Patent GB-970538-A (GB)
Title: Improvements in or relating to releasable fastening devices
Inventor: PICKARD PAUL ROBERT
IPC: E05B65/32
Filed: 1960-01-15
Abstract: 970,538. Door latches. WILMOTBREEDEN Ltd. Jan. 13, 1961 [Jan. 15, 1960], No. 1487/60. Heading E2A. A releasable door fastening device has an internal releasing mechanism which is connected to a link 16 of a remote control linkage of internal releasing means and is associated with a safety mechanism to which the link is also connected, the arrangement being such that when the safety mechanism is moved to the safety position it uncouples in the operative sense, the remote control link and the releasing mechanism to render a normally releasing movement of the releasing means inoperative to release the device. As shown the device comprises a back plate 2 which is adapted to be mounted on a vehicle door pillar and on which is mounted a multi-lobe cam 3 (not shown) for engagement with a keeper which is adapted to be mounted on a corresponding body pillar of the vehicle. The cam and keeper are of the shape and function disclosed in Specification 926,956. Mounting on the cam spindle 4 on the inner side of the back plate is a cam plate 6 having two arms 6a and 6b and a torsion spring 7 around the spindle 4 has its ends engaging the arm 6a and the back plate 2 to urge the cam 3 into its normal coupling position. A contactor lever 8 pivotally mounted on the back plate 2 has an inwardly directed arm 8a which extends upwardly for engagement with the stem 9 of a push button mounted on the outer side of the door the arm 8a also extending downwardly to engage the arm 6a; thus depressing the push button causes rotation of the cam 3 to unlatch the door. A bell crank remote control lever 14 of the internal releasing mechanism is pivotally mounted on a flange portion 13 of the back plate and the lever is urged by a torsion spring 15 to its normal resting position against an abutment 11 of the back plate. An arm 14a of the lever 14 is arranged for engagement below the inwardly directed arm 6b of the cam plate 6 and rotation of the lever 14 by a handle on the inside of the door through the link 16 rotates the cam 3 to its releasing position. The link 16 engages an elongated slot 17 formed in the lever 14 the slot being slightly cranked to provide an abutment shoulder 18 with which the end of the link engages. Pivotally mounted on the flange portion 13 is a lever 19 of the safety mechanism, an arm 19a of which projects through the back plate to enable the position of the safety lever to be adjusted. The arm 19a is inaccessible when the door is closed. Spring means 20 are provided to index the arm to its two positions. The safety lever has a second arm 19b which is formed with an elongated slot 24 and the end of the link 16 passes through this slot in addition to passing through the slot 17 in the lever 14. In the safety position of the lever 19 the two slots 17, 24 are aligned so that the end of the link 16 can move freely therealong without being effective to move the lever 14 to release the cam 3; with the safety lever in its other position the inner end of the slot 24 is aligned with the abutment shoulder 18 in the slot 17 so that operation of the link 16 moves the lever 14 to release the cam 3. A locking mechanism operable from inside the door is provided which comprises a shaft 22 operated by a knob 23, the shaft passing through an aperture in the flange portion 13 and being rotatable from an inoperative to a locking position in which it prevents operation of the push button in a known manner. To prevent the safety lever being moved to its safety position when the outside push button is locked, the safety lever is provided with a notch 28 and the arrangement is such that the notch can only pass over the locking shaft 22 when it is in the position in which the push button is unlocked; if the push button is locked the shaft 22 blocks movement of the lever 19. In a modification instead of the safety lever being connected directly to the link 16 it is connected to it by a swinging link which is pivoted to the end of the lever 19 and also pivoted to the link 16. Specification 970,537 also is referred to.