Abstract: An illuminating circuit for the key slot in a locking device is made up of a high intensity light source which is mounted on the face plate of the lock in close proximity to the key slot, a piezoelectric crystal is mounted within or adjacent to the lock to respond to vibrations created, for example, by tapping on the face plate to generate an electrical signal, and a control circuit including a timer and battery respond to the electrical signal generated by the crystal to energize a light source for a predetermined time interval after receiving the electrical signal from the crystal.

Abstract: A lock structure with a warning device, in which an additional set of tumblers are installed on the four sides of the cylinder body, the plug member and the sliding sleeves; in case of a wrong key being inserted into the cylinder body, the tumblers will be touched and projected outwards to trigger off a warning device.

Abstract: A protective device for a padlock as typically used on the cargo doors of a trailer portion of a truck/trailer combination. Particularly, the device is intended to protect the lock from the environment and to provide a warning of unauthorized access. The preferred embodiment includes a base which is fastened to the door and surrounds the keeper of the lock assembly, a cover pivotally mounted to the base and enclosing the lock, a switch mounted to the cover for detecting displacement of the cover from its closed position and an audible alarm responsive to the switch for emitting a warning signal.

Abstract: A locking arrangement with built-in alarm mechanism utilizing a contact between portions of a split bolt arrangement as the prime security measure is described. Correct sequencing of both the locking and unlocking actions is required to prevent alarm. Two realizations are described: a self-contained unit for building doors; and an automobile unit with central alarm, alarm sensors for ignition and other locations subject to tampering (hood, trunk, battery), and a set resistance method to prevent disarming by either circuit opening or shorting techniques.

Abstract: A vehicle anti-theft device includes a lock body carried on the vehicle and having a key receiving a slot. A pair of bore holes are spaced apart from each other in a predetermined pattern and extend through the lock body, which is transparent to a particular frequency of electromagnetic radiation. The key includes a first radiation reflective area aligned with one of the bore holes and a second non-reflective area aligned with the other bore hole. A systems controller includes a pair of radiation emitters and associated radiation detectors. A pair of fiber optic cables connect the radiation emitters and the radiation detectors to the bore holes. The systems controller generates control signals in response to radiation reflected from the key through the optic cables. If a proper pattern of radiation is reflected through the optic cables, the vehicle will be operated in a normal manner.

Abstract: A tamper-proof device for detecting opening and closing events of a secure container is characterized by a fiber optic cable having a first portion connected with a fixed member of the container and a second portion connected with a movable locking member of the container so that the cable is bent or flexed when the container locking member is moved between open and closed positions. Light pulses are transmitted through the cable and variations in the pulses resulting from bending of the cable are detected to indicate opening and closing of the container.

Abstract: A remote monitoring system for a multi-position loading dock facility having a vehicle restraint lock at each loading/unloading position is disclosed. The monitoring system includes a data processor, and a keyboard and monitor associated therewith, which may be coupled to lock sensing switches and other signalling devices at each loading/unloading position. The data processor, supplied with the developed signals corresponding to the condition of a truck at each loading/unloading position, is operable to continually process these signals to allow display and recording of a plurality of types of data.

Abstract: Automobiles such as a cash carrying car, truck, police car and so on, are prevented from being ridden away during loading or unloading cash or goods or being robbed by robbers after having been forcibly stopped on road. When a door of the automobile is opened, a opened-door detection switch operates and a first-control means stores in its memory the switch's action and cuts off an engine start-up circuit. The engine can be restarted when a registered password is entered into the device through a password inputting means, whereby a second-control means stores the signal and enters a resetting signal into the first control means to restore the engine start-up circuit. At the same time, a resetting signal produced by a reset signal generating means is inputted into the second control means which is thereby restored to the initial state.

Abstract: A door lock is provided with three alarm switches for activating an alarm system. The first switch has a first pair of contacts which are formed by a spring urging a tumbler pin and a metallic sleeve in which the spring is inserted. The second switch has a second pair of contacts which are urged toward each other and disposed on two opposite sides of a tongue connected to a tumbler for oeprating a lock bolt. The third switch has a third pair of contacts operable by a slide bar slidably disposed along the lock bolt. When an attempt is made to pick the lock, the first switch is closed to activate the alarm system; when an attempt is made to pull the lock cylinder out of the door, the second switch is closed to activate the alarm system; and when an attempt is made to pry open the door, the third switch is closed to activate the alarm system.

