GB2332470A

GB2332470A - Latch member restraint

Info

Publication number: GB2332470A
Application number: GB9723781A
Authority: GB
Inventors: Reginald George Hill
Original assignee: R G TRADE SUPPLIES AND ENGINEE
Current assignee: R G TRADE SUPPLIES AND ENGINEE
Priority date: 1997-11-12
Filing date: 1997-11-12
Publication date: 1999-06-23
Also published as: GB2332470A9; GB9723781D0

Abstract

A latch assembly 10 comprises a body 12 and an elongate latch member 14 slidably extending through the body 12, between latched and unlatched positions, and a spring urged ball bearing 52 engageable selectively in one of three slots 38,40,42 on the member 14 to restrain the latch in a latched, intermediate or unlatched position, such that a greater force than that which would otherwise cause sliding of the latch member 14, is required to move it away from the respective position.

Description

1 LATCHES 2332470 This invention concerns improvements in or relating to

latches.

Latches as used on lorries to for example hold up drop down sides or ramps, are often of the spring bolt type. This type comprises for instance a slidable elongate member which is urged by a spring into a closed position, with a projection being provided on the elongate member selectively engageable with a formation on the latch body to allow the latch to be selectively held open. This type of latch is also widely used in engineering and general steel fabrication. Such arrangements whilst generally working well have disadvantages and can for example catch a person's hand if the elongate member is let go of whilst under the force of the spring.

According to the present invention there is provided a latch assembly, the assembly comprising a body and an elongate latch member slidably mounted on the body so as to be movable between a latched position extending from the body to be engageable for instance with a corresponding component or formation, and an unlatched position closer to the body, means being provided which restrain the latch member from movement relative to the body at least when in one of the latched or unlatched positions, such that a greater force than that which would otherwise cause sliding of the latch member, is required to slidingly move the latch member away from said position.

The restraining means preferably comprises a sprung member engageable with the latch member at least when the latch member is in said position. Preferably the sprung member is engageable with the latch member at all times, and a formation is provided on the latch member to be engaged by the sprung member when in said position to restrain relative movement.

Formations may be provided on the latch member to correspond to the latched and unlatched positions, and a formation or formations may be provided to correspond to an intermediate position or positions. The or each 2 formation may comprise a recess, or a slot extending around the latch member.

The sprung member may be located so as to restrainably extend from a formation on the body. A spring may be located in said formation engageable with the sprung member. The sprung member may comprise a ball bearing.

Means may be provided on the latch member to prevent same from being slid fully away from the body.

The body may comprise a casing which encloses the restraining means and a part of the latch member.

A handle may be provided on the latch member, desirably at or towards the non-latching end thereof.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:- Fig. 1 is a diagrammatic sectional side view of a latch assembly according to the invention; Fig. 2 is a diagrammatic plan view of the assembly of Fig. 1; and Fig. 3 is a diagrammatic end view of the assembly of Fig. 1.

The drawings show a latch assembly 10 comprising a body 12 and an elongate latch member 14 slidably extending through the body 12. The left hand end 16 (as shown in Figs. 1 and 2) of the member 14, constitutes a latching part and is selectively engageable with an appropriate formation or component which includes a socket. The right hand end 18 of the latch member 14 constitutes a handle, and comprises a handle in the form of a pin 20 slidably located in a hole 20 provided in a shoulder 24 on the end 18.

i 3 The body 12 comprises a base plate 26 from which an upstanding cover 28 extends. The base plate 26 has a generally rectangular configuration with mounting holes 30, and with the longer sides thereof waisted. The cover 28 is of a generally narrower rectangular configuration with rounded corners. Aligned openings 32,34 are provided at each end of the cover 28 with nylon bushes 36 located therein to guide the member 14 extending therethrough.

Three spaced circumferential rounded slots 38,40,42 are provided on the member, each 14 spaced respectively further from the end 16. A circular clip 44 is provided on the member 14 to the right hand side of the slot 42 to prevent the member 14 being fully removed from the body 12 in one direction, with the shoulder 24 and pin 20 preventing removal in the opposite direction.

