GB1375752A - - Google Patents

Abstract

1375752 Locking mechanisms A K NIILOLA 7 Jan 1972 [8 Jan 1971] 735/72 Heading E2A A combination lock mechanism of the type which is put in unlocking condition by turning external rings, provided with symbols, into their respective unlocking positions comprises a body sleeve 2 on which the rings 1 are rotatably mounted and in which is arranged an actuating shaft 7, the body sleeve having a slot in which is slidable a locking bar 6 which prevents relative rotation between the actuating shaft and the body sleeve except when the locking bar is in register with a notch 5a in each ring of sufficient depth to allow outward sliding of the locking bar which thereby releases the actuating shaft for rotation within the sleeve. As shown in Figs. 1 and 4, the actuating shaft 7 is provided with a groove 9 with inclined sides so that rotation of the shaft urges the locking bar into the notches 5a when all of the rings are in their unlocking positions. In an alternative construction, Fig. 7, the actuating shaft has a plurality of projections 14 each of which has a sloping edge and the inner edge of the locking bar has depressions 15 each of which has a corresponding sloping edge so that axial displacement of the shaft urges the locking bar into the notches. The rings also have false notches which are too shallow to permit unlocking and, for each ring, the false notches and the unlocking notch cooperate with a spring-loaded ball 10 to locate the ring in positions corresponding to the symbols. The locking bar is biassed to the locking position by springs 8. To enable the unlocking combination to be changed, each of the rings is formed in two parts which can be disposed in various angular relationships to change the unlocking combination. In a modification, the combination lock mechanism includes a pin tumbler, cylinder lock mechanism, the actuating shaft containing the key slot and the radial bores for the tumblers being disposed in the actuating shaft and the sleeve as shown in Fig. 10.