Patent ID: 12247688

DESCRIPTION OF THE EMBODIMENTS

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.

FIG.1Ashows one example of a pipe splitting assembly100including a pneumatic hammer102and a hammer nose assembly104. In one example, a pipe pulling assembly106is coupled with pneumatic hammer102. For instance, the pipe pulling assembly106is pulled behind the pneumatic hammer102as the pipe splitting assembly100is pulled and driven to split an existing pipe. The pipe pulling assembly106positions a new replacement pipe within the space originally occupied by the existing pipe. An air line110is shown inFIG.1Aextending into the pipe pulling assembly106. The air line110is coupled with the pneumatic hammer102and provides a source of compressed air to operate the hammer and drive the hammer nose assembly104and split the existing pipe.

Referring now toFIG.1B, another example of a pipe splitting assembly112is shown. The pipe splitting assembly112differs from the pipe splitting assembly100in that the pipe splitting assembly112does not include a pneumatic hammer, such as the pneumatic hammer102, shown inFIG.1A. In other respects, the pipe splitting assembly112is similar to the pipe splitting assembly100. For instance, the assembly112includes a pipe splitting assembly104and a pipe pulling assembly106sized and shaped for pulling a replacement pipe108.

One example of a pipe splitting assembly104is shown inFIG.2A. The pipe splitting assembly104includes a pipe splitting cutter200(e.g., cutter). The cutter includes cutter blades202sized and shaped to engage with an interior of an existing pipe and cut and break apart the existing pipe as the pipe splitting assembly100is pulled through. The cutter cable lumen204extends through the pipe splitting cutter200toward an expander212. As will be described in further detail below, additional lumens within the pipe splitting assembly104align with the cutter cable lumen204and extend through the other components of assembly104to form a composite cable lumen.

As shown inFIG.2A, the pipe splitting assembly104includes a rotatable joint206. In one example, the rotatable joint includes an assembly of joints providing an articulated linkage between expander212including a cable coupling therein and the cutter200. The rotatable joint206includes a joint bar208extending between the cutter200and the expander212. In another example, a joint nut216, a part of a cable coupling including the expander212, is positioned adjacent to the joint bar208and forms a portion of the rotatable joint206.

The pipe splitting assembly104further includes a coupling214sized and shaped to engage and connect with at least one of the pneumatic hammer102or a pipe pulling assembly (described below). In one example, the coupling214includes features to maintain a coupling between the pipe splitting assembly104and the pneumatic hammer102or pipe pulling assembly during operation of a pipe splitting assembly100. Coupling features of the coupling214include, but are not limited to, threading, mechanical interfits, mechanical fasteners including pins, screws, bolts and the like.

Referring now toFIG.2B, the pipe splitting assembly104is shown in cross section. As previously described, the pipe splitting assembly104includes a series of lumens aligned to provide an overall cable lumen extending through the pipe splitting assembly from the cutter200to the expander212(e.g., the cable coupling). For instance, the cutter includes the cutter cable lumen204, the joint bar includes the joint cable lumen232, the joint nut210includes a nut cable lumen234, the expander212having the cable coupling therein includes a housing cable lumen236and an anchor cable lumen238. The composite cable lumen formed by these lumens allows the passage of a cable extending form a winch through the existing pipe through a cutter proximal end216to the expander212to facilitate connection of each of these components along the cable and transmission of pulling forces through the cable to the expander and into the connective rotatable joint206and cutter200.

