Electronic combination lock with time delay feature to control opening

Abstract

An electronic lock is provided with a timer capability to delay the operability of the lock for a preset period of time following the proper and correct entry of a combination into the lock. This delay prevents the lock from opening until both the time has expired and an access code entered following the time delay. If the access code entered after the time delay is incorrect, a further time delay or penalty delay will prevent the operator from an immediate attempt to enter a second access code. If a second access code is entered after the penalty delay and also is 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 to operate the lock which is offset by a predetermined value from the authorized combination will indicate by alarm at a remote monitoring center that the lock is being opened and may be opened under duress to the operator. The combination of the time delay as well as the entry of the alarm combination provide an opportunity for the monitoring center personnel either to react or to notify the appropriate security/law enforcement personnel to respond to a potential robbery.