Abstract: Reminder apparatus to be carried by a user with a key constructed to remind the user as to the last operation in which the key was used with respect to a lock. The key includes an operation sensor which stores the time of the last key operation, and a display which, upon manual operation of the key, displays the time of the last key operation.

Abstract: A keyless electronic combination lock is adaptable for placement on a door, and operates independently of any other locks and without a central control system. The lock has a keypad for entering combinations, a random access memory (RAM) into which the entered data is loaded, a microprocessor, and an electrically erasable programmable read only memory (EEPROM). One or more entry codes for opening the lock are stored in the EEPROM and loaded into the RAM when the lock is powered-up. To open the lock, one of these codes or a master entry code must be entered at the keypad. Each entry code can be individually prevented from opening the lock by entering a corresponding individual lock-out code. All of the entry codes can be locked-out by entering a master lock-out code, by entering all of the individual lock-out codes or by throwing a dead bolt. The master entry code works regardless of the lock-out status and regardless of the dead bolt. To change lock-out status, the lock-out code is simply reentered.

Abstract: An electronic locking system comprises a conventional mechanical lock and a key associated therewith, said key having a built-in code transmitter and receiver, preferably an infrared sensitive photo-detector which cooperates with the code transmitter. The receiver is connected to an electronic control unit which is arranged to register a coded signal emitted from the key and transmitted to the receiver. When the signal is acceptable the electronic control unit is activated. The electronic control unit is provided with a memory element contains no information on any coded signal. After transmission of the coded signal of the associated key the coded signal is stored permanently in the memory element whereafter the electronic control unit will accept only precisely this coded signal in order to be activated.

Abstract: A car theft proofing system includes a sensor disposed in a cylinder lock for detecting insertion into the cylinder lock of a door key or other article, an alarm device for giving an alarm, an alarm drive device for driving the alarm device, a control unit for causing the alarm device to give the alarm in response to signals received from the sensor and the alarm drive device, and a radio transmitter for transmitting a radio wave upon insertion of the article. The alarm drive device includes a portable remote control transmitter and a receiver disposed on a car body. The remote control transmitter includes an abnormality alarm for transmitting a theft signal in response to the radio wave transmitted from the radio transmitter.

Abstract: A system for automatically locking a lavatory door on an aircraft from a remote location comprises means for activating the system, means for sensing the presence of a person in the lavatory, means for locking the lavatory when it is unoccupied and means for selectively overriding the system to allow entry by authorized personnel.

Abstract: A car theft proofing system includes a sensor attached to a door lock mechanism for detecting insertion into the door lock mechanism of a door key or other article, an alarm device for giving an alarm, an alarm drive device for driving the alarm device, a control unit for causing the alarm device to give the alarm in response to signals received from the sensor and the alarm drive device, and a radio transmitter for transmitting a radio wave upon insertion of the article. The alarm drive device includes a portable remote control transmitter and a receiver disposed on a car body. The remote control transmitter includes an abnormally alarm for transmitting a theft signal in response to the radio wave transmitted from the radio transmitter.

Abstract: A car theft proofing system includes a sensor a sensor disposed adjacent a cylinder lock for detecting insertion into the cylinder lock of a door key or other article, an alarm device for giving an alarm, an alarm drive device for driving the alarm device, a control unit for causing the alarm device to give the alarm in response to signals received from the sensor and the alarm drive device, and a radio transmitter for transmitting a radio wave upon insertion of the article. The alarm drive device includes a portable remote control transmitter and a receiver disposed on a car body. The remote control transmitter includes an abnormality alarm for transmitting a theft signal in response to the radio wave transmitted from the radio transmitter.

Abstract: A car theft proofing system includes a sensor attached to or mounted adjacent a cylinder door lock for detecting insertion into the door lock of a door key or other article, an alarm device for giving an alarm, an alarm drive device for driving the alarm device, and a control unit for causing the alarm device to give the alarm in response to signals received from the sensor and the alarm drive device.

Abstract: A combination illuminated entry and door lock switch for a vehicle door lock assembly which provides voltage signals to a single wire bus and smart sensor multiplex control system for controlling turning on interior lights of the vehicle when a door handle is operated and for disarming a vehicle alarm system when a door key is turned in a door lock cylinder. Another embodiment includes a keyboard mounted in a cavity of the door handle assembly which permits sending voltage signals over the single wire bus to the smart sensor multiplex control system to control a variety of drivers and other control devices.

