GB414292A - Improvements in or relating to combination locks - Google Patents

Abstract

414,292. Permutation locks. PRINA, G., 10, Via Pollenzo, Turin, Italy. Jan. 4, 1934, No. 362. Convention date, Jan. 4, 1933. [Class 44.] A sliding bolt 1 is locked by spring-pressed pivoted tumblers 10 which engage with a notch 1<1> in the bolt and can be disengaged from the outside of the door by cams 20 carried by permutation discs 18 and co-operating with arms 10<a> of the tumblers ; from the inside of the door, the tumblers can be disengaged by depressing a spring plunger 11 which acts directly on the tumblers and means such as a bayonet slot may be provided to hold the plunger depressed and the locking mechanism inoperative. The bolt, slidable in straps 2 on a plate P, is operated from inside by a knob 8 and from outside by a follower arm formed in two parts 4, 5 pivoted together at 22, the part 4 being secured on a handle spindle 6 and the free end of the part 5 engaging with a socket 9 on the bolt ; the parts 4, 5 are normally held in alignment by a spring 23 and relative pivotal movement is limited by a pin 4<1> and slot 5<1>. When the spindle 6 is turned to withdraw the bolt, the upper end of the part 4 closes a signalling circuit by co-operation with a switch 24 and the connection of the parts 4 and 5 permits sufficient rotation of the spindle to close the circuit also when the bolt is locked. The permutation discs 18 are set by a sleeve member 14 which has an operating knob 15, is slidable and rotatable on the spindle 6, and carries a tooth 16 to engage with one of a number of notches 18<1> in each disc whereby the discs can be set in succession. Each cam 20 is adjustably attached to its disc 18 by a set screw engaging with one of a number of holes 20<1> in the disc corresponding to the notches 18<1>. Each disc 18 is provided with recesses 18<11> with which a spring-pressed pawl 19 engages, and in setting, the disc is turned clockwise to bring it to its zero position in which it is stopped by a tooth 18<111> engaging with a shoulder 19<1> on the pawl and then anti-clockwise for a predetermined number of clicks produced by the pawl snapping into the recesses 18<11>. A single spring 21 is provided for the tumblers and the pawls.