The cutter200includes a cutter proximal end216and a cutter distal end218. The cutter distal end218, in one example, includes a cutter fitting220sized and shaped for reception within a joint bar socket222of the joint bar208. In a similar manner to the cutter200the joint bar208includes a joint bar fitting224sized and shaped for reception within a joint nut socket226. As will be described in further detail below, the rotatable joint206including the joint bar208, fittings220,224and sockets222,226enables the pipe splitting assembly104to articulate relative to the pneumatic hammer102or pipe pulling assembly. For example, the cutter200is capable of rotating relative to the expander212and the pneumatic hammer102coupled with the expander. The fittings220,224and sockets222,226form ball and socket joints and allow rotation of the cutter200relative to the pneumatic hammer102while enabling the pneumatic hammer102to continue providing dynamic percussive forces to the pipe splitting assembly104including the cutter200. Stated another way, the pipe splitting assembly104including the rotatable joint206provides an articulating guide that navigates the pneumatic hammer102or pipe pulling assembly through an existing non-linear pipe while also providing a cutter200capable of splitting the non-linear portions of the existing pipe where the pipe splitting assembly104is not otherwise aligned with the pneumatic hammer102.

Additionally, the rotatable joint206allows articulation of the cutter200relative to the expander212including the cable coupling therewithin. Pulling forces transmitted from a winch through the cable extending into the pipe splitting assembly104are transmitted to the expander212. The pulling forces transmitted to the expander212are further transmitted in compression through the rotatable joint206. The rotatable joint206transmits the pulling forces from the expander212into the cutter200where the cutter200is at any angle relative to the expander212while the cutter200remains engaged with the rotatable joint interposed between the cutter and the expander212. Put another way, the surfaces of the rotatable joint206(e.g., the cutter fitting220, joint bar fitting224, socket222and joint nut socket226) are continuously engaged during articulation of the pipe splitting assembly104. Engagement between these sockets and fittings transmits compressive forces to the cutter200from pulling of the expander212through the pipe splitting assembly where the cutter200is in substantially any orientation relative to the expander212while coupled through the rotatable joint206.

Referring again toFIG.2B, the expander212is shown in this example with a cable gripping housing228coupled around a cable gripping anchor230. As described in further detail below, the cable gripping anchor230extends around a cable extending through the housing cable lumen236within the expander212. Pulling of the cable moves the cable gripping anchor proximally into engagement with the tapered surfaces of the cable gripping housing228. Engagement of the cable gripping anchor with the cable gripping housing228compresses the cable gripping anchor around the cable and forms a tight interfit to anchor the cable within the pipe splitting assembly104. Additional pulling forces from the cable are transmitted into the cable gripping housing228and the expander212from the cable gripping anchor230. Pulling forces are thereafter transmitted through the rotatable joint206into the cutter200. Stated another way, the cable gripping anchor230and cable gripping housing228cooperate to clamp around a cable extending into the anchor cable lumen238and housing cable lumen236.

Another example of a pipe pulling assembly300is shown inFIGS.3A-C. As shown inFIG.3A, the pipe pulling assembly300includes an expander coupling302coupled with a pipe anchor304. In one example, the expander coupling302is rotatable relative to the pipe anchor304to facilitate easy coupling between the expander coupling302and an expander of a pipe splitting assembly or pneumatic hammer and coupling of the pipe anchor304with the pipe and lubricant line used for lubricating a replacement pipe, such as replacement pipe108shown inFIGS.1A-B. The pipe pulling assembly300further includes a pipe sleeve306sized and shaped to rotate around the pipe anchor304. As described in further detail below, the pipe sleeve306couples around a replacement pipe positioned along the pipe anchor304and clamps the replacement pipe over the pipe anchor304.

Referring now toFIG.3B, the pipe pulling assembly300is shown in an exploded view. The expander coupling302is spaced from the pipe anchor304with an anchor bolt308disposed therebetween. The anchor bolt308couples the expander coupling302with the pipe anchor304and permits relative rotational movement between the pipe anchor and expander coupling. As shown inFIG.3B, the expander coupling302includes an expander coupling lumen310sized and shaped to receive the head of the anchor bolt308for coupling of the expander coupling302to the pipe anchor304. The pipe anchor304includes an anchor lumen312sized and shaped for reception and engagement of the anchor bolt308. For instance, the anchor lumen312includes threading corresponding to threading along the anchor bolt308.

