GB2333321A

GB2333321A - Releasable latch

Info

Publication number: GB2333321A
Application number: GB9826515A
Authority: GB
Inventors: Kevin Dennis John Evans
Original assignee: McKechnie UK Ltd
Current assignee: McKechnie UK Ltd
Priority date: 1997-12-22
Filing date: 1998-12-02
Publication date: 1999-07-21
Also published as: GB9826515D0; GB9727104D0

Abstract

A latch for attachment to a first member 3 at an aperture therethrough and adapted to releasably attach also to a support surface of a second member 4 at an aperture therein. The latch comprises: a first element 1 for attachment to a first member 3 at an aperture therethrough, the first element 1 having a flexible guide component having a chamfered guide surface, and a shoulder (106, Fig 1) adjacent to the chamfered surface for engaging a surface of the first element adjacent the aperture to mount the first element on the first member; a substantially L-shaped second element 2 having first and second limbs, pivotally mounted within the first element about a pivot axis disposed substantially at the junction of the first and second limbs, the first limb having, on one side, a chamfered end face adjacent to a latching shoulder 222, for guiding the limb through an aperture in a second member 4 to which the first member 3 is to be latched in use, the second limb extending adjacent to a surface of the first element; and a spring 20 disposed between the second limb and the adjacent surface of the first element to bias the first limb in the direction of the one side of the first limb. The latch is of resilient plastics material and the first member 3 may be a removable panel or door while the second member may be a supporting frame element.

Description

UNIVERBAL LATCH The present invention relates to a universal latch of the type for providing releasable attachment of first and second members such as a panel and a support.

Many such fasteners are known, but it is desirable for the latch to be readily attached to a first member and for the latch to operate automatically to latch the first member to the second member when it is presented thereto, whilst at the same time assuring that the latch has as few parts as possible in order to simplify both its manufacture and assembly.

According to the present invention there is provided a latch comprising: a first element for attachment to a first member at an aperture therethrough, the first element having a flexible guide component having a chamfered guide surface, and a shoulder adjacent to the chamfered surface for engaging a surface of the first element adjacent the aperture to mount the first element on the first member; a substantially L-shaped second element having first and second limbs, pivotally mounted within the first element about a pivot axis disposed substantially at the junction of the first and second limbs, the first limb having, on one side, a chamfered end face adjacent to a latching shoulder, for guiding the limb through an aperture in a second member to which the first member is to be latched in use, the second limb extending adjacent to a surface of the first element; and a spring disposed between the second limb and the adjacent surface of the first element to bias the first limb in the direction of the one side of the first limb.

Preferably, the latch is formed of a resilient plastics material. The spring may comprise a leg, integrally formed with the second limb of the second element and resiliently disposed against the adjacent surface of the first element in order to bias the rotation of the second element as described. Forming the latch of a resilient plastics material also enables the guide component, which may include one or more legs, to provide a snap fit connection of the latch to the first member.

Preferably, the first element is also substantially Lshaped and has first and second limbs along which generally are disposed the first and second limbs of the second element. This allows the second limb of the second element to act as an operating lever to move the first limb, against the bias of the spring, out of engagement with the second member in order to release the latch.

Preferably the pivoting of the second element within the first is achieved by means of one or more at least part circular surfaces on the second element, engaged with partially surrounding supporting surfaces in the first element. The supporting surface or surfaces on one side of the part circular surface(s) may be movable generally in the direction in which the first limb of the second element extends, to allow the latch to be used readily with different thicknesses of the second member or with different spacing between the first and second members.

The movable supporting surface(s) may be attached to an actuating button or the like to allow a user to move the second element relative to the first element.

An abutment or abutments, sized appropriately for the aperture in the first member, may be provided disposed to prevent displacement of the flexible component after attachment to the first member.

Three examples of latches constructed in accordance with the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is an isometric view of a first latch from one side and above; Figure 2 is an isometric view of the underside of the first latch, but with the second element removed for clarity; Figure 3 is a longitudinal section through the first latch; Figure 4 is a isometric view similar to Figure 1, but showing the latch disposed on first and second members; and Figures 5 to 8 are views corresponding to Figures 1 and 2, and 3 and 4, of a second and a third latch respectively.

The latch shown in Figures 1 to 4 is formed of a resilient plastics material and comprises a first element 1 in the form of a generally L-shaped housing 10 and a second, generally L-shaped element 2, pivotally disposed within the housing 10 of the first element.

The housing 10, has a pair of limbs, 100, 101 and, from the lower (as seen in the figures) side of the limb 101, extend two pairs of legs 102, 103. As can be seen from Figures 1 and 2 particularly, the legs 103 are smaller than the legs 102 and are designed to be resiliently flexible towards the legs 102. Each of the legs 102, 103 has a chamfered guide surface 104, 105, respectively, adjacent to which guide surfaces are respective shoulders 106, 107. In use, the housing 10 is presented to an aperture in a first member 3 (see Figure 4) in a tilted orientation and the legs 102 inserted through the aperture, the shoulders 106 of the legs 102 being hooked underneath the first member 3 on one side of the aperture. The latch is then rotated, causing the chamfered surfaces 105 of the legs 103 to ride against the opposite side of the aperture and being moved resiliently towards the legs 102 until the shoulders 106, 107 have passed through the aperture, at which time the legs 103 are able to snap back outwardly to the position shown in Figure 3 to locate the latch in the aperture.

