Abstract: A group of associated transponders are respectively attached to a plurality of objects, such as sensors or containers. Each transponder includes a memory, a transmitter, a receiver and a controller. The memory stores group data, which includes data related to the respective attached objects. The controller causes the transmitter to autonomously transmit a group interrogation signal and to transmit a response signal in response to receipt of a group interrogation signal from another transponder of the group. The response signal includes at least some of the stored group data. The receiver receives both the group interrogation signals and the response signals from the other transponders of the group. The controller controls the transmitter and receiver and causes the memory to store data related to the respective object to which the transponder is attached and to store the group data included in the received response signals.

Abstract: A group of associated transponders are respectively attached to a plurality of objects, such as sensors or containers. Each transponder includes a memory, a transmitter, a receiver and a controller. The memory stores group data, which includes data related to the respective attached objects. The controller causes the transmitter to autonomously transmit a group interrogation signal and to transmit a response signal in response to receipt of a group interrogation signal from another transponder of the group. The response signal includes at least some of the stored group data. The receiver receives both the group interrogation signals and the response signals from the other transponders of the group. The controller controls the transmitter and receiver and causes the memory to store data related to the respective object to which the transponder is attached and to store the group data included in the received response signals.

Abstract: A group of associated transponders are respectively attached to a plurality of objects, such as sensors or containers. Each transponder includes a memory, a transmitter, a receiver and a controller. The memory stores group data, which includes data related to the respective attached objects. The controller causes the transmitter to autonomously transmit a group interrogation signal and to transmit a response signal in response to receipt of a group interrogation signal from another transponder of the group. The response signal includes at least some of the stored group data. The receiver receives both the group interrogation signals and the response signals from the other transponders of the group. The controller controls the transmitter and receiver and causes the memory to store data related to the respective object to which the transponder is attached and to store the group data included in the received response signals.

Abstract: A batteryless, portable frequency divider, such as used in presence detection systems for article surveillance or as used for article-location determination, includes a series LC resonant circuit connected directed across a parallel LC resonant circuit. One circuit is resonant at a first frequency and the other circuit is resonant at a second frequency that is a plural-integer-divided quotient of the first frequency. In one class of embodiments, either or both of the series and parallel resonant circuits includes a variable capacitance element, such as a varactor, in which the capacitance varies in accordance with the voltage across the variable capacitance element. The variation of the capacitance of the variable capacitance element in response to variations in energy in the higher-frequency resonant circuit resulting from receipt electromagnetic radiation at the first frequency causes the lower-frequency resonant circuit to transmit electromagnetic radiation at the second frequency.

Abstract: A device for enabling attachment of a shoplifting detection tag to an article to be protected includes a first attachment rod having an eyelet at one end, a center portion having a bend, and a straight portion at the opposite end from the eyelet suitable for insertion into a clutch mechanism of a shoplifting detection tag; and a second attachment rod having an eyelet at one end, a center portion having a bend, and a straight portion at the opposite end from the eyelet. The first and second attachment rods and the eyelets thereof are of such relative dimensions that the first and second attachment rods may be fitted together to encompass a portion of the article to be protected by passing the straight portion of the first rod through the eyelet of the second rod and by passing the straight portion of the second rod through the eyelet of the first rod, while allowing the straight portion of the first rod to be inserted into the clutch mechanism of the shoplifting detection tag.

Abstract: An EAS presence detection system includes a transmitter for transmitting an electromagnetic radiation signal of a first predetermined frequency into a surveillance zone; a tag for attachment to an article to be detected within the surveillance zone, the tag containing a transponder including a material that, when in the presence of a magnetic bias field within a predetermined magnetic field intensity range, responds to detection of electromagnetic radiation of the said first predetermined frequency by transmitting electromagnetic radiation of a second predetermined frequency that is either a multiple harmonic or a frequency-divided quotient of the first predetermined frequency or at the first frequency; a detection system disposed for detecting radiation of the second predetermined frequency within the surveillance zone; and a magnetic field source for providing a magnetic bias field within the predetermined magnetic field intensity range within the surveillance zone.

Abstract: An apparatus for releasing locked components of a theft-deterrent device includes a seat for receiving a component of the theft deterrent device that contains a clutch and a ferromagnetic anvil that is positioned by a spring to force the clutch to apply pressure against an inserted pin that is anchored in another component of the device so as to restrain the pin from release from the clutch; and a magnet with a pole piece coupled thereto, with the magnet and the pole piece being disposed for movement between a protracted position and a retracted position. When magnet and the pole piece are in their protracted position the pole piece is disposed about the sides of the clutch-containing component and applies magnetic flux from the magnet that is directed to overcome the force of the spring and reposition the ferromagnetic anvil to thereby relax the pressure applied against the pin by the clutch so that the pin-anchoring component can be released from the clutch-containing component.