The pipe anchor304as shown inFIG.3Bextending between an anchor proximal portion316and an anchor distal portion318with an anchor intermediate portion317therebetween. The pipe anchor304includes an anchor exterior surface314extending between the proximal and distal portions314,316. Lubricant passages320are shown positioned around the anchor exterior surface314and form a lubricant distributor as a portion of a lubricating system. As will be described in further detail below, the lubricant passages320are configured to distribute a lubricating fluid to the exterior of the pipe anchor304and an exterior surface of the replacement pipe108. The lubricant decreases the skin friction of the replacement pipe and decreases the force needed to pull the replacement pipe108through existing piping and surrounding soil and rock. In one example, the lubricating fluid includes a solution of water and polymer that provides enhanced lubricity to the solution. In one option, the lubricating fluid includes a liquid polymer emulsion containing partially hydrolyzed polyacrylamid/polyacrylate (PHPA) copolymer sold under the trademarked name EZ-MUD assigned to Baroid Industrial Drilling Products. In another example, the lubricating fluid includes a solution of water and clay, such as Bentonite.

The pipe sleeve306is spaced from the pipe anchor304to show a sleeve flange326. In one example, the sleeve flange326includes threading sized and shaped to engage and couple the pipe sleeve306with corresponding threading extending along the anchor exterior surface314. In one example, the threading extending along the anchor exterior surface314extends from the anchor proximal portion316toward the anchor distal portion318(the threading shown near the anchor distal portion318is sized and shaped for engagement with the replacement pipe108and therefore has a smaller diameter). The threading extending along the anchor exterior surface314from near the anchor proximal portion316allows the pipe sleeve306to rotatably couple with the pipe anchor304. After the replacement pipe108(seeFIGS.1A, B) is threaded on to the threaded surface near the anchor distal portion318, the pipe sleeve306is tightened distally by rotating the sleeve relative to the pipe anchor304. As shown inFIG.3C, the pipe sleeve306includes a sleeve tapered surface328having a slight outward taper from the anchor proximal portion316toward the anchor distal portion318. The sleeve tapered surface328engages around the replacement pipe108and clamps the replacement pipe108on the anchor distal portion318thereby ensuring a tight fixed coupling between the pipe pulling assembly300and the replacement pipe108.

Referring again toFIG.3C, the interior of the pipe anchor304, including a lubricant conduit322is shown. The lubricant conduit322is sized and shaped to transmit a lubricating fluid from the anchor distal portion318toward the anchor proximal portion316for delivery through the lubricant passages320. The lubricant conduit322cooperates with the lubricant passages320to form a lubricant system. In one example, the pipe anchor304includes a lubricant line connector324. The lubricant line connector324optionally includes a coupling feature sized and shaped to receive a quick connect coupling. The quick connect coupling is fixed along the lubricant line connector324and is able to rotate therein while remaining fixed to the pipe anchor304. A fluid line capable of passing a lubricating fluid is connected to the lubricant line connector324to transmit fluid into the pipe anchor304for distribution through the lubricant passages320. The rotatable coupling between the lubricating fluid line and the pipe anchor304permits rotation of the pipe anchor304, for instance, for coupling with a replacement pipe, such as replacement pipe108, without disengaging the lubricating line from the pipe anchor304.

The anchor bolt308is shown inFIG.3Ccoupled between the expander coupling302and the pipe anchor304. As previously described, the anchor bolt308rotatably couples the expander coupling302with the pipe anchor304and permits rotation of the pipe anchor304for coupling with a replacement pipe, such as replacement pipe108shown inFIGS.1A, B. In a similar manner, the expander coupling302is rotatable relative to the pipe anchor304to permit rotation of the expander coupling302for engagement with an expander, for instance, an expander of a pipe splitting assembly, such as the pipe splitting assembly104shown inFIG.1B. As will be described in further detail below, the anchor bolt308in another example, provides a bridging lubricant conduit between the pipe anchor304and the expander coupling302. The bridging lubricant conduit passes lubricating fluid into the expander for application of the lubricating fluid to the exterior of the expander and further reductions of skin friction of the pipe pulling assembly300. The enhanced reduction of skin friction facilitates easier pulling of the pipe pulling assembly300and the replacement pipe108.

