Patents Assigned to Insituform Intl Inc
  • Method of cutting apertures in lining in underground pipes
    Patent number: 4577388
    Abstract: A method for re-establishing side connections to an underground pipe after the same has been lined with a rigid lining of synthetic resin is disclosed, and in the method a cutter of the unit located in the pipeline moves in accordance with a pre-programmed contour which matches the contour of the side connection, thereby effectively and quickly to re-establish the side connection.The pre-programmed arrangement may be generated by sensing the side connection profile prior to the lining operation.
    Type: Grant
    Filed: November 9, 1984
    Date of Patent: March 25, 1986
    Assignee: Insituform Intl Inc
    Inventor: Eric Wood