Electronic combination lock with time delay.

摘要

An electronic lock (8) is prevented from being opened until both a set time delay has expired after entry of a valid combination, and a valid access code has been entered during a time window following the time delay. If the access code is incorrect, a further (penalty) time delay prevents the operator from immediately entering a second access code. If the second access code is also incorrect, the entire lock operation resets and the operation of the lock must begin with the re-entry of the correct combination. The entry of a combination which is offset by a predetermined value from the authorized combination still allows the lock to open, but also activates an alarm at a remote monitoring center to indicate that the lock is possibly being opened under duress. The combination of the time delay as well as the entry of the alarm combination provide an opportunity for the monitoring center personnel to react to a potential robbery. <IMAGE>