Patents by Inventor Sydney J. Field

Sydney J. Field 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).

  • Control damper
    Patent number: 4275762
    Abstract: A control damper for controlling the flow of air or other gaseous fluid through a duct, comprising a line of blades each of which is so supported for rotation in a surrounding frame that the blades are swingable about parallel axes to open or close an opening in the frame and to be movable at will to intermediate positions between their fully-open and fully-closed positions, in which the blades are of aerofoil shape.
    Type: Grant
    Filed: August 20, 1979
    Date of Patent: June 30, 1981
    Assignee: Actionair Equipment Limited
    Inventor: Sydney J. Field
  • Shut-off damper
    Patent number: 4256143
    Abstract: A shut-off damper comprising a line of blades which are supported in a surrounding frame for rotary motion about substantially parallel axes to open or close an opening in the frame, and springy sealing strips each provided with a lining or cover of synthetic rubber or other resilient material so that the end portions of the blades make sealing contact with the said linings or covers to reduce or prevent the leakage of fluid past the blades when they are in their fully-closed positions.
    Type: Grant
    Filed: November 13, 1979
    Date of Patent: March 17, 1981
    Assignee: Actionair Equipment Limited
    Inventors: Robert J. Magill, Sydney J. Field
  • Shut-off damper
    Patent number: 4244397
    Abstract: A shut-off damper having blades of a generally streamlined shape with the trailing edges of the blades comprising fluid sealing means extending along those edges so that a seal is formed between adjacent blades when the blades are in their closed positions.
    Type: Grant
    Filed: August 20, 1979
    Date of Patent: January 13, 1981
    Assignee: Actionair Equipment Limited
    Inventors: Robert J. Magill, Sydney J. Field
  • Smoke and fire shield damper
    Patent number: 4184288
    Abstract: A combination smoke and fire shield damper comprising a line of blades each of which is so supported for rotation in a surrounding frame that the blades are swingable about parallel axes to open or close an opening in the frame, in which the blades are provided with "opened-out" trailing edges so that the leading edge of each blade interlocks with the trailing edge of an adjacent blade when the blades are in their fully-closed positions.
    Type: Grant
    Filed: June 16, 1978
    Date of Patent: January 22, 1980
    Assignee: Actionair Equipment Limited
    Inventors: Robert J. Magill, Sydney J. Field