摘要 |
<p>Title of the Invention: Locks A security lock for use on sliding doors or gates has a pair of hook bolts which are thrown apart or withdrawn together according to the position of a head on a reciprocable slide. Each bolt has a recess mated to the head with front and rear driving surfaces, this geometry being related to the pivot points of the bolts such that the head drives the bolts positively between their thrown and withdrawn positions with no lost motion and without the need for spring-biasing of the bolts. The slide is deadlocked by a pack of levers, to which a second lever pack is linked, two lever packs being provided so that non-palindromic key-stepping can be employed. If required, the slide can be double-thrown by successive use of two different correct keys, for which different key-hole positions and are provided to cooperate with the lever packs.</p> |