FIGS.4A-Cshow detailed views of the pipe anchor304. As previously discussed, the pipe anchor304extends between an anchor proximal portion316and an anchor distal portion318. In one example, the pipe anchor304includes threading extending along the anchor exterior surface314from near the anchor distal portion318toward the anchor proximal portion316. The threading near the anchor distal portion318is sized and shaped to couple with an interior surface of a replacement pipe108(seeFIGS.1A, B). For instance, the threading near the anchor distal portion318is configured to tap the interior of the replacement pipe108and thereby fix the replacement pipe108along the pipe anchor304. In still another example, the pipe anchor304includes a second threaded surface (with a diameter larger than the threading for tapping and fixing of the replacement pipe108) extending from near the anchor proximal portion316toward the anchor distal portion318. The threading is sized and shaped to engage with corresponding threading extending along the sleeve flange326of the pipe sleeve306(SeeFIGS.3B, C). As previously discussed, the pipe sleeve306is rotated relative to the pipe anchor304to move the pipe sleeve306over the replacement pipe108coupled along the anchor distal portion318. Movement of the pipe sleeve306over the replacement pipe108clamps the replacement pipe along the anchor distal portion318. In one option, the pipe anchor304is rotated relative to the pipe sleeve306and the expander coupling302shown inFIGS.3A-Cthrough engagement of a tool along tool surfaces402extending around the pipe anchor304. The tool surfaces402are sized and shaped to receive a tool, such as a wrench, to provide torque to the pipe anchor304for rotation relative to the pipe sleeve306and expander coupling302to adjust one or more of the pipe sleeve, expander coupling or pipe anchor.

Also shown inFIGS.4A,4Bare the lubricant passages320spaced around the anchor exterior surface324. In one example, the pipe anchor304includes one lubricant passage320. In another example, the pipe anchor304includes two or more lubricant passages320spaced around the anchor exterior surface314at a desired interval (e.g., every 90 degrees). In still other examples, additional lubricant passages320are spaced around the anchor exterior surface314providing an array of lubricant passages320around the anchor exterior surface314to enhance the application of lubricant to the replacement pipe108as the replacement pipe is drawn through an existing pipe and surrounding soil and rock.

As shown inFIG.4C, the lubricant passages320are in communication with the lubricant conduit322extending from the anchor distal portion318longitudinally toward the anchor proximal portion316. As previously described, lubricating fluid provided through the lubricant conduit322is distributed through the lubricant passages320to the anchor exterior surface314. Optionally, the lubricating fluid is provided under high pressure through the lubricant conduit322and projects from the lubricant passages320dispersed around the anchor exterior surface314in jets that spray the existing pipe, surrounding soil and rock as well as the replacement pipe108with a lubricating fluid to decrease the friction between the replacement pipe and the surrounding materials and facilitating pulling of the replacement pipe.

In one example, the pipe anchor304including the lubricant passages320and lubricant conduit322is formed by machining of a material such as hardened steel. Lubricant passages320and lubricant conduit322are formed within the pipe anchor304by machining. In another example, the pipe anchor304is formed with another method including molding out of a high strength composite material. The lubricant passages320and lubricant conduit322are thereafter drilled into the composite resin of the pipe anchor304. In still another example, the lubricant passages320and the lubricant conduit322are molded within the pipe anchor304as the pipe anchor is formed.

