Patents by Inventor Geoff C. Gerhardt

Geoff C. Gerhardt 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).

  • Patent number: 6962077
    Abstract: A method and system for measuring the flow rate of a liquid or gas within a flow channel utilizing a centrally located excitation source and a plurality of sensor means. Said excitation means is comprised of a heating element coupled with an alternating current generator. Of the plurality of sensor means, at least one of said sensors is located in a position upstream of the excitation source location, and additionally a second of said plurality of sensors is located in a position downstream of the excitation source. Instantaneous fluid flow rate is calculated utilizing a high gain differential amplifier electrically coupled to said sensors, wherein the convectively induced inductive gradient of the flowing fluid is compared to the symmetrical zero flow induction gradient. Following such a comparison, a voltage signal proportional to the flow of fluid within the channel is derived.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: November 8, 2005
    Assignee: Waters Investments Limited
    Inventors: Geoff C. Gerhardt, Keith Fadgen
  • Publication number: 20040170510
    Abstract: A method for supplying solvent to an ultra-high pressure liquid chromatography system using a hydraulic amplifier. The hydraulic amplifier system includes a hydraulic cylinder comprising a primary piston chamber in which a primary piston is disposed and a secondary piston chamber in which a secondary piston is disposed. The cross-sectional area of the primary piston is larger than the cross-sectional area of the secondary piston. The difference in the cross-sectional areas of the pistons creates an amplification of the pressure in the primary piston chamber and a reduction in flow rate.
    Type: Application
    Filed: March 1, 2004
    Publication date: September 2, 2004
    Inventors: Geoff C. Gerhardt, Bruce J. Compton
  • Publication number: 20040118201
    Abstract: A method and system for measuring the flow rate of a liquid or gas within a flow channel utilizing a centrally located excitation source and a plurality of sensor means. Said excitation means is comprised of a heating element coupled with an alternating current generator. Of the plurality of sensor means, at least one of said sensors is located in a position upstream of the excitation source location, and additionally a second of said plurality of sensors is located in a position downstream of the excitation source. Instantaneous fluid flow rate is calculated utilizing a high gain differential amplifier electrically coupled to said sensors, wherein the convectively induced inductive gradient of the flowing fluid is compared to the symmetrical zero flow induction gradient. Following such a comparison, a voltage signal proportional to the flow of fluid within the channel is derived.
    Type: Application
    Filed: December 23, 2002
    Publication date: June 24, 2004
    Applicant: Waters Investments Limited
    Inventors: Geoff C. Gerhardt, Keith Fadgen
  • Patent number: 6712587
    Abstract: A hydraulic amplifier system for an ultra-high pressure liquid chromatography system. The hydraulic amplifier system includes a hydraulic cylinder comprising a primary piston chamber in which a primary piston is disposed and a secondary piston chamber in which a secondary piston is disposed. The cross-sectional area of the primary piston is larger than the cross-sectional area of the secondary piston. The difference in the cross-sectional areas of the pistons creates an amplification of the pressure in the primary piston chamber and a reduction in flow rate.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: March 30, 2004
    Assignee: Waters Investments Limited
    Inventors: Geoff C. Gerhardt, Bruce J. Compton
  • Publication number: 20030118459
    Abstract: A hydraulic amplifier system for an ultra-high pressure liquid chromatography system. The hydraulic amplifier system includes a hydraulic cylinder comprising a primary piston chamber in which a primary piston is disposed and a secondary piston chamber in which a secondary piston is disposed. The cross-sectional area of the primary piston is larger than the cross-sectional area of the secondary piston. The difference in the cross-sectional areas of the pistons creates an amplification of the pressure in the primary piston chamber and a reduction in flow rate.
    Type: Application
    Filed: December 21, 2001
    Publication date: June 26, 2003
    Inventors: Geoff C. Gerhardt, Bruce J. Compton
  • Publication number: 20030094206
    Abstract: Methods and devices for the management of fluid flow within nanoscale analytical systems, comprising a freeze thaw valve having differing geomentries to constrict a frozen plug within the freeze thaw segment. The freeze thaw valve is directed to use in high-pressure analytical systems. The geometry of an inner diameter of a channel or tube within a freeze thaw segment is configured to cause constriction of a freeze plug when axial force is applied. The constriction is used in the flow-path of a freeze thaw valve to prevent movement of the frozen plug at high pressures to avoid valve leakage.
    Type: Application
    Filed: November 19, 2001
    Publication date: May 22, 2003
    Inventors: Geoff C. Gerhardt, Edouard S. P. Bouvier, Theodore Dourdeville
  • Patent number: 6557575
    Abstract: Methods and devices for the management of fluid flow within nanoscale analytical systems, comprising a freeze thaw valve having differing geomentries to constrict a frozen plug within the freeze thaw segment. The freeze thaw valve is directed to use in high-pressure analytical systems. The geometry of an inner diameter of a channel or tube within a freeze thaw segment is configured to cause constriction of a freeze plug when axial force is applied. The constriction is used in the flow-path of a freeze thaw valve to prevent movement of the frozen plug at high pressures to avoid valve leakage.
    Type: Grant
    Filed: November 19, 2001
    Date of Patent: May 6, 2003
    Assignee: Waters Investments Limited
    Inventors: Geoff C. Gerhardt, Edouard S. P. Bouvier, Theodore Dourdeville