Patents by Inventor David J. Mitchell

David J. Mitchell has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20140255169
    Abstract: A turbine including a plurality of stages, each stage including a rotatable disk and blades carried thereby. An annular gap defined between a pair of adjacent rotatable disks. A sealing band is located in opposing sealing band receiving slots formed in the adjacent disks to seal the annular gap, the sealing band including band engagement structure. A disk engagement structure is defined in the pair of adjacent rotatable disks. The disk engagement structure extends axially into the pair of adjacent rotatable disks and circumferentially aligns with the band engagement structure. A clip member is positioned in engagement with the sealing band through the band engagement structure and in engagement with the pair of adjacent rotatable disks through the disk engagement structure. The clip member restricts movement of the sealing band in only a circumferential direction of the slots.
    Type: Application
    Filed: March 8, 2013
    Publication date: September 11, 2014
    Inventors: Christopher J. Muller, David J Mitchell, Michael J Olejarski
  • Patent number: 8803703
    Abstract: A circuitry adapted to operate in a high-temperature environment of a turbine engine is provided. A relatively high-gain differential amplifier (102) may have an input terminal coupled to receive a voltage indicative of a sensed parameter of a component (20) of the turbine engine. A hybrid load circuitry may be coupled to the differential amplifier. A voltage regulator circuitry (244) may be coupled to power the differential amplifier. The differential amplifier, the hybrid load circuitry and the voltage regulator circuitry may each be disposed in the high-temperature environment of the turbine engine.
    Type: Grant
    Filed: July 12, 2012
    Date of Patent: August 12, 2014
    Assignees: Siemens Energy, Inc., Arkansas Power Electronics International, Inc.
    Inventors: David J. Mitchell, John R. Fraley, Jie Yang, Cora Schillig, Bryon Western, Roberto Marcelo Schupbach
  • Patent number: 8797179
    Abstract: A telemetry system for use in a combustion turbine engine (10) that includes a first sensor (306) in connection with a turbine blade (301) or vane (22). A first telemetry transmitter circuit (312) is affixed to the turbine blade and routes electronic data signals, indicative of a condition of the blade, from the sensor to a rotating data antenna (314) that is affixed to the turbine blade or is on a same substrate as that of the circuit. A stationary data antenna (333) may be affixed to a stationary component (323) proximate and in spaced relation to the rotating data antenna for receiving electronic data signals from the rotating data antenna. A second sensor (335) transmits electronic data signals indicative of the stationary component to a second telemetry circuit (332), which routes the signals to the stationary antenna. The stationary antenna transmits the electronic data signals to a receiver (338).
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: August 5, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Ramesh Subramanian, Anand A. Kulkarni, David J. Mitchell, Bjoern Karlsson, Rod Waits, John R. Fraley
  • Patent number: 8766720
    Abstract: A circuitry (120) adapted to operate in a high-temperature environment of a turbine engine is provided. The circuitry may include a differential amplifier (122) having an input terminal (124) coupled to a sensing element to receive a voltage indicative of a sensed parameter. A hybrid load circuitry (125) may be AC-coupled to the differential amplifier. The hybrid load circuitry may include a resistor-capacitor circuit (134) arranged to provide a path to an AC signal component with respect to the drain terminal of the switch (e.g., 126) of a differential pair of semiconductor switches 126, 128, which receives the voltage indicative of the sensed parameter.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: July 1, 2014
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, John R. Fraley, Jie Yang, Cora Schillig, Roberto Marcelo Schupbach, Bryon Western
  • Patent number: 8742944
    Abstract: An integrated, self-powered, sensing and transmitting module (300) that can be placed within an operating environment, such as by being affixed to a gas turbine engine component, in order to sense the local operating environment and to deliver real-time operating environment data to a location outside of the environment. Such a module may integrate a power element (302); a sensing element 9304); and a transmitting element (308) on a single substrate (320) within a single housing (310). Both sensors and circuitry components are formed directly on or in the substrate in novel configurations to decrease the size and weight of the module.
