GB2321928A - Latch Assembly - Google Patents

Abstract

Latch assembly for vehicle doors or other closure includes a unitary resilient buffer 26 (FIG.2) located and supported both by walls of a core of the latch and by flanges or tabs of a body of the latch engaging in grooves or slots e.g.44 of the buffer, the buffer having both a portion 30 which coacts with a striker received and engaged by the latch to hold the closure closed and a portion 28 which coacts with a claw or other retention component which secures the striker. The buffer accommodates manufacturing tolerances and wear and damps out rattles.

Description

LATCH ASSEMBLY This invention relates to latch assemblies for securing doors and other closure on passenger and other vehicles. The latch assemblies may be used for passenger doors, or for such closures as boot or trunk lids, tailgates, bonnets and the like.

The latch assembly is usually mounted on the door or other closures to coact with and engage a striker element on the door post or other frame. However, for some applications the latch assembly may be mounted on the fixed post or other frame to coact with a striker carried on the door or other closure, one common example being a vehicle bonnet latch.

In all cases it is important that the mechanism of the latch engages the striker positively whenever the door or other closure is closed, and that it cannot be accidentally displaced or released from its secured condition. Hence the striker needs to be brought into accurate alignment with the operative parts of the latch assembly despite the effects of unavoidable manufacturing tolerances, vibration and flexure of the closure and its frame, and wear and tear. It is also desirable that operation is not unduly noisy, and that the noise of e.g.

a door closing and latching is indicative of reliable and secure operation through the life of the vehicle.

Furthermore any play between the striker and the latch assembly and/or in the mechanism itself in the closed condition may result in unacceptable rattles and squeaks and will also cause additional wear on locating surfaces and other parts which will rapidly worsen the condition.

To reduce noise and to accommodate wear and misalignment in latch assemblies and coating strikers it is known to form interengaging parts thereof of wear resistant plastics materials having a limited degree of resilience, and/or to incorporating resilient pads or buffers. The incorporation of the additional components necessary for this add to the costs and difficulties of manufacture and assembly.

The object of the present invention is to provide improvements in the manufacture, assembly and operation of latch assemblies giving simple and economical construction.

According to the invention there is provided a latch assembly for operative mounting on a door or other closure or on a frame therefore for releasable engagement with a striker of the other of the frame or closure to secure the closure in its closed condition, said assembly including a latch body having a mouth in which the striker is received, and a releasable retention component automatically engaging and retaining the striker at an inward closed position thereof in the mouth; characterised in that said assembly further includes a unitary resilient buffer of elastomeric material shaped for location in the latch body with a first portion positioned for operative abutment by the striker at said closed position and a second portion positioned for operative abutment by the retention component on its engagement with the striker.

The retention component may be a bifurcated rotating claw angularly displaced by entry of the striker into the mouth between limbs of the claw, the claw being releasably retained in engaged condition by a coacting pawl; with the said second portion of the buffer being abutted by an end part of one said limb.

Preferably the buffer includes one or more grooves or slots for receiving one or more flanges or tabs of the body.

The or each said flange or tab may serve to locate the buffer in a simple quick assembly manner and may also serve to reinforce either or both portions thereof. One or more said flanges or tabs may itself be flexible or resilient in whole or in part to supplement the damping and cushioning action of the buffer.

An example of the invention is now more particularly described with reference to the accompanying drawings, wherein: FIGURE 1 is a perspective view of part of an assembled vehicle door latch assembly; FIGURE 2 is an enlarged perspective view of a buffer of said assembly; FIGURE 3 is a first sectional view showing the relationship of a striker with one portion of the buffer in said assembly; and FIGURE 4 is a second sectional view showing the relationship of a claw with another portion of the buffer in said assembly.

The latch assembly 10 shown in part in Figure 1 will be mounted in known manner in the door structure (not shown) of a passenger vehicle to coact with a cylindrical striker 12 (figures 3 and 4) mounted on the door post (not shown) for releasably securing the door in closed position in known manner.

Assembly 10 has a composite latch body (Figure 1) comprising a right angled pressed metal outer shell 14 to be secured to the door structure, a right angled pressed metal cover plate 16 whose major part extends in spaced parallel relationship to the major part of shell 14, and a moulded plastics body core 18 omitted in Figure 1 for clarity but shown in section in Figures 3 and 4 which encloses and locates the mechanism and other components of the assembly, being sandwiched between said major parts.

