Patents by Inventor Thomas E. Llewellyn

Thomas E. Llewellyn 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).

  • Pressure change responsive device
    Patent number: 4237354
    Abstract: A pressure switch unit capable of withstanding high pressures without losing its low pressure sensitivity or calibration includes a magnetically actuated switch responsive to the magnetic field of a permanent magnet mounted on a hermetically sealed bellows which contains on its interior a substantially incompressible liquid. The amount of liquid hermetically sealed within the bellows is selected to be sufficient to prevent any portion of the bellows from exceeding its elastic limit when the bellows is compressed by exposure to excessively high pressures.
    Type: Grant
    Filed: December 21, 1978
    Date of Patent: December 2, 1980
    Assignee: Textron Inc.
    Inventors: John D. Rockenfeller, Thomas E. Llewellyn