GB618958A - Improvements in or relating to fastenings for locks and latches and other purposes - Google Patents

Abstract

618,958. Latches. BIALKOWSKI, L. S. Feb. 15, 1946, Nos. 4832/46 and 28414/45. [Class 44] A door latch comprises a latch casing a, Fig. 1, recessed at h, a sliding latch frame c, fixed to the latch bolt band orifices at g, a sliding bar e recessed at i and a ball f selectively to engage one of the members a or e with the middle one c. The sliding bar e is mounted on the latch frame c and carries an arm l loaded by a spring j. The latch is shown in the locked position, the ball f locking the frame c to the casing a. A rotatable cam m on the handle spindle engages the arm l of the slidable bar e moving it to allow the ball to pass into the recess i and free the latch frame which is retracted by engagement between the arm l and a stop pin o<1> on further rotation of the cam. The recesses h, i are shaped to cause the ball to move to the required position. The latch springs n bear against a sliding plate o which. bears on the cam to return it, when released, to the original position. The bolt is retained retracted when the door is opened by a spring- loaded hook member p allowed to engage in a recess i<1> in the latch by the outward movement of a spring-loaded auxiliary bolt r. The bolt is ,shot when the door is slammed to move the auxiliary bolt inwardly. The bolt may be deadlocked by turning the cam clockwise so that the nose g engages the orifice c<1> in the bottom of the frame c where it is retained by the engagement between the nose m<1> of the cam and the notch u on the plate o.. The bolt may be retained in the fully retracted position by turning the cam in the opposite direction. The sliding bar e and the ball f may be replaced by a catch w, Fig. 6, pivoted to the frame c, normally engaging a recess x in the latch case and released by the pressure of the cam on the other arm v<1>.