Abstract: A security tag, attachable to an article of merchandise by means of a tack received by the tag, includes means for sensing the presence of the head of the tack. The sensing means causes activation of an alarm circuit in response to displacement of the tack head relative to the tag resulting, for example, from an unauthorized attempt to withdraw the tack from the tag, or severance of the tack head. The tack may be coupled to the tag by means of a length of coaxial cable which may be used to attach the tag to an article to be safeguarded. The cable includes a pair of conductors normally insulated from each other. Contact between the conductors caused, for example, by an attempt to cut the cable, results in activation of the alarm circuit.

Abstract: A merchandise security system sensor encloses a microswitch operated by an overtravel actuator projecting from the sensor housing. The microswitch is adapted to be electrically connected to a monitoring system which generates an alarm signal in response to a change of state of the microswitch. Attachment of the sensor to a protected article operates to depress the microswitch actuator and places the microswitch in a first state. Unauthorized removal of the sensor from the article releases the actuator causing the microswitch to revert to its initial state thereby triggering the alarm.

Abstract: A security system for monitoring retail merchandise such as garments includes a radio frequency transmitter tag attachable to the garment by a cable passed through a portion of the garment. The cable has one end affixed to the tag housing and a free end slidably disposed in the housing whereby the tag and cable form a variable length closed loop preventing removal of the tag from the garment. The cable includes a pair of conductors insulated from each other and connected between the transmitter circuit and a capacitive discharge power supply inside the tag. An attempt to cut the cable causes the conductors to come into contact thereby energizing the transmitter which transmits a modulated radio frequency signal burst. The capacitive discharge supply is powered by a battery whose longevity approaches shelf life. An arrangement for removing the cable from the tag by authorized personnel is also disclosed.

Abstract: An electronic security system for monitoring merchandise and the like is provided which is responsive to any change of state in the electrical connections thereto thus providing for the detection of virtually any tampering with the merchandise or security system. Conductive loop sensors attached to the merchandise are releasably coupled to series-connected modular sensor monitoring units which in turn are connected to a single control box enclosing latching and alarm circuits. Each monitoring unit is preferably adapted to receive a plurality of conductive loops. Severing of any of the loops, as well as disconnection or reconnection of the loops, the monitoring units or the control box activates the alarm. A time-out circuit controls the length of time of alarm activation and is switchable between long and short alarm durations.Means facilitating the mounting of the manifold units and control box on existing T-stand and wall rack clothing displays, are also disclosed.

Abstract: A coherent frequency, velocity responsive electronic surveillance system detects the motion of a transponder relative to two receiving antennas on opposite ends of a surveillance zone positioned at the exit of a retail store. Motion in opposite directions relative to the two antennas indicates that the transponder is within the surveillance zone. As a means of reducing false alarms, motion of a transponder proximate to, but outside the zone is distinguished from motion inside the zone because motion outside the zone is in the same direction relative to both antennas. False alarms are reduced even further by requiring detection of motion through a selected distance before indicating an alarm.

Abstract: A time limited coherent frequency doppler radar system monitors a precisely bounded merchandise detection zone for motion of a transducer therein. False alarms are reduced without limiting sensitivity by limiting the maximum radar signal propogation times to control the outer boundaries of the detection region and by requiring a selected minimum motion within the detection zone. An even more precisely bounded merchandise surveillance zone can be realized by using two spaced-apart radar systems having overlapping detection zones.

Abstract: A reusable, pneumatically releasable security tag for monitoring merchandise such as a garment, is disclosed. Encapsulated within the tag is a transponder element which reradiates a radio frequency signal to trigger an alarm when a tagged article is carried through a surveillance zone. The tag includes a housing concealing a one-way latch spring fastener for receiving and gripping the shank of a tack inserted through the garment and into the housing. The housing defines a chamber sealed by a generally horizontally oriented diaphragm adapted to be deflected by pressurized air admitted into the chamber through a small inlet. An actuator interposed between the diaphragm and the latch spring fastener is adapted to engage and deflect the fastener to a tack-releasing configuration upon the admission of pressurized air into the chamber.A resilient pad may be inserted under the head of the tack.

Abstract: A releasable, reusable, tamperproof device for attaching an anti-theft monitor to an article of merchandise is disclosed. The attachment device includes a tack adapted to be passed through the monitor and the article and into a keeper. The keeper encloses a one-way fastener of the type having opposed legs defining surfaces for gripping the pointed shank of the tack. Compression of the opposed legs to a releasing position permits withdrawal of the tack. In accordance with one embodiment, the keeper includes openings through which rotatable key means are insertable for engaging and displacing the legs to the tack-releasing position. In another embodiment the keeper incorporates flexible diaphragms dividing the keeper into a pair of side chambers separated by a central chamber enclosing the one-way fastener. Pressurization of the side chambers deflects the diaphragms into engagement with the fastener legs and causes displacement thereof to the tack-releasing position.

Abstract: A releasable, reusable, tamperproof device for attaching an anti-theft monitor to an article of merchandise is disclosed. The attachment device includes a tack adapted to be passed through the monitor and the article and into a keeper. The keeper encloses a one-way fastener of the type having opposed legs defining surfaces for gripping the pointed shank of the tack. Compression of the opposed legs to a releasing position permits withdrawal of the tack. In accordance with one embodiment, the keeper includes openings through which rotatable key means are insertable for engaging and displacing the legs to the tack-releasing position. In another embodiment the keeper incorporates flexible diaphragms dividing the keeper into a pair of side chambers separated by a central chamber enclosing the one-way fastener. Pressurization of the side chambers deflects the diaphragms into engagement with the fastener legs and causes displacement thereof to the tack-releasing position.