Abstract: A door chain device not allowing the disengagement of its engaged member from a door-side member by manipulating the chain from the outside. In the door chain device wherein a chain is fixed at one end to the door frame and has an engaging member at the other end, the engaging member has a flanged end which is inserted into a through hole made in the door-side locking member and then fitted into a slit extending from the through hole. The improvement is comprised of the flanged end having a permanent magnet, a door-side member having a bottom plate made of a ferromagnetic material, the bottom plate having an oval hole at a position corresponding to the through hole. Thereby when the flanged end reaches the oval hole the magnetic balance therein is broken to generate a magnetic force by which the flanged end is turned in the oval hole and therefore it cannot pass out from the hole.

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 locking device has a trigger bolt for fastening a dead bolt and can be released by actuating a cooperating assembly placed in a door frame from a remote control room. A lock case placed in a door includes a turnable inner operating element provided with an inside thumb-turn operable from the inside, a turnable outer operating element provided with an outside thumb-turn operable from the outside, a turning lever drivable by the operating element, a dead bolt movable forwards to lock and backwards to unlock by the action of the turning lever, and a locking device for locking the dead bolt in a locking position.

Abstract: A door chain-locking device comprises a door-frame side locking unit and a door side locking unit. The frame-side locking unit has a locking bolt for permanently securing thereon the fixed-end link of a chain and a case for fixing the locking bolt. The door-side locking unit has an engaging bolt operable to engage thereon one of the middle part's links of the chain fixed at its fixed end link to the door-frame side locking bolt and also to engage the free-ended link of the chain when the door is being closed and to be lifted out of engagement with the free-end link of the chain after disengagement of the middle part's link therefrom.

Abstract: A gas shut-off device comprising a housing having a gas inflow hole and a gas outflow hole, the housing including therein a first shut-off valve with permanent magnets for closing and opening the gas flow passage, a partition having an opening formed therein for allowing gas to flow little by little from the inflow side into the outflow side, a second shut-off valve with permanent magnets for shutting off the flow of gas through the opening in the partition; and a solenoid having a rotary element being rotatable in forward and reverse directions according to a signal from a gas detector and a signal from a reset service respectively, the rotary element having a first permanent magnet to attract or repel the permanent magnet of the first shut-off valve at each stop position of the rotary element and a second permanent magnet to attract or repel the permanent magnet of the second shut-off valve at each stop position of the rotary element.

Abstract: An electrical shock-preventable key unit has a case for slidably accommodating a key body, a slide plate and an electrical shock preventing system. The slide plate engages with the key body and slides reciprocally to position it in the extended position or in the retracted position. The electrical shock preventing system comprises a conductive member provided on the case, a resistor for attenuating the current due to static electricity, and a conductive contact piece which comes into contact with the key body in the extended position, and operates to prevent the user from receiving an electrical shock upon locking or unlocking.

Abstract: The lock device comprises a locking portion and a fixing portion. The locking portion comprises a rotation lever mounted on a door side and turned by rotating a thumbturn or a key, a dead bolt engaging with the rotation lever and performing lock and release of the lock device by turning the rotation lever, a trigger bolt for locking the dead bolt, a rotating plate operating in a direction of draw in the dead bolt to the door side, and a latch bolt drawn in to the door side by the action of the rotating plate. The fixing portion comprises a strike mounted on a frame side of the door, a pressing lever for locking the dead bolt and pressing the trigger bolt onto the strike, means for causing the pressing lever to operate, and means for releasing press operation of the pressing lever and causing the trigger bolt to project to the door frame side.

Abstract: A door lock device for automobile, including a manual lock member provided inside of the door for locking and unlocking the door, and a key or laser key for unlocking the door, is so arranged that the engine is made operable only when the door is unlocked with the key or the laser key.

Abstract: A door lock control system including keys each having a memory storing information of the key number and the key owner's face as video data. When the key is inserted into the door lock, the face image is reproduced on a CRT according to the face information stored in the key. A TV camera also takes the face image of the key handling person for displaying same on another CRT so that one can judge, by comparison of the face images on CRT, whether the person is the same as the key owner. The system further includes a central storage unit in which a portion of the video data in each key is stored as a collation word. Upon insertion of the key into the door lock, the collation word is read out according to the information of the key number stored in the key. The read out word is compared with the portion of the video data stored in the key to check whether the key is one of those owned by the predetermined key owners.

