Other

Weatherford/lamb, Inc.

University of Calgary

Universal Skate Sharpener Ltd.

Trofimenkoff Engineering, Ltd.

Frederick N Trofimenkoff

James William Haslett

Marvin L Holbert

Robert E Smallwood

Chun O Li

Faramarz Sabouri

Daniel J Paslawski

Joseph A Consay

David H Weiler

Donald M Dobie

Jai Bhagwan

Sandro P Poscente

Warren Myrfield

James H Hannaford

An insulator for a subsurface signal transmitting apparatus. The insulator includes a housing, a mandrel axially disposed inside the housing, a first insulating material disposed between the housing and the mandrel, a first sleeve formed of a second insulating material disposed between the housing and a first tubular member and the first tubular member coupled to the mandrel.

Subsurface signal transmitting apparatus

A subsurface signal transmitting apparatus including an insulation coupler, a carrier device for mounting the telemetry instrumentation, and a by-pass system for avoiding pressure build-up either above or below the apparatus. The insulation coupler includes a housing member having a central opening defined by an interior surface extending in the longitudinal direction and a mandrel member having an exterior surface spaced from the interior surface of the housing member to provide a gap or clearance with an insulating bonding material occupying the clearance. The surfaces are oriented so that when the coupling is in tension at least a portion of the two surfaces experience interacting forces towards each other in the longitudinal direction of the coupling and in event of failure of the bonding material, the mandrel member is unable to withdraw from the housing member. The by-pass system includes a by-pass tube which extends through central openings of the insulation coupler and carrier device and provides for electrically insulating one end of the assembly from the other but allows for pressure equalization via a fluid passageway. The carrier device has a cylindrical body forming external channels for concealing instruments about is circumference.

The subsurface signal transmitting apparatus ( ) including an insulation coupler ( ), a carrier device ( ) for mounting the telemetry instrumentation ( ), and a by-pass system for avoiding pressure build-up either above or below the apparatus. The insulation coupler ( ) includes a housing member ( ) having a central opening ( ) defined by an interior surface ( ) extending in the longitudinal direction and a mandrel member ( ) having an exterior surface ( ) spaced from the interior surface ( ) of the housing member ( ) to provide a gap or clearance ( ) with an insulating bonding material ( ) occupying the clearance. The surfaces are oriented so that when the coupling is in tension at least a portion of the two surfaces that when the coupling is in tension at least a portion of the two surfaces experience interacting forces towards each other in he longitudinal direction of the coupling and in event of failure of the bonding material, the mandrel member is unable to withdraw from the housing member. The by-pass system includes a by-pass tube ( ) which extends through central openings ( ) of the insulation coupler ( ) and carrier device ( ) and provides for electrically insulating one end of the assembly from the other but allows for pressure equalization via a fluid passage-way ( ). The carrier device ( ) has a cylindrical body ( ) forming external channels ( ) for concealing instruments ( ) about its circumference.

A subsurface signal transmitting apparatus including an insulation coupler, a carrier device for mounting the telemetry instrumentation, and a by-pass system for avoiding pressure build-up either above or below the apparatus. The insulation coupler includes a housing member having a central opening defined by an interior surface extending in the longitudinal direction and a mandrel member having an exterior surface spaced from the interior surface of the housing member to provide a gap or clearance with an insulating bonding material occupying the clearance. The surfaces are oriented so that when the coupling is in tension at least a portion of the two surfaces experience interacting forces towards each other in the longitudinal direction of the coupling and in event of failure of the bonding material, the mandrel member is unable to withdraw from the housing member. The by-pass system includes a by-pass tube which extends through central openings of the insulation coupler and carrier device and provides for electrically insulating one end of the assembly from the other but allows for pressure equalization via a fluid passage-way. The carrier device has a cylindrical body forming external channels for concealing instruments about its circumference.

An electrical network creates a differential voltage signal and comprises a plurality of first impedance elements of substantially equal values which are connected to form an impedance bridge. The impedance of at least one of the first impedance elements changes in response to at least one selected external condition to which the first impedance elements are exposed. The network also comprises a second impedance element which has two nodes. The second impedance element is connected at these nodes between a first pair of the first impedance elements. The differential voltages are measured between these nodes and between another node or nodes with magnitudes and signs being dependent upon the change in the impedance of the first impedance elements.

Resistance bridge and its use in conversion systems

A clock-controlled voltage-to-frequency converter comprising a reference voltage source, an integrator for receiving the reference voltage and a variable input voltage and producing an output having a triangular waveform, the integrator including a capacitor which is charged at a rate proportional to the input voltage and discharged at a rate proportional to the difference between the reference voltage and the input voltage, the charging and discharging occurring during a time interval T.sub.o, a clock pulse source for generating a continuous series of clock pulses, a counter responsive to the clock pulses for terminating the discharging of the capacitor and initiating the charging of the capacitor at a fixed time interval following termination of the charging of the capacitor, a logic circuit responsive to the output of the integrator for terminating the charging of the capacitor and initiating the discharging of the capacitor when the integrator output rises above a preselected threshold level, the time required for the capacitor to charge to the threshold level varying in accordance with the magnitude of the input voltage.

Clock-controlled voltage-to-frequency converter

A clock-controlled pulse width modulator comprising an integrator for receiving a variable input voltage and producing an output having a triangular waveform, the integrator including a capacitor which is charged at a rate proportioal to the input voltage and discharged at a rate proportional to the difference between a reference voltage and the input voltage, the charging and discharging occurring during a time interval T.sub.o, a clock pulse source for generating a continuous series of clock pulses, a counter receiving the clock pulses and producing a binary control signal which changes state in response to the counting of a preselected number of clock pulses, the control signal having a period T.sub.o, and control means for terminating the charging of the capacitor and initiating the discharging of the capacitor in response to the first clock pulse following a selected transition in the control signal, and means for terminating the discharging of the capacitor and initiating the charging of the capacitor in response to the first clock pulse following the discharge of the capacitor to a preselected threshold level.

Clock-controlled pulse width modulator

A voltage-to-frequency and analog-to-digital conversion circuit using a microprocessor-controlled capacitor charge-discharge scheme provides high resolution and low component count and is particularly suitable for use with resistance bridge transducers.

Voltage-to-frequency and analog-to-digital converter circuit

Grinding apparatus is disclosed with the preferred embodiment being an automatic ice skate sharpening machine. The workpiece is secured to the frame, and a grinding wheel, mounted on a longitudinally moveable carriage, is biased against the workpiece for relative grinding movement. Sensing means are provided for detecting the grinding resistance of the workpiece on the grinding wheel, and control means responsive to the sensing means are provided for regulating the bias of the grinding wheel against the workpiece, in order to avoid chattering.

Growing community of inventors

Calgary, Canada

Frederick N Trofimenkoff