GB831446A - Locks for doors - Google Patents

Abstract

831,446. Locks; sliding bolts. LEGGE & CO. Ltd.. J., LEGGE, W. H., and PENNINGS, B. May 23, 1958 [June 19, 1957], No. 19252/57. Class 44 A door lock having a dead bolt 10 operable either by a key from one side of the door, or by a turn knob 23 from the other side, is characterized in that means operable by the key are provided for dead-locking the bolt in its locking position after the key has shot out the bolt into the locking position and in completing a full revolution to enable it to be resumed. The bolt 10, having a head guided in a hole in the front end of a lock casing 12 and a lath 13 with a key notch 14 and a talon 15, is guided on a stump 16 fixed to the casing 12. The stump 16 projects through a guide slot 17 (in the lath 13) and into a gating 18 in a security lever 19 which is urged downwardly by a leaf spring 21 and is pivoted at 20 to the bolt lath 13. The turn 23, on the inside of the door, carries a camdisc 24 with a V-notch 25 engaged by a peg 26 on the security lever 19. A deadlocking means for the bolt comprises a bell-crank lever 30 which is pivoted, at 31, to the casing 12 below the bolt 10 and has, on its rear face, a cam surface with abutments 33, 34. Rotation of the turn 23 in the bolt shooting direction, with the bellcrank lever 30 in the inoperative position, first causes the cam-disc 24, co-operating with the peg 26, to raise the security lever 19 so that the grating 18 is freed from the stump 16. While maintaining the security lever raised the cam-disc 24 shoots the bolt into its locking position and finally allows the security lever 19 to lower so that the rear pocket of its gating 18 embraces the stump 16. The sequence of operation in reverse takes place if the turn 23 is rotated in the opposit direction. For operating the bolt from the outer side of the door the closure plate side of the casing 12 rotatably receives, a crank-disc 27 which is mounted coaxially with the turn 23 and has a pin 28 which co-operates with the underside of the security lever 19 and with the notch 14. The crank-disc 27 has a central slotted thimble 29 adapted to be engaged, and driven, by the connecting bar, not shown, of the key-operable plug of a cylinder lock. After the crank-pin 28 has moved the bolt into the fully shot position, and with continued rotation, it engages the cam abutment 34 and trips the bell-crank lever 30 so that its forward edge engages in a V-notch 32 in the lath 13 to dead-lock the bolt 10. Release of the dead-locking means can be effected only by reverse operation of the crank-disc 27 the pin 28, in this case, engaging the'cam abutment 33 to trip the bell-crank lever 30 into its inoperative position. Operation of the turn 23 does not dead-lock the bolt, however a bolt shot by the turn can be unlocked either by the turn or, by the key-operated crank disc. The bell-crank lever 19 carries a spring-loaded plunger 36 which co-operates with the cap side of the closure plate of the casing 12.