Patent GB-794079-A (GB)
Title: Combination lock
Inventor: HIRN CHARLES MICHAEL
IPC: E05B37/08
Filed: 1956-04-18
Abstract: 794,079. Permutation locks. MOSLER LOCK CO. April 18, 1956, No. 11839/56. Class 44 A combination lock comprises a series of notched tumbler discs 270, Fig. 2, and a notched driver disc 18 operable from the exterior of the lock for setting-up the tumbler discs with the notches in predetermined positions, a manually operable slide plate 26 operatively connected with a bolting means 27. Fig. 1, and shiftable from a bolting position to an unlocking position and a fence means 29 operatively connected with the slide plate 26 and movable towards and away from the driver disc 18 and the tumbler discs 270, wherein the fence means 29 is biased by spring means 35 away from the tumbler discs 270 and driver disc 18. which latter is adapted to be rendered inoperable for modifying the settings of the tumbler discs, when the slide plate 26 is out of full bolting position (shown in Fig. 1). The lock casing 11 is mounted on a tube 13 passing through a door 10 and the driver disc 18 is adjustably secured on a stem 15 having an operating knob 16 and slidable within the tube 13 between two positions determined by grooves 20 on the stem engageable selectively with the down-turned end 25 of a leaf spring 22 carried in a groove 23 in the tube 13. When the driver disc 18 is in the axial position shown in Fig. 2, a driver lug 19 thereon can operatively engage the adjacent tumbler disc 270 to drive the discs 270 in known manner. The fence 29 mounted on a pivot pin 30 has a lateral lug 31 and finger 33, Fig. 5, the lug 31 engaging in a cam slot 28 in the slide plate 26. The finger 33 is disposed to the left of the disc 18 in Fig. 2, and in the path of reciprocation of the disc 18 and the disc 18 can only be moved axially to the position shown in Fig. 4, when the notch 34 therein is aligned with the finger 33. In this position the driver lug 19 cannot operate the discs 270. The bolt 27, Fig. 1, is held in the shot position by means of the spring 35 and lug 31 and to open the lock the discs 270 must first be set so that the notches therein are in register with the edge 32 of the fence 29. Thereafter the notch 34 is registered with the finger 33 and the disc 18 is then moved axially to the position shown in Fig. 4. On turning the knob 16 the notch 34 engages the finger to pivot the fence 29 and the edge 32 enters the notches in the discs 270 to allow the slide 26 to be retracted by the lug 31. If an attempt is made to open the lock without using the correct combination the disc 18 cannot be moved axially until the notch 34 and finger 33 are aligned. When however the finger and notch are aligned and the disc 18 is moved axially, the operative connection between the disc 18 and discs 270 is broken and the notches in the latter cannot be aligned. Consequently on turning the disc 18 the fence edge 32 engages the periphery of at least one disc 270. As soon as the disc 18 is released to move axially the fence is urged, by the spring 35, out of contact with the discs 18 and 270 so that it is then impossible to operate the discs 270 by sound or feeling. In the embodiment of Fig. 6, a door 36 is provided at its edges with sliding bolts (not shown) connected to the outer ends of rods 37 pivoted at their inner ends to an operating plate 38 mounted on a stud 67 rotatable by an exterior lockable handle (not shown). The plate 38 is retained in its locking position by a bolt 49 on a slide plate 48. The bolt 49 is shot by a spring-urged fence 54 engaging a stud 65 on the slide 48. The edge 86 of fence 54 co-operates with notches in tumbler discs (not shown) operable from a dial knob by a driver disc 53 having a notch 52 co-operable with a lug 51 on the slide 48. If the exterior handle is operated to turn the plate 38 when the tumbler discs are not correctly set, the lug 51 engages partly in the notch 52 or with one of a number of notches 66 in the periphery of the disc 53, according to the position of the latter and consequently the disc cam no longer be rotated to operate the tumbler discs. As soon as the exterior handle is released to release the lug 51 from the driver disc 53 the fence 54 is urged away from the tumbler discs. When the combination is correctly set the tumbler notches are aligned in a radial plane at an angle to a radial plane passing through the axis of the disc 53 and the centre of the lug 51. A latch 69, retained inoperative by a pin 70 on the cover of the lock casing 46, has a lug 71 which enters an edge notch 72 on the slide plate 48 when the lock cover is displaced by violence to the lock. In a further embodiment described with reference to Fig. 9 (not shown), an operating plate for plural sliding bolts is locked by a bolt on a slide plate provided with an integral fence to engage notches in tumbler discs and a driver disc when all are aligned, the slide plate being shot by a spring. The operating plate in this case co-operates with a cam on a block pivoted to the lock casing adjacent the lock bolt and urged outwardly of the casing by the fence.