Abstract: In a device for deterring theft of a protected article, including a pin and clutch respectively embodied in two components that are adapted to be locked together on opposite sides of a portion of the protected article to prevent unauthorized removal of the device from the article, the pin-containing component contains two fragile elongated glass vials that fracture when at least a predetermined pressure is applied thereto, with the vials containing a detrimental substance that would damage an article attached to the device if such substance were to be released from the vial; and the head of the pin includes a breaker element having a wedge-shaped surface of a fiber-loaded-reinforced thermoplastic, (which does not scratch glass), for applying more than the predetermined pressure against the vial in response to the pinhead being moved in response to application to the two components of at least a predetermined threshold separation force, to thereby completely fracture the vials by inducing a high bending stress

Abstract: A device for deterring theft of a protected article, including a pin and clutch for attaching the device to the article, with the pin and clutch being embodied in two components that are adapted to be locked together on opposite sides of a portion of the protected article to prevent unauthorized removal of the device from the article. One component includes a plurality of fragile elongated vials that fracture when flexed longitudinally, with each vial containing a detrimental substance that would damage the article if the vial were to be fractured while the device was attached to the article.

Abstract: A clutch mechanism includes a ferromagnetic anvil having an axial bore for axially receiving a pin; a cup axially aligned with the anvil for receiving a pin that is axially received by the bore of the anvil, wherein the anvil is longitudinally movable along its bore axis with respect to the cup; a spring for forcing the anvil toward a confining end of the cup; balls in the cup for engaging the pin when the anvil is forced toward the confining end of the cup, with the balls being disposed to apply radial pressure against the pin to firmly clutch the pin and thereby restrain the pin from longitudinal movement when the balls are forced toward the confining end of the cup; and a ferromagnetic shield disposed axially in relation to the anvil for diffusing magnetic flux applied axially to the anvil by a magnet external to the clutch mechanism so as to prevent less than a predetermined amount of the axially applied magnetic flux from overcoming the spring and forcing the anvil to move away from the confining end of

Abstract: A magnetometer for detecting variations in a DC magnetic field. The magnetometer includes a magnetic field variation sensitive device that resonates at a characteristic resonant frequency by converting energy stored therein as a result of being excited by electromagnetic radiation at twice the resonant frequency when biased by a DC magnetic bias field within a predetermined field intensity range in which the amplitude of the resonance varies with variations of the field intensity.

Abstract: A batteryless, portable, transponder useful in a tag for a presence detection system. The transponder detects electromagnetic radiation at a first predetermined frequency and responds to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency. The transponder includes an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency.

Abstract: A batteryless, portable, frequency divider consists of a single resonant circuit consisting of an inductor and a diode. The resonant circuit detects electromagnetic radiation at a first predetermined frequency and responds to said detection by transmitting electromagnetic radiation at a second frequency that is one-half of the first frequency. The circuit is resonant at the second frequency when the voltage across the diode is zero. The frequency divider is utilized in a presence detection system that uses a tag containing the frequency divider. The system transmits electromagnetic radiation at the first frequency into a surveillance zone, and detects the second frequency to detect the presence of the tag in the surveillance zone.

Abstract: A batteryless, portable, frequency divider, consisting of a single resonant circuit including a nonlinear inductor having a core made of amorphous magnetic material; and a capacitance connected in series with the inductor to define a resonant circuit that detects electromagnetic radiation at a first predetermined frequency and responds to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency. The resonant circuit may further include a second inductor connected in series with the nonlinear inductor and the capacitance to define the resonant circuit. The core of the nonlinear inductor includes an elongated thin flat ribbon of low coercivity amorphous magnetic material.

Abstract: A ball clutch mechanism for restraining a pin from longitudinal movement, including an anvil, a radially symmetrical cup, a spring and two two-ball sets of uniformly dimensioned balls. The anvil has an axial bore for axially receiving the pin. The cup has a confining end, a tapered interior wall and a predominantly open end covering the anvil and axially aligned with the anvil for axially receiving a pin that is axially received by the bore of the anvil. The anvil is longitudinally movable along its bore axis with respect to the cup. The spring forces the anvil toward the confining end of the cup. The first set of balls engages the anvil and is forced by the anvil toward the confining end of the cup by the spring. The second set of balls is in the extreme confining end of the cup for clutching the pin.

Abstract: A batteryless, portable, frequency divider including a first LC circuit that is resonant at a first frequency for receiving electromagnetic radiation at the first frequency; a second LC circuit that is resonant at a second frequency that is one-half the first frequency; and a transistor coupling the first and second LC circuits for causing the second LC circuit to transmit electromagnetic radiation at the second frequency in response to the first LC circuit detecting electromagnetic radiation at the first frequency. The first and second LC circuits respectively include inductance coils that are positioned orthogonally to one another so as not to be mutually coupled. The frequency divider is operable solely from unrectified energy at the first frequency provided in the first circuit upon receipt of the electromagnetic radiation at the first frequency detected by the first LC circuit.

Abstract: In a device for deterring theft of a protected article, including a pin and clutch respectively embodied in two components that are adapted to be locked together on opposite sides of a portion of the protected article to prevent unauthorized removal of the device from the article, the pin-containing component contains two fragile elongated glass vials that fracture when at least a predetermined pressure is applied thereto, with the vials containing a detrimental substance that would damage an article attached to the device if such substance were to be released from the vial; and the head of the pin includes a breaker element having a wedge-shaped surface of a fiber-loaded-reinforced thermoplastic, (which does not scratch glass), for applying more than the predetermined pressure against the vial in response to the pinhead being moved in response to application to the two components of at least a predetermined threshold separation force, to thereby completely fracture the vials by inducing a high bending stress