Abstract: A car theft proofing system includes a sensor attached to or mounted adjacent a cylinder door lock for detecting insertion into the door lock of a door key or other article, an alarm device for giving an alarm, an alarm drive device for driving the alarm device, a control unit for causing the alarm device to give the alarm in response to signals received from the sensor and the alarm drive device, and a radio transmitter for transmitting a radio wave upon insertion of the article. The alarm drive device includes a portable remote control transmitter and a receiver disposed on a car body. The remote control transmitter includes an abnormality alarm for transmitting a theft signal in response to the radio wave transmitted from the radio transmitter.

Abstract: A security system has a wall mounted assembly for installation adjacent an entry door and includes a motion detector for sensing intruders, an alarm for sounding a warning, an alarm circuit, a radio receiver responsive to two codes, and an electric door striker. A portable miniature transmitter has two transmission codes to activate the receiver, one for toggling the alarm circuit between armed and disarmed condition and for releasing the door upon disarming the alarm circuit. When the circuit is armed the motion detector is able to activate the alarm. The second transmission code activates the alarm if the circuit is armed. Remote self contained motion detector and transmitter units for use in other rooms use the second code to activate the alarm when motion is detected by those units.

Abstract: Alarm system for multi-compartment, postal mailbox arrays incorporating a plurality of individual mail compartments contained behind a primary access door. The system comprises an alarm secured adjacent the mailbox array and coupled thereto by switches coupled to each access door and to the postal lock for that door. The postal lock is modified with an aperture which exposes the internal operation thereof for a switch mounted thereon. In this manner authorized actuation of the lock disengages the alarm system to prevent it from sounding when the access door is opened. Forced opening of the access door without first disengaging the system through the postal lock will otherwise set off the alarm. In this manner a number of access door switches may be coupled to a single alarm box which itself may be constructed for preventing unauthorized deactivation by the utilization of similar switch sensors disposed therein.

Abstract: A device for use with security systems for residential or commercial buildings is disclosed which prevents an entrance door to the building both from being locked without first activating the security system, and from being unlocked without first deactivating the security system. The system uses an electromechanical interlock to prevent a deadbolt from being moved from an unlocked position to a locked position until the security system is armed. The eletromechanical interlock also prevents the deadbolt from being moved from the locked position to the unlocked position until the security system is disarmed.

Abstract: A device for actuating a warning device includes a contactor for actuating an electric circuit of the warning device, which contactor is operated for switching-in by means of a movable touch pin, which touch pin, by means of a spring force acting thereon, follows the relative movement between a fixed point and a point belonging to a door leaf, a window or the like, so that when the distance between these two points is increased, the touch pin moves so much that the contactor is operated into its switching-in position. In order to form a small unit, which can be built-in into the conventional securing plates of doors, windows and the like, the touch pin is connected with a catch, which in its catching position holds the touch pin in a fixed position, at least against movements in the direction in which the spring force acts.

Abstract: A housing is positionable within a door frame and includes an upper and lower compartment. The lower compartment includes a conventional dead-bolt latch with a secondary bolt operative by means of an associated handle. The secondary bolt includes an upwardly depending switch extending from the first compartment housing the dead-bolt and secondary bolt into the overlying second compartment housing circuitry operative to actuate an audible alarm response to the switch upon repositioning of the secondary bolt from an extended to a retracted position.

Abstract: A key has reed switches which are disposed within a head of the key, and switch actuators comprising bias magnets disposed adjacent the reed switches, respectively, and a pair of first driving magnets and second driving magnets which are disposed at the front end face of a cylinder lock and alternately magnetized in opposite directions. In response to the close proximity of the bias magnet and its corresponding driving magnet, the corresponding reed switch is actuated according to the mutual coaction between each bias magnet and its corresponding magnet. The rotation of the key for locking the cylinder lock and the rotation of the key for unlocking the cylinder lock are made to correspond with open and closed states of the reed switches, or the most recent of a locking signal and an unlocking signal.

