US 5,439,320 A · Pipe splitting and spreading system

Abstract

The invention discloses a system for splitting and spreading existing underground pipe and pipe fittings. A plurality of cutter wheels are positioned within a cutter assembly frame. A first cutter wheel cuts the pipe and scores the pipe fittings. A second cutter wheel rides in the path cut in the pipe by the first cutter wheel and cuts the pipe fittings. A plurality of paired pipe expanders are formed on the outer periphery of the cutter assembly frame. Pipe expanders contact the inner surface of the pipe wall and keep the cross section of the pipe circular while the cutter wheels cut through the pipe and pipe fittings. Also, the paired pipe expanders keep the cutter wheels in a vertical alignment and thirdly, they loosen and scrape residue and built-up material from the inner wall of the pipe. A mandrel is connected to the trailing end of the cutter assembly and to a pipe adapter which in turn is connected to a foremost section of new pipe. The mandrel spreads the cut pipe and fittings and pulls the pipe adapter and the new pipe through the bore of the existing pipe. A train comprised of multiple sections of steel rods is connected to a leading end of the cutter assembly and pulls the cutter assembly and mandrel and pipe adapter and the new pipe through the bore of the existing pipe and pipe fittings. Cable/winching means or hydraulic means supply the motive power to use and operate the system.

Claims25

Dependent claims

A pipe splitting and spreading system for replacing existing underground utility pipe and pipe fittings with new pipe comprising in combination:

a cutter assembly having an elongated frame and a leading end and a trailing end and a plurality of co-aligned cutter wheels mounted longitudinally in the cutter assembly, the first cutter wheel for cutting through the existing utility pipe and scrubbing a scoring line on the existing utility pipe fittings, the second cutter wheel for cuttably engaging the existing utility pipe fittings in the scoring line, and cutting the existing utility pipe fittings along the scoring line, the cutter assembly further including a plurality of pipe expanders adapted for frictionally expanding the interior wall of the existing underground pipe and pipe fittings wherein the distance between extremities of one of the paired pipe expanders is greater than an inside diameter of the existing pipe;
a mandrel having a first section adapted for coupling to the trailing end of the cutter assembly and a second section adapted for coupling to a pipe adapter, the mandrel being of a sufficient size to expand the existing cut underground pipe and pipe fittings as it traverses through a bore of the existing underground utility pipe and pipe fittings;
and means for engaging the cutter assembly and pulling the cutter assembly and the mandrel and the pipe adapter and the new pipe connected to the pipe adapter through the bore of the existing underground utility pipe and pipe fittings.

A pipe splitting and spreading system for replacing existing underground utility pipe and pipe fittings with new pipe comprising in combination:

a cutter assembly having an elongated frame and a leading end and a trailing end and a plurality of co-aligned cutter wheels mounted longitudinally in the cutter assembly, the first cutter wheel for cutting through the existing utility pipe fittings, the second cutter wheel for cuttably engaging the existing utility pipe fittings in the scoring line and cutting the existing utility pipe along the scoring line, the cutter assembly further including a plurality of pipe expanders adapted for frictionally expanding the interior wall of the existing underground pipe and pipe fittings wherein the distance between extremities of at least one of the pipe expanders is greater than an inside diameter of the existing pipe;
a train of steel rods and couplings having threaded ends adapted for coupling to each other, the train guiding the cutter assembly through the existing utility pipe and pipe fittings;
a mandrel having a first section adapted for threadable coupling to the trailing end of the cutter assembly and a second section adapted for threadable coupling to a pipe adapter, the mandrel being of a sufficient size to spread the existing underground pipe and pipe fittings as it traverses through a bore of the existing underground utility pipe and pipe fittings;
hydraulic means for intermittently engaging each steel rod in axial communication and pulling the plurality of steel rods and the cutter assembly and the mandrel and the pipe adapter and the new pipe through the bore of the existing underground utility pipe and pipe fittings;
and
a plurality of rod guides for urging each steel rod to remain in axial alignment with the other steel rods in the train.

3 more elements

Dependencies are inferred from the claim text.

Pipe splitting and spreading system

Life of this patent

Pipe splitting and spreading system

Life of this patent

Abstract

Claims25