    Type: Grant
    Filed: August 31, 2009
    Date of Patent: June 3, 2014
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian
  • Patent number: 8717095
    Abstract: Chopper circuitry may be adapted to operate in a high-temperature environment of a turbine. A first semiconductor switch (122) may have a first terminal coupled to receive a first output signal from a first leg (148) of a differential amplifier (150). A second switch (128) may have a first terminal coupled thru a first resistive element (R1) to a second terminal of the first semiconductor switch. The first terminal of the second semiconductor switch may be coupled to receive thru a second resistive element (R2) a second output signal from a second leg (152) of the amplifier. Switches (122,128) may be responsive to a switching control signal to respective gate terminals of the switches to supply an output signal, which alternates in correspondence with a frequency of the switching control signal from a first amplitude level to a second amplitude level, which effectively provides a doubling amplification factor.
    Type: Grant
    Filed: July 9, 2012
    Date of Patent: May 6, 2014
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Jie Yang, Roberto Marcelo Schupbach, John R. Fraley, Cora Schillig, Bryon Western
  • Patent number: 8662746
    Abstract: A gas turbine component (49) may be instrumented to provide a plurality of signals indicative of thermal measurements in a high temperature combustion environment of the gas turbine. A thermocouple arrangement may include a first thermocouple leg (50) disposed within a thickness of the component. At least two or more thermocouple legs (52, 53, 54) is each electrically connected to the first leg to form individual thermocouple junctions (56, 57, 58, 59) along the first leg for conversion of respective thermal gradients to respective electrical signals, such as electromotive force (emf) based voltages. The thermocouple arrangement may be used in combination with a thermographic system (70) to calculate heat flux over a region of the turbine component.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: March 4, 2014
    Assignee: Siemens, Energy Inc.
    Inventors: Ramesh Subramanian, Anand A. Kulkarni, Vinay Jonnalagadda, David J. Mitchell
  • Patent number: 8629783
    Abstract: In a telemetry system for use in an engine, a circuit structure (34) affixed to a moving part (20) of the engine is disposed for amplifying information sensed about a condition of the part and transmitting the sensed information to a receiver external to the engine. The circuit structure is adapted for the high temperature environment of the engine and includes a differential amplifier (102, 111) having an input for receiving a signal from a sensor (101, 110) disposed on the part. A voltage controlled oscillator (104, 115) with an input coupled to the output of the amplifier produces an oscillatory signal having a frequency representative of the sensed condition. A buffer (105, 116) with an input coupled to the output of the oscillator buffers the oscillatory signal, which is then coupled to an antenna (26) for transmitting the information to the receiver.
    Type: Grant
    Filed: June 19, 2012
    Date of Patent: January 14, 2014
    Assignees: Siemens Energy, Inc., Arkansas Power Electronics International, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch, Rod Waits, Roberto Schupbach, John R. Fraley, Alexander B. Lostetter, Brice McPherson, Bryon Western
  • Publication number: 20140009222
    Abstract: Chopper circuitry may be adapted to operate in a high-temperature environment of a turbine. A first semiconductor switch (122) may have a first terminal coupled to receive a first output signal from a first leg (148) of a differential amplifier (150). A second switch (128) may have a first terminal coupled thru a first resistive element (R1) to a second terminal of the first semiconductor switch. The first terminal of the second semiconductor switch may be coupled to receive thru a second resistive element (R2) a second output signal from a second leg (152) of the amplifier. Switches (122,128) may be responsive to a switching control signal to respective gate terminals of the switches to supply an output signal, which alternates in correspondence with a frequency of the switching control signal from a first amplitude level to a second amplitude level, which effectively provides a doubling amplification factor.
    Type: Application
    Filed: July 9, 2012
    Publication date: January 9, 2014
    Inventors: David J. Mitchell, Jie Yang, Roberto Marcelo Schupbach, John R. Fraley, Cora Schillig, Bryon Western
  • Publication number: 20140002191
    Abstract: A circuitry (120) adapted to operate in a high-temperature environment of a turbine engine is provided. The circuitry may include a differential amplifier (122) having an input terminal (124) coupled to a sensing element to receive a voltage indicative of a sensed parameter. A hybrid load circuitry (125) may be AC-coupled to the differential amplifier. The hybrid load circuitry may include a resistor-capacitor circuit (134) arranged to provide a path to an AC signal component with respect to the drain terminal of the switch (e.g., 126) of a differential pair of semiconductor switches 126, 128, which receives the voltage indicative of the sensed parameter.