Referring again toFIG.4C, in one example the pipe anchor304includes a second lubricant conduit400in communication with the lubricant conduit322. The second lubricant conduit400extends from the lubricant conduit322into the anchor lumen312sized and shaped for reception of the anchor bolt308. As will be described in further detail below, the second lubricant conduit400transmits lubricating fluid from the lubricant conduit322into the anchor lumen312where it is then delivered through a lumen of the anchor bolt308into an expander such as an expander of the hammer nose assembly or pipe splitting assembly104shown inFIGS.1A, B. Lubricating fluid is spread over the exterior surface of the expander and substantially decreases the skin friction of the expander to decrease the force needed to pull the pipe pulling assembly300and pipe splitting assemblies100,112through existing piping, soil and rock.

The expander coupling302is shown in detail inFIGS.5A, B. The expander coupling302includes a coupling base506and a coupling projection500extending from the coupling base. As shown in bothFIGS.5A, B the coupling projection500has a smaller perimeter than the coupling base506. The projection500is sized and shaped for reception within an expander such as an expander used with the pipe splitting assembly or hammer nose assembly104shown in FIGS. IA, B. In one example, the coupling projection500includes a threaded surface sized and shaped to engage with a corresponding thread surface within the expander of the hammer nose assembly or pipe splitting assembly104. Rotation of the expander coupling302couples the coupling projection500within the expander and longitudinally retains the expander coupling302with the hammer nose assembly or pipe splitting assembly. In another example, the coupling projection500includes a quick connect surface sized and shaped to engage with the corresponding quick connect surface of the expander. In still another example, the coupling projection500includes but is not limited to one or more of a series of mechanical features sized and shaped to engage with corresponding mechanical features of the expander. In one example, the expander coupling302is rotated relative to the pipe anchor304through tool surfaces502provided on the perimeter of the coupling base506. The tool surfaces502are sized and shaped to receive corresponding surfaces of a tool, such as a wrench, to rotate the expander coupling302.

Referring now toFIG.5B, one example of a bolt seat504is shown. The bolt seat504is sized and shaped to receive the head of the anchor bolt308shown inFIGS.3B, C. To couple the expander coupling302with the pipe anchor304, the bolt308is fed through the expander coupling lumen310and into the anchor lumen312. As previously described, the surfaces surrounding the anchor lumen312are correspondingly threaded to the bolt308. Rotation of the bolt308couples the expander coupling302to the pipe anchor304. In a similar manner to other components of the pipe pulling assembly300, the expander coupling302is constructed with but not limited to metals, resins and the like having sufficient structural integrity to withstand the pulling forces needed to split an existing pipe and pull a replacement pipe, such as replacement pipe108, into position within surrounding soil and rock.

A detailed view of the pipe sleeve306is shown inFIG.6A, B. As previously described, the pipe sleeve306includes a sleeve flange326sized and shaped to engage with a corresponding mechanical fitting surface extending along the anchor proximal portion316shown inFIG.3B. In one example, the sleeve flange326includes threading corresponding to threading extending along the anchor proximal portion316. Tool surfaces602are provided along the perimeter of the pipe sleeve306and are used to rotate the pipe sleeve306relative to the pipe anchor304and correspondingly move the pipe sleeve306over a replacement pipe108coupled around the anchor distal portion318. As previously described above, the sleeve tapered surface328engages against the replacement pipe108and clamps the replacement pipe along the anchor distal portion318.

The anchor bolt308shown inFIGS.3B, C is shown in detail inFIGS.7A, B. The anchor bolt308includes a bolt head700and bolt shaft702extending from the bolt head. As previously described, the bolt shaft702includes threading corresponding to threading within the anchor lumen312of the pipe anchor304(seeFIG.3C). The anchor bolt308is coupled between the expander coupling302and the pipe anchor304to connect the pipe pulling assembly300with the pipe splitting assembly100(e.g., to a pneumatic hammer102or a pipe splitting assembly104as shown inFIGS.1A, B).

