Patent GB-651678-A (GB)
Title: Improvements in lock mechanisms
IPC: E05B65/00
Filed: 1948-09-15
Abstract: 651,678. Locks. NILSSON, F. Sept. 15, 1948, No. 24252. Convention date, Sept. 29, 1947. [Class 44] A lock of the kind operated by a key in the form of a thin perforated strip which enters a guide having axially displaceable locking pins extending transversely of the guide and adapted to enter the perforations in the key, the pins 25, 26, Figs. 1, 2a, the pins are mounted in and adapted to couple together two members 11, 16, which are mounted for displacement relative to each other and to the housing 10, one member 16 being displaceable to a limited extent only, and the other member 11 being provided with an abutment entering the key guide. On insertion the key engages this abutment and rotates both members to the limiting position of member 16, at the same time permitting movement of the pins to uncouple the two members. Further movement of the key moves member 11 only, and operates the bolt or catch connected thereto. In the form shown in Figs. 1, 2a, 2c, the members 11, 16 are mounted to rotate in the housing. The member 11 is formed with an annular recess 12, providing a hub 13 and a rim 14, and the member 16 is housed in a central bore 15 and provided with a flange 17 having a circular slot 18 in which engages a pin on the housing so that member 16 is rotatable only between two limiting positions. A spring 20 normally holds member 16 in the position of Fig. 2a. A pin 21, Fig. 1, on member 11 extends through an annular slot in the housing and is adapted to be coupled to the catch of a locking bolt, for example. A leaf-spring 24 housed in a recess in the member 16 and secured to the hub 13 holds the two members in frictional engagement. Pins 25, 26 mounted in the member 11 with their inner ends entering bores in the member 16, are biassed by springs 29 in outward direction but are normally held in locking position by contact of their outer ends with a guide surface 31 formed by a flange 32 on the cover of the housing. Flange 32 is interrupted between points 34 and 35, so that a key guide channel 36 is formed. A further narrow groove 38 is formed in the wall of the housing, the bottom of this groove being provided with locking teeth 39. The key 41 is inserted through an aperture 40, and makes contact with an abutment 42 on member 11, rotating the latter, together with member 16. Meanwhile, holes in the key corresponding to the positions of the pins allow the latter to move outwardly to the position of Fig. 2c, so that member 16 is uncoupled from member 11, which is at the limit of its travel. Further insertion of the key rotates member 11 to cause operation of the lock mechanism by means of the pin 21. A key with wrongly placed holes will not allow complete movement of member 11 since the pins will not be moved to uncouple the two members. The outer ends of the pins are reduced in diameter to enter the holes in the key, so that the pin movement is limited, and if a false key with larger holes is used, the pins are projected until they engage between the teeth 39 in the housing, thus preventing further movement. In a modified form a sliding member 51, Figs.7a, 7c is displaced against the action of a spring 52 by means of a second sliding member 53 which is moved by means of the key 56. The two members are normally coupled together by means of a two-part locking pin 58, 63, which, when the member 51 reaches the position of Fig. 7c is depressed by the action of a leafspring 64 so as to uncouple the two members and allow member 53 to move independently to the position shown and actuate the lock. On return to the normal position, the pin 58 is lifted by means of a plate 66, a hole in which co-operates with the inclined side of a notch in the pin when the edge of plate 66 abuts against the wall of the casing.