Patents Represented by Law Firm Whitham, Curtis & Whitam
  • Corrugated resin pipe
    Patent number: 5839477
    Abstract: The external shape of a pipe wall is formed of sectionally rectangular wall portions and sectionally circular wall portions which are disposed alternately in an axial direction of the pipe, and the internal shape of the pipe wall is formed into a substantially linear circular-cylindrical surface. The whole of the pipe wall is formed of a material of synthetic resin or rubber.
    Type: Grant
    Filed: April 9, 1997
    Date of Patent: November 24, 1998
    Assignee: Totaku Industries, Inc.
    Inventor: Teluo Murayama