Patents by Inventor Prabhakar P. Rao
Prabhakar P. Rao 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).
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Patent number: 6143573Abstract: A modular vial autosampler has a storage area for vials containing samples to be analyzed and at least one modular sampling station. A vial transfer mechanism lifts a sample vial from the storage section, moves it to a station for identification and then to a sampling station, and under central control activates the sampling station for obtaining a sample for analysis. The vial transfer mechanism is movable in x, y, and z directions to capture and move a selected vial. The autosampler has a series of valves operable under central control to selectively introduce two different standards into the sample, and after obtaining the sample, for rinsing and purging the conduits or lines and needles to reduce sample carryover. The modular vial autosampler includes controls to selectively sample either a gas or a liquid using many of the same components.Type: GrantFiled: October 23, 1996Date of Patent: November 7, 2000Assignee: Tekmar CompanyInventors: Prabhakar P. Rao, Edmund T. Lewis, Thomas B. Green
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Patent number: 6056921Abstract: A modular vial autosampler has a storage area for vials containing samples to be analyzed and at least one modular sampling station. A vial transfer mechanism lifts a sample vial from the storage section, moves it to a station for identification and then to a sampling station, and under central control activates the sampling station for obtaining a sample for analysis. The vial transfer mechanism is movable in x, y, and z directions to capture and move a selected vial. The autosampler has a series of valves operable under central control to selectively introduce two different standards into the sample, and after obtaining the sample, for rinsing and purging the conduits or lines and needles to reduce sample carryover. The modular vial autosampler includes controls to selectively sample either a gas or a liquid using many of the same components.Type: GrantFiled: April 24, 1997Date of Patent: May 2, 2000Assignee: Tekmar CompanyInventors: Prabhakar P. Rao, Edmund T. Lewis, Thomas B. Green
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Patent number: 5998217Abstract: A modular vial autosampler has a storage area for vials containing samples to be analyzed and at least one modular sampling station. A vial transfer mechanism lifts a sample vial from the storage section, moves it to a station for identification and then to a sampling station, and under central control activates the sampling station for obtaining a sample for analysis. The vial transfer mechanism is movable in x, y, and z directions to capture and move a selected vial. The autosampler has a series of valves operable under central control to selectively introduce two different standards into the sample, and after obtaining the sample, for rinsing and purging the conduits or lines and needles to reduce sample carryover. The modular vial autosampler includes controls to selectively sample either a gas or a liquid using many of the same components.Type: GrantFiled: April 24, 1997Date of Patent: December 7, 1999Assignee: TEKMAR CompanyInventors: Prabhakar P. Rao, Edmund T. Lewis, Thomas B. Green
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Patent number: 5993744Abstract: A modular vial autosampler has a storage area for vials containing samples to be analyzed and at least one modular sampling station. A vial transfer mechanism lifts a sample vial from the storage section, moves it to a station for identification and then to a sampling station, and under central control activates the sampling station for obtaining a sample for analysis. The vial transfer mechanism is movable in x, y, and z directions to capture and move a selected vial. The autosampler has a series of valves operable under central control to selectively introduce two different standards into the sample, and after obtaining the sample, for rinsing and purging the conduits or lines and needles to reduce sample carryover. The modular vial autosampler includes controls to selectively sample either a gas or a liquid using many of the same components.Type: GrantFiled: February 8, 1999Date of Patent: November 30, 1999Assignee: Tekmar CompanyInventors: Prabhakar P. Rao, Edmund T. Lewis, Thomas B. Green
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Patent number: 5948360Abstract: A modular vial autosampler has a storage area for vials containing samples to be analyzed and at least one modular sampling station. A vial transfer mechanism includes an arm having a gripper that lifts a sample vial from the storage section, and the arm moves it to a station for identification and then to a sampling station, and under central control activates the sampling station for obtaining a sample for analysis. The vial transfer mechanism gripper is movable in X, Y, and Z directions to capture and move a selected vial and includes an alignment guide for the vials. Potentiometers are used for providing signals indicating arm position and the control is provided with updated information for calibration of the potentiometers and also updated position information for the arm relative to a fixed home position is obtained.Type: GrantFiled: August 29, 1997Date of Patent: September 7, 1999Assignee: Tekmar CompanyInventors: Prabhakar P. Rao, Thomas B. Green, Harry W. Schmidt, Larry J. DaPrato, Greg J. Herman, Michael A. Hill
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Patent number: 4575313Abstract: A pressure controller includes a set point switch mechanism by which a selectable pressure to be maintained in a pressure vessel can be set. The actual pressure in the pressure vessel is detected and converted into a corresponding electrical signal by a suitable pressure transducer. Electrical signals from the set point switch mechanism and the transducer are utilized by a computer to generate control signals for controlling a volume adjustment mechanism which adjusts the effective volume of the pressure vessel and adjusts the quantity of pressurizing fluid disposed in the vessel. The volume adjustment mechanism includes a piston disposed in a cavity which is connectable with the chamber of the pressure vessel. The volume adjustment mechanism also includes a stepper motor which can be moved in precise increments to adjust the position of the piston in the cavity.Type: GrantFiled: September 19, 1984Date of Patent: March 11, 1986Assignee: Halliburton CompanyInventors: Prabhakar P. Rao, Jim B. Surjaatmadja, Jack C. Penn
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Patent number: 4567765Abstract: A fluid chamber assembly having an improved shape to enhance the reception of the first arrival of the signal from the transmitter transducer which has passed through the cement or fluid sample within the fluid chamber assembly and an improved sealing arrangement for the fluid chamber assembly.Type: GrantFiled: July 5, 1984Date of Patent: February 4, 1986Assignee: Halliburton CompanyInventors: Prabhakar P. Rao, John J. Moon, Jr.
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Patent number: 4409662Abstract: Temperature of a heating device is controlled by a microprocessor in an electrical circuit which electrically communicates temperature control signals to the heating device. The control signals are generated from a predetermined compilation of data stored in the electrical circuit or from external data which can be entered and used to control the temperature in the heating device to a selectable value at a rapid rate or to achieve one or more temperatures at selected rates. The external data entry and control is provided by a human-electronic interface.Type: GrantFiled: December 29, 1980Date of Patent: October 11, 1983Assignee: Halliburton CompanyInventor: Prabhakar P. Rao
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Patent number: 4259868Abstract: Methods and apparatus for the nondestructive testing of cement slurry samples as a function of time are disclosed. A sample placed in a temperature and pressure controlled autoclave is coupled to transducer means under computer control. Ultrasonic energy is propagated through the sample and the transit time is measured. A predetermined relationship relating transit time to compressive strength is employed and enables the determination of compressive strength. The measurements are repetitively performed on up to eight samples simultaneously and the time history of the development of compressive strength is recorded.Type: GrantFiled: October 1, 1979Date of Patent: April 7, 1981Assignee: Halliburton CompanyInventors: Prabhakar P. Rao, David L. Sutton