Abstract: An apparatus easily movable inside pipes for cutting off projections in the interior of the pipe along the inner surface of the pipe. The apparatus includes a carrier movable inside the pipe. The carrier is provided with a shaft reciprocatingly movable axially of the pipe and rockingly rotatable circumferentially of the pipe, a rocking block movable with the shaft and a drive device for the shaft. The rocking block has a cutter blade reciprocatingly movable axially and radially of the pipe as projected forward from the block axially of the pipe, and drive devices for the blade.

Abstract: A method of forming a rigid or semirigid plastics tube lining over the inner surface of a branch pipe portion as joined at its one end to an underground main pipe through the other end thereof substantially open to the surface of the ground as a work opening, the method being characterized by inserting a rigid or semirigid plastics tube into the branch pipe portion from the work opening with the forward end of the tube substantially closed, and subsequently supplying a fluid into the tube to inflate the tube radially of the branch pipe by applying heat and pressure to the tube with the fluid from inside directly or indirectly and thereby line the branch pipe portion with the rigid plastics tube. The pipe portion can be lined from the ground surface efficiently without necessitating labor for excavation of the ground, cutting off the branch pipe portion and restoring the piping to the original state.

Abstract: The present invention provides a method of repairing the joint portions of an existing gas pipe by a repairing device which is movable inside the pipe under remote control. The repairing device can be moved into and out of the gas pipe through a work opening formed in an upper portion of the gas pipe by boring means with gas flowing through the pipe and free of the hazard of gas leakage. This reduces the labor required for forming the work opening to start the repair work and for restoring the work opening portion to complete the repair work, consequently assuring a shortened work period and a reduced cost.

Abstract: A method of forming a rigid or semirigid plastics tube lining over the inner surface of a branch pipe portion as joined at its one end to an underground main pipe through the other end thereof substantially open to the surface of the ground as a work opening, the method being characterized by inserting a rigid or semirigid plastics tube into the branch pipe portion from the work opening with the forward end of the tube substantially closed, and subsequently supplying a fluid into the tube to inflate the tube radially of the branch pipe by applying heat and pressure to the tube with the fluid from inside directly or indirectly and thereby line the branch pipe portion with the rigid plastics tube. The pipe portion can be lined from the ground surface efficiently without necessitating labor for excavation of the ground, cutting off the branch pipe portion and restoring the piping to the original state.

Abstract: A grouting rod is formed with a first channel, a second channel (or channels) surrounding the first channel and a third channel which is normally in communication with the first channel. A piston valve is vertically movably received in an upper portion of the third channel. When the piston valve is raised, upper lateral communication holes and upper discharge holes which are formed in the upper peripheral wall of the third channel are closed by the piston valve and concurrently the second channels are permitted to communicate with a lower portion of the third channel through lower lateral communication holes also formed in the upper peripheral wall of the third channel. When the piston valve is lowered, the upper lateral communication holes and upper discharge holes are opened and concurrently the second channel(or channels) is prevented from communicating with the lower portion of the third channel through the lower lateral communication holes.