This invention relates to an alarmed lock, suitable for installation in either doorways or automobiles, which contains: a dual bolt system requiring correct sequential acitvation or deactivation to prevent alarm; protection against disarming by a potential intruder; an integral power source for sounding the alarm.
Two bolts locks are generally characterized by separate key requirements, by electrically coded controls by rotating combination controls, or by a combination of the above. Rice (U.S. Pat. No. 4,772,877) proposed a method for indicating the security situation on safes using the properties of rotating combination locks, Peterson (U.S. Pat. No. 3,890,608) proposed a method for opening a door using a combination of electrical control an sensing from a remote location, Humphrey (U.S. Pat. No. 4,663,611) proposed a built-in alarm for flexible loops wherein continuity is assured by the physical construction of the lock (joined in a closed-loop arrangement), and Kletzmaier has proposed (U.S. Pat. No. 4,563,886) using two bolts wherein one is manually activated while the other is electrically actuated. Hsu (U.S. Pat. No. 4,726,206) proposed an alarmed lock whose alarming purpose was to control access to the keyed cylinder.