Dual action detent for tamper resistant lever lock mechanism
OwnerDaniel MacMillaninventor
Life of this patent
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Abstract
A lever lock apparatus having a sliding bolt, a detent mechanism for locking the bolt against sliding movement and a plurality of levers. When using the appropriate key, the detent moves to allow the bolt to be slid to a locked or unlocked position. When the lock is under attack, and an inward force is applied to the bolt, the detent moves so as to maintain a detent fence away from the levers. Keeping or moving the fence away from the levers impairs the ability to pick or otherwise attack the lock.
Claims20
A key actuated lever lock comprising:
- a bolt apparatus adapted to be slidable between a locked position and an unlocked position, the bolt having a boss;
- a plurality of levers, wherein each lever comprises a gate, and wherein the gates are alignable;
- a movable detent apparatus having a fence, the fence being biased to move into gates when the gates are aligned;
- and
- a stump positioned on the movable detent, the stump being in interfering engagement with the boss when a force is applied to the bolt while the gates are not aligned, and where the interfering engagement maintains the fence away from the levers.
In a lock having a sliding bolt that defines a bolt head and a bolt tail plate extending therefrom, a detent mechanism for locking said bolt against sliding movement, the detent mechanism comprising:
- a trapezoidal stump extending laterally from said detent and defining opposed downwardly and outwardly extending surfaces;
- said bolt tail defining a pair of upwardly opening spaced notches separated by an upwardly projecting boss of inverted trapezoidal configuration and defining downwardly and inwardly extending sloping surfaces;
- said detent stump engaging said boss to lock said bolt against sliding movement;
- whereby an external force on said bolt in the unlock direction causes a sloping surface on said boss to engage a sloping surface on said stump to lock said stump against release from said tail plate boss and thereby thwart attempts to unlock said lock without a key.
A detent for use with a swinging tumbler lock mechanism comprising an elongated detent arm and a trapezoidal stump integral with and extending laterally from said detent arm, said stump defining downwardly and outwardly sloping surfaces.
A method of thwarting efforts to open without a key a sliding bolt lock having a sliding bolt, swinging tumblers and a detent, comprising:
- urging said detent away from said tumblers in response to a force on said sliding bolt in a direction tending to open said lock.
A method of opening a key actuated lever lock, the lever lock comprising a slidable bolt apparatus, a movable detent having a fence, and a plurality of levers wherein each lever has a gate, the method comprising:
- inserting an appropriate key;
- turning the key to uniquely position the plurality of levers to align the gates;
- and
- turning the key to cause a thrower to contact the bolt apparatus and urge the bolt to a locked position;
- moving the detent fence into the aligned gates;
- and
- turning the key to urge the bolt to a unlocked position.
A key actuated lever lock comprising:
- a bolt apparatus adapted to be slidable between a locked position and an unlocked position, the bolt having a boss;
- a plurality of levers, wherein each lever comprises a gate, and wherein the gates are alignable;
- a movable detent apparatus having a fence, the fence being biased to move into gates when the gates are aligned;
- at least one spring for biasing the detent;
- and
- a protrusion element attached to the detent and in contact with the at least one spring, said protrusion further stabilizing the detent.
Dependencies are inferred from the claim text.