초록 ▼

The lock comprises an improvement in a lock of the type having a cylinder with an associated internal cavity, a key operated lock plug rotatably mounted in the cylinder cavity and a coupling mounted for rotation relative to the lock cylinder for association with a lock member that is movable upon ro

The lock comprises an improvement in a lock of the type having a cylinder with an associated internal cavity, a key operated lock plug rotatably mounted in the cylinder cavity and a coupling mounted for rotation relative to the lock cylinder for association with a lock member that is movable upon rotation of the coupling between locked and open states. Shoulders are provided on the plug and coupling and upon effecting relative rotation between the coupling and plug through a change key the shoulders can be selectively brought into interfering, facing relationship to prohibit withdrawal of the plug or misaligned to allow removal of the plug. An access key, that is longer than the change key, in a fully seated position in the plug keyway, extends into the coupling opening and is thereby keyed to the coupling so that turning of the control key directly operates the coupling. Structure is provided for preventing shifting of the lock member from its locked state in the absence of a key being in the keyway.

대표청구항 ▼

In a lock having a lock cylinder provided with an internal cavity, a key operated lock plug having a keyway, said lock plug being removably mounted in said lock cylinder cavity to be rotatable about a first axis relative to the lock cylinder with a key inserted in said keyway and locked against rota

In a lock having a lock cylinder provided with an internal cavity, a key operated lock plug having a keyway, said lock plug being removably mounted in said lock cylinder cavity to be rotatable about a first axis relative to the lock cylinder with a key inserted in said keyway and locked against rotation in said cavity in the absence of a key in the keyway, and a coupling rotatably mounted in said lock cylinder for rotation about said first axis and having associated therewith a lock member that is movable upon rotation of the coupling in a limited range between a locked state and an open state with the coupling in locked and unlocked positions respectively, the improvement comprising: means provided on the plug for cooperation with the coupling selectively to prevent withdrawal of the plug from the cavity with the plug inserted fully into the cavity and the plug and coupling being disposed in a first relative rotational position, and to allow withdrawal of the plug from the cavity with the plug inserted fully into the cavity and the plug and coupling in a second relative rotational position, said coupling having spaced edges defining an opening extending axially with respect to the lock cylinder; a first key having a length preselected so that when said first key is in a fully inserted position in the keyway a portion of the first key extends into said coupling opening so that rotation of the first key brings said key portion into contact with one of said spaced edges to effect rotation of the coupling; a second key having a length such that when the second key is fully inserted in the keyway it does not extend into the opening, whereby with said second key relative rotation between the plug and coupling can be effected between the first and second relative rotational positions; and means for preventing rotation of the coupling in either direction relative to the plug with the coupling in the locked position, whereby the lock member cannot be moved from its locked state to its open state without insertion of a key in the keyway.