Abstract: Interlocks are described that prevent the bolt of a bolt lock from being displaced to the unlocked position by the use of impact and inertial of the lock parts, heat and the displacement of the cover plate of the lock housing.

Abstract: A combination lock/deadbolt is connected to a push-to-open panic-bar device to operate in response to push-bar operation, thereby withdrawing both the push-bar latchbolt and the deadbolt permitting instantaneous and unrestricted egress from a secured area. To maintain the security of the area from unauthorized entry from outside the secured area, a connection between the push-to-open device and the combination lock/deadbolt assembly is implemented with a lost motion connection. The lost motion device, preferably is a flexible cable transmitting force only in tension, assures that any operation of the combination lock/deadbolt will not effect the security provided by the push-to-open device. Further, the push-to-open device may be provided both with a conventional key cylinder lock and a knob, ever, or thumb lever release on the door exterior.

Abstract: A combination lock/deadbolt assembly connection technique is disclosed for connecting the bolt of the combination lock to the deadbolt of the deadbolt assembly to provide a lost motion connection while at the same time to retain the ability to position a magnetic anti-attack interlock within the bolt of the combination lock. A connecting shaft is disposed between the bolt and the deadbolt and a spring bias force introduced between the two bolts. The shaft may be attached rigidly at one end to either the lock bolt or deadbolt. The opposite end is loosely attached by retaining rings or retaining rings to accommodate the movement of the loosely attached bolt with respect to the shaft thereby providing a lost motion connection. A compression spring is disposed intermediate to the lock bolt and the deadbolt to provide a separating or extending force.

Abstract: An electronic combination lock is provided with and incorporates the enhanced feature of covert entry detection and notification. Whenever the bolt of an electronic lock provided with this enhancement is retracted to its withdrawn or unlocked position and whenever the lock has not received an authorized combination enabling the movement of the bolt, movement of the bolt is detected and the electronics of the lock is powered for a time sufficient to record an indication of the covert entry in its non-volatile memory. Upon normal operation at a subsequent time, the indication of covert entry is read from the non-volatile memory and a visual indication is displayed to the operator to inform the operator that covert entry has occurred.

Abstract: A combination lock is described where the combination that is used to open the lock is generated on a separate computer system using information that is contained in the lock and a series of steps that combine selected items of the information contained in the lock and alter the results of the results of the combination of the information items. The lock incorporates a computer processor-which performs the identical steps to generate an authorized combination after a combination is entered into the lock. When the two combinations match, the lock is enabled for opening. At least some of the information items used in the generation of the combinations change with each successful opening of the lock, rendering the combination generated by the computer system useable for only a single opening of the lock.

Abstract: A lock is described which has the capability to generate or encrypt a close number which is then displayed to the operator of the lock to be used to verify the locking of the lock. This number must be reported to a central dispatch operation where it is compared with a number similarly generated using identical starting values and an identical encryption algorithm. Comparison of the two numbers, resulting in a compare equal will indicate that the lock has been locked since the lock encryption operation is dependent upon the repowering of the lock. The lock is repowered after it has been opened by rotation of the dial which will extend the bolt and through the rotation of the dial drive a stepper motor/generator to provide electrical power to the lock.

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.

Abstract: A monitoring and control system is disclosed which samples a plurality of output ports and lines from the microprocessor and the system electronics of an electronic lock to determine whether the bolt is extended, retracted, or the enabling stepper motor has been activated. The presence of a change key may be monitored and the efficacy of a change key controlled to only permit the changing of the combination of the lock when the central monitoring station approves such a change.

Abstract: To prevent the opening of an electronic combination lock by using a strong magnet to operate a stepper motor, a magnetic interlock is included in the lock structure. A magnetic pin is held in a retracted position by a small magnet when a strong attack magnet is positioned to attempt to open the lock, the magnetic pin is attracted from the holding magnet and extended to bridge the bolt and lock housing, blocking the retraction of the bolt.

Abstract: A bolt retraction mechanism is descrbied that is enabled by an electronic signal to a stepper motor which causes the lock to be openable. The lock is internally powered by a generator operable by the operator. The operation of the generator is separate from the lock operations.

Abstract: A high security bolt lock is described having the ability to reencrypt the combination code for the lock each time a key is used and thus partially defeat the use of an unauthorized key. The lock may be operated by a temporary one time use key. The key for the lock carries a data storage means and battery to provide a date/time stamp and key identification for any key used. The key and lock may be coded to only allow access in a particular time block, or only in conjunction with an other key. The access to the lock may be controlled such that two keys must be used in a prescribed order to gain access through the lock.