摘要:
A protective device for key-operated door locks, comprises a housing mountable to the door over the keyhole of a lock mounted within the door; a guard plate movable to a blocking position to block access to the keyhole, or to an unblocking position to permit access to the keyhole; and a rotary knob rotatable to a plurality of positions and having markings thereon indicating its position. A transmission mechanism including a plurality of notched code discs is provided between the rotary knob and the guard plate for moving the guard plate from its locking position to its unlocking position when the code discs have been positioned to predetermined coded positions such that further rotation of the knob moves the guard plate from its blocking position to its unblocking position.
摘要:
A tamper-resistant steering column lock incorporating an improved combination lock is disclosed. The improved combination lock includes an array of discs, each having an electrically conductive member extending therethrough. The disc at one end of the array is connected to the active terminal of the vehicle's electrical system and the disc at the other end of the array is grounded. When the discs are rotated to align the electrically conductive members, a circuit is completed to a solenoid or the like which regulates movement of a locking bolt between its locked and unlocked positions.
摘要:
A combination control device for rotative members such as ignition locks, home locks and the like wherein rotation of the actuating member (key) is prohibited until the various elements of the control device are in preselected positions. Unauthorized manipulation of the device will result in the sounding of an alarm if the device is wired to do so.