Patent GB-1028081-A (GB)
Title: Combination lock
IPC: E05B37/16
Filed: 1963-02-22
Abstract: 1,028,081. Locks. VULCANA CORPORATION. Feb. 22, 1963 [June 4, 1962], No. 7159/63. Heading E2A. A combination lock comprises operatively connected members relatively movable with respect to each other, a plurality of tumblers 54 carried by one of said members 24 and engageable in channels 55 formed in another of said members 25, a first and second set of axially movable selectors 30 mounted in a third of said members 26 and the selectors of any given set being selectively engageable with the tumblers to hold the tumblers in securing engagement with the channels, the selectors having clearance seats 52, 53 into which the tumblers recede to be free from the channels and actuation means 27 carried by the member 24 for imparting axial movement singly to each of the selectors of the given set either to present a said clearance seat to its tumbler or to retain its tumbler in each channel. In the construction shown the member 25 is part of the casing of a padlock and the hasp 16 of the padlock is released by rotating the member 24 through a small angle relative to the member 25 since an extension 23 of a latch part 22 engages a slot 31 in the member 24 so that rotation of the member 24 moves the latch part 22 against the pressure of a spring 47 to enable a link part 21 to be moved by a pull on the hasp 16, the link part 21 and the latch part 22 forming a toggle. The actuation means 27 are push buttons which are carried by the member 24 and they are collectively biased forwardly by a rubber ring 43. The selectors 30 are carried by the member 26 in axial apertures and each has two grooves 50 and 51 and the two tumbler clearance seats 52 and 53. When any of the selectors is in its extreme left-hand position as shown in Fig. 5 and with a detent 46 engaging the groove 50, its clearance seat 53 is so positioned that it is aligned with its tumbler 54 and the tumbler is therefore out of engagement with its seat 55 in the member 25; when the selector is in its extreme right-hand position the tumbler is out of alignment with the clearance seat 53 and is held in engagement with its channel 55 so that the members 24 and 25 are locked together. The selector has an alternative position in which the detent 46 is in engagement with the groove 51 instead of the groove 50 and in this position the seat 52 is in alignment with the tumbler in the right-hand position of the selector and out of alignment in the left-hand position; since the member 24 can only be rotated to release the hasp when all the tumblers are aligned with the seats in their selectors the releasing combination can be varied by engaging either a groove 50 or a groove 51 of each selector with its detent this determining which of the push buttons 27 must be depressed to release the hasp. The detents 46 are carried by the member 26 and are urged outwardly by the rubber ring 43 into the grooves 50 or 51. To re-lock the hasp a knob 41 of the member 26 is pressed inwardly against the pressure of a spring and the pressure of the detent 46 against the selectors 30 which are in the right-hand position, moves all the selectors to the left and when the knob 26 is released all the selectors are moved by the pressure of the detent 46 to the right. To enable the selectors to be rotated to change the combination a rear closure plate of the padlock can be removed when the hasp is in its unlocked position. In the locked condition of the hasp the latch part 22 engages a projection 18 on the closure plate to prevent its removal. A second set of selectors is provided and the member 26 can be pulled forward against the resilience of the ring 43 to release a projection of the member 25 from a slot in the member 26; this enables the member 26 to be rotated and when it is released the projection becomes engaged with a second slot and the second set of selectors is then aligned with the detents 54; this enables two different people to unlock the padlock using separate combinations. If desired more than two sets of selectors can be provided. In a modification the projection and slots are omitted and the member 26 is then freely rotatable relative to the member 25 and to determine the correct position alignment means in the form of numbers are provided on the member 24 and the member 26 has a marker which is alignable with any of the numbers; with this modification the total number of combinations is equal to the number of selectors.