GB816147A - Improvements relating to door latches - Google Patents

Abstract

816,147. Catch fastenings. GENERAL ELECTRIC CO. Dec 6, 1955 [Dec. 6, 1954], No. 34990/55. Class 44 A door latch adapted to co-operate with a strike 8 for latching, a door 2 in a closed position comprises a latch bolt 11 pivoted on a supporting structure 9 and movable between a latching position and a retracted position, the bolt having a latching arm 14 adapted to engage the strike in the latching position and a control arm 15 for moving the bolt between said positions and over-centre mechanism effective yieldably to hold the bolt in the latching and retracted positions, said medhanism including a spring 20 and a single link 19 connected between the bolt and the supporting structure, actuating means adapted to engage the control arm for moving the bolt from the latching position to the retracted position to permit opening of the door and the strike directly engaging the control arm upon the closing of the door to snap the bolt from the retracted position back to the latching position. As shown the bolt is attached to the supporting structure 9 by means of a pivot pin 16 and has a roller 17 for engaging the strike. The link 19 is pivotally attached to the supporting structure 9 by means of a pin 21 and engages the latch bolt by means of a pin 23 engaging a slot 22 in the link 19. The spring 20 surrounds the link 19 and it is mounted between washers 24, 25 which engage the pins 21, 23. Thus the pressure of the spring on the pin 23 tends to hold the bolt either in its latching or in its retracted position. The actuating means comprises a handle 27 which is pivoted on a flange 28 of the outer wall 3 of the door by means of a pin 29 and one end of which bears against a push rod 30 which is slidably mounted in a sleeve 31. The push rod engages a roller 33 which is mounted in curved slots 34 in opposite walls of the supporting structure 9 and the roller in turn engages the control arm 15 of the latch bolt. Thus when the handle is pulled the push rod moves the latch bolt through the roller over its dead centre position to its retracted position. The latch bolt can also be moved from its latching to its reof the door. In a modification the link 19 tracted position by pressure on the inside is pivotally connected to the latch bolt and has a pin and slot connection with the supporting structure 9. The spring extends between the pin of the pin and slot connection with the supporting structure and the pivot pin of the latch bolt on the supporting structure.