Abstract: A method and system for repairing, replacing or installing an underground pipeline using an appropriate tool head. A coolant, preferably a cryogenic liquid, is injected in front of the tool head to embrittle or otherwise reduce the toughness of the material ahead of the tool head. Although suitable for use involving boring or drilling of the ground to install the underground pipeline, the method and system of this invention are particularly suitable for use in connection with pipe splitting and pipe bursting, where a pig disposed within the underground pipeline is connected with the appropriate tool head forming a space between the pig and the tool head into which the coolant is introduced. The pipe between the pig and the tool head is embrittled by the coolant, reducing the resistance of a pipe to splitting or bursting which, in turn, reduces the force required for the pig to pull the tool head as the pig is motivated through the pipe.

Abstract: An apparatus for replacing underground plastic pipe consisting of a mole, flexible cable, pulling devise and water pump. The mole is a cone shaped tool consisting of a nose section, cutting blades, water nozzles and a hose barb. The flexible cable is inserted through the existing pipe, one end is attached to the pulling devise and the other end is attached to the nose section of the mole. Replacement pipe is attached to the hose barb section of the mole on one end and to the water pump on the other end. As the pulling devise pulls the mole along the path of the existing pipe, the cutting blades split the existing pipe and water from the nozzles erode and moisten the soil surrounding it. The cone shape of the mole expands the split pipe out into the moistened soil, creating clearance for the new pipe being pulled into place.

Abstract: A rod pushing and pulling machine includes at least one hydraulic cylinder having a front end thereof engagable with a reaction surface at an entry opening of an existing pipeline or borehole, a spindle assembly, and a dual vise assembly. The spindle assembly includes a frame, a spindle shaft rotatably mounted in the frame, a distal end of the spindle shaft being threaded for engagement with a mating thread of a rod, a drive system for rotating the spindle shaft in threading and unthreading directions, the spindle frame being secured to a rear end of the hydraulic cylinder for pushing or pulling of a rod string engaged to the spindle shaft upon extension or retraction of the hydraulic cylinder, and a support assembly for the spindle shaft.

Abstract: The invention relates to a tool for longitudinally subdividing buried sewer pipes having an asymmetric, generally oval cross section, made substantially of a support shoe opposing a cutting blade acting in the direction of the pipe axis. The device also has two side cutting blades and is moved through the old pipe by means of a rod and a cylindrical calibration mandrel.

Abstract: Pipe splitting apparatuses and systems including a replaceable blade, and methods therefor, are provided. In various examples, a cable retention and release mechanism is configured to releasably engage a cable and includes one or more segments of a pipe splitting apparatus including a cable passage. A segmented collet includes tapered segments and is disposed within a tapered portion of a cable passage of the one or more segments. Channel surfaces of the tapered segments together form a cable channel through the segmented collet. The cable channel is configured to widen in a disengaged position of the segmented collet and narrow in an engaged position of the segmented collet. A spring is disposed within the spring pocket of the one or more segments to bias the segmented collet distally in the engaged position.

Abstract: A pipe splitting assembly includes an articulating hammer nose assembly having a pipe splitting cutter and a rotatable joint coupled with the pipe splitting cutter. A pneumatic hammer is distal to the articulating hammer nose assembly, The pneumatic hammer is configured to drive the articulating hammer nose assembly proximally away from the pneumatic hammer. The rotatable joint is coupled between the pipe splitting cutter and the pneumatic hammer, and the articulating hammer nose assembly is rotatable into one or more angles relative to the pneumatic hammer through the rotatable joint. A cable coupling is interposed between the pneumatic hammer and the articulated hammer nose assembly. The cable coupling is configured to attach a cable to the pipe splitting assembly. The cable coupling and the rotatable joint are configured to transmit to the pipe splitting cutter a compression force from the cable coupling and dynamic percussive forces from the pneumatic hammer.

