摘要 |
An automatic locking mechanism engages a deadbolt lock after a prescribed time interval following entry. The mechanism employs a spring-operated mechanical timer, which may be actuated when a key or thumbturn is turned to unlock the door, and avoids the need for a key to set the deadbolt. The mechanism includes a gear system for retracting and inserting the deadbolt and a mechanical restraint to withhold the deadbolt until the timer has expired. In a suggested embodiment, a cam attached to one of the timer gears removes the restraint when the timer runs down. This deploys the deadbolt, automatically locking the door. In another embodiment, automatic locking may optionally be disabled by inhibiting coupling between the gear system and the timer spring.
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