A restraining arrangement 46 is provided on the underside of the top of the cover 28 and engageable with the latch member 14. The arrangement 46 comprises a downwardly open cylindrical housing 48 with an inwardly turned flange 50 at its lower open end. A ball bearing 52 is located within the housing 48 so as to be extendable through the lower opening but restrained in the housing 48 by the flange 50. A spring 54 is provided between the ball bearing 52 and the underside of the cover 28 to urge the ball bearing 52 out of the housing 48.

In use, the latch member 14 can be freely slid relative to the body 12, but when the ball bearing S2 engages in any of the slots 38,40,42, an extra force is required to further slide the member 14. Accordingly, the latch member 14 will be restrainably held in any of these positions, with the ball bearing 52 located in any of the slots 38,40,42, corresponding respectively to a fully latched position, intermediate position and an unlatched position.

There is thus described a latch assembly with a number of advantageous features. The positive restraining of the latch assembly in a latched, intermediate or unlatched position provides for secure latching, whilst the lack of direct spring loading on the latch assembly provides for safer use. The 4 provision of the cover again provides for safer operation and also prevents dirt from interfering with operation of the latch. The cover also provides a pleasing appearance to the assembly. The assembly is of relatively straightforward construction and can thus be inexpensively and robustly manufactured.

Various modifications may be made without departing from the scope of the invention. For example, a different number of formations may be provided on the latch member. In some applications it may only be necessary to provide a single formation to provide for secure latching. In other applications it may be appropriate to have two or perhaps a greater number of formations. A different restraining arrangement may be provided and a sprung member other than a ball bearing could be used. The sprung member could be restrained in a different manner. If the housing for the bearing is mounted on a plate which fastens onto the cover, this provides for a particularly straightforward making of the assembly.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

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Claims

1. A latch assembly, the assembly comprising a body and an elongate latch member slidably mounted on the body so as to be movable between a latched position extending from the body to be engageable for instance with a corresponding component or formation, and an unlatched position closer to the body, means being provided which restrain the latch member from movement relative to the body at least when in one of the latched or unlatched positions, such that a greater force than that which would otherwise cause sliding of the latch member, is required to slidingly move the latch member away from said position.

2. A latch assembly according to claim 1 wherein the restraining means comprises a sprung member engageable with the latch member at least when the latch member is in said position

3. A latch assembly according to claim ? wherein the sprung member is engageable with the latch member at all times.

4. A latch assembly according to claims 2 or 3 wherein a formation is provided on the latch member to be engaged by the sprung member when in said position to restrain relative movement.

S. A latch assembly according to claim 4 wherein formations are provided on the latch member to correspond to the latched and unlatched positions.

6. A latch assembly according to any of the preceding claims wherein a formation is provided on the latch member to be engaged by the sprung member when in an intermediate position to restrain relative movement.

7. A latch assembly according to claim 6 wherein a plurality of formations are provided to correspond to a plurality of intermediate positions.

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8. A latch assembly according to any of claims 4 to 7 where-in the or each formation comprises a recess.

9. A latch assembly according to any of claims 4 to 7 wherein the or each formation comprises a slot extending around the latch member.

10. A latch assembly according to claim 2 or any of claims 3 to 9 when dependent on claim 2, wherein the sprung member is located so as to restrainably extend from a formation on the body.

11. A latch assembly according to claim 10 wherein a spring is located in said formation engageable with the sprung member.

12. A latch assembly according to claim 2 or any of claims 3 to 11 when dependent on claim 2, wherein the sprung member comprises a ball bearing.

13. A latch assembly according to any of the preceding claims wherein means are provided on the latch member to prevent same from being slid fully away from the body.

14. A latch assembly according to any of the preceding claims wherein the body comprises a casing which encloses the restraining means and a part of the latch member.

15. A latch assembly according to any of the preceding claims where-in a handle is provided on the latch member.

16. A latch assembly according to claim 15 wherein the handle is provided at or towards the non-latching end of the latch member.

17. A latch assembly substantially as hereinbefore described with reference to the accompanying drawings.

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18. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.