Alarm system with two locks - has delay system for blocking alarm if second lock is opened within predetermined time

摘要

The alarm lock system is used for doors requiring special protection for preventing forcible entry attempts by unauthorised persons. The door to be protected has two locks. When the first lock has been released, a delay arrangement is initiated which switches on the alarm system after elapse of a time period. The alarm signal is blocked when the second lock is released within a specified time interval which is less than the lapsed time of the delay arrangement after the release of the first lock. The second lock has also contacts whic disconnect the delay arrangement without triggering alarm.