In another example, the anchor bolt308includes a bolt lubricant conduit704extending from a bolt proximal portion706adjacent to the bolt head700to the bolt distal portion708. The bolt lubricant conduit704cooperates with the second lubricant conduit400of the pipe anchor304and the anchor lumen312to transmit lubricating fluid into the expander coupled with the expander coupling302. As described in further detail below, the lubricating fluid transmitted into the expander is distributed over the expander surface and reduces the skin friction of the expander thereby minimizing the forces needed to pull the pipe splitting assembly100including the pipe pulling assembly300through the surrounding soil, rock and first existing pipe. The threading along the bolt shaft702tightly engages with corresponding threading within the anchor lumen312of the pipe anchor304to substantially prevent the passage of lubricating fluid around the perimeter of the bolt shaft702and out of the pipe anchor304(for instance, between the expander coupling302and the pipe anchor304). Instead, the anchor bolt308provides a bridging lubricant conduit that passes the lubricating fluid from the pipe anchor304toward an expander of one or more of the pneumatic hammer102or pipe splitting assembly104(SeeFIGS.1A, B). Optionally, where lubrication of the expander is not desired, the anchor bolt308including the bolt lubricant conduit704is exchanged for a solid bolt. The solid bolt seals the juncture between the pipe anchor304and the expander coupling302to prevent passage of lubricating fluid to the expander coupling302and the expander.

One example of the pipe pulling assembly300is shown inFIGS.8A, B coupled with a pipe splitting assembly800. The pipe splitting assembly includes an expander802having an expander tapered surface803that tapers toward a cutter804rotatably coupled with the expander802. A lubricant gap806is between the cutter804and the expander802. One example of the lubricant gap806corresponds to a rotatable joint206, such as the rotatable joint shown inFIGS.2A,2b.

Referring now toFIG.8Bone example of a cable gripping anchor808is shown coupled around a cable807. As will be described in further detail below, the cable gripping anchor808is constructed with a plurality of jaws extending around the cable807. Engagement of the plurality of jaws with the tapered housing service810extending along an interior perimeter of the expander803compresses the anchor jaws around the cable807and locks the cable807longitudinally relative to the pipe splitting assembly800and pipe pulling assembly300. Pulling forces are transmitted from the cable807to the pipe splitting assembly800and pipe puller assembly300. The cable807extends through a cable lumen812toward the cutter804. The cable807extends from a cable anchor recess814within the expander802through the cutter804and from there it is coupled with a pulling apparatus, for instance a wench, to pull the pipe splitting assembly800and pipe puller assembly300through an existing pipe.

As previously described, the lubricant conduit322of the pipe anchor304delivers a lubricating fluid to the lubricant passages320extending through the pipe anchor304to the anchor exterior surface314. As shown in one example inFIG.8Bthe lubricating fluid distributed through the lubricant passages320forms pipe puller lubricant jets818. The pipe puller lubricant jets818disperse the lubricating fluid to the exterior of the pipe anchor304. As the pipe puller assembly300is pulled through an existing pipe the lubricant is delivered along the exterior surface of the replacement pipe108(seeFIGS.1A, B) and the lubricating fluid decreases the skin friction around the replacement pipe108and correspondingly decreases the pulling force needed to pull the pipe puller assembly300and replacement pipe108.

As shown inFIG.8B, the pipe anchor304further includes a second lubricant conduit400extending into the anchor lumen312. The anchor lumen312is sized and shaped to receive the anchor bolt308including the bolt lubricant conduit704. As previously described, the bolt lubricant conduit704serves as a bridging lubricant conduit between the pipe anchor304and the expander coupling302. Lubricant fluid delivered through the second lubricant conduit400into the anchor lumen312is delivered through the bolt lubricant conduit704into the cable anchor recess814of the expander802. Because the cable grouping anchor808is constructed with a plurality of separate anchor jaws the lubricating fluid within the cable anchor recess814is able to pass between the anchor jaws and into the cable lumen812.

