Patent GB-432676-A (GB)
Title: Combination lock
IPC: E05B37/04
Filed: 1934-11-19
Abstract: 432,676. Permutation locks. WOLF, J., 9, Bayer-strasse, Munich, Germany. Nov. 19, 1934, No. 33305. Convention date, Nov. 21, 1933. [Class 44] A keyless combination lock has a number of tumblers, normally engaging notches in the latch bolt, which are adapted to be successively disengaged by axial movements of a spindle carrying a control disc with teeth in particular positions, the spindle being turned to different positions before each axial movement in order to release the tumblers in a definite order, and each tumbler as it is released is retained by a bar which is tripped to cause the tumblers to re-engage the bolt whenever the spindle is axially moved with the control disc in an incorrect position. A bolt 4 pressed outwards by a spring 8 is guided by a staple 5, and a pin 7, and has rack teeth 11 adapted to be engaged by a pinion 12 on a spindle 10 for withdrawing the bolt. Three tumblers 13, 14, 15 are pivoted on a rod 16, the tumbler 15 engaging the end of the bolt 4, when shot, and the other two tumblers engaging notches 17, 18 in the bolt, and all three tumblers are urged into their locking position by springs 19. Associated with the tumblers is a member 25 pivoted at 24 and carrying a bar 22 which is urged by springs 23 against steps 42 on the tumblers. These steps are of different depths from front to rear on the three tumblers so that provided the tumblers are raised in their correct order, beginning with the one having the rearmost step, the bar 22 can successively engage recesses 26 in the tumblers and hold them out of engagement with the bolt. The tumblers are moved by teeth 43a, 43<b> on a control disc 20 detachably secured on the end of a spindle 10 which is normally urged to the outside of the door by a spring. The spindle slides through a dial 28 having numbers or other characters and by turning the spindle until the code number comes opposite a pointer 29 one of the teeth 43<a>, 43b is brought opposite to the appropriate tumbler and an axial movement of the spindle 10 raises the tumbler into engagement with the bar 22. When all three tumblers have been raised the bolt can be withdrawn by the pinion 12. The disc 20 has a series of holes 33 any one of which can be brought into engagement with a pin 34 on the spindle to change the code number by undoing a nut 40, or the disc may be completely removed and replaced by another one having teeth in different relative positions. The member 25 carries two pivoted members 31 urged by springs 32 into the position shown. When the disc 20 is correctly set gaps 44 therein come opposite the members 31 which are consequently not moved when the spindle 10 is depressed. Should an incorrect setting be given, however, the disc hits one or other of the members 31 and the member 25 carrying the bar 22 is moved to let fall any tumbler that has already been raised. The members 31 tilt against the action of their springs 32 as the spindle 10 returns to its normal position. The tumblers may be held out of action when required by moving a slider 30 on the inside of the door and can be re-engaged by moving a knob 27 connected to the member 25. A handle 41 enables the bolt to be withdrawn from the inside of the door. The disc 20 may co-operate with a switch 37, 38 to illuminate a lamp 35 behind the dial 28.