GB499483A - Improvements in combination locks - Google Patents

Abstract

499,483. Permutation locks. MARTINS, P. Sept. 21, 1938, No. 27519. [Class 44] In a permutation lock having a tumbler 12 resting against the edges of discs 4, whose notches 6 are alignable, by the rotation of a knob, to enable the tumbler to be introduced therein to release the bolt, the tumbler is in the form of a spring held against the discs by its own resiliency. When the kink 13 in the tumbler enters the notches 6 to allow the end 14 of the tumbler to spring out of the notch 11 in the bolt 9, the bolt is retracted by a spring 10. Before the tumbler can re-engage the bolt, the combination must be scattered and to enable this to be done by a partial turn of the knob, the tumbler 12 is movable longitudinally by virtue of the resiliency of the part 16. One disc 4 is fixed to the knob spindle 2 and, when the knob is turned, this disc moves the tumbler, which carries with it the other discs until the kink 13 slips out of the notches 6. Brake blocks 7, pressed against the edges of the discs by a spring 8, prevent accidental rotation of the tumblers. In a modification, the tumbler is not free to move longitudinally and when the knob is turned to displace the kink 13 from the notches 6, the loose discs are not scattered. In a further modification, one end of the tumbler is again fixed, but disc-scattering is effected by mounting a brake block on an extension of the end 14 of the tumbler instead of on a separate spring, so that when the kink 13 is disengaged from the notches 6 by turning the disc fixed to the knob spindle, the other discs are scattered by the consequent movement of the brake block.