Abstract: Systems and methods for concurrently destroying old pipes and installing new pipes in their place. An exemplary embodiment is a pipe bursting and replacement tool that includes a body and first and second connectors. The body has a shape that generally tapers from a smaller diameter at the front end to a larger diameter at the rear end. The taper need not be smoothly increasing, but may alternatively be stepped. The first connector couples the body to a pulling rod to and allows the body to be misaligned with the rod to relieve stress on the connection between the two. The second connector couples the replacement pipe to the body so that the replacement pipe can be pulled behind the body into the space previously occupied by an old pipe that is burst by the tool.

Abstract: A method for installing an underground pipe using a ground piercing tool comprises the steps of: fitting an expander onto a front nose of the tool, securing the pipe to the expander so that the ground piercing tool is disposed inside of the pipe, operating the tool in forward mode over a run to pull the pipe into the ground, removing the ground piercing tool from the expander and pipe by moving it in a rearward direction through the newly installed pipe, and leaving the expander in the ground, preferably to form the front end of the newly installed pipe. It is not required that each of the foregoing steps be conducted in the order recited. For example, the expander could be secured to the pipe after which the expander and pipe could be fitted over the tool.

Abstract: A pipe extracting tool for use with first and second pipes mated together and having a gasket disposed therebetween includes an arcuate blade and a driving member portion extending radially outwardly from the arcuate blade. The arcuate blade is sized and shaped to surround an outer circumference of the first pipe and slide between the outer circumference of the first pipe and an inner circumference of the second pipe to disengage the gasket from one of the first and second pipes.

Abstract: A pipe splitter is shown including a splitter body having a central opening configured to accept a pulling or pushing member. An expander has an entry profile smaller than an inner diameter of a pipe to be split and an expanded profile that is larger than the inner diameter of the pipe to be split. A protrusion is disposed on the expander. The protrusion is configured to concentrate splitting stress at a location on the pipe. The concentrated splitting stress is greater than a threshold stress of the pipe to burst the pipe. In some examples, a method of pipe splitting is described.

Abstract: The invention relates to an apparatus and a method for joining a pipe conduit to a drilling device, expanding device or pull-in device, in which a pulling-force generator arranged in the drilling device, expanding device or pull-in device exerts a compressive force on a pipe conduit, to be pulled in, via a pulling means and an adapter and thereby holds the individual short pipes of the pipe conduit together and reduces the mechanical stress to which the short pipes are subjected.

Abstract: An apparatus and method for internal repair of pipes and conduits, such as sewer pipes, pressurized water mains, water wells, and natural gas lines. The conduit repair apparatus includes a sleeve with locking mechanism to lock the sleeve in a tubular configuration. The sleeve is made of metallic or rigid plastic sheet having perforations. Some of the perforations are shaped like elongated slots and strips. A number of resilient O-rings are applied over the outer surface of the sleeve. A resilient membrane is applied over the O-rings. In one embodiment, a reinforcement band is used, and an additional layer of O-rings are included between the membrane and the reinforcement band.

Abstract: A cable retention and release mechanism includes a cable gripping device including a cable passage. A cable extends through the cable passage. A cable gripping device collar is movably coupled around the cable gripping device. An outer cable gripping device surface is seated against a cable gripping device receiving inner surface preventing movement of the cable gripping device relative to the cable gripping device collar. The cable gripping device receiving inner surface clamps the cable gripping device on the cable and prevents sliding movement of the cable. A jack is movably coupled with the cable gripping device collar. In a first engaged position the jack is engaged against the cable gripping device proximal end. In a second engaged position the jack unseats the outer cable gripping device surface from the cable gripping device receiving inner surface and releases the clamping of the cable.

Abstract: Systems, methods and devices for the remote control of a robot which incorporates interchangeable tool heads. Although applicable to many different industries, the core structure of the system includes a robot with a tool head interface for mechanically, electrically and operatively interconnecting a plurality of interchangeable tool heads to perform various work functions. The robot and tool head may include several levels of digital feedback (local, remote and wide area) depending on the application. The systems include a single umbilical cord to send power, air, and communications signals between the robot and a remote computer. Additionally, all communication (including video) is preferably sent in a digital format. Finally, a GUI running on the remote computer automatically queries and identifies all of the various devices on the network and automatically configures its user options to parallel the installed devices.