Abstract: A device for securing a combination dial lock is comprised of a base member, a bridge member, which is pivotally mounted on the base member, and a cover member which substantially envelopes both the base member and the bridge member. The bridge member includes a pin member projecting from a tip thereof for being inserted in a complementary opening in the combination dial to secure the dial against rotation. Tamper alarm circuitry is provided to generate a tamper alarm signal if an attempt is made to tamper with the combination dial or to damage the device. An alarm will also be generated if the lock remains in an unsecure state for more than a predetermined time interval, which is deemed adequate for an authorized user to conduct legitimate business in the compartment which is being protected by the combination dial lock.

Abstract: A control arrangement for a combined central locking and burglar alarm system for motor vehicles is constructed in such a manner that an accidentally tripped false alarm can be deactivated in a single manner by a designated key and a key detection switch associated with a door locking cylinder, so that the activation state of the burglar alarm system is automatically adapted to the existing locking state of the central locking system.

Abstract: In a burglarproof system for an automotive vehicle, a door key cylinder arranged at a vehicle door includes a cylindrical body and a rotor accommodated therein. An acting section provided at the rotor extends radially from an axis thereof. A door key switch arranged in the vicinity of the door key cylinder detects the acting section to output a key-operation detection signal, when the rotor is angularly moved by turning operation of a key to bring a door locking mechanism to an unlocked position. A door lock switch detects in which one of the locked and unlocked positions the locking mechanism is. A stealing detector is provided for outputting a stealing detection signal when the stealing detector does not receive the key-operation detection signal from the door key switch, but receives the lock-releasing detection signal from the door lock switch. A burglarproof unit executes operation for a burglarproof in response to the stealing detection signal.

Abstract: A door lock including a housing, a bolt assembly, a lock mechanism engaged with the bolt assembly and capable of being operated to move the bolt assembly from a locked to an unlocked position, and vice versa. The door lock includes a first switch secured to the housing and in the moving path of the bolt assembly, and adapted to couple with an alarm apparatus, for turning on the alarm apparatus when the bolt assembly is moved to the locked position, and for turning off the alarm apparatus when the bolt assembly is moved to the unlocked position.

Abstract: An electronic lock system includes a lock which is selectively lockable and unlockable in response to an input signal; and buffer means for (1) receiving user commands and generating the input signal only in response to one or more preselected user commands, (2) identifying certain parameters incident to the locking or unlocking of said lock and (3) transmitting said parameters. A microprocessor includes a memory coupled to the buffer means for recording the parameters, and a central processor selectively interrogates the microprocessor and records the parameters. An interface is coupled between the microprocessor and the central processor and transmits the parameters from the microprocessor memory to the central processor in response to the interrogation.

Abstract: An emergency gate release for a lattice type gate having a lock on the gate for locking the gate to a static structure. The gate release includes a lock release mechanism on one side of the gate for unlocking the gate and a rotatable release knob connected to the lock release mechanism for actuating the lock release mechanism to unlock the gate without a key. The release knob is located on one side of the gate at a location remote from the lock and inaccessible from the other side of the gate.

Abstract: A padlock comprises a battery-powered, built-in alarm which operates when the padlock's shackle is severed or forced open. The battery and alarm can be tested by opening the lock with a key, rotating the short leg of the shackle away from the lock body and then depressing the shackle, or optionally, by depressing the short leg. The alarm is turned on in response to the momentary closing of a switch when one shackle leg moves outwardly upon severance or forcible opening. The alarm may be an audible signal or an inaudible signal transmitted as a radio wave to a remote receiver at which an audible or visible signal is actuated. The audible signal generated at the lock escapes from the lock body through sound ports. Both audible and inaudible signals may be generated at the lock simultaneously.

Abstract: An information carrier (17) has formations (20,21) which are engaged by contact elements (30,32) during insertion of the carrier into a receiving member (39) the movement of the contact elements is amplified and transmitted by levers (26,33) to respective means (25,34) for providing electrical signals representing movement of the contact elements.

Abstract: The monitoring arrangement consists of permanent magnets (M1, M2, M3) of different strengths which are associated with a closure mechanism. Combined in a structural unit (1), these act as signal transmitters. The structural unit (1), is, for example, so positioned in door leaf that, in the closed position of the mechanism the permanent magnets (M1, M2, M3) lie opposite sensors (S1, S2, S3) which are associated with a surrounding frame. These sensors combined in a structural unit (2), act as signal pick-ups, at which different voltages, which are increased by amplifiers V1, V2, V3, are applied as a result of differing magnetic field strengths. The output voltages thereof are adjustable by respective potentiometers and can be regulated to the threshold voltages of comparators (K1to K6).