    Type: Application
    Filed: June 29, 2012
    Publication date: January 2, 2014
    Inventors: David J. Mitchell, John R. Fraley, Jie Yang, Cora Schillig, Roberto Marcelo Schupbach, Bryon Western
  • Publication number: 20140002050
    Abstract: A voltage regulator circuitry (50) adapted to operate in a high-temperature environment of a turbine engine is provided. The voltage regulator may include a constant current source (52) including a first semiconductor switch (54) and a first resistor (56) connected between a gate terminal (G) and a source terminal (S) of the first semiconductor switch. A second resistor (58) is connected to the gate terminal of the first semiconductor switch (54) and to an electrical ground (64). The constant current source is coupled to generate a voltage reference across the second resistor 58. A source follower output stage 66 may include a second semiconductor switch (68) and a third resistor (58) connected between the electrical ground and a source terminal of the second semiconductor switch. The generated voltage reference is applied to a gating terminal of the second semiconductor switch (58).
    Type: Application
    Filed: June 29, 2012
    Publication date: January 2, 2014
    Inventors: David J. Mitchell, John R. Fraley, Jie Yang, Cora Schillig, Bryon Western, Roberto Marcelo Schupbach
  • Patent number: 8599082
    Abstract: A bracket assembly is used to mount a wireless telemetry component proximate a rotating component of a combustion turbine engine (10), wherein the wireless telemetry component includes an RF transparent ceramic cover (128). The bracket assembly comprises a first mounting bracket (125) on a surface proximate the rotating component that includes a first (138) and second (139) bracket member spaced apart from one another. The first (138) and second (139) bracket members are disposed generally perpendicular to a direction of centrifugal forces generated by the rotating component. At least one of the first (138) or second bracket (139) members is inclined toward the other bracket member and disposed at an acute angle relative to the surface (141) proximate the rotating component.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: December 3, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni
  • Patent number: 8564449
    Abstract: A component including a surface subject to wear by an electrically conductive wear counterface (50). The component comprises a substrate (10); one or more material layers (32) overlying the substrate (10); a wear surface layer (16) overlying the one or more material layers (32); a first pair of spaced apart and electrically open wear sensor conductors (12/14) disposed in the substrate (10), in the one or more material layers (32), or in the wear surface layer (16); a first wear warning electrical circuit (68/69/70/74) for communicating with the first pair of conductors (12/14) for providing a first wear warning; and wherein when the wear counterface (50) has worn overlying layers, the wear counterface (50) interconnects the first pair of conductors (12/14) to activate the first wear warning circuit (68/69/70/74).
    Type: Grant
    Filed: January 12, 2010
    Date of Patent: October 22, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni
  • Patent number: 8525036
    Abstract: A circuit assembly (34) resistant to high-temperature and high g centrifugal force is disclosed. A printed circuit board (42) is first fabricated from alumina and has conductive traces of said circuit formed thereon by the use of a thick film gold paste. Active and passive components of the circuit assembly are attached to the printed circuit board by means of gold powder diffused under high temperature. Gold wire is used for bonding between the circuit traces and the active components in order to complete the circuit assembly (34). Also, a method for manufacturing a circuit assembly resistant to elevated temperature is disclosed.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: September 3, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch, Rod Waits, Roberto Schupbach, John R. Fraley, Alexander B. Lostetter, Brice McPherson, Bryon Western
  • Patent number: 8527241
    Abstract: A telemetry system for use in a combustion turbine engine (10) having a compressor (12), a combustor and a turbine (16) and includes a sensor (118) in connection with a turbine blade (111) or vane (23). A transmitter assembly (117) includes a telemetry transmitter circuit/transceiver may be affixed on a turbine blade (111) or seal plate (115) proximate the turbine blade with a first connecting material (119) deposited on the turbine blade (111) for routing electronic data signals, indicative of a condition of the turbine blade (111), from the sensor (118) to the telemetry transmitter circuit/transceiver. An induction power system for powering the telemetry transmitter circuit/transceiver may include a rotating data antenna (116) affixed to the seal plate (115) with an electrical connection (122) between the telemetry transmitting circuit/transceiver for routing electronic data signals from the telemetry transmitter circuit/transceiver to the rotating data antenna (119).
