Patent GB-1183047-A (GB)
Title: Improvements in or relating to Door Latches
Inventor: JEAVONS PHILIP SWINGEWOOD
IPC: E05B65/32
Filed: 1966-07-15
Abstract: 1,183,047. Latch fastenings. WILMOTBREEDEN Ltd. 10 Feb., 1967 [15 July, 1966], No. 31795/66. Heading E2A. A door latch has a recessed body 1 and a latch member 9 in the form of a rotatable disc the periphery of which, viewed in the axial direction, is in part arcuate and in part notched for latching engagement with a striker, the latch member being received in the body recess 7 with the boundary of the recess locating and providing a bearing for the latch member, which is also formed for engagement by detent means 24 which acts to retain the latch member in the latching position. In the construction shown the body is a block moulded from a synthetic plastics material which in use fits externally against an edge panel of the door, a back plate fitting internally of the panel 2; the latch member in the form shown fits wholly in the recess 7 and is held in place by a cover plate, four screws holding the cover plate to the body and the body and back plate to the edge panel of the door, the screws passing through the cover plate and the body to engage threaded bores in the back plate. In addition to the recess 7 the body has a recess 8 in which the detent means 24 is disposed, the detent means pivoting on a pivot 25. The detent means is biased into engagement with the latch member by a spring 20 which also engages a peg which projects from the inner face of the latch member, to bias the latch member to the unlatching position. The detent means is provided with a hook shaped trailing end portion 26, which is engageable with either of two notches 22, 23 in the latch member, the notch 22 providing a safety latching position and the notch 23 a fully latching position. The detent means is connected by a link 29 with a spring biased contactor lever 29, the lever being pivoted from outside of the door by means of a push button to raise the detent means from engagement with the latch member via the link 29, the contactor lever also being pivoted to releasing position from inside the door via a bell crank remote control lever 36; both the levers 27 and 36 are mounted on the back plate. Also mounted on the back plate is a locking lever 44 which controls sliding movement of a locking pin 42, one end portion of which is slidable in a bore 43 in the body 1 and which in the locking position engages underneath the leading end portion of the detent means 24 so that the detent means cannot be released. The locking lever 44 has a boss 46 with a non-circular bore 47 for coupling to a locking shaft of a key operated locking mechanism mounted on the outer door panel and the locking lever can also be connected to an internal door locking member, for example, a sill control member; the locking lever 44 is retained in both the locking and the unlocking positions by an overcentre spring. The keeper consists of a mounting plate 16 and a generally U shaped loop 14 of steel rod with side limbs 15 which have cranked end portions welded to the mounting plate; the body and the cover plates are provided with aligned slots 18 and 19 (not shown) for receiving the keeper loop and the latch member has a latching notch 13 into which the leading striker limb 15 enters during closing movement of the door; the striker limb 15 turns the latch member to the latching position against the bias of the spring 20, the detent means engaging the notch 23 to hold it in this position. In the latching position the leading limb 15 of the striker is wedged between the upper side of the slot 18 and the lower side of the latching notch 13 to provide vertical restraint and prevent door rattle; the loop formation of the striker provides anti-burst characteristics to prevent separation of the striker and latch member both longitudinally and laterally of the vehicle in a crash. When the latch member 9 is in the unlatching position the detent lever 24 is disposed partially in front of the bore 43 which contains the locking pin and hence the latch cannot be locked with the door open. In a modification instead of the latch member fitting wholly in the recess 7 it has a stepped periphery to provide a reduced diameter portion which bears against the recess boundary.