Patents by Inventor Donald C. Upchurch

Donald C. Upchurch 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: 5508009
    Abstract: A sterilization method is provided which includes the steps of measuring the pressure within a sterilization chamber injecting a sterilant vapor into a flow of carrier gas, introducing the sterilant vapor and carrier gas into and through a sterilization chamber, and adjusting the rate of sterilant vapor injection to reach a pre-determined percentage of saturation limit for the sterilant vapor in the chamber, immediately following the introduction of sterilant vapor and carrier gas into the chamber, in response to the measured pressure. The predetermined saturation limit is selected to optimize the rate of sterilization, while avoiding substantial condensation of the sterilant.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: April 16, 1996
    Assignee: American Sterilizer Company
    Inventors: James R. Rickloff, Donald C. Upchurch, Robert W. Childers
  • Patent number: 5482683
    Abstract: A method is provided for detecting moisture in a sterilization chamber or other enclosure (including moisture present on the external or lumened surfaces of an instrument or other load placed in the enclosure). The method includes the steps of exhausting air from the enclosure under vacuum until the pressure in the enclosure is reduced from a starting pressure to a predetermined subatmospheric pressure which is above the saturation pressure of water, and then a second predetermined subatmospheric pressure which is below the saturation pressure of water or other liquid. The times taken to reach each pressure from the starting pressure are measured and their difference is calculated and compared to a reference time difference pre-established for a dry system (or, alternatively, in a known, leak-free system, only the pull-down time period to reach the second subatmospheric pressure is measured and compared to a pre-recorded reference pull-down time for a dry system).
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: January 9, 1996
    Assignee: American Sterilizer Company
    Inventors: Vipul B. Sheth, Donald C. Upchurch
  • Patent number: 5445792
    Abstract: A sterilization method is provided which includes the steps of measuring the pressure within a sterilization chamber injecting a sterilant vapor into a flow of carrier gas, introducing the sterilant vapor and carrier gas into and through a sterilization chamber, and adjusting the rate of sterilant vapor injection to reach a pre-determined percentage of saturation limit for the sterilant vapor in the chamber, immediately following the introduction of sterilant vapor and carrier gas into the chamber, in response to the measured pressure. The predetermined saturation limit is selected to optimize the rate of sterilization, while avoiding substantial condensation of the sterilant.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: August 29, 1995
    Assignee: American Sterilizer Company
    Inventors: James R. Rickloff, Donald C. Upchurch, Robert W. Childers
  • Patent number: 5317896
    Abstract: A method is provided for detecting moisture in a sterilization chamber or other enclosure (including moisture present on the external or lumened surfaces of an instrument or other load placed in the enclosure). The method includes the steps of exhausting air from the enclosure under vacuum until the pressure in the enclosure is reduced from a starting pressure to a predetermined subatmospheric pressure which is above the saturation pressure of water, and then a second predetermined subatmospheric pressure which is below the saturation pressure of water or other liquid. The times taken to reach each pressure from the starting pressure are measured and their difference is calculated and compared to a reference time difference pre-established for a dry system (or, alternatively, in a known, leak-free system, only the pull-down time period to reach the second subatmospheric pressure is measured and compared to a pre-recorded reference pull-down time for a dry system).
    Type: Grant
    Filed: March 13, 1992
    Date of Patent: June 7, 1994
    Assignee: American Sterilizer Company
    Inventors: Vipul B. Sheth, Donald C. Upchurch