3M Innovative Properties Company

Minnesota Mining and Manufacturing Company

Other

Ziyad Hanna Doany

Michael E Hamerly

Curtis L Shoemaker

Ding Wang

William C Egbert

Terrence H Joyce

Dean M Dowdle

Timothy A Parkinson

Gary A Morris

Corey M Willson

A marker device for locating buried infrastructure comprises a cover, a marker detectable underground by a magnetic field detecting locating device; and a holder formed from a compliant material. The marker has a diameter smaller than an inner diameter of the cover. The marker is secured between an inner surface of the cover and a first surface of the holder. The holder is configured to attach to an outer surface of a utility valve cap of an underground valve.

Marker device for underground infrastructure

A magneto mechanical resonator device comprises a ferromagnetic resonator element having a length substantially equal to an integer multiple (N) of a &#xbd; wavelength of a resonant frequency of the ferromagnetic resonator element, wherein the ferromagnetic resonator element is formed from an amorphous metal material, wherein N is at least 2, and at least one bias magnetic element disposed along a lateral side of the ferromagnetic resonator element.

Magneto-mechanical marker with enhanced frequency stability and signal strength

A magnetoelastic resonator device comprises a housing, at least one elliptically-shaped or substantially elliptically-shaped magnetoelastic element disposed within the housing, and at least one bias magnet disposed in the housing, wherein the at least one elliptically-shaped or substantially elliptically-shaped magnetoelastic element is configured to couple to an external magnetic field at a particular frequency and convert the magnetic energy into mechanical energy, in the form of oscillations.

Elliptically-shaped resonator markers with enhanced frequency stability and gain

A tape format magnetoelastic resonator device comprises a continuous ribbon of amorphous magnetic material having a plurality of separate, hinged magnetoelastic resonator strips formed from the ribbon, linearly displaced along a longitudinal axis of the ribbon, wherein each magnetoelastic resonator strip is configured to couple to an external magnetic field at a particular frequency and convert the magnetic energy into mechanical energy, in the form of oscillations.

Tape format magnetoelastic resonator markers

A magneto mechanical resonator device comprises a plurality of ferromagnetic elements disposed in a stacked arrangement, each ferromagnetic element having a first lengthwise end and a second lengthwise end. A first bias magnetic element is disposed adjacent to the first lengthwise end of the stacked arrangement and a second bias magnetic element is disposed adjacent to the second lengthwise ends of the stacked arrangement. A clamping element is disposed in a central lengthwise region of the stacked arrangement to restrict the vertical displacement of the plurality of ferromagnetic elements with respect to each other at the central lengthwise region, wherein the first and second ends experience flaring movement.

An article, system and method related to a magnetomechanical marker used to mark stationary assets. Magnetomechanical markers can be arranged in clusters and associated with stationary assets, including assets buried underground. Markers can be associated with an asset by being attached to the asset, arranged in a particular spatial relationship with the asset, or in any other appropriate way. A portable locating device can be used to generate an alternating magnetic field to activate the magnetomechanical marker and thus locate the asset.

Magnetomechanical markers for marking stationary assets

A system for locating a position marker includes a locating device for locating the position marker, and a GPS device communicatively coupled to the locating device that provides GPS coordinate data when the position marker is located by the locating device. Electronic memory is provided in at least one of the locating device and the GPS device for storing a data record associating the GPS coordinate data with the located position marker.

GPS interface for locating device

A method for simultaneously reading a serial number and/or other information from multiple colliding RF signals from RF identification tags requires minimal additional logic in the tag's processor and provides for a powerful and rapid sorting and identification scheme. This technique employs a primary communication channel and multiple secondary channels. A locator or reader unit interrogates the tags, which respond with an RF signal. Upon receiving multiple signals, the locator or reader unit commands the RFID tags and requires them to transmit another response, which is transmitted in one of the secondary channels based on a portion of their unique serial identification number, thereby forcing the tags to sort in the secondary channels. These secondary channels are assigned using a portion of the unique serial identification numbers for the tags. The reader then detects an acknowledgment in the occupied secondary channels and commands a tag in a particular channel to move to the primary channel. Once the signal is transmitted in the primary channel, the reader reads the identification number. If there is further collision, the collided tags are returned to the secondary channel and sorted again using a different portion of their ID number. This process continues until all the tags are sorted and identified. Once the tags are all sorted, the tags are assigned yet another channel distinct from the secondary channels that are used for sorting.

Collision arbitration method and apparatus for reading multiple radio frequency identification tags

An extended range coil for an inductance-capacitance tuned circuit and a method for its manufacture. The extended range coil comprises a wire-wound planar spiral portion, having a circumference, and a wire-wound wall portion joined to the wire-wound planar spiral portion and extending outward from the circumference thereof. An extended range coil according to the present invention may use a continuous length of wire for winding the wire-wound planar spiral portion and the wire-wound wall portion.

Extended range passive marker

An apparatus for locating obscured conduits, such as buried cables, employs a novel signal processing technique to increase the sensitivity of the apparatus, particularly in congested areas. The cable locating apparatus is similar to prior art dual-peak detection devices which compare signals from two parallel induction coils, but a phase shift is introduced into one of the signals prior to the comparison. This phase shift serves to minimize the effects of side minima in the response curve of prior art dual-peak devices. This effect is enhanced by adding a gain mismatch to the two detected signals. The locator preferably operates with analog signals to reduce expense.

Apparatus for locating buried conductors using phase-shifted signals

An adapter for a conventional conductor locator allows the locator to additionally detect the presence of passive, electronic markers. The adapter includes an electronic marker locator and a wireless interface housed in a common body which may be releasably attached to the conductor locator. The electronic marker locator, which may comprise conventional circuitry, outputs a marker detection signal to the wireless interface, which conditions the signal so that it is compatible with the input sensor of the conductor locator. The wireless interface includes an output antenna which is positioned adjacent the input sensor of the conductor locator when the adapter is attached thereto. If the conductor locator is of the type which may receive test signals at different operating frequencies, then the wireless interface also includes a modulator to selectively convert the marker detection signal to one of these operating frequencies. The electronic marker locator portion of the adapter may also be selectively adjusted to detect different discrete marker frequencies. The adapter may operate in a sleep mode, wherein the output signal of the wireless interface is disabled, but the wireless interface may still alert the user to the presence of an electronic marker by an audible alarm.

Conductor locator adapter for electronic markers

An amplifier which has special application as an induction coil driver. A multi-frequency signal is used to modulate the pulse width of a square wave, resulting in a pulse modulated signal. The pulse modulated signal is divided into two delay signals. The falling edge of each pulse is delayed in one of the delay signals, while the rising edge of each pulse is delayed in the other delay signal. This creates a 'dead band' between the two signals for each pulse. The signals are used to drive two metal oxide semiconducting field-effect transistors, which are connected to positive and negative power supplies. The switching of the MOSFETs occurs during the dead band which, when combined with a novel inductor-diode circuit, results in high-efficiency power transfer. The amplified modulated signal is then subjected to a low-pass filter which cancels out the square wave carrier and switching noise. The amplified analog signal may then be applied to a non-tuned induction coil.

Growing community of inventors

Austin, TX, United States of America

Ziyad Hanna Doany