In one example the cable807has a smaller diameter than the inner diameter of the cable lumen812thereby permitting the lubricating fluid under pressure to flow toward the cutter804. The lubricating fluid is delivered through the cable812to the lubricant gap806between the cutter804and expander802. Expander lubricant jets816are formed that distribute the lubricating fluid over the expander tapered surface803of the expander802. The lubricating fluid delivered through the lubricant gap806decreases the skin friction of the expander802and further minimizes the pulling forces needed to pull the pipe splitting assembly800and pipe puller assembly300through an existing pipe and surrounding rock and soil.

An example of the cable gripping anchor808is shown inFIG.9. The cable gripping anchor808includes an anchor body900extending from an anchor proximal end902toward an anchor distal end904. As shown inFIG.9, the anchor body900, in one example, is composed of one or more separated anchor jaws908. The anchor jaws908extend around the anchor cable lumen906where the cable will extend when the pipe splitting assembly800is assembled. The anchor body900including the anchor jaws908includes a tapered anchor surface912having a shape corresponding to the housing tapered surface810shown inFIG.8B. As described in further detail below, the tapered anchor surface912is sized and shaped to engage with the housing tapered surface810and compress the cable gripping anchor808around the cable to lock the assembly of the cable gripping anchor and the expander802on the cable. The tapered anchor surface912tapers from the anchor distal end904toward the anchor proximal end902.

Near the anchor distal end904a retaining band groove914extends around the anchor body900. The retaining band groove914is sized and shaped to receive a retaining band, such as an elastomeric band. When the retaining band is positioned within the retaining band groove914the separate anchor jaws908are retained around the anchor cable lumen916and the cable. The retaining band ensures the anchor body900remains in an assembled state around the cable before the cable gripping anchor808is engaged with the tapered housing surface810.

In operation, the cable807is positioned within the cable gripping anchor808(seeFIG.8B). As the cable807is pulled proximally, for instance by a rotating spool at one end of an existing pipe, the cable gripping anchor808is pulled due to friction between the cable and the interior surface of the anchor engaged along the cable (e.g., through slight engagement caused with a retaining band within the retaining band groove914). Movement of the cable gripping anchor808proximally engages the anchor tapered surface912with the housing tapered surface810. Continued movement of the cable gripping anchor808into the tapered housing surface810compresses the anchor jaws908around the cable and clamps the cable gripping anchor808around the cable807. The cable gripping anchor808is locked in place between the cable and the expander802. The cooperative engagement between the expander802, anchor808and the cable807locks the cable in place relative to the cable gripping anchor808and the expander. Continued proximal pulling of the cable transmits pulling forces from the cable gripping anchor808to the expander802and the cutter804. The pulling forces from the cable are transmitted proximally through the pipe splitting assembly800by compression.

As further shown inFIG.9, the anchor jaws908are physically separated to permit compression of the cable gripping anchor808around the cable. The separation between adjacent jaws908forms lubricant slots910configured to deliver lubricant fluid from the pipe pulling assembly300to the lubricant gap806between the expander802and the cutter804(SeeFIGS.8A, B). As shown inFIG.8B, the lubricant fluid passes through the cable lumen812and is distributed around the expander tapered surface803from the lubricant gap806. The lubricant slots910through the cable gripping anchor808continue the path between the lubricant conduit322where the lubricant fluid enters the pipe pulling assembly300and the lubricant gap806.

Referring toFIG.8B, lubricating fluid is provided to the pipe pulling assembly300and the pipe splitting assembly800during a splitting operation. The lubricating fluid is delivered under pressure to the lubricant conduit322and distributed through the lubricant passages320extending to the anchor exterior surface314. As shown inFIG.8B, in one example, the lubricating fluid is delivered under sufficient pressure to generate pipe puller lubricant jets818. The jets818arrayed around the pipe anchor304distribute the lubricating fluid over the anchor exterior surface314. As the pipe pulling assembly300is pulled through the existing pipe and surrounding soil or rock, the lubricating fluid is spread over the replacement pipe108exterior surface (seeFIGS.1A, B) and minimizes the skin friction of the replacement pipe. The decreased skin friction minimizes the forces needed to pull the pipe pulling assembly through the existing pipe.

