Patent GB-1097649-A (GB)
Title: Combination locking mechanism
IPC: E05B37/02
Filed: 1966-03-08
Abstract: 1,097,649. Locking switches. C. COLLAROJuly 19, 1966 [March 8, 1966], No. 10160/66 Heading H2B. [Also in Division E2] A combination locking mechanism comprises a housing 1 containing an axially movable shaft 2 which extends through a number of rotatable locking rings 3, the shaft having a number of projections forming a key which in conjunction with the rings prevents movement of the shaft from a locked to an unlocked position except when all the rings are rotated into pre-determined positions which are indicated by cyphers on their peripheries forming the correct combination which is visible through the housing, each ring being formed from inner and outer annular parts 13 and 16 which can engage with each other in different relative angular positions to vary the combination and a resetting mechanism being provided which is operable by a member 35 extending outside the housing, movement of the member causing the inner parts to move axially relative to the outer parts to disengage them and allow the outer parts to be rotated relatively to the inner parts and subsequent movement of the member back to its initial position causing the inner parts to move back into re-engagement with the outer parts so that the combination is changed. The inner part of each locking ring is in the form of a bush each of which has a bore with two sections of different diameter; the smaller of the two sections is of the same length as that of the projections on the shaft 2 and has a diameter which is just larger than that of the shaft 2; this section has a groove 14 along its length to receive the corresponding projection. The larger of the two sections is the same length as the gaps between the projections and has a diameter which is greater than the width of the shaft 2 and the projection together. Each inner part has a decagonal flange 15 and the outer part has a bore which opens into a ten sided recess 17 which is engageable with the flange 15 in any one of ten positions; each of the outer parts has a flange 18 which is divided by grooves 19 into ten sections which are numbered from 0 to 9 the flanges extending slightly through slots 20 in the top of the housing. A leaf spring 21 is associated with each ring and engages any of the grooves 19 to prevent unwanted movement; guide stops 21a for each ring stop any axial movement of the outer parts. The shaft 2 is moved between locked and unlocked positions by a handle 4 which is rigidly connected to a link 5 which is connected to the shaft 2 via a link 6; the shaft moves against the bias of a spring 26 which tends to return it to the locked position. The re-setting mechanism has two plates 29, 30 which are joined by a cross bar 31 the plates being pivotally connected to a bearing 10 which supports the shaft 2; the plates carry rollers 33 and 34 which bear on the end face of the nearest inner part 13 and the plate 29 extends upwards through a slot in the top of the housing to form the re-setting member 35. The combination is re-set by first moving the locking rings to the unlocking combination and then moving the shaft to the unlocked position by turning the handle 4; the re-setting member 35 is then pushed towards the locking rings causing the plates 29 and 30 to pivot and the rollers to engage the face of the adjacent inner part so that it is pushed along the shaft 2 until its flange 15 moves out of engagement with the recess 17 in the outer part; since the inner parts are all in contact the remaining inner parts are similarly moved so that their flanges move out of engagement with the recesses 17. The outer parts are then rotated to change the combination and when the member 35 is released the inner and outer parts are re-engaged by the action of a spring 38. As shown the shaft 2 actuates a switch 28 by depressing its plunger 7 when in the unlocked position.