Safety mechanism to prevent forcing of locks - comprises sprung pivoting disc which releases pin and immobilises bolt

摘要

The mechanism consists of a disc (21) which is able to pivot inside the lock-casing. In its normal position, it lies parallel to the front surface (12) of the lock and is held in position by a spring (33). If an attempt is made to force the lock using some kind of tool, pressure exerted on the disc (21) causes it to pivot against the action of the spring. During this movement, a pin (28) is released which holds the disc in such a way that the bolt of the lock is immobilised.