Abstract: A puller is provided with a number of advantages. Pullers are described that have a high power to weight ratio, and a high power to volume ratio. Examples of pullers and pulling systems include configurations that provide high cable friction in a small device volume. Examples of pullers and pulling systems also include constant force pulling which is desirable in particular for small diameter pipe replacement. Using pullers and pulling systems as described, minimally invasive pipe replacement operations are possible. Reversible pullers are also provided that decrease the amount of time needed to burst or split multiple segments of pipe.

Abstract: A bore hole reaming apparatus characterized by one or more cleaning devices such as bursting heads attached to a pull rod and typically having one or more mandrels attached thereto in tandem for pulling a length of pipe through a pre-bored opening using a pulling apparatus. In a typical embodiment the bore hole reaming apparatus is characterized by a pair of bursting heads mounted in spaced-apart relationship in tandem on the pull rod and fitted with one or more mandrels attached to a third bursting head. The mandrel(s) is typically secured to a fourth bursting head by a cable and the fourth bursting head is attached to a string of typically HDPE pipe to be pulled through the bore hole. The mandrel(s) straighten irregularities and clean, smooth and enlarge the bore hole to facilitate pulling the pipe string through the bore hole with minimum friction on the pipe.

Abstract: A splitter system and methods are shown. Examples of splitter systems provide limited possibility of damage to adjacent utilities in the ground. Further, examples of splitter systems relax a shape memory of split pipe, which in turn reduces friction in a splitting operation. Configurations are further shown that provide lubrication to splitting operations in a number of locations along a splitter system. Configurations are also shown that provide electrical isolation to cutting blades.

Abstract: A device and method for pipe replacement is shown. One advantage of devices and methods provided includes a splitting blade that provides a progressive cut into challenging pipe configurations such as ductile materials, thin walled pipes, corrugated pipes, or combinations of these properties. A pipe splitter and method is also shown that includes at least one hoop tensioning feature protruding from a body portion to pull the pipe against at least one splitting blade and increase splitting effectiveness.

Abstract: A method for reforming or rerounding an underground pipe includes the initial steps of inserting a reforming tool into the underground pipe and locating the pipe reforming tool at a location to be reformed. At least two arms of the reforming tool are then extended into engagement with the inner periphery of the underground pipe, which arms push the underground pipe outwardly in a manner effective to change its cross-sectional shape. The arms may then be retracted and the tool withdrawn from the pipeline. Such “reforming” or “rerounding” tool is preferably mounted at the distal end of a rod string so that the tool can be pushed, pulled and/or spun by operation of the rod pulling and pushing machine powering the rod string.

Abstract: This document discusses, among other things, devices, apparatuses, and methods for the replacement of existing underground pipes. In general, an apparatus comprises a body, including a receiving portion, and a breaking assembly adapted to be positioned within the receiving portion and detachably coupled to the body. In one example, the body and the breaking assembly are adapted, when coupled, to split the existing underground pipe when pulled therethrough using one or more cutting wheels. In varying examples, each cutting wheel radially protrudes out of a breaking assembly housing an increasing amount along a length of the apparatus allowing for a clean, progressive cut of the existing pipe. In another example, the body and the breaking assembly are adapted, when coupled, to burst the existing pipe when pulled therethrough. Advantageously, the present devices, apparatuses, and methods may provide replacement of underground pipes requiring minimal excavation and making economical use of parts.

Abstract: Inversion liners are provided which in a first embodiment include first and second flexible fabric layers joined to first and second high strength fiber containing layers and joined in tubular form. The first and second flexible fabric layers face one another. The second glass fiber containing layer further is bonded to a thin, third flexible fabric layer. A substantially fluid impermeable layer is applied to the opposite side of the thin, third flexible fabric layer.

Abstract: A device and method for pipe replacement is shown. A pipe replacement device is shown that includes at least one scoring wheel to provide a more progressive cut that provides consistency in the split of the pipe. A pulling force is reduced using pipe replacement devices and methods in a splitting operation. A pipe replacement device is shown that includes at least one skid structures with a long and consistent profile. In methods shown, friction between a pipe replacement device and the pipe being split is reduced.

