GB441530A - Improvements in or relating to door locks - Google Patents

Abstract

441,530. Night latches. STALBERG, H. A., 49, Kungsgatan, Eskilstuna, Sweden. June 13, 1935, No. 17057. [Class 44] A door lock openable from the outside by a key-operated cylinder lock and from inside by a handle has its latch bolt arranged to be held in a non-locked intermediate position, when the door is opened, by the engagement of two spring hooks, these hooks, when the latch is depressed by the closing of the door, springing apart to permit the bolt to shoot home in which position it is deadlocked by a tumbler lever. The latch bolt can also be held in its completely retracted position by the tumbler lever until the latter is raised by the key or handle. A latch bolt 8 is retractable by a finger 10 on a barrel 11 which is moved by a handle having a shank fitting within a non-circular slot 21 in the barrel or by a plate 20 connected to a cylinder lock. The finger also raises a tumbler lever 7 having two notches 12, 13, Fig. 3, for engaging a triangular projection 14 on the bolt when in its shot or completely retracted positions respectively. Movement of the lever 7 also causes movement of a lever 6 to withdraw a second latch 3 which is normally operated by a follower 5. Two hooked members 16, 18 pivoted respectively to the lock case at 17 and to the bolt are normally urged into the positions shown by springs. As the bolt is retracted by the finger 10 the member 16 is raised by the finger end until its hooked end is in the path of the hooked end of the member 18. If the bolt is then allowed to return by reversing the movement of the finger 10 the hooks engage before the pin 14 can enter the recess 12 in the tumbler 7. Pressing in the latch bolt then allows the hooked members to spring apart, the member 16 being no longer engaged by the finger 10, and the bolt can shoot home. The barrel 11 has an axial slot 23 engaging a pin 24 on a member 22 containing the slot 21 so that the ends of the member 22 can lie flush with the lock case as it is inserted into a mortice. The outer case 25 of the cylinder lock is then secured to the lock case and in so doing a projection 19<a> on the cylinder presses out the member 22 to engage further along the handle shank.