Abstract: A magnetic key lock provided with an alarm system, the key lock including a normally closed first switch and a normally open second switch, both switches being connected to the alarm system so that the alarm system is activated when the first and second switches are both closed. The second switch is associated with a tumbler of the lock so that the second switch is closed upon movement of the tumbler when a key or lock pick is inserted into the key slot of the lock. A magnetic sensor is provided adjacent to key slot so that a proper magnet-bearing key can activate the magnetic sensor before the second switch is closed by the tumbler movement in order to delay activation of the second switch for a selected time period to allow the proper key to open the first switch while opening the lock for inactivating the alarm system. A futher switch is provided to test the working ability of the alarm system. The alarm system can include a wirelessly controlled remote alarm.

Abstract: An anti-theft system for sensing the removal of an ignition lock assembly from its housing utilizing a grounding switch within the housing that is biased to disconnect an electrical path when the ignition switch is forcibly removed. An associated circuit provides continuous monitoring of the conduction path within the housing when the ignition switch it turned off.

Abstract: The status corresponding to the presence or absence of articles at their reserved locations is detected by means of an optical switch comprising an emitter which sends infra-red rays toward a receiver. The article obstructs these rays and hence its presence is detected. The information obtained from the optical switches is processed and used for servicing or billing.

Abstract: An electromagnetic door lock system employs an electromagnetic lock which magnetically bonds with an armature plate. An acoustical sensor generates a detection beam. The detection beam is directed toward the doorknob. Reflected energy is received and electronically processed to detect the presence of a foreign object in the vicinity of the doorknob. The lock automatically deactuates when a foreign object is detected in the vicinity of the knob. The electromagnetic lock, sensor and processing circuitry are mounted in a housing which is located near the top of a doorway. An audio alarm and status light indicators are mounted at the housing to indicate the status of the lock.

Abstract: An interior door knob for conventional lockable door latches includes a hollow knob with a cylindrical neck having conventional means for engaging and rotating the latch spindle to mechanically move the door bolt and an actuator mechanically engaging the locking mechanism of the door latch and extending through the cylindrical neck into the housing and being movable between a first and a second position. A battery, an acoustic/visual indicating means and a normally-open microswitch electrically connected in series are mounted in a component module received within the knob housing. The microswitch switches responsive to the position of the actuator for indicating when the locking mechanism of the door latch is not locked.

Abstract: A security system includes a microcomputer with an auxiliary read-only memory and a key device including a similar read-only memory, each of the read-only memories containing corresponding pluralities of corresponding binary combination codes. Under the control of the microcomputer the codes are read and compared. If the combinations and the sequence do not compare, the system will not unlock and an alarm will be generated. The read-only memories are of the programmable type, so that changes in the combinations and sequences can be accomplished easily. A plurality of visual indicators and an audible alarm provide the user and personnel in the secure area with information concerning the status of the system.

Abstract: A vehicle theft detector apparatus includes a key cylinder attached to a door or an opening/closing part, this cylinder having a built-in key switch which sends locked and unlocked signals to an alarm device and a locking device, the lead wires from this lock switch leading to the alarm device and locking device via connectors. When the key cylinder is removed for the purpose of entering the vehicle, the lead wires attached to the cylinder are pulled out from the connector and then the thief enters the vehicle, the alarm is sounded and the thief detected. The above-mentioned detector apparatus is provided with apparatus for taking up the slack in the lead wires, thus ensuring that the connector is immediately disconnected no matter how slightly the cylinder is pulled outwards.

Abstract: An electronic lock and key includes an electronic key which produces a specific electric signal such as a frequency signal, photo signal or logic signal when inserted into the key holder of the lock; and an electronic lock which is comprised of a power source, a key holder, a lock signal generator, and a signal comparing circuit that compares the signal of said key and the signal of said lock signal generator.

Abstract: A locking system comprises a lock mechanism including a casing structure adapted to be mounted to one of a door and a door frame and having a front plate with an aperture therein; a latch bolt mounted with respect to the casing structure for movement between a first position wherein a portion thereof extends from the front plate of the casing structure for latching engagement with the other of the door and door frame, and a second, retracted position wherein the same portion thereof is held out of position for said latching engagement. A deadlock member is mounted to the casing for movement between a blocking position wherein the deadlock member will prevent movement of the latch bolt to the second, retracted position, and a non-blocking position wherein the latch bolt is free to move to the retracted position. An operating disc is rotatably mounted coaxially with the latch bolt and coupled to rotate the latch bolt through a lost motion type of connection.