Abstract: This document discusses, among other things, devices, apparatuses, and methods for the replacement of existing underground pipes. In general, an apparatus comprises a body, including a receiving portion, and a breaking assembly adapted to be positioned within the receiving portion and detachably coupled to the body. In one example, the body and the breaking assembly are adapted, when coupled, to split the existing underground pipe when pulled therethrough using one or more cutting wheels. In varying examples, each cutting wheel radially protrudes out of a breaking assembly housing an increasing amount along a length of the apparatus allowing for a clean, progressive cut of the existing pipe. In another example, the body and the breaking assembly are adapted, when coupled, to burst the existing pipe when pulled therethrough. Advantageously, the present devices, apparatuses, and methods may provide replacement of underground pipes requiring minimal excavation and making economical use of parts.

Abstract: A method for reforming or rerounding an underground pipe includes the initial steps of inserting a reforming tool into the underground pipe and locating the pipe reforming tool at a location to be reformed. At least two arms of the reforming tool are then extended into engagement with the inner periphery of the underground pipe, which arms push the underground pipe outwardly in a manner effective to change its cross-sectional shape. The arms may then be retracted and the tool withdrawn from the pipeline. Such “reforming” or “rerounding” tool is preferably mounted at the distal end of a rod string so that the tool can be pushed, pulled and/or spun by operation of the rod pulling and pushing machine powering the rod string.

Abstract: A pipe bursting and pulling apparatus for use in replacing horizontal underground pipes including a cylindrical body with a tapered forward section including means for attaching one of a cable, rod, rope or chain, the cylindrical body including an annular inner wall defining a longitudinally extending, rearwardly opening recess, a shaft passing through the recess, a plurality of gripping jaws, at least one of the jaws including a pipe gripping tooth extending radially outward relative to a longitudinal axis of the shaft, a tapered expander connected to the shaft and configured to fit between the jaws, the expander forcing the jaws outward to clamp a replacement pipe inserted into the cylindrical body between the jaws and the inner wall when pulled by the shaft, a stop, the stop limiting the forward travel of the expander and preventing outward radial travel of the jaws after the tooth has been engaged in the wall of the replacement pipe whereby the tooth penetrates to a depth of no more than 35% of the thickn

Abstract: Trenchless pipe replacement apparatus equipped with articulated lead sections that flex and accommodate an irregular path of an old pipe line. The articulated lead sections are coupled together by a flexible joint that allows the lead section assembly to flex and follow the path of the old pipe line that may be irregular due to misaligned pipe sections, dropped joints and other irregularities.

Abstract: A puller is provided with a number of advantages. Pullers are described that have a high power to weight ratio, and a high power to volume ratio. Examples of pullers and pulling systems include harmonic drive gear reduction elements and configurations that provide high cable friction in a small device volume. Examples of pullers and pulling systems also include constant force pulling which is desirable in particular for small diameter pipe replacement. Using pullers and pulling systems as described, minimally invasive pipe replacement operations are possible. Reversible pullers are also provided that decrease the amount of time needed to burst or split multiple segments of pipe.

Abstract: A pipe splitting assembly includes a pipe splitter, for instance, a cutter with one or more blades. An expander is flexibly coupled with the pipe splitter and allows the pipe splitter to rotate out of alignment with the longitudinal axis of the expander. In one example, the pipe splitter includes a cylindrical base portion and a frusto-conical base portion proximal to the cyclindrical base portion, and an exterior surface of the frusto-conical base portion is flush with an exterior surface of the expander. In another example, the expander has a larger outer perimeter than the cutter. Optionally, the pipe splitting assembly further includes a puller shoulder sized and shaped to couple with the expander, and a puller sleeve adapted to receive and hold a replacement pipe.

