| 摘要 |
<p>In a pin tumbler-type cylinder lock having an auxiliary tumbler stack, the bottom pin of the auxiliary tumbler stack has a recessed underside for receiving a projection on the key to form a detent. The invention provides a n additional functionality that has not previously been associated with the auxiliary tumbler stack. When the projection on the key as seated, it preven ts the key from being withdrawn from the keyway while the plug is in any rotational position in which the drive and bottom pins are not substantially aligned. Thus, the key is retained whenever the plug has been rotated.</p> |
