Patents by Inventor William A. Riddell

William A. Riddell 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).

  • Cylindrical screen construction for a filter and method of producing the same
    Patent number: 4969999
    Abstract: A cylindrical screen construction for a filter and a method of producing the screen. A sheet of metal screen containing a multiplicity of holes is rolled into cylindrical form and the longitudinal edges of the sheet are joined by a thermoplastic connecting strip. The strip is generally H-shaped in cross section having a pair of opposed longitudinal grooves that receive the respective edges of the sheet. Heat and pressure are applied to the strip causing the thermoplastic material to fuse and penetrate the holes along the side edges of the screen to provide a smooth surfaced mechanically interlocked joint between the edges.
    Type: Grant
    Filed: December 4, 1989
    Date of Patent: November 13, 1990
    Assignee: Nelson Industries Inc.
    Inventor: William A. Riddell