Abstract: A system for breaking the skin friction between an underground pipe section and the surrounding soil. The system uses a pipe twisting device attached to one end of the pipe section. The pipe twisting device applies a torsional force to the pipe section so as to torsionally deform the pipe section. Such deformation breaks the skin friction between the pipe section and the surrounding soil. After the skin friction is broken along the entire length of the pipe section, an apparatus configured to apply an axial force to the pipe section pulls the pipe section out of the soil.

Abstract: An apparatus for gripping and pulling a wire strand. The apparatus is carried by a cylinder assembly attached to a frame. The cylinders provide force to pull the strand. Jaws are situated in a jaw block, and are tapered such that movement of the jaw block by the cylinders will tend to force the jaws closer to one another within a tapered cavity. Movable, spring-loaded J-rods are provided to retain the jaws within the jaw block when desired. The J-rods can be rotated to a position which does not retain the jaws when the wire strand is being added to, or removed from, the apparatus.

Abstract: A wire pulling assembly for pulling a wire carrying tooling through an underground environment. The pulling assembly includes a cyclical vise carried by one or more hydraulic cylinders attached to a frame. The cylinders have a pulling stroke and a retraction stroke. A powered reel is used to store the wire as it is removed from the ground. During a pulling stroke, the reel is hydraulically isolated such that cable is stripped from the reel with tension maintained in the cable. During a retraction stroke, a motor turns the reel to load excess cable onto the reel.

Abstract: A machine for extracting a ductile pipe. The machine has a vise which can grip the pipe, and a wire clamp. Each of the wire clamp and vise are supported on a carriage which is movable relative to a frame. This enables the vise to grip and pull the ductile pipe. Additionally, a wire strand may be disposed through the pipe from a far end to the end at which the machine is placed. The wire clamp allows the machine to pre-stress the strand to improve the extraction of the ductile pipe.

Abstract: A method for breaking the friction between a buried pipe section and its surrounding soil. A linear actuator or a pneumatic impact mole pushes on one end of the pipe section while a pipe extractor pulls on the opposing end of the pipe section. In an alternative embodiment, a device is used to excite the pipe section's natural vibrational frequency while a pipe extractor pulls on one end of the pipe section. After the friction between the pipe section and its surrounding soil is broken, the pipe extractor may remove the pipe section from its borehole. In another embodiment, the pipe section may be cut into smaller sections and each section may be individually removed from the ground using a pipe extractor. Alternatively, the smaller pipe sections may be individually loosened from the surrounding soil and then rejoined before being removed from the ground by a pipe extractor.

Abstract: A machine for extracting a ductile pipe. The machine has a vise which can grip the pipe, and a wire clamp. Each of the wire clamp and vise are supported on a carriage which is movable relative to a frame. This enables the vise to grip and pull the ductile pipe. Additionally, a wire strand may be disposed through the pipe from a far end to the end at which the machine is placed. The wire clamp allows the machine to pre-stress the strand to improve the extraction of the ductile pipe.

Abstract: A machine for extracting a ductile pipe. The machine has a vise which can grip the pipe, and a wire clamp. Each of the wire clamp and vise are supported on a carriage which is movable relative to a frame. This enables the vise to grip and pull the ductile pipe. Additionally, a wire strand may be disposed through the pipe from a far end to the end at which the machine is placed. The wire clamp allows the machine to pre-stress the strand to improve the extraction of the ductile pipe.

Abstract: A method for enlarging a crushed section of a ductile pipe. A wire rope having a bead or plurality of beads attached to the rope is placed in a ductile pipe. When a series of beads is used, each of the beads is sequentially larger. The wire rope is pulled through the crushed section, and the ductile pipe conforms to the larger diameter of the beads. The crushed section of pipe may be expanded so that a larger wire rope suitable for pipe extraction may be passed through. Alternatively, the pipe may be reformed and expanded to near or greater than its original size. The pipe may then be coated or a smaller slip-lined pipe may be placed within the original pipe.

Abstract: A wire pulling assembly for pulling a wire carrying tooling through an underground environment. The pulling assembly includes a cyclical vise carried by one or more hydraulic cylinders attached to a frame. The cylinders have a pulling stroke and a retraction stroke. A powered reel is used to store the wire as it is removed from the ground. During a pulling stroke, the reel is hydraulically isolated such that cable is stripped from the reel with tension maintained in the cable. During a retraction stroke, a motor turns the reel to load excess cable onto the reel.

Abstract: A method for enlarging a crushed section of a ductile pipe. A wire rope having a bead or plurality of beads attached to the rope is placed in a ductile pipe. When a series of beads is used, each of the beads is sequentially larger. The wire rope is pulled through the crushed section, and the ductile pipe conforms to the larger diameter of the beads. The crushed section of pipe may be expanded so that a larger wire rope suitable for pipe extraction may be passed through. Alternatively, the pipe may be reformed and expanded to near or greater than its original size. The pipe may then be coated or a smaller slip-lined pipe may be placed within the original pipe.

