Security Tag Systems, Inc.

Xlink Enterprises, Inc.

Link Enterprises Corporation

Lincoln H Charlot, Jr

Lucian G Ferguson

Fred W Herman

John L Lynch

David L Acosta

James H Swindell

Dennis L Hogan

Ming R Lian

Carter W Clarke, Jr

Douglas A Drew

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.

Autonomous interrogating transponder for direct communications with other transponders

Antenna with octagon-shaped center

Antenna with square-shaped center

Antenna with round-shaped center

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. In another class of embodiments, the parallel circuit is resonant at the higher first frequency and the series circuit is resonant at the frequency-divided second frequency; the frequency divider includes a three-terminal semiconductor switching device having a control terminal, a reference terminal, and a controlled terminal, which is connected directly across both resonant circuits and between the inductance and the capacitance of the series resonant circuit and which switches on and off in response to variations in energy in the parallel resonant circuit resulting from the parallel resonant circuit receiving electromagnetic radiation at the first frequency to cause the series resonant circuit to transmit electromagnetic radiation at the second frequency.

Signal-powered frequency-dividing transponder

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. The attachment rods are made from steel rods that are hardened so as not to be cuttable with hand tools.

Non-cuttable device for attachment of shoplifting detection tag

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. The magnetic field source includes a coil disposed in or adjacent the surveillance zone and an adjustable current source for causing a current to flow through the coil to provide a magnetic bias field within the surveillance zone. The coil is a large aperture solenoid coil wound on a core of metallic material of high permeability and high magnetic saturation. The core may be shielded from the electromagnetic radiation field of the first predetermined frequency by a non-ferrous electrically conductive tube disposed around the coil. The amplitude of the current is adjusted to provide a magnetic bias field within said predetermined magnetic field intensity range within the surveillance zone. The amplitude of the current is varied to sweep the intensity of the magnetic bias field through such a range of magnetic field intensities as to cause the magnetic bias field within each portion of the surveillance zone to be within said predetermined magnetic field intensity range during at least a portion of said sweep. A control system is coupled to the detection system and the adjusting means to determine whether detection by the detection means of electromagnetic radiation at the second predetermined frequency is due to the movement of a tag through the surveillance system or is due to the presence of a stationary tag in or near the surveillance zone.

Adjusting magnetic bias field intensity in EAS presence detection system

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. The magnet and the pole piece are forced into their protracted position by a spring; and a flange is attached to the pole piece for enabling the magnet and the pole piece to be moved to their retracted position by applying pressure against the flange to overcome the force of the spring. When the magnet and the pole piece are in their retracted position, the attraction between the magnet and the anvil is less and the sides of the clutch-containing component are exposed so that the clutch-containing component can easily be gripped at its sides and removed from the seat. Also, when the magnet and the pole piece are in their retracted position, the releasing apparatus does not then enable the pin-anchoring component to be released from the clutch-containing component; and the releasing apparatus further includes a lock for locking the magnet and the pole piece in their retracted position to prevent unauthorized use of the releasing apparatus.

Release of pin-clutch mechanism in theft-deterrent device

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 without prematurely cracking the vials, and to thereby release the substance contained therein before the components are separated by prying or pulling the components apart. A pliable seal is disposed between the breaker element and the vials for preventing the detrimental substance that is released from the fractured vials from entering the head space and for expelling the released detrimental substance through the adjacent opening in response to pressure applied against the seal by the breaker element by the movement of the pinhead that results in the vials being fractured.

Expulsion of detrimental substance from theft-deterrent device

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. The vial-containing component is so structured as to include a plurality of regions in which the vial-containing component flexes more easily in a predetermined direction than in other directions and regions, with the predetermined direction of easier flexing being different in different said given regions; and the vials are respectively disposed within each of the given regions of the vial-containing component such that when any of the given regions of the vial-containing component is flexed in the predetermined direction of easier-flexing for said given region, the vial disposed in said region is flexed longitudinally and fractures to thereby release the substance contained therein. The other component is so structured as not to flex when the attempt is made to pry the vial-containing component from the other component while the two components are locked together, thereby concentrating flexure forces resulting from said prying in the vial-containing component.

Detrimental-substance-containing theft-deterrent device

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 the cup. The clutch mechanism further includes a radially disposed pole piece for directing magnetic flux applied radially by a pole piece coupled to the magnet so that at least a predetermined amount of the radially applied magnetic flux is so concentrated axially in the anvil as to overcome the force of the spring and force the anvil to move away from the first end of the cup.

Pin-clutch mechanism for theft-deterrent device

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. The magnetometer further includes an excitation circuit for exciting the device to resonate at the characteristic resonant frequency at an amplitude level that remains constant when the DC magnetic bias field intensity does not vary and is within the predetermined field intensity range; a DC voltage source within the excitation circuit for biasing the device with a DC magnetic bias field that is within the predetermined field intensity range; and a sensing instrument for sensing the amplitude of the resonance of the device at the characteristic resonant frequency. A variation in the amplitude of the resonance sensed by the sensing instrument indicates a variation in the intensity of the DC magnetic bias field. The magnetometer is utilized in a variety of different systems, including a system for actuating an output instrument, such as a traffic signal controller, in response to a predetermined threshold variation in a DC magnetic bias field, such as occurs when a motor vehicle moves into the vicinity of the magnetometer; a system for probing for materials whose presence affects the intensity of a DC magnetic bias field, such as buried pipes or ferromagnetic mineral deposits; a system for communicating in the low frequency range of the electromagnetic spectrum; and a system for guiding a probe with respect to the location of an object whose presence causes a variation in the intensity of a magnetic bias field.

Magnetometer for detecting DC magnetic field variations

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. In one embodiment the transponder includes a thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anisotropy defining a magnetomechanical resonant frequency 'f' in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the ribbon responds to the detection of electromagnetic radiation having a frequency '2f' by transmitting electromagnetic radiation at a subharmonic of the frequency '2f'; and means for biasing the ribbon with the predetermined magnetic bias field. In another embodiment, the transponder consists 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 the resonant circuit. The core of the nonlinear inductor includes an elongated thin, flat ribbon of low coercivity amorphous mangetic material. It has been observed that this resonant circuit exhibits a bifurcated frequency-division characteristic in relation to the amplitude of the detected electromagnetic radiation at the first predetermined frequency, whereby additional frequency divisions occur as the amplitude is increased. A coded tag includes two amorphous magnetic material transponders that detect electromagnetic radiation at different frequencies.

Frequency-dividing transponder and use thereof in a presence detection

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.

Growing community of inventors

St. Petersburg, FL, United States of America

Lincoln H Charlot, Jr