Patent GB-436400-A (GB)
Title: Improvements in or relating to permutation locks
IPC: E05B19/18
Filed: 1934-05-30
Abstract: 436,400. Locks. DEUTSCH, L. E., 5946, Hohman Avenue, Hammond, Indiana, U.S.A. May 30, 1934, No. 16144. [Class 44] A change-key lock has permutation mechanism comprising actuator bars which can be selectively engaged with tumblers to provide the desired setting. In the form shown in Figs. 1, 2, a revolving barrel 17 has removable end and body segments, missing from Fig. 2, and houses slidable actuator bars 23 and tumblers 22 guided by corresponding steps in the barrel interior, itself being rotatably mounted in a case 10 having a removable segment 11. A segmental rib 53 on the barrel engages a groove in segment 11 when in the locked position, so that the segment can only be removed to gain access to the mechanism to change the setting after unlocking the barrel and rotating it to disengage rib and groove. Each actuator bar has an offset portion 24 with a projection 25 which can be engaged in either of two recesses in the corresponding tumbler. Each tumbler has reduced bolt-like extensions 27 at each end, capable of entering apertures 28 at the front and rear ends of the casing, to lock the barrel. The actuator bars are held in the normal position by springs 29, and selected members are set so that their extensions 27 engage apertures at the front end, the others having their extensions 27 clear of the apertures at both ends. The actuator bars are selectively moved inwards against the action of the springs by insertion of a suitable key in the key-hole 19. A correct key releases the selected tumblers, but an incorrect one may fail to release these tumblers from the front apertures, or may operate one or more of the other tumblers causing their extensions to enter apertures at the rear of the casing, so retaining the barrel locked. In the modification shown in Figs. 11, 12, the tumblers are rotatable, of generally cylindrical form, and housed, in diametrically disposed pairs, partly in the barrel 14<1> and partly in the case 10<1>. Each tumbler is in two parts 26<1>, 27<1>, the surface of separation between the parts conforming, in the unlocked position, with the cylindrical surfaces of the case and barrel, allowing the latter to be rotated. Coiled springs 36<1> bias the tumblers to the release position. The part 26<1> of each tumbler has an extension 30<1> to co-operate with the actuator bars, and the part 27<1> has a dove-tail sectioned rib 28<1> engaging an undercut groove in the case, to retain the part 27<1> in the case when the barrel is removed to alter the setting. The barrel may be removed after unlocking, by rotation to bring a projection thereon, not shown, and normally engaging an annular groove 24<1> in the case, into register with a longitudinal groove, not shown, leading to the end of the case. The actuator bars 32<1> have projections 31<1> so disposed that selected bars, as shown, engage the extensions 30<1> of the left-hand pair of tumblers, to hold these in locking position, the others resting near the extensions of the right-hand pair of tumblers, which are normally in released position. Insertion of the key in aperture 18<1> moves selected actuator bars to the right against the action of coiled springs 34<1> encircling guide-pins 33<1>, allowing the lefthand tumblers to be rotated to release position by their springs 36<1>. An incorrect key also operates one or more bars co-operating with the right-hand tumblers, rocking one or both to locking position. As described, the barrel has an extension 15<1> engaging a rotatably mounted end piece with an arm 13<1> which serves to operate a bolt or other fastening. Fig. 6 shows a key suitable for use with the above locks, and comprising bits 36, 37 corresponding in number and disposition with the actuator bars of the lock, and housed in a casing having removable side plates to give access to the interior. Selected members 36, 37 have projections 41 engaged in slots 43 of a slidable member 39 which terminates in a head 52 with anti-friction roller 45, and is held retracted by a spring 48. Other members 36, 37 have projections 42 engaging slots 44 in a fixed frame, to hold them stationary. A plunger 49 has a wedge portion 51 which, when depressed, moves member 39 against the action of spring 48, to project selected members 36, 37 from the end of a key, so that when the key is inserted, the corresponding actuator bars are operated.