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: September 3, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Ramesh Subramanian, Cora Schillig, Anand A. Kulkarni, Vinay Jonnalagadda, Bulent Acar, Sankar Nellian, James P. Williams, Edward R. Roesch
  • Patent number: 8519866
    Abstract: A telemetry system for use in a combustion turbine engine (10) having a compressor (12), a combustor and a turbine (16) that includes a sensor (50, 74) in connection with a turbine blade (18) or vane (22). A telemetry transmitter circuit (210) may be affixed to the turbine blade (18) with a first connecting material (52, 152) deposited on the turbine blade (18) for routing electronic data signals from the sensor (50, 74) to the telemetry transmitter circuit (210), the electronic data signals indicative of a condition of the turbine blade (18). An induction power system for powering the telemetry transmitter circuit (210) may include a rotating data antenna (202) affixed to the turbine blade (18) with a second connecting material (140) deposited on the turbine blade (18) for routing electronic data signals from the telemetry transmitter circuit (210) to the rotating data antenna (202).
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: August 27, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch, Rod Waits, John R. Fraley, Roberto M. Schupbach, Alexander B. Lostetter
  • Patent number: 8515711
    Abstract: A diagnostic system and method for monitoring operating conditions of turbine machine components (18, 19, 22, 23) that comprise one or more non-contact sensors (24, 31) that detect an operating condition of a turbine component (18, 19, 22, 23) over a defined region of the component. In addition, point sensors (50) are provided that detect and monitor the same operating condition within the defined region. Data generated from the point sensor (50) is used to calibrate the non-contact sensor (24, 31) and the data generated by the non-contact sensor (24, 31).
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: August 20, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Ramesh Subramanian, Nancy H. Ulerich, Paul J. Zombo
  • Patent number: 8458899
    Abstract: A circuit assembly (34) resistant to high-temperature and high g centrifugal force is disclosed. A printed circuit board (42) is first fabricated from alumina and has conductive traces of said circuit formed thereon by the use of a thick film gold paste. Active and passive components of the circuit assembly are attached to the printed circuit board by means of gold powder diffused under high temperature. Gold wire is used for bonding between the circuit traces and the active components in order to complete the circuit assembly (34). Also, a method for manufacturing a circuit assembly resistant to elevated temperature is disclosed.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: June 11, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: David J. Mitchell, Anand A. Kulkarni, Ramesh Subramanian, Edward R. Roesch, Rod Waits, Roberto Schupbach, John R. Fraley, Alexander B. Lostetter, Brice McPherson, Bryon Western
  • Patent number: 8357454
    Abstract: A ceramic thermal barrier coating (TBC) (18) having first and second layers (20, 22), the second layer (22) having a lower thermal conductivity than the first layer for a given density. The second layer may be formed of a material with anisotropic crystal lattice structure. Voids (24) in at least the first layer (20) make the first layer less dense than the second layer. Grooves (28) are formed in the TBC (18) for thermal strain relief. The grooves may align with fluid streamlines over the TBC. Multiple layers (84, 86, 88) may have respective sets of grooves (90), Preferred failure planes parallel to the coating surface (30) may be formed at different depths (A1, A2, A3) in the thickness of the TBC to stimulate generation of a fresh surface when a portion of the coating fails by spalling. A dense top layer (92) may provide environmental and erosion resistance.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: January 22, 2013
    Assignee: Siemens Energy, Inc.
    Inventors: Anand A. Kulkarni, David J. Mitchell, Ramesh Subramanian, Andrew J. Burns
  • Publication number: 20130008179
    Abstract: An inductance-stable ultra high temperature circuit coupling transformer (50) used to transmit and receive alternating current power and/or data signals (29?, 33?). Primary (30?) and secondary (34?) windings are formed on nanostructured laminated (31?) primary and secondary steel cores (32?) having a Curie temperature exceeding an ultra high operating temperature. The operating range can extend from ambient to 250° C. or to in excess of 550° C. or up to 700° C. with a change in inductance of less than 10% in various embodiments.
    Type: Application
    Filed: July 6, 2011
    Publication date: January 10, 2013
    Inventors: David J. Mitchell, Cora Schillig, Rod Waits, Anand A. Kulkarni