Patents by Inventor David P. Bagshaw

David P. Bagshaw 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).

  • Check valve and spring to prevent forward and reverse thermosiphoning in solar collector systems
    Patent number: 4541412
    Abstract: A freeze protection system allows the working fluid contained in the communicating tubes of the solar collector to drain from both the input and output tubes of the collector when a first predetermined temperature of the working fluid is detected and to fill the collector via both the input and output tubes when a second predetermined temperature is detected. The invention includes valve mechanism, of the spool valve variety, that communicate the working fluid to be heated to the collector and therefrom to a storage tank, a valve actuator and a sensor.
    Type: Grant
    Filed: February 16, 1983
    Date of Patent: September 17, 1985
    Assignee: Sunspool Corporation
    Inventors: David P. Bagshaw, Michael A. Kast, Harry T. Whitehouse
  • Freeze protection apparatus for solar collectors
    Patent number: 4450868
    Abstract: A freeze protection system allows the working fluid contained in the communicating tubes of the solar collector to drain from both the input and output tubes of the collector when a first predetermined temperature of the working fluid is detected and to fill the collector via both the input and output tubes when a second predetermined temperature is detected. The invention includes valve mechanisms, of the spool valve variety, that communicate the working fluid to be heated to the collector and therefrom to a storage tank, a valve actuator and a sensor.
    Type: Grant
    Filed: April 30, 1981
    Date of Patent: May 29, 1984
    Inventors: Eugene F. Duval, David P. Bagshaw, Michael A. Kast, Gilbert M. Masters, Harry T. Whitehouse
  • Freeze protection apparatus for solar collectors
    Patent number: 4395882
    Abstract: A support member is used to mount a heat motor and at least one electrical resistance heating element for actuating said heat motor. The support member is made of a thermally conductive material with cylindrical openings which receive the motor and heating element(s). Heat from the resistance element actuates the motor by heat conductance through the support.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: August 2, 1983
    Assignee: Sunspool Corporation
    Inventors: Michael A. Kast, David P. Bagshaw, Harry T. Whitehouse
  • Freeze protection apparatus for solar collectors
    Patent number: 4280478
    Abstract: A freeze protection system allows the working fluid contained in the communicating tubes of the solar collector to drain from both the input and output tubes of the collector when a first predetermined temperature of the working fluid is detected and to fill the collector via both the input and output tubes when a second predetermined temperature is detected. The invention includes valve mechanisms, of the spool valve variety, that communicate the working fluid to be heated to the collector and therefrom to a storage tank, a valve actuator and a sensor.
    Type: Grant
    Filed: November 13, 1978
    Date of Patent: July 28, 1981
    Inventors: Eugene F. Duval, David P. Bagshaw, Michael A. Kast, Gilbert M. Masters, Harry T. Whitehouse