Patents by Inventor Michael J. Darnall

Michael J. Darnall 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).

  • Centrifugally cast pipe
    Patent number: 5266370
    Abstract: A centrifugally cast plastic pipe comprised of a polymer derived from monomers polymerized in bulk is provided. A pressurized cylindrical mold provides smooth inner and outer surfaces. Pipes with a wall thickness of from 1/8 inch to 3 inches and an outer diameter of 1 inch to 12 feet are provided.
    Type: Grant
    Filed: April 3, 1991
    Date of Patent: November 30, 1993
    Assignee: PTI/End-Corr, Inc.
    Inventors: Charles S. Woodson, Michael J. Darnall, Norman A. Deumite
  • Centrifugally cast pipe
    Patent number: RE36340
    Abstract: A centrifugally cast plastic pipe comprised of a polymer derived from monomers polymerized in bulk is provided. A pressurized cylindrical mold provides smooth inner and outer surfaces. Pipes with a wall thickness of from 1/8 inch to 3 inches and an outer diameter of 1 inch to 12 feet are provided.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: October 12, 1999
    Assignee: A. O. Smith Corporation
    Inventors: Charles S. Woodson, Michael J. Darnall, Norman A. Deumite