GB1030921A - Improvements in and relating to cylinder locks - Google Patents

Abstract

1,030,921. Locks. CHUBB & SONS LOCK & SAFE CO. Ltd. Feb. 20, 1964 [Feb. 21, 1963], No. 7018/63. Heading E2A. A lock comprises a cylindrical magazine 10 rotatably mounted in a casing 18, the magazine housing a stack of plates each adapted to be displaced radially of the magazine, between positions in which, respectively, the plate extremities do, and do not, project beyond the periphery of the magazine, under the action of a key insertable into a tunnel formed by apertures 16 in the stacked plates, wherein the stack comprises plates of two or more kinds which differ from one another as regards one or more of the location, size and shape of the key aperture and each plate is moved by the sliding action of its respective key section against the edge of its aperture as a result of turning the key. The hollow cylinder 10 has longitudinal slots 11 along opposite sides and terminates in a flat sided shank 12. Parallel edges 15 on the plates slide against the inner flat surfaces 14 of the cylinder 10, the respective dimensions of the surfaces 14, 15 being of such a size as to allow movement of the plates to one of the extreme positions, i.e. with the plates extending beyond the periphery of the magazine. The key has profiled sections each corresponding to the aperture of the plate with which it co-operates. The key profile is of such a shape that on rotating the key the plate moves radially of the magazine and on a reverse rotation the plate returns to its former position. In one embodiment the plates are of equal length but the aperture is in different positions, similar positions being given the same references, i.e. 1, 3, 5, 7 or 9, e.g. for a plate having a central aperture the numeral reference is 5-5. The aperture shape may be varied provided the corresponding key profile actuates the plate. The size of the aperture may also be varied. The housing 18 has slotted recesses 19 into which the plates are displaced by rotation of the key, preventing rotation of the magazine. On rotation of the key in the unlocking sense the plates are withdrawn into the magazine leaving it free to rotate in the housing 18 to effect movement of e.g. a bolt or door latch. To prevent or increase the difficulty of opening the lock by manipulation or other tampering the plates may be formed with notches 20 which in the locked position extend into recesses 19 and which are in alignment with ribs 21 so that if rotation of the plates is forced the notches move into engagement with the ribs 21 and prevent unlocking. The plates may also be cut away as shown at 20, 25 in Fig. 2c (not shown). The trailing edge of the plate may be formed with saw-teeth 23 (Fig. 2d, not shown) which engage with a lip 24 if an attempt is made to force the lock.