Abstract: An apparatus for bursting pipe is preferably adapted to receive rotational energy from the inner member of a dual-member drill string. In a preferred embodiment, a plurality of pipe-bursting members, driven by the interconnected inner members, cut or burst a subterranean pipe. In another preferred embodiment, a plurality of screw drives move the pipe-bursting members between an expanded position and a retracted position in response to rotation of the interconnected inner members.

Abstract: An apparatus for repairing an underground pipe includes a mandrel having a first expander capable of extending and retracting in a radial direction, a system for causing radial expansion and retraction of the expander when in position at a pipe location in need of repair, a resilient stiffening frame disposable in a tubular configuration outside of the expander, such that the expander can be used to expand the frame into contact with the inside of the pipe, and a suitable arrangement for confining a flowable cement between the expander and the inside of the pipe to form a repair band upon setting of the cement. In a preferred form of the invention, the expander comprises a central inflatable bladder, and the system controlling radial extension and retraction of the expander includes a line supplying pressurized air to the bladder.

Abstract: A puller is provided with a number of advantages. Pullers are described that have a high power to weight ratio, and a high power to volume ratio. Examples of pullers and pulling systems include harmonic drive gear reduction elements and configurations that provide high cable friction in a small device volume. Examples of pullers and pulling systems also include constant force pulling which is desirable in particular for small diameter pipe replacement. Using pullers and pulling systems as described, minimally invasive pipe replacement operations are possible. Reversible pullers are also provided that decrease the amount of time needed to burst or split multiple segments of pipe.

Abstract: An impactor for use with a directional boring machine for replacement of underground pipes includes a bursting head having a rearwardly opening recess and a front end opening that communicates with the recess. An inlet pipe is connected at its front end to a distal end of the drill string and extends into the recess of the bursting head through the front end opening. A striker is mounted for sliding movement along the inlet pipe, and a distributing mechanism responsive to pressure fluid supplied through the drill string and inlet pipe causes the striker to reciprocate in the rearwardly opening recess of the head to deliver forward impacts against the bursting head. The striker and distributing mechanism are mounted in a tubular housing, and a pulling connection is provided by which the impactor can be pulled by the drill string while the striker is delivering impacts against the head in the same direction as a pulling force exerted by the drill string.

Abstract: A method for predicting the location of stress corrosion cracking in a steel gas pipeline in which in-line stress corrosion cracking smart tool data, external low level metal loss data and soil characterization data are compiled to predict the location of stress corrosion cracking in a steel gas pipeline segment.

Abstract: A pipe breaking assembly is shown with a modular design that allows a user to more economically purchase a single base unit that is adaptable using a number of elements. Combinations of elements such as blade portions and expander cones, etc. allow the modular assembly to be tailored to a variety of job conditions. A pipe breaking assembly is shown that includes a particular configuration where a blade portion is located in front of a shortened expander cone. The shortened expander cone provides a lower contact area that in turn reduces friction.

Abstract: A cable pulling machine of the invention includes a frame, a mechanical linkage including first and second links having first and second cable gripping shoes disposed thereon respectively in opposed positions, a latching cylinder actuable to cause the mechanical linkage to pivot on multiple axes to bring the shoes into engagement with a cable disposed therebetween, a main cylinder having one end mounted on the frame and actuable to move the linkage in a manner effective to pull the cable in a pulling stroke once the latching cylinder has brought the shoes into engagement with the cable, and a mechanism for extending and retracting the main and latching cylinders. The machine may also include a mechanism for holding the cable in tension between pulling strokes, such as a pivoting wedge mechanism as described hereafter.

Abstract: A cutting system for splitting pipes includes a main body and at least one blade and at least two blade mount assemblies by which the blade may optionally be connected to the main body. The first blade mount assembly, in a particular fitted state, holds the blade at a different distance from the longitudinal axis of the main body than the second blade mount assembly.

Abstract: A method of advancing a mole to define a passageway through a composition between first and second locations spaced from each other a substantial first distance. The method includes the steps of: attaching the mole to a cable; providing a support; providing a cable pulling assembly on the support; and operating the cable pulling assembly to cause a pulling force on the cable to be continuously applied through the cable pulling assembly to the cable and therethrough to the mole to thereby cause the mole to be advanced in a path a substantial second distance at least partially over the first distance between the first and second locations.

