Patents by Inventor Douglas A. Matthews

Douglas A. Matthews 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).

  • Patent number: 4401336
    Abstract: A hollow core holder comprising a hollow cylinder with a passive cam locking element eccentrically rotatably mounted inside the cylinder such that a portion of the edge of the cam protrudes through a slot in the wall of the cylinder in one rotation status and is wholly within the cylinder in another rotation status. As the core holder is inserted into a hollow core, the cam comes into contact with the core, holding the core to the core holder until a release mechanism rotates the cam into the cylinder, out of contact with the core.
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: August 30, 1983
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Douglas A. Matthews