Patents by Inventor Gerhard Harmsen

Gerhard Harmsen 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).

  • Method and device for welding polyolefinic objects
    Patent number: 3998682
    Abstract: A method and apparatus for butt welding two surfaces of different polyethylenes by heating the two surfaces up to different temperatures at which the viscosities of the two different polyethylenes of the two surfaces are equal. The heating device for heating the polyethylene surfaces comprises two separate plates which can be heated up to different temperatures. The device is also provided with pressure regulating means for controlling the pressure at which the two surfaces are pressed onto each other.
    Type: Grant
    Filed: November 22, 1974
    Date of Patent: December 21, 1976
    Assignee: Wavin B.V.
    Inventor: Gerhard Harmsen