Patent GB-864305-A (GB)
Title: Improvements in or relating to releasable fastening devices
Inventor: CHANARYN VICTOR
IPC: E05B65/32
Filed: 1956-06-26
Abstract: 864,305. Latches. WILMOT-BREEDEN Ltd. June 20, 1957 [June 22, 1956], No. 19342/56. Class 44. A releasable fastening device comprises two parts between which relative angular and translatory movements occur in a common plane as the parts move to a relative coupling position, the formation of the parts being such that in the coupling position surface portions thereof contact each other substantially at the centre of relative angular movement and so that the reaction force therebetween as a result of any tendency for relative translatory movement in the reverse direction to that occurring during the fastening operation, is directed substantially through that centre and imposes no turning movement tending to produce relative angular movement in the uncoupling direction. As applied to a motor vehicle door latch and shown diagrammatically in Figs. 1, 4 and 5, the device comprises a substantially G-shaped keeper 21 fixed to a body pillar of the vehicle and an angularly movable cam 22 carried by a door pillar. The cam which is spring-biased to the position shown in Fig. 1, is pivotal about a centre 23 and carries a roller 27. As the door is moved from the open position, Fig. 1, to the closed position, Fig. 5, the cam is rotated by engagement of the roller with a nose 29 on the keeper, such that the leading end 24 of the cam is guided into the mouth of the keeper to a " safety lock " position, Fig. 4, and thereafter into a fully locked position, Fig. 5, in which the roller is maintained in contact with the inner surface 36 of the upper jaw of the keeper and in which the lower surface of the cam rides over a radiussed portion 34. The position of the surface 36 is adjustable by means of an adjustable wedge 45 to ensure contact of the surface 36 with the roller 27. The keeper 21 is adapted to engage a guide 39 carried by the door pillar to ensure correct alignment of the keeper with the cam 22. In the arrangement according to Figs. 8 and 9, the cam is formed integrally with a boss 22a mounted on a cam plate 55 which also carries one end of the roller pivot 27b and is pivoted on a bearing 23a secured to a back plate 56. The cam 23 and roller 27 project outwardly from the back plate through a hole 59 cut in the guide plate 39 and the sheet metal 58 of the door pillar. The cam is loaded by a spring 60 on a stud 61, the free end 60a of which, Fig. 10, bears on a stud 62 on the cam plate 55 and projecting through a slot 63 in the back plate 56. The cam 22 is releasable from the fastened position by an outside push button 66 through a plate 64, a portion 65 of which acts on the stud 62. The cam is also releasable from the inside, through a lever 72 pivoted on the back plate 56 and having a, portion 74 which underlies a portion 75 of the plate 64. The lever is controlled remotely by a handle (not shown). The push button incorporates a key cylinder to permit the cam to be locked against release by the push button. In order to render the push button ineffective from the inside, a locking lever 79, Fig. 13, pivoted on a portion 56a of the back plate 56, includes a boss 83 having a V- shaped groove 86 thereon which co-operates with a pin 85 carried by the push button shaft 68. The other end of the lever 79 projects through a slot 88 in the portion 56a and co-operates with the lever 72, such that rotation of lever 72 in a direction opposite that to effect release of the cam 22, rotates the push button shaft 68 to an inoperative position. A spring-loaded lever 93 pivoted on the back plate 56 co-operates with the push button shaft to prevent the latter being turned to inoperative position when the door is open. The device is applicable to vehicle doors in which internal locking and unlocking means comprise a sill knob 105 for connection to lever 79. The keeper 21 may be constructed as a plate having serrations 101 on its rear surface by which it is engaged with the body pillar. Also the keeper may consist of two cam-engaging surface portions. The upper and/or lower flanges 39a of the guide plate 39 may be formed to embrace a recessed part 103, Fig. 9 of the keeper to prevent longitudinal displacement of the door and body pillars. In another arrangement, Figs. 18 and 19, a cam plate 112, which is secured to a boss 110 rotatably mounted on a guide plate 39b, carries lugs 113, 114, 115 which project inwardly of the door. The cam plate is biased to its locking position by a spring 116, one end 118 of which engages a hole 113a in the lug 113 and the other end of which abuts a stop mounted on a back plate 109. The cam is releasable by a push button 121 through a nylon link 123 and ball 127 connection operative on a contactor plate 124 pivotally mounted on a boss 125 projecting inwardly from the cam plate, and having a part 147 which is engageable with the lug 115. Remote control of the cam is effected by a lever 130 pivoted to a portion 109a of the back plate 109 and including an arm 132. An arm 133 of lever 130 is connected to the cam plate 112 by a strap 134, preferably of nylon, one end of which slidably engages a slot in the arm 133 and the other end of which engages between the lugs 114 and 115, so that anticlockwise rotation of lever 130 rotates the cam plate to release the cam. Locking of the latter from the inside is effected by turning the lever 130 in a clockwise direction, a limb 140 extending from the arm 133 being brought into engagement with a step 141 formed in the contactor plate 124 to prevent rotation of the latter and hence rotation of the cam, by the push button.