Patent GB-478861-A (GB)
Title: Improvements in or relating to combination locks
IPC: E05B37/00
Filed: 1937-02-12
Abstract: 478,861. Permut ation locks. FUCHS L. Feb. 12, 1937, Nc 4247. [Class 44] In a combination look having a plurality of locking mem bers, the setting mem ber 6 is provided wit] operating holes 16 equally spaced in an endless row and is so arranged that it is movable with respec to a fixed scale but does not return to its initial position, auto matic means for the progressive coupling of the setting member with the locking members being provided. The latch 5, Fig. 4, is withdrawn by a handle 9 acting on spindle 13, the follower 93 co-operating with the projection 91. The latch 5 cannot be withdrawn until the projection 84 on lever 82 is removed from the path of the stop 88 which is only possible when the bolt 4 is fully withdrawn and projection 84 rests in the deep notch 87. The bolt 4 is withdrawn by a handle 8 attached to a spindle 12 through the rack 100 and pinion 99 and this is not possible until the projection 72 of lever 71 is lifted clear of the notches 73 or 75. To unlock the door from the locked position shown in Fig. 4, the spindle 12 is first turned counterclockwise until the follower 98 is clear of the end of the lever 79, which allows spring 70 acting through lever 71 to raise projection 72 slightly, but the pinion 58 lying in the path of catch 68 prevents complete clearance unless the recesses 67, formed behind one of the tooth gaps, are in line. These recesses are set through member 6 by dialling the first number of the combination, the stop lever 7 being rocked in a clockwise direction. In consequence the plate 44 rigidly attached to spindle 11, is turned and carries with it the freely rotatable member 38 by means of projections 39 and 45. The pawl 48 attached to plate 44 also engages the first cam 33 on the toothed segment 31. At the same time the pinion 19, Fig. 5, the first wheel 52, and corresponding pinion 58 are rotated so that the first recess 67 lies in the path of catch 68. When the lever 7 is released after dialling, the spring 41 brings back the plate ring 38, plate 44 and catch 7 to the starting position determined by stop 42. At the same time the toothed arc 31 is carried round by pawl 48 until the latter is separated by the fixed arc 49 from the first cam 33. The toothed arc 31 rotates the pinion 26 which acting through screw shaft 25 moves sleeve 24 and connects pinion 19 to the second wheel 52. The recess 67 on the second pinion 58 is similarly set and the procedure is repeated until finally all the recesses are in line and latch 4 may then be withdrawn. After the last dialling operation the pinion is displaced into the recess 27 of casing 1. The latch may be secured in any of its limiting positions by turning the stop 7 in an anticlockwise direction. The plate 44 participates in this movement and the carrier 46 attached to it brings the wheels 52 back as far as stop 55, the pinions 58 having been previously released by the projection 72 engaging one of the notches 73, 75. The projection 50 detaches pawl 30 from the pinion 26, so that the arc 31 under the action of spring 35 returns it to its starting position. The combination may be changed by setting the locking members to the old combination and withdrawing latch 4 to allow the head 72 of lever 71 to engage the shallow notch 74. This allows the tongue 64 on lever 62 to clear the tongue 77, and the lever 62 with pin 59 and pinions 58 may be drawn clear of wheels 52 by means of cam 66 whilst the catch 68 remains engaged with the recesses 67. The wheels 52 are then set by dial 6 to the desired combination and the lever 62 returned to its normal position shown in Fig. 5. As there is no return movement of the dial 6 after setting, it is practically impossible to ascertain the figures of the combination by wear of the dial, and the use of a prime number for the number of holes 16 adds greatly to the security. The dial can be designed as a disc, cylinder or band loop.