GB886681A - Improvements in or relating to catches for doors - Google Patents

Abstract

886,681. Catches. BORSANI, G. May 6, 1958, No. 14497/58. Class 44. A catch for holding a door 2 in a closed position comprises a casing 1, adapted to be fixed to the door 2, in which is pivotally mounted at 3 a latch 4 biased by a spring 6 to a position in which it projects from the casing I and a plate 14 for retaining the latch 4 in a retracted position in engagement with a striker 8, the plate 14 being adapted to be disengaged from the latch 4 by a small displacement of the latch 4 further towards the casing 1 from the retracted position, the latch 4 then moving -under the loading of the spring 6 into the projected position. The plate 14 is mounted on pins 10 and 11 carried by the casing 1, the pins 10 and 11 passing through slots 12 and 13, respectively in the plate 14; the slot 13 is of inverted L-shape with the pin 11 engaging the short leg of the L. A spring 16 is disposed between a projection 17 on the plate 14 and an arm 18 on the latch 4, and it is tensioned by the latch 4 moving to the retracted position by the latter engaging the striker 8 when the door is closed, during which movement a cam 19 on the latch 4 displaces the plate 14 laterally to a position 14<SP>1</SP>, Fig. 2, against the action of the spring 16, until the cam 19 passes beyond the plate 14, Fig. 3b. Upon the force closing the door ceasing, the latch 4 moves slightly in the opposite direction under the action of the spring 16, until the cam 19 is engaged by a hook 15 on the plate 14 whereupon the plate 14 pivots to disengage the pin 11 from the short leg of the slot 13, Fig. 3c. To open the door 2 pressure is exerted on it in the closing direction so that the cam 19 is disengaged from the hook 15 whereupon the plate 14 is moved upwards by the spring 16, releasing the latch 4 which, due to the action of the spring 6, moves to the projected position thus opening the door 2. This latter movement of the latch 4 causes the arm 18 thereon to move the plate 14 downwards and then to pivot it on the pin 10 so as to re-engage the pin 11 in the short leg of the slot 13.