Patent GB-926955-A (GB)
Title: Improvements in or relating to releasable fastening devices
Inventor: JEAVONS PHILIP SWINGEWOOD
IPC: E05B65/32
Filed: 1958-07-11
Abstract: 926,955. Latches. WILMOT-BREEDEN Ltd. July 10, 1959 [July 11, 1958; Feb. 7, 1959], Nos. 22275/58 and 4353/59. Class 44. A releasable fastening device for a motorvehicle door, for example, comprises a striker 1 and a catch in the form of a cam 2, the latter being rotatably mounted and having a translatory and an angular movement relative to the striker 1 during the fastening operation, and a spring-loaded wedge member 10 which undergoes translatory movement with the cam 2 and is displaced relatively to the latter as a result of the relative translatory movement, the wedge member 10 providing restraint against relative movement of the striker 1 and cam 2 in a direction transverse to the direction of the translatory movement when the device is fastened and the arrangement being such that the relative angular movement which brings the oam 2 and the striker 1 to an intercoupled position occurs as a direct result of the displacement of the wedge member 10. The striker 1 is fixed to a body pillar of the vehicle and the cam 2 is rotatably mounted in a plate 6 carried by the vehicle door, a nylon moulding 7 being attached to the plate 6 and having a pair of spaced outwardly-extending sections 8, 9 between which is defined a guide channel for receiving the striker 1. The cam 2 is of segmental shape offset from a centre 3 about which it is angularly movable and is urged by a torsion spring 4 to its door-closed position in which it engages the striker 1, Fig. 2 (not shown); when the door is open, the cam is retained in its disengaged position, shown in Fig. 1, by a detent lever 5 which engages a shoulder 28 on a plate 29 fixed to a spindle 23 of the cam 2. The detent lever 5 is coupled to the wedge member 10 by means of an integral tongue 25 which projects into a recess 26 in the wedge member and the spring-load of the latter urges the lever 5 into engagement with the shoulder 28. The striker 1 is in the form of a block having a shallowly recessed end 1b for engagement with a face 2a on the cam 2 when the door is in its closed position. In operation, when the door is moved to its latter position, the striker 1 first makes contact with a face 2b on the cam 2 which projects slightly into the guide channel between the sections 8, 9, and this contact imparts to the cam a small angular movement which relieves the frictional pressure on the detent lever 5. Upon further closing movement of the door the striker 1 displaces the wedge member 10 to disengage the detent lever 5 from the shoulder 28 so that when the door is fully closed the cam 2 is turned by the spring 4 to engage the striker 1. In the latter position of the cam 2 any inadvertent opening movement of the door is prevented since the reaction force due to such movement acts through the centre 3. For opening the door there is provided externally of the latter a push-button, Fig. 6 (not shown), which is connected by a stem to a lever-type handle mounted internally of the door; when the button is pushed or the lever pulled a projection on the stem engages an arm 22 fixed on the spindle 23, to rotate the cam 2 to its disengaged position. Mounted in the push-button is a key-operable lock operation of which locks the door by rotation of the stem so that the projection thereon does not engage the arm 22. In the modification, Figs. 7 to 9 (not shown), the sections 8, 9 forming the guide channel for receiving the striker 1 are provided on the plate 6 and the end 1b of the striker is flat but inclined to the vertical. To provide a safety lock the face 2b of the cam 2 is stepped by a projection at its end furthest from the centre 3. In a modification described in the first Provisional Specification, the striker is provided with a flange adapted to engage under the guide section 9 on the moulding 7. Specifications 864,305, 871,895 and 926,956 are referred to.