Patent GB-791769-A (GB)
Title: Improvements in and relating to locks
IPC: E05B55/00
Filed: 1955-07-12
Abstract: 791,769. Latches. JACOBSON VAN DEN BERG & CO. July 12, 1955 [July 13, 1954], No. 20201/55. Class 44 Relates to a safety latch bolt lock with a latch bolt guided in a casing, a non-rotatable axially movable hollow latch pin traversing the latch bolt for moving the latter from its locking position and projecting on both sides of the lock casing with outer projecting parts and handles on its outer ends, one of which is rotatably mounted, a locking member for the latch bolt in the latch pin, and a rotatable internal control element for the locking member. According to the invention, transverse slits are provided at one end of the latch pin and in the adjacent end of the rotatable internal control element, the slits co-operating with an oppositely disposed solely axially movable plate-like locking member in one of the handles for securing the rotatable internal control element against rotation in one of its end positions when the plate-like locking member is advanced in axial direction and extends in the transverse slits of the internal control element and the latch pin. As shown, a spring- loaded bolt 1 comprises a transverse part 3 behind which is located a latch pin 6 carrying door handles 7 and 8. A rotatable member 26 is disposed in a channel 25 of the latch pin 6 and is connected with locking members 27 guided in the latch pin 6 for movement into or out of engagement therewith when the member 26 is rotated, the locking members 27 being also engageable with slits 28 in the bolt 1. The handle 8 is provided with a cylinder lock 29, a coupling on which is engageable with a slit 31 in the member 26 for moving the locking members 27 into or out of engagement with the bolt 1. The bolt 1 is movable from a locking position to an unlocked position by axial movement of the latch pin 6 which is provided with bars 33 thereon for co-operation with pegs 34 or the like on the bolt. The handle 7 is provided with a rotatable driving means 36, an inclined face 37 of which co-operates with a complementary face 40 on a spring-loaded non- rotatable locking member 39. A locking piece 41 of the member 39 is engageable in a slit 44 in the member 26 and a slit 45 in the latch pin 6 when the member 39 is advanced by rotation of the driving means 36, to prevent rotation of the member 26 either by rotation of handle 7 or by operation of the lock 29 of handle 8. In a modification, Figs. 4 to 7 (not shown), the rotatable driving means 36 is replaced by a spring-loaded push button having attached thereto a resilient member which is engageable with a member slidable on a locking member to displace a spring- loaded locking lever out of engagement with the handle 7 and to move the locking member into and out of the locking position for the member 26. In a further arrangement, Figs. 8-15 (not shown), also comprising a push button for locking the member 26, the locking piece of Figs. 1-3 is of plate form and is provided with a stop on one side thereof which co-operates with a projection on a member pivoted to the latch pin 6, such that successive operations of the button locks and unlocks the member 26. Two buttons may be provided, operation of one freeing the other.