GB2059883A

GB2059883A - Automatic vehicle tailboard latch

Info

Publication number: GB2059883A
Application number: GB8022639A
Authority: GB
Original assignee: HAYDE M; MAHRER P
Current assignee: HAYDE M; MAHRER P
Priority date: 1979-09-12
Filing date: 1980-07-10
Publication date: 1981-04-29
Also published as: IE791731L

Abstract

A latch lever (6) pivoted to the tipping section, is disengageable from a cooperating retainer (18) on the flap (17), by telescoping push rod (8) under compression between the latch lever and the vehicle chassis during the tipping action. <IMAGE>

Description

SPECIFICATION Automatic tailboard latch This invention relates to a latch for opening a rear flap or tailboard of the tipping section on a tipping vehicle.

In particular, it relates to a latch which operates automatically as tipping commences, without the need for operator intervention.

Tipping vehicles or tipping trailers are used extensively in industry and agriculture. Prior to tipping a trailer, it is normally necessary for the driver to get out of the vehicle and manually unlock the rear flap or tailboard, walk back to the trailer, execute the tipping operation, and get out of the vehicle in order to secure the rear flap once again. All these operations not only absorb operator time but also involve waste of fuel by the vehicle.

It is an object of this invention to overcome the above recited problem by providing a device for the automatic releasing and securing of a flap of a tipping vehicle.

The invention therefore provides an automatic latch for a top-hinged flap of a tipping section on a vehicle chassis, which latch comprises a cooperating pair of latch members located one on the flap and the other on the tipping section, said latch members being adapted for engagement on closure of the flap, and means responsive to tipping beyond a limiting angle for releasing the latch, thereby releasing the flap.

Preferably, the latch of the invention comprises a latch retainer fixed to the flap, a latch lever pivotally attached to the tipping section at a first point, a push rod pivotally attached to the latch lever at a second point to the rear of the tipping axis, a cooperating guide member pivotally attached to the chassis and slidably engageable with the push rod during tipping, and stop means for preventing said slidable engagement at and beyond the limiting angle of tip, to open the latch by pressure of the thus restrained push rod against the latch lever.

In a preferred embodiment, one of the push rod and the guide member is a hollow cylinder adapted to receive the other in telescopic manner. Preferably the stop means comprises an obstruction in the bore of the cylinder, such as an end wall thereof, or a transversely extending pin located in a hole or holes through the wall thereof. Preferably the position of the stop means is adjustable, in the longitudinal direction of the push rod. Again preferably the latch lever comprises a camsurfaced hook adapted to catch and be retained by the latch retainer. It is also preferred that spring means be provided to bias the latch lever into the engaged condition. The bias is preferably adjustable.

The invention will be appreciated in greater detail from the following description of a preferred embodiment given by way of exam ple only with reference to the accompanying drawings in which: Figure 1 is a side elevation of a tipping trailer; Figure 2 is an enlarged detail taken from Fig. 1; Figure 3 is a view of the detail of Fig. 2, showing the trailer in a partially tipped position.

Referring now to the drawings, a tipping trailer 1 having a fixed chassis 2 and a tipping section 3 is attached conventionally to a tractor 4 at 5. A latch 6 is pivotally mounted at 7 on the tipping section 3. A rod 8 is pivotally mounted on the latch 6 at 9 and slidably engages a hollow cylinder 10 which cylinder is pivotally attached to the vehicle chassis 2 of the tipping trailer 1 at 1 2. A spring 1 3 is attached to the tipping section 3 at 1 4 and is also coupled to a tension bar 1 5 by conventional means. Tension bar 1 5 is attached to the latch 6 at 16. A flap 1 7 having a latch retainer 1 8 is hinged to the tipping section 3 by means of hinges 19.A stop 20 located on the tipping section 3 limits the latch 6 from pivoting in an anti-clockwise direction about 7 (as shown in the drawing) when the flap 1 7 has been released. The tipping 3 pivots about the fixed chassis 2 at 21.

A conventional tipping mechanism 22 and associated hydraulic feed lines 23 from the tractor 4 enable the trailer to tip.

In use, and with the tipping section 3 in the horizontal position, latch 6 engages the latch retainer 1 8 on the flap 1 7 and by means of the tension bar 1 5 and associated spring 1 3 maintains the flap in the closed position.

As the tipping section 3 commences to tip, the rod 8 begins to slide down the cylinder 10. As soon as the rod 8 meets the bottom of the cylinder 10, further tipping causes the rod 8 to raise the latch 6 which pivots at 7. The latch then disengages from the latch receiver 1 8 and the flap 1 7 swings open about the hinges 1 9 under gravity. The angle of elevation of the tipping section 3 at which the flap 1 7 opens may be adjusted by adjusting the length of the rod 8.

As the tipping section 3 returns to its horizontal position the latch retainer 1 8 attached to the flap 1 7 momentarily raises the latch 6 by a camming action thereby enabling the flap 1 7 to be secured by the latch 6.

It should be noted that the point 9 of pivoted attachment of the rod 8 to the latch 6 is to the rear of the tipping axis 21, referred to the normal direction of travel of the vehicle as defining "rear". Thus when the tipping section 3 pivots about axis 21, the pivot 9 moves in an arc which has a downward component, thereby driving the rod 8 further into the cylinder 1 0. The bottom of the hollow interior of the cylinder 10 serves as a stop for said motion of the rod 8, but alternative stop means can be used, as, for example, a hole or holes through the cylinder wall or walls, with a cooperating pin located in said hole or holes, and extending transversely of the rod 8.

Claims

1. An automatic latch for a top-hinged flap of a tipping section on a vehicle chassis, which latch comprises a cooperating pair of latch members located one on the flap and the other on the tipping section, said latch members being adapted for engagement on closure of the flap, and means responsive to tipping beyond a limiting angle for releasing the latch, thereby releasing the flap.

2. A latch as claimed in claim 1 which comprises a latch retainer fixed to the flap, a latch lever pivotally attached to the tipping section at a first point, a push rod pivotally attached to the latch lever at a second point to the rear of the tipping axis, a cooperating guide member pivotally attached to the chassis and slidably engageable with the push rod during tipping, and stop means for preventing said slidable engagement at and beyond the limiting angle of tip, to open the latch by pressure of the thus restrained push rod against the latch lever.

3. A latch as claimed in claim 2 wherein, of the push rod and the guide member, one is a hollow cylinder adapted to receive the other in telescopic manner.

4. A latch as claimed in claim 3, wherein the stop means comprises an obstruction in the bore of the cylinder, such as an end wall thereof, or a transversely extending pin located in a hole or holes through the wall thereof.

5. A latch as claimed in claim 4 wherein the position of the stop means is adjustable, in the longitudinal direction of the push rod.

6. A latch as claimed in any of claims 1 to 5, wherein the latch lever comprises a camsurfaced hook adapted to catch and be retained by the latch retainer.

7. A latch as claimed in claim 6 wherein spring means bias the latch lever into the engaged condition.

8. A latch as claimed in claim 7 wherein the bias is adjustable.

9. A latch as claimed in claim 1, substantially as herein described.