Abstract: A reversible pipe ramming tool used in horizontal pipe replacement operations. The tool is powered by a pneumatic hose attached to a rear end of the tool. The tool has forward and rearward fluid paths, which can either communicate with one another or stand in isolation. Fluid flow along the forward fluid path, when it is maintained in isolation from the reverse fluid path, causes the tool to move in a forward direction. Fluid flow along the forward fluid path, when it is maintained in communication with the reverse fluid path, causes the tool to move in a rearward direction. The tool is switched between forward and reverse by flowing fluid through a pilot fluid path in fluid communication with a valve. Movement of a shuttle within the valve selectively isolates the forward fluid path from the reverse fluid path.

Abstract: A pipe extraction machine can be used to remove a buried pipe from the ground. The machine has a carriage with jaws that grip the buried pipe. While gripped, the carriage moves relative to a support structure to pull the pipe out of the ground. Jaws are actuated by rotating clamp plates and maintained in opposition by static horizontal grooves. The jaws remain opposed and aligned during rotation of the clamp plates. A pipe shear may remove the pipe one piece at a time. A pipe puller can be used at the back end of the pipe being removed to simultaneously install a new pipe along the same path.

Abstract: A machine for extracting a ductile pipe. The machine has a vise which can grip the pipe, and a wire clamp. Each of the wire clamp and vise are supported on a carriage which is movable relative to a frame. This enables the vise to grip and pull the ductile pipe. Additionally, a wire strand may be disposed through the pipe from a far end to the end at which the machine is placed. The wire clamp allows the machine to pre-stress the strand to improve the extraction of the ductile pipe.

Abstract: A pipe extraction machine can be used to remove a buried pipe from the ground. The machine has a carriage with jaws that grip the buried pipe. While gripped, the carriage moves relative to a support structure to pull the pipe out of the ground. Jaws are actuated by rotating clamp plates and maintained in opposition by static horizontal grooves. The jaws remain opposed and aligned during rotation of the clamp plates. A pipe shear may remove the pipe one piece at a time. A pipe puller can be used at the back end of the pipe being removed to simultaneously install a new pipe along the same path.

Abstract: A hinged cover overlays an opening that provides access to a pressurized inversion drum. A releasable latch assembly holds the cover in a closed and locked position. The latch assembly comprises a plurality of first knuckles formed in the cover that are interlaceable with a plurality of second knuckles formed in the body adjacent the opening. The latch assembly further comprises a rotatable latch pin that may be installed within the first and second knuckles. The latch assembly is moved from an unlocked to a locked position by rotation of the latch pin within the knuckles.

Abstract: A pipe extraction machine can be used to remove a buried pipe from the ground. The machine has a carriage with jaws that grip the buried pipe. While gripped, the carriage moves relative to a support structure to pull the pipe out of the ground. Jaws are actuated by rotating clamp plates and maintained in opposition by static horizontal grooves. The jaws remain opposed and aligned during rotation of the clamp plates. A pipe shear may remove the pipe one piece at a time. A pipe puller can be used at the back end of the pipe being removed to simultaneously install a new pipe along the same path.

Abstract: A method for breaking the friction between a buried pipe section and its surrounding soil. A linear actuator or a pneumatic impact mole pushes on one end of the pipe section while a pipe extractor pulls on the opposing end of the pipe section. In an alternative embodiment, a device is used to excite the pipe section's natural vibrational frequency while a pipe extractor pulls on one end of the pipe section. After the friction between the pipe section and its surrounding soil is broken, the pipe extractor may remove the pipe section from its borehole. In another embodiment, the pipe section may be cut into smaller sections and each section may be individually removed from the ground using a pipe extractor. Alternatively, the smaller pipe sections may be individually loosened from the surrounding soil and then rejoined before being removed from the ground by a pipe extractor.

Abstract: A hinged cover overlays an opening that provides access to a pressurized inversion drum. A releasable latch assembly holds the cover in a closed and locked position. The latch assembly comprises a plurality of first knuckles formed in the cover that are interlaceable with a plurality of second knuckles formed in the body adjacent the opening. The latch assembly further comprises a rotatable latch pin that may be installed within the first and second knuckles. The latch assembly is moved from an unlocked to a locked position by rotation of the latch pin within the knuckles.

Abstract: An adapter may be used to impart ramming force on a pipe having a larger diameter than the ramming tool. The adapter has a set of collets which interface with a conical nose on the ramming tool. The adapter further has a split ring that engages with the pipe and either the collet set or an intermediate cone. The split ring has gaps which are bridged by a cam connector. The cam connector may, through rotation of a cam pin, modify the size of the gaps in the split ring. Expansion of the split ring within a pipe allows the ring to hold its position without relying on a weldment or other more permanent connection.

Abstract: A reversible pipe ramming tool used in horizontal pipe replacement operations. The tool is powered by a pneumatic hose attached to a rear end of the tool. The tool has forward and rearward fluid paths, which can either communicate with one another or stand in isolation. Fluid flow along the forward fluid path, when it is maintained in isolation from the reverse fluid path, causes the tool to move in a forward direction. Fluid flow along the forward fluid path, when it is maintained in communication with the reverse fluid path, causes the tool to move in a rearward direction. The tool is switched between forward and reverse by flowing fluid through a pilot fluid path in fluid communication with a valve. Movement of a shuttle within the valve selectively isolates the forward fluid path from the reverse fluid path.