Patent GB-616370-A (GB)
Title: Latching mechanism
IPC: E05B65/32
Filed: 1946-05-31
Abstract: 616,370. Latches. ENDTER, W. A. May 31, 1946, No. 16628. Convention date, June 1, 1945. [Class 44] Latch mechanism, particularly for vehicle doors of the kind described in Specification 606,340 comprises a swinging bolt engaging a keeper, and eccentric means exerting opposing thrusts against the bolt and the member carrying the bolt, e.g. the door, to progressively move the latter towards the door post. Preferably, the mechanism embodies an eccentric centre or shaft upon which the bolt is rotatably mounted and also for bodily movement within the range of the shaft eccentricity, and the eccentric shaft is spring-urged to thrust the bolt against the keeper. Dogging or holding means are also mounted on the eccentric shaft to hold the latter against retrograde movement The latching mechanism is contained in a casing 10, Figs. 1 and 2, mounted, e.g. on the door, while the keeper parts 13, 14 are mounted on the door pillar, the keeper 13 being engaged by the bolt, and the bolt housing 15 being pressed against the projecting lug 14 by the bolt thrust against the keeper 13. The bolt 27, holding dog 40, and the control levers are mounted on a shaft 19 which is rotatably and eccentrically mounted on a pin 18 supported by the housing 15 and a plate 16. The angular position of the shaft 19 on the pin 18 is controlled by a lever 21 integral with a sleeve 22 having an internal lug engaging in a groove in the shaft. Lever 21 is offset, and a spring 26 acting on it tends to rotate shaft 19 anticlockwise as shown in Fig. 1. The bolt 27 is rotatably carried on the shaft outside the sleeve 22 and within the housing 15, and has a downwardly-extending, keeper-engaging face 31. The bolt is biassed to rotate, in anti-clockwise direction in Fig. 1, by a spring 38 which acts on a lever arm 32 integral with a sleeve 33 mounted to rotate on shaft 19 and interlocked with the bolt by an arm 34 which enters a recess in the bolt and extends outside the other parts on shaft 19 between sleeve 33 and bolt 27. The holding or dogging lever 40 is carried by a sleeve 36 mounted on shaft 19 between sleeves 22 and 33, and has a curved end surface 41 engaging against an arcuate abutment 42 which has its centre of curvature at the centre of the pin 18. Lever 40 is urged to rotate about shaft 19 by means of a coil spring 43 round the shaft. A projection 46 on sleeve 36 lies under and is engageable by a lug 47 on bolt-control lever 32. Projection 46 also engages with the angular part of the offset control lever 21. The mechanism for actuating the latch may, as shown, comprise a verticallysliding link 48, biassed upwardly by a spring 53. An arm 54 on this link overlies and is engageable with lug 47 on the bolt-control lever arm 32. The outside handle is secured to a spindle 56 carrying a follower 57 which depresses link 48 to unlatch the bolt. As the bolt is rotated, holding dog 40 and eccentric shaft 19 are rotated in the same direction by contact of lug 47 with projection 46 on the holding dog sleeve and engagement of projection 46 with lever arm 21. The inside operator, controlled by a link 58, comprises a lever 59 pivoted on pin 50 and having an arm 60, the offset end of which is engageable with arm 54. Locking may be effected by blocking link 48 against downward movement by means of a segment 63 fixed to a key controlled spindle 62. Action of the parts in closing is shown in Figs. 3, 4, 5. Bolt 27 first abuts edge 65 of keeper 13, and is cammed upwardly until it drops into the safety notch 66. By their interengagernent through lugs 47 and 46 and lever 21, the holding dog and the control sleeve and therefore the eccentric shaft, rotate with the bolt, though in this position, end 41 of dog 40 is not in contact with abutment surface 42. Upon further closing movement, the bolt rides over the high point 68 of the keeper, and snaps down into the position of Fig. 4, at which point surface 39 of the bolt control arm 32 abuts the flange 12 of the casing. Disengagement of lugs 46 and 47 frees holding-dog 40 to turn on shaft 19, so that it moves into contact with abutment surface 42, and shaft 19 is also freed to rotate under pressure of spring 26, so that opposing thrusts are exerted, one through the bolt against the keeper, and the other through pin 18 on the door to force the latter in closing direction. This tends to advance the bolt into the keeper to the fully engaged position of Fig. 5, while the dog 40 is advanced along abutment 42 by spring 43 to hold shaft 19 against retrograde movement.