Patent GB-877502-A (GB)
Title: Improvements in or relating to latching mechanisms
Inventor: JAKEMAN HARRY
IPC: E05B65/00
Filed: 1956-10-08
Abstract: 877,502. Latch fastenings. WILMOTBREEDEN Ltd. Oct. 8, 1957 [Oct. 8, 1956], No. 30546/56. Class 44. A latching mechanism comprises a latch member 19, an actuating member 23 and a striker 18, the latch member being mounted for angular movement about an axis to enable it to enter into latching engagement with the striker as a result of engagement therewith during a latching operation and having three spaced surface portions against the first 40 of which the actuating member bears to hold the latch member in the latching position and against a second 33 of which the actuating member bears when the latch member is in the unlatching position to prevent return movement of the actuating member to its original position, the actuating member being movable from engagement with the first surface portion should the latch member be in the latching position when not engaged with the striker, to bear against the third surface portion 41 which it engages to turn the latch member to the unlatching position. As shown in Fig. 6 the latch member and actuating member are both carried by a back-plate 15 and the actuating member is mounted on a pivot pin 22 and is urged in the latching direction by a torsion spring 34 surrounding the pivot pin. The surface portions are parts of a substantially L-shaped opening 30 in the latch member and the 'actuating member has a pin 29 which enters the opening to engage the surface portions. The surface portion 33 is shaped to give a progressive wedging action as the pin moves nearer to its right-hand end as shown. The actuating member is moved to the latch member releasing position either by a flexible cable 26 or by means of a lever handle 49 which engages a plunger 45 which in turn moves the actuating member. The surface portion 40 is a recess in the opening 30 into which the pin 29 moves under the loading of the spring 34. The latch member has a recess 22 which engages the end of the striker and when the door is moved to closed position a portion 38 of this recess engages the striker and rotates the latch member into engaging position with the striker, the pin 29 being forced out of the portion 40 so that it can move to latching position against the surface portion 33. In a modification in addition to the cable and the lever handle 49 the actuating member can be moved to unlatching position by a rigid link member which is attached to it near to the point of attachment of the cable. The actuating lever handle and the plunger 45 can be replaced by a push-button. It is also possible with a modified construction to provide the actuating member with a finger pad by means of which it can be operated directly. The actuating member can also be moved by a rotatable handle through an arm. The opening 30 instead of being closed can be open at the end opposite the portion 40 and in a further modification instead of the surface portions 30 and 40 being in an opening they can be on the periphery of the latch member. In a still further modification the actuating member is made slidable instead of being pivoted.