GB597985A - Improvements in or relating to door latches and locks - Google Patents

Abstract

597,985. Locks and latches. BACK. HOUSE, H. T; March 29, 1946, Nos. 7629/47 (divided out of 9886/46 [597,984]), and 22743/46; [Class 44] A door latch mechanism of the kind having two independently operable handles, each of which may be operated in one direction to retract the bolt and in the reverse direction to block the bolt in shot position, is combined with a key lock operable from one side to block the latch. The latching mechanism shown is of the kind described in Specification 597,984 comprising a pivoted pawl 111, shown dotted in the free position, which may be engaged by one of the arms 108, 109 independently actuated by the handles so as to bring it into the position shown in full lines where the arm 113 of the pawl engages the face 110 of the latch to prevent retraction and the arm 115 to engage the arm 109 not already turned to prevent its now being turned in the locking direction. The key lock 121 is provided with a bolt 122 adapted to move the pawl 111 to the locking position. 'The lock 121 has a cylindrical casing and is mounted in a cylindrical housing in which it is registered by a member 175 engaging a longitudinal groove in the casing. In the form shown, the member 145 is constituted by the head of a pivot of a plate 117 turnable to block either of the arms 108, 109 in the blocking direction as described in Specification 597,983. Alternatively, the key lock may be outside the casing of the latching mechanism, the key lock bolt actuating a pin passing through the pivot 116 to engage the pawl. Specifications 496,776, 572,586 and 597,949 also are referred to.