Patents by Inventor Stephen John Pratt

Stephen John Pratt 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).

  • Method and apparatus for locating internal transfer leaks within fuel cell stacks
    Patent number: 6662633
    Abstract: A method for locating an internal transfer leak in a fuel cell stack by applying a substantially constant gas pressure difference between a first fluid stream passage and a second fluid stream passage, wherein gas pressure in the second fluid stream passage is higher than gas pressure in the first fluid stream passage. A test gas is supplied to the second fluid stream passage and a test liquid is supplied to the first fluid stream passage. A parameter indicative of flow rate of the test gas exiting the first fluid stream passage is measured as the test liquid fills the first fluid stream passage. An apparatus for locating an internal transfer leak in a fuel cell stack is also provided.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: December 16, 2003
    Assignee: Ballard Power Systems Inc.
    Inventor: Stephen John Pratt
  • Method and apparatus for locating internal transfer leaks within fuel cell stacks
    Publication number: 20030110837
    Abstract: A method for locating an internal transfer leak in a fuel cell stack by applying a substantially constant gas pressure difference between a first fluid stream passage and a second fluid stream passage, wherein gas pressure in the second fluid stream passage is higher than gas pressure in the first fluid stream passage. A test gas is supplied to the second fluid stream passage and a test liquid is supplied to the first fluid stream passage. A parameter indicative of flow rate of the test gas exiting the first fluid stream passage is measured as the test liquid fills the first fluid stream passage. An apparatus for locating an internal transfer leak in a fuel cell stack is also provided.
    Type: Application
    Filed: December 19, 2001
    Publication date: June 19, 2003
    Applicant: Ballard Power Systems Inc.
    Inventor: Stephen John Pratt