GB953052A - Door fastenings - Google Patents

Abstract

953,052. Latches. WILMOT-BREEDEN Ltd. July 1, 1960 [July 3, 1959; Jan. 5, 1960], Nos. 22884/59 and 317/60. Heading E2A. A door fastening of the link latch type comprises a spring loaded toggle linkage which is extended when the latch piece is in a latched position, release means for collapsing the toggle linkage to release the fastening, and a further toggle linkage which is extended when the latch piece is in the unlatched position and must be collapsed before latching can take place, the two toggle linkages utilizing a common link. A fastening, Fig. 1, comprises a latch piece 6 pivoted at 24 to a back plate 2, a generally triangular shaped lever 13 pivoted at 14, and a link 19, the lever 13 and link 19 forming a toggle linkage which is collapsed from the position shown to allow latching to take place. In addition, a cover plate 25 and a link 15 operatively connecting the lever 13 to the latch piece 6 are provided. Collapse of the linkage is caused by a keeper 1 which, when it contacts a face 29 of a lever 28 pivoted at 24 rotates the lever 28 to push the pivot point 18 over centre. In the latched position Fig. 5, a second toggle linkage formed by the lever 13 and a link 22 prevents rotation of the latch piece to an unlatched position until the linkage is collapsed by means of a handle actuated rod 27 which is shifted against a spring loading. A central handle operates two door fastenings simultaneously, the handle when turned clockwise, rotating a cam 43, Fig. 7, to shift operating links 35 and 37, the links having pins 52 situated in slots 44 in the cam. The links 35 and 37 are thus moved inwardly against springs 53. A lever type handle may be used in which cam portions integral with the handle bear against levers to shift the operating links.