| 摘要 |
<p>A cylinder lock system employing a key having a projection extending from each opposing parallel edge of the key blade, the projections respectively operating an auxiliary pin tumbler stack and cooperating with a groove in the lock shell to retain the key in the lock after plug rotation from the key insertion position. The key retaining projection also cooperates with the driver pin of the auxiliary pin tumbler stack to prevent key trapping, i.e., the presence and size of the retaining projections keeps the auxiliary driver pin from engaging the keyway. The cooperation between the key retaining projection and the auxiliary driver pin is permitted by providing the lock with two shear lines, located on different diameters, which are simultaneously operable by a single key.</p> |