Abstract: A burglarproof device which can facilitate the activation of an alarm system and can provide lock-out protection. It uses a set of correct-signal generating reed switches and a set of incorrect-signal generating reed switches to activate the alarm signal, and the input of a correct signal within the preset lock-out time after receipt of an incorrect signal will not be able to open the door lock or disarm the alarm system.

Abstract: A medicien cabinet has a housing and a door. The door is provided with an electrically operated lock which is operable by using the push keys. The opening code for the lock is initially set by inserting four keys into four holes in a four by ten array of holes provided in the casing on the inside of the door. The circuits for the code pre-setting and code inputting circuits are provided on a membrane.The cabinet is provided with a light emitting diode (LED) and a buzzer which can be operated by timing means at set intervals. The LED and the buzzer also operate while the door is open.Additional facilities may also be provided on the cabinet.

Abstract: This invention is an alarm lock which uses a key-releasable cable to secure an article to be protected to a fixed object. Should the cable be cut, a coded audio alarm is emitted, alerting the owner of the article. The cable contains a conductor which is connected to an alarm circuit sensitive to a resistance in series with the cable. Attempts to defeat the cable by jumpering or cutting or otherwise varying the resistance causes the alarm to be set off. Pulling the cable (tampering) also causes the alarm to operate, for a fixed period of time. The lock unit can be fixed to the handle bars of a bicycle and the alarm sound can be generated manually whereby it can be used as a horn.

Abstract: A building has at least one security guard post to control the secured building exits, each of which has an unlocking instrumentality, without forbidding their emergency use. When activating the unlocking instrument to open a secured exit, there is a transmission of information to the security guard post and an initiation of a delay during which the security guard can forbid the opening of the exit. The unlocking instrument can also visually indicate events at the exit. The apparatus has an electro-mechanical lock, a sensor which is sensitive to motion of the unlocking instrument, a control line linking each door to be controlled to the security guard post, and a central electronic processing unit. A surveillance circuit responds to the sensor. A security circuit frees the unlocking instrument when a fault is detected.

Abstract: Apparatus for arming and disarming a vehicle alarm in response to locking and unlocking of an entranceway to the vehicle has a cylinder mounted in the housing and adapted to be rotated relative thereto by the turning of a key inserted therein in one direction for locking said entranceway and the opposite direction for unlocking said entranceway. A slidable member signals that the alarm has been armed. The alarm is armed and disarmed by the movement of a first cam fixedly mounted on one of the cylinder and the housing and a plurality of switches fixedly mounted on the other of the housing and the cylinder. The first cam engages one of the switches to arm the alarm when the cylinder is rotated to one position and engages another of the switches to disarm the alarm when the cylinder is rotated to another position. A second cam freely mounted in circumscribing relationship to the cylinder rotates upon the turning of said cylinder with an unauthorized key thereby actuating another switch to sound the alarm.

Abstract: The invention is concerned with a personal alarm device which can be used for a variety of alarm purposes. In one application, the device is used to sound an alarm when there is an impending attack. This is accomplished, after cocking of the alarm, by simply releasing a removable member which falls away. In another application of the device, the alarm can be carried in a purse or other receptacle and is effective to sound the alarm if the purse is moved away from the hand of the user. In still another application, the device may be used to detect the opening of a window or the relative movement of two members which are normally in substantial engagement with each other. In still another arrangement, the device is used for detecting the withdrawal of the latch bolt of a door.The device employs an electrically-operated alarm, a battery and two switches, all mounted within a housing.

Abstract: A security system includes a microcomputer with an auxiliary read-only memory and a key device including a similar read-only memory, each of the read-only memories containing corresponding pluralities of corresponding binary combination codes. Under the control of the microcomputer the codes are read and compared. If the combination and the sequence do not compare, the system will not unlock and an alarm will be generated. The read-only memories are of the programmable type, so that changes in the combinations and sequences can be accomplished easily. A plurality of visual indicators and an audible alarm provide the user and personnel in the secure area with information concerning the status of the system.