging positions in a linear direction towards and away from a hinge connection of the gate.

6. A catch mechanism according to any one of the preceding Claims, wherein the latch is slidable within a housing from which it projects to engage the gate.

7. A catch mechanism according to Claim 6, wherein the latch has an engagement face and an end portion of said face remote from the housing contacts the gate during engagement.

8. A catch mechanism according to Claim 7, wherein the engagement face is planar.

9. A catch mechanism according to Claim 7, wherein the engagement face is bulbous at said remote end portion.

10. A catch mechanism according to any one of the preceding Claims, wherein the latch is springloaded into engagement with the gate.

11. A catch mechanism according to Claim 10, wherein the latch has an angled surface which the gate when closing can contact, and the force thus exerted by the gate on the angled surface can move the latch into its disengaged position against the action of the spring, thus allowing the gate to close.

12. A catch mechanism according to any one of the preceding Claims, wherein the connection means is adjustable in length.

13. A catch mechanism for a gate mounted on one of two relatively movable interconnected members of a tipping arrangement, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

14. A vehicle having a tipping body which has a gate actuated by a catch mechanism according to any one of the preceding Claims.