Abstract: Devices and methods for streamlining the completion of work functions within a lateral pipe connected to a main pipe. A variety of different lateral devices may be used to aid in the process of relining the main or lateral pipe. A lateral location device is inserted into the lateral pipe prior to relining of the main pipe and is subsequently used to aid in the conventional cutting of the main-lateral interface. A lateral cutting device actually performs the main-lateral cutting process from within the lateral or from within the main. A lateral inspection device crawls up the lateral for inspection via camera. A lateral relining device aids in the placement of a liner used to reline the lateral pipe. Each of these interchangeable work functions may be optional performed by one or more lateral devices, often carried and inserted by a delivery device.

Abstract: A method for installation of an underground pipe includes an initial step of boring a pilot hole through the ground at a predetermined grade angle by extending a drill string having a steerable boring bit mounted thereon through the ground. Upon reaching an end location for the pilot hole, the bit is removed from the drill string, and an expander having a diameter greater than the pilot hole is attached to the drill string, which expander is backed by an impact device such as a pneumatic impactor including a striker that delivers repeated impacts to a rearwardly facing surface of the expander, and by a pipe drawn along behind the expander. The expander is pulled back through the pilot hole at the grade angle while the impactor is operated to aid progress of the expander through the ground and pull the pipe into place behind the expander.

Abstract: The concrete pipe recycling machine is transportable to job sites for breaking apart concrete pipe and recycling the concrete and the steel reinforcement therein. The concrete pipe recycling machine has a mandrel type anvil which presses the top of the pipe upward toward a hammer which impacts the outside of the pipe such that the energy imparted by the hammer is reflected by the anvil and breaks down the concrete. The concrete aggregate processed by the hammer fall through open mesh with a conveyor thereunder to transport the concrete pieces for recycling. The anvil rotates in gear fashion to rotate the pipe and the hammer traverses axially to reach all portions of the surface of the pipe. The anvil support opens to admit a new pipe to be recycled and to release the steel cage inside of the pipe when the concrete is removed therefrom.

Abstract: A method for the cutting of underwater structures below the level of the sea bottom on which they are installed, comprises determining an ideal plane of cutting, having considered the characteristic features of the structure i.e. its morphology and its positioning on the bottom, the shape and consistency of the bottom itself, and the depth below the level of the bottom at which the cut must be effected; positioning and anchoring of a cutter in proximity of the cutting area; obtainment of at least one perforation or boring in proximity of the structure through the bottom at least up to the predetermined level for the cutting of the structure, along a direction parallel to the cutting direction and preferably lying on the cutting plane; and introduction of the cutter inside the perforation or boring and cutting of the structure. An apparatus for carrying out the method is also provided.

Abstract: A tandem rod or cable apparatus for bursting and replacing pipe, which includes a frame, two sets of oppositely-disposed hydraulic cylinders having piston rods, each of which pairs of piston rods are attached to a yoke, with a gripping element provided in each yoke for independently gripping a rod or cable extending through the aligned gripping elements. One end of the rod or cable is attached to a bursting and stored energy head and the other end extends through the gripping elements, typically to a reel (in the case of a cable) for taking up slack in the cable. Advancement of the bursting and stored energy head through a defective pipe to be burst and typical simultaneous replacement with an attached replacement pipe is effected by operation of the two sets of hydraulic cylinders and the corresponding gripping elements to push or pull the rod or pull the cable.

Abstract: A tool assembly and a process for using it is provided, wherein a single elongate handle member may be used, through a small hole at the ground surface, to reach underground pipes for installing different sized strap “T” couplings on different sized pipes, and for driving sleeve members associated with said strap “T” couplings, pneumatically, from above ground, to engage pipes at various locations below ground.

