GB1349016A - Cylinder lock mechanisms - Google Patents

Abstract

1349016 Cylinder locks ANSALA OY 13 Oct 1971 47614/71 Heading E2A A cylinder lock mechanism comprises a housing 3 containing a cylinder 2 carrying a stack of tumblers 7 which in the locking condition engage one or more grooves in the housing to prevent rotation of the cylinder and which are retracted by rotating a key to enable the cylinder to be turned in an operative direction, a disc 4 being provided in the cylinder between the stack and an internal face of the cylinder, the disc having ratchet teeth which are in engagement with ratchet teeth 5 on the cylinder, the arrangement being such that when the key is rotated in the operative direction to retract the tumblers 7 the disc 4 is rotated relative to the cylinder, but when the key is rotated in the opposite direction, relative rotation of the discs and cylinder is prevented by the ratchet teeth, so preventing the projection of the tumblers from the cylinder whereupon the cylinder can be rotated in the direction opposite to the operative direction beyond its initial position in which the tumblers are engaged with the groove(s), the ratchet teeth being released by a spring 12 when the stack of tumblers is pulled by the key towards the front of the mechanism thus enabling the tumblers to turn relative to the cylinder as the key is pulled out of the mechanism; the stack of tumblers being restored to its normal position after being pulled by the key by a spring 10, provided at the opposite end of the housing and acting on the tumblers through a disc 11.