The second element 2, also substantially L-shaped, is disposed within the housing 10 and retained therein by a spring leg 20 integrally formed with and extending divergently outwardly from a second limb 21. The first limb 22 of the second element 2 extends generally away from the second 21, substantially at right angles, and has, at its free end, a sideways extending protrusion 220, which defines a chamfered end face 221 and an adjacent shoulder 222.

At the junction between the first and second limbs 22, 21 of the second element 2, a part circular-sectioned protrusion 23 is formed (as shown in Figure 3) to provide for pivoting of the second element 2 within the first element 1. The protrusion 23 extends laterally beyond the limbs 21, 22 to provide circular cylindrical side portions (not shown) which engage against surfaces 108, 109, 110 within the housing 10, to allow pivotal movement of the second element 2 within the first element 1 against the bias of the spring leg 20 which, on assembly, snaps behind an abutment 111 protruding downwardly from the underside of the first limb 100. The first limb 100 has a part circular cutout 112 which allows the end of the second limb 21 to be visible from above.

To prevent stresses being applied to the resilient legs 103 after the housing 10 has been attached to the first member 3, a pair of abutments 113 are provided extending downwardly from the limb 101, disposed to abut the same side of the aperture as the legs 103 during insertion.

As can be seen best from Figures 3 and 4, the latch is used to attach the first member 3 (which may be a removable panel, door or the like), to a support 4, which may be a frame member. When the first member 3 is presented to the second member 4, carrying the latch 1, the guide surfaces 104 of the legs 102 and the chamfered end face 221 pass through the aperture 40 in the second member 4, both the surfaces 104 and 221 engaging the respective sides of the aperture 40 if necessary in order to accurately position the latch and hence the first and second members 3, 4. The limb 22 of the second member 2 is resiliently urged leftwards as shown in Figure 3 during insertion through the aperture 40 against the bias of the spring leg 20, and is snapped back into the position shown in Figure 3 after the protrusion 220 has passed through the aperture 40, whereupon the shoulder 222 engages the underside of the member 4, to complete the latching.

The variants shown in Figures 5 to 8 are substantially similar to the latch described above in connection with Figures 1 to 4, but, additionally, provide vertical (as seen in the figures) compliance to allow different spacings between the members 3, 4 and/or a different thickness of the support member 4.

This is achieved, in the example of Figures 5 and 6, by providing the upper limb 100 of the housing 10 with a resilient leg 114 on which is mounted a raised portion 115 to act as an actuating button, the underside of which engages against the part circular protrusion 23 on the second element 2, and which can thus be moved downwardly as indicated by the arrows in Figure 6 against the bias of a pair of metal leaf springs 116 which abut the underside of the pivot protrusions on the second element 2.

The variant shown in Figures 7 and 8 comprises a separate button 115' disposed in an aperture 117 formed in the upper limb 100, but provides the same functionality as the variant of Figures 5 and 6.

In other respects, the latches of Figures 5 to 8 are substantially identical to the latch of Figures 1 to 4 and, for simplicity, the reference numerals have not been repeated.

Claims

CLAIMS 1. A latch comprising: a first element for attachment to a first member at an aperture therethrough, the first element having a flexible guide component having a chamfered guide surface, and a shoulder adjacent to the chamfered surface for engaging a surface of the first element adjacent the aperture to mount the first element on the first member; a substantially L-shaped second element having first and second limbs, pivotally mounted within the first element about a pivot axis disposed substantially at the junction of the first and second limbs, the first limb having, on one side, a chamfered end face adjacent to a latching shoulder, for guiding the limb through an aperture in a second member to which the first member is to be latched in use, the second limb extending adjacent to a surface of the first element; and a spring disposed between the second limb and the adjacent surface of the first element to bias the first limb in the direction of the one side of the first limb.
2. A latch according to claim 1, wherein the latch is formed of a resilient plastics material.
3. A latch according to claim 1 or claim 2, wherein the spring comprises a leg, integrally formed with the second limb of the second element and resiliently disposed against the adjacent surface of the first element in order to bias the rotation of the second element.
4. A latch according to any of claims 1 to 3, wherein the first element is also substantially L-shaped and has first and second limbs along which generally are disposed the first and second limbs of the second element.
5. A latch according to any preceding claim, wherein the pivoting of the second element within the first is achieved by means of one or more. at least part circular surfaces on the second element, engaged with partially surrounding supporting surfaces in the first element.
6. A latch according to claim 5, wherein the supporting surface or surfaces on one side of the part circular surface(s) are movable generally in the direction in which the first limb of the second element extends, to allow the latch to be used readily with different thicknesses of the second member or with different spacing between the first and second members.
7. A latch according to claim 5 or claim 6, wherein the movable supporting surface(s) are attached to an actuating button to allow a user to move the second element relative to the first element.
8. A latch according to any preceding claims, wherein an abutment or abutments, sized appropriately for the aperture in the first member, are provided disposed to prevent displacement of the flexible component after attachment to the first member.
9. A latch substantially as described with reference to the accompanying drawings.