Abstract: A bundle of tubes or pipes is arranged without trenches according to a fluid-assisted drilling method. A bore channel is made in a first boring step and the bore channel is widened when the bore/flushing head is removed therefrom, the bundle of tubes being drawn into the bore channel. The bundle is composed of individual tubes and flanges arranged lengthwise at a distance from and used as spacers for the tubes. A method is also described, wherein a rotational decoupling device prevents the rotational movement of the bore/flushing head produced during the removal process from being transmitted to the bundle of tubes. The bundle of tubes are supported by stabilizing devices inside the bore channel in the same spatial position as that of the tubes in relation to each other and the surrounding environment and are drawn through the bore channel.

Abstract: An apparatus for bursting pipe is preferably adapted to receive rotational energy from the inner member of a dual-member drill string. In a preferred embodiment, an oscillating pipe-bursting member, driven by the interconnected inner members, cuts or bursts a subterranean pipe. In another preferred embodiment, a screw drive moves a pipe-bursting member between an expanded position and a retracted position. In another preferred embodiment, the pipe-bursting member is an arm moveable in response to operation of a screw drive. In yet another preferred embodiment, the pipe-bursting member is hydraulically actuated. This invention increases the efficiency of pipe-bursting operations by utilizing rotation energy generated by a horizontal directional boring system.

Abstract: A cable pulling apparatus for pulling a work load attached to a cable, including at least one cable-pulling device for engaging the cable. The cable-pulling device or devices each includes at least one cable-pulling member fitted with a cable-gripping element for pulling the cable and the workload.

Abstract: A tandem rod or cable apparatus for bursting and replacing pipe, which includes a frame, two sets of oppositely-disposed hydraulic cylinders having piston rods, each of which pairs of piston rods are attached to a yoke, with a gripping element provided in each yoke for independently gripping a rod or cable extending through the aligned gripping elements. One end of the rod or cable is attached to a bursting and stored energy head and the other end extends through the gripping elements, typically to a reel (in the case of a cable) for taking up slack in the cable. Advancement of the bursting and stored energy head through a defective pipe to be burst and typical simultaneous replacement with an attached replacement pipe is effected by operation of the two sets of hydraulic cylinders and the corresponding gripping elements to push or pull the rod or pull the cable.

Abstract: A pipe breaking assembly is shown with a modular design that allows a user to more economically purchase a single base unit that is adaptable using a number of elements. Combinations of elements such as blade portions and expander cones, etc. allow the modular assembly to be tailored to a variety of job conditions. A pipe breaking assembly is shown that includes a particular configuration where a blade portion is located in front of a shortened expander cone. The shortened expander cone provides a lower contact area that in turn reduces friction.

Abstract: An impactor for use with a directional boring machine for replacement of underground pipes includes a bursting head having a rearwardly opening recess and a front end opening that communicates with the recess. An inlet pipe is connected at its front end to a distal end of the drill string and extends into the recess of the bursting head through the front end opening. A striker is mounted for sliding movement along the inlet pipe, and a distributing mechanism responsive to pressure fluid supplied through the drill string and inlet pipe causes the striker to reciprocate in the rearwardly opening recess of the head to deliver forward impacts against the bursting head. The striker and distributing mechanism are mounted in a tubular housing, and a pulling connection is provided by which the impactor can be pulled by the drill string while the striker is delivering impacts against the head in the same direction as a pulling force exerted by the drill string.

Abstract: A pipe bursting and pulling apparatus for use in replacing horizontal underground pipes including a cylindrical body with a tapered forward section including means for attaching one of a cable, rod, rope or chain, the cylindrical body including an annular inner wall defining a longitudinally extending, rearwardly opening recess, a shaft passing through the recess, a plurality of gripping jaws, at least one of the jaws including a pipe gripping tooth extending radially outward relative to a longitudinal axis of the shaft, a tapered expander connected to the shaft and configured to fit between the jaws, the expander forcing the jaws outward to clamp a replacement pipe inserted into the cylindrical body between the jaws and the inner wall when pulled by the shaft, a stop, the stop limiting the forward travel of the expander and preventing outward radial travel of the jaws after the tooth has been engaged in the wall of the replacement pipe whereby the tooth penetrates to a depth of no more than 35% of the thickn