Patents by Inventor Friedrich-Wilhelm Schwiers

Friedrich-Wilhelm Schwiers 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).

  • Door-operated safety shutoff system
    Patent number: 4439894
    Abstract: A safety system operatively connected with a door, includes an air line, a pressure difference generator communicating with the air line and operatively connected with the door for altering the pressure of air in the air line when the door moves from a closed position to an open position and a pressure-responsive switch operatively connected with the air line for presenting an output indication in response to the alteration of air pressure in the air line.
    Type: Grant
    Filed: September 11, 1981
    Date of Patent: April 3, 1984
    Assignee: Trutzschler GmbH & Co. KG
    Inventors: Friedrich-Wilhelm Schwiers, Trutzschler