Abstract: A device for unlocking a door locked with a door lock apparatus of a type which is comprised of a latch bolt and a trigger bolt capable of locking the latch bolt and of preventing the latch bolt from being retracted when the door is closed. The unlocking device is mounted on a door frame supporting the door and includes a strike having openings through which the trigger and latch bolts are inserted, and a stopper plate moveable between a service position where it is engaged by the trigger bolt to prevent trigger bolt from protruding from the strike and a non-service position where the trigger bolt is permitted to protrude from the strike so as to release the locking of the latch bolt with the trigger bolt. The stopper plate is moved by a solenoid actuated by remote control. The unlocking device is further provided with a pushing member which moves the latch bolt, which has been released from the trigger bolt, out of the strike, whereby the door may be opened by mere pushing without rotating a door knob.

Abstract: A protective signaling device for the prevention of theft of an automobile, which is arranged to generate an alarm only when the engine of the automobile is started without the use of its ignition key, i.e. without switching an ignition switch of the automobile on. The device includes a pickup capable of detecting a radio wave generated as an electrical noise when the engine is started and of generating a first detection signal upon detection of the radio wave, and a detector adapted for generating a second detection signal when the ignition switch is in the off position. Means is provided for allowing the actuation of an alarm only upon receipt of both of the first and second detection signals at the same time.

Abstract: A surveillance apparatus for the detection and prevention of damages due to fires, gas, robbery and other destructive conditions of a building which has a large number of rooms each furnished with a telephone set and a door provided with a lock. The telephone cables extending between respective rooms and a main terminal board of the building are utilized as wires for transmitting detection signals of detectors provided in respective rooms to indicators provided in a central surveillance room during the locking of the door.

Abstract: In the gas meter comprising a housing made of non-magnetic material and provided with gas inlet and outlet, a driver section provided with a rotating member rotated in accordance to the flow amount of gas, and a meter driven by the driver section to display the flow amount of gas, a detector device for detecting whether or not gas is being used in a room or inside a house characterized by a magnetic material attached to the rotating member, by a sensor or sensors attached to the outer face of the housing to detect the rotation of the rotating member, and by a display driven by the output of the sensor to display whether or not gas is being used.

Abstract: A lock device comprising a fixed cylindrical member, a rotatable member fitted into said fixed member and rotated to cause a dead bolt to be reciprocated and having a key hole extending along the axial center line thereof, and a means for locking said fixed member to said rotatable member by a plurality of permanent magnets arranged according to a predetermined pole pattern, wherein said locking means can be released so as to enable the lock device to be locked and unlocked when a key having a plurality of permanent magnets embedded on both sides thereof according to the predetermined pole pattern is inserted into the key hole, characterized by a fixed guide cylinder rotatably housed in said fixed member, an engaging means for fixing the fixed guide cylinder to said fixed member and releasing the fixed guide cylinder from said fixed member, a pattern reading means for detecting the pole pattern of said key, and a driving means for driving said engaging means to fix said fixed guide cylinder to the fixed membe

Abstract: A locking device comprising driving members driven by a thumb turn from insie a room and by a key from outside the room, dead bolts brought into engagement with the driving members to advance or retreat to lock or unlock the room, and switches for detecting the advance and retreat of the dead bolts. Said dead bolts are formed by dividing the thickness of a dead bolt to two parts while said driving members by dividing the thickness of a driving member to two parts, said dead bolts are brought into engagement with said driving members to advance or retreat, and one of said driving members is driven by the thumb turn while the other by the key. An engaging means is provided between said driving members or dead bolts in such a way that said driving member driven by the thumb turn is rotated integral with the other driving member driven by the key only when the latter is rotated to lock the room.

Abstract: A key holding member of elongated shape having a rod of permanent magnet embedded therein or a sheet of permanent magnet adhered thereto, which, when put into its corresponding opening for receiving the key holding member in the key box provided at the front of a hotel or the like, comes close to a reed switch provided in the key box. In this manner the reed switch is rendered operative to close or open the electrical circuits connected to the reed switch so as to turn "on" or "off" a lamp which shows that the room is left absent and to cause an alarming device to alarm whenever the room is broken into or a fire starts in the room.