Patent GB-547793-A (GB)
Title: Improvements in and relating to latches
IPC: E05C1/16
Filed: 1940-09-17
Abstract: 547,793. Latches. YALE & TOWNE MANUFACTURING CO. Sept. 17, 1940, No. 14301. Convention date, Oct. 10, 1939. [Class 44] The invention relates to door latches of tubular type which can be mounted in bores provided in the door, provided with inside and outside bolt-retracting handles and with a locking device slidable parallel to the handle spindles and adapted to prevent operation by the outside handle. In a latch of the above type arrangement is made whereby retraction of the bolt by the inside handle or on closing the door releases the locking device if previously in locking position. As shown a bolt 12 is slidably mounted in a tubular housing 10 which houses a spring, not shown, for shooting the bolt. The tail 14 of the bolt projects from the inner end of the housing. A cylindrical housing 20 has end-plates 18, 19 secured in place by bent-over lugs 21 which also secure plates 37, 38 apertured to guide the slidable locking member 36 shown in locking position. Inner end, plate 18, also has lugs, not shown, which overlie the inner face of the door and are apertured to receive securing screws. The side of the cylinder towards the bolt is gapped and a bolt-retracting member 17 is slidably guided by the edges of the gap and by the shouldered inturned ends of lugs 18a, 19a on the end plates 18, 19. Member 17 has parallel side limbs connected at one end by a cross-bar 55 from which projects a tongue 16 engaged in an aperture 15 in the bolt tail. The other ends of the side members are secured to a plate 24 apertured to receive a fixed guide pin 22 riveted to the cylinder wall and surrounded by a spring 23 which bears against plate 24 to urge member 17 towards locking position. The short inside and outside handle spindles are of conventional screwed type on which the handles can be adjusted and secured by screws. Only inside handle 42 is shown and this is rotatable in a bearing provided in a rose-plate 45 which also has an aperture through which a press-button 40 on the inner end of locking member 36 normally projects under action of a spring 39. The outside handle has a rose-plate, not shown, covering the outer end of member 36. To the inner end of inside spindle 26 are riveted a thimble 30 and plate 28, disposed on opposite sides of end-plate 18, as shown, to prevent axial movement of the spindle, the thimble being rotatably engaged in an aperture in the endplate. Outside spindle 32 carries a similar plate 33 and thimble. Plates 28, 33 have arcuate upstanding flanges 29, 34 the ends of which bear against plate 24 and serve to retract the bolt when either of the handles is rotated. Member 36 is bent to provide an offset projection 35 which normally lies in front of a forwardly bent lug 41 on plate 24 with member 36 in released position. As button 40 is pressed into the locking position shown, the lug 41 is cammed to the left by the projection and then snaps back under action of spring 23 into engagement behind the projection to hold member 36 in locking position with the projection 35 received in a gap in flange 34 to hold the outside handle against operation. When the lug 41 moves to the left on retraction of the bolt either by operation of the inside handle or on closing the door, projection 35 is released and spring 39 restores member 36 to its release position with button 40 projecting from rose-plate 45.