Patents Examined by P. M. Frechette
  • Patent number: 4830539
    Abstract: An apparatus for propelling a plurality of pipes arranged in series comprises basic thrusting means for generating a thrust to be applied to the pipes and intermediate thrusting means for receiving the thrust from the basic thrusting means and applying the received thrust to one of the pipes. The intermediate thrusting means includes a press head provided with a portion displaceable to a position where the portion is capable of abutting against the rear end face of one of the pipes when the intermediate thrusting means is advanced while displaceable to another position where the portion does not interfere with the advance of the following pipes when the intermediate thrusting means is removed and an intermediate body extending rearward from the press head such as to receive the thrust from the basic thrusting means and apply the received thrust to the press head.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: May 16, 1989
    Assignee: Kabushiki Kaisha Iseki Kaihatsu Koki
    Inventor: Toshio Akesaka