The assembled body defines a mouth 20 opening to the right as viewed in the drawings and having inwardly convergent side walls, into which striker 20 enters as the door closes.

A retention component is in this example, a bifurcated rotating claw 22 pivoted in the body in conventional manner to intercept and engage with striker 12 as it enters mouth 20, turning the claw anticlockwise to the secured and closed condition shown in the drawings, claw 22 being releasably retained by a pawl 24 (Figure 4) in known manner.

To cushion both striker 12 at its full travel into mouth 20 and claw 22 in its fully engaged position the assembly incorporates a unitary resilient buffer 26 formed as a single moulding of elastomeric material, best seen in Figure 2. An upper first portion 28 of the buffer coacts with the free end of the uppermost limb of claw 22 in the engaged position as seen in Figure 4 and a second lower portion 30 laterally offset from portion 28 coacts with striker 12 as shown in Figure 3.

The non-acting faces of portion 28 are located and supported by nesting within a shaped top wall portion 32 of body core 18 which includes a downwardly extending abutment 34 backing portion 28 adjacent the claw limb end, this abutment locating in turn against a horizontal flange 36 of cover plate 16 which extends from the top edge of the major part of the latter to the inner face of the major part of outer shell 14 just within top wall 32.

The striker engaging second portion 30 of buffer 26 is closely surrounded by inner walls of core 18 for full location and support leaving only the face at the inner end of mouth 20 exposed for abutment by striker 12. The upper face of portion 30 locates against flange 36 and said inner walls include vertically spaced upper and lower outwardly divergent portions 38, 40 defining, in part, mouth 20.

Upper portion 38 extends inwardly to form a resilient leaf 42 having a distal end which locates in a groove 44 of buffer portion 30.

This not only contributes to positive location of buffer 26 in the assembly but also resiliently supports leaf 42 to engage snugly against striker 12 in the closed condition.

The single piece buffer 26 and its manner of location in the latch body greatly facilitates assembly as it can be placed in position in a single operation as the sandwich construction described above is put together, it being fully located and supported for effective operation without the use of fasteners or other subsidiary locating components.

Furthermore it provides effective cushioning of both the striker and the claw in a particularly simple manner to ensure that the operation of closing the door and claw/striker engagement is effected with satisfactory noise levels and providing good perceived quality of operation judged by sound. Rebound energy as the door is slammed closed with sufficient force for latch engagement is dissipated by the resilient resistance of the buffer, so reducing noise generation.

Furthermore, the continued cushioning action of the buffer, backed up in case of the striker by the arrangement of leaf 42, gives flexibility of location compensating for manufacturing tolerances and subsequent wear while providing a degree of positive location in the closed condition, and also resists or damps out any tendency to generate rattles or squeaks as well as avoiding or reducing play of the components which could cause wear in the long term.

Claims (6)

1. A latch assembly for operative mounting on a vehicle door or other closure or on a frame therefore for releasable engagement with a striker of the other of the frame or closure to secure the closure in its closed condition, said assembly including a latch body having a mouth in which the striker is received, and a releasable retention component automatically engaging and retaining the striker at an inward closed position thereof in the mouth; characterised in that said assembly further includes a unitary resilient buffer of elastomeric material shaped for location in the latch body with a first portion positioned for operative abutment by the striker at said closed position and a second portion positioned for operative abutment by the retention component on its engagement with the striker.

2. An assembly as in claim 1 wherein the retention component is a bifurcated rotating claw angularly displaced by entry of the striker into the mouth between limbs of the claw, the claw being releasably retained in engaged condition by a coacting pawl; with the said second portion of the buffer being abutted by an end part of one said limb.

3. An assembly as in claim 1 or 2 wherein the buffer includes one or more grooves or slots for receiving one or more flanges or tabs of the body.

4. An assembly as in claim 3 wherein the or each said flange or tab serves to locate the buffer in a simple quick assembly manner and also serves to reinforce either or both portions thereof.

5. An assembly as in claim 3 or 4 wherein one or more said flanges or tabs is itself flexible or resilient in whole or in part to supplement the damping and cushioning action of the buffer.

6. A latch assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.