Abstract: There is provided a new and useful alarm system for use on a school bus having an ignition switch, a master switch, a rear door switch, the alarm system comprises a plurality of electromechanical circuits arranged so as to effect a resting state in which the system is inoperable, a stand-by state activated by actuating the ignition switch, a latching state from which the system may be armed, an armed state in which the system is operable, alarm means to indicate an alarm state, and a disarmed state in which the system is deactivated. There is also provided deactivation means positioned at a rear of the bus to deactivate the alarm system while in the armed state or the alarm state, wherein the alarm system is integral with the ignition switch, the master switch and the door switch of the bus.

Abstract: A security device for use in retail stores for the prevention of retail theft, which includes an alarm mechanism which generates an alarm signal in response to electrical power being applied through a switch mechanism. The switch mechanism is controlled by a signal provided by a closed circuit mechanism. Whenever a closed circuit condition is created, for example, by cutting the cable which mechanically connects the retail item to the security device, electrical power is applied to the alarm mechanism. Thus, if a battery is used to supply electrical power, such battery is only drained during closed circuit conditions, maximizing battery life.

Abstract: A product monitoring device including a releasable locking device adapted to be secured to a product and actuatable between locked and unlocked positions. The locking device consists of a pair of movable members, one of which mounts a bimetallic member consisting of bimetal elements having different temperature coefficients of expansion, the bimetal elements being separated by an insulator. The locking device includes a detent cooperatively associated with the bimetallic member to maintain the members in a locked position. The device uses an electrifiable key for heating the bimetallic elements to effect displacement thereof relative to the detent to facilitate movement of the members to an unlocked position. The device incorporates structural features which increase strength in operation, and further serve to make unauthorized opening and/or breakage of portions, with the intent of permitting separation from an article to which attached, more difficult.