Patents by Inventor R. Gorden Threlfall

R. Gorden Threlfall 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).

  • Laboratory fume hood control apparatus having rotary sash door position sensor
    Patent number: 6358137
    Abstract: A fume hood control apparatus for controlling the flow of air through the fume hood in a manner whereby the effective size of the total opening to the fume hood, including the portion of the opening that is not covered by one or more sash doors will have a relatively constant average face velocity of air moving into the fume hood. The apparatus includes a simple and reliable sash door sensing means for sensing the position of the moveable sash door by using a rotary position sensor with a lever arm mechanism which translates horizontal or vertical movement to rotary movement for determining the position of the sash door. The apparatus compensates for nonlinearity that result from the translation.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: March 19, 2002
    Assignee: Siemens Building Technologies, Inc.
    Inventor: R. Gorden Threlfall