| 摘要 |
<p>The invention relates to an improvement in a key-actuated pin tumbler lock (10) of the type having: a cylindrical core (12) rotatable in a lock housing (24) via a rotational path (30), a plurality of pin tumblers (14, 16) received in bores (22, 23) journalled in the core (12) and lock housing (24), each bore (22, 23) containing a set of pin tumblers comprising one core (14) and one housing pin (16), biassed towards the core (12), and having a a pin junction (20) therebetween, and a key slot (28) in the core (12), whereby insertion in the key slot (28) of a key (31) having thereon suitable bits is adapted to align the pin junctions (20) with the rotational path (30) of the core (12) in the lock housing (24), and to permit the core (12) to rotate within the housing (24). The improvement comprises a retaining mechanism (32, 34) adapted to bias at least one of the pin tumblers (14, 16) towards engagement with the rotational path (30) of the core (12), the mechanism (32, 34) being adapted to restrain rotation of the core (12) until release of the or each biassed pin tumbler (14, 16) upon insertion of a key (31) including, as well as the suitable bits, means (35) for disengaging the retaining mechanism (32, 34) from engagement with the or each biassed pin tumbler (14, 16). <IMAGE></p> |