Where the anchor bolt308is coupled between the expander coupling302and the pipe anchor304lubricating fluid is also delivered through the bolt lubricant conduit704to the expander802of the pipe splitting assembly800. As described above, the lubricating fluid moves through the lubricant slots of the cable gripping anchor808and is fed through the cable lumen812of the expander802. The lubricating fluid is distributed to the expander tapered surface803through the lubricant gap806. Where the lubricating fluid is delivered with sufficient pressure expander lubricant jets816are formed that distribute the lubricating fluid over the expander tapered surface803and the surrounding existing pipe, rock and soil. The lubricating fluid around the expander tapered surface803further minimizes the skin friction of the consolidated replacement pipe108, the pipe pulling assembly300and the pipe splitting assembly800. The anchor bolt308, the anchor lumen814, the cable lumen812, lubricant slots910and the lubricant gap806form additional portions of the lubricant system of the pipe anchor304.

FIG.10shows one example of a pipe pulling assembly1000. The pipe pulling assembly1000is configured for coupling with a pneumatic hammer102(the pneumatic hammer102extends to the right of the page). The pipe pulling assembly1000includes a pipe puller1002(e.g., a pipe anchor) coupled with the replacement pipe108. A lubricant distributor1004is coupled between the pipe puller1002and a first swivel intermediate1006. The first swivel intermediate1006is correspondingly coupled with the second swivel intermediate1008, and the intermediates1006,1008permit relative rotation between the pipe puller1002and lubricant distributor1004relative to the expander1010. As further shown inFIG.10, the expander1010includes an expander coupling1012sized and shaped to couple the expander1010with the second swivel intermediate1008.

Referring now toFIG.11, a detailed view of the pipe pulling assembly1000is shown. The components shown inFIG.10are assembled inFIG.11. For instance, the pipe puller1002is coupled with the first swivel intermediate1006and the first swivel intermediate1006is correspondingly coupled with the second swivel intermediate1008and the expander1010. As shown in the example inFIG.11, the expander1010is coupled with the pneumatic hammer102. The lubricant distributor1004, shown first inFIG.10, is coupled within the pipe puller1002. As will be further described in further detail below, the lubricant distributor1004is configured to deliver a lubricant fluid to the pipe puller1002. The lubricant fluid is distributed through lubricant passages1100situated within a lubricant gap1102between the pipe puller1002and the first swivel intermediate1006. Delivery of the lubricant fluid through the lubricant passages1100and lubricant gap1102provides a source of lubricant for the pipe puller exterior surface1104. As the pipe pulling assembly1000is drawn or driven through an existing pipe and surrounding soil and rock, the lubricant fluid delivered to the pipe puller exterior surface1104is swept along the replacement pipe108and substantially minimizes the skin friction of the replacement pipe as well as the skin friction of the pipe puller1002thereby decreasing the forces needed to move the pipe pulling assembly1000through an existing pipe and surrounding rock and soil.

FIGS.12A-Cshow one example of a lubricant distributor1004. As shown inFIG.12A, the lubricant distributor1004includes a distributor body1200extending between a distributor proximal end1202and distributor distal end1204. A pneumatic lumen1206extends through the lubricant distributor from the distributor proximal end1202to the distributor distal end1204. The pneumatic lumen1206, in one example, is sized and shaped to receive a compressed air line for coupling with a pneumatic hammer, such as pneumatic hammer102shown inFIGS.1A and10. Optionally, the pneumatic lumen1206is sized and shaped to act as a pneumatic conduit and thereby directly delivers compressed air to the pneumatic hammer for operation of the hammer. As shown inFIGS.12A-C, a lubricant conduit1208extends from the distributor distal end1204toward a lubricant discharge1210. The lubricant discharge1210extends from the interior of the lubricant distributor1004through the exterior of the lubricant distributor.

Referring toFIGS.12B and12C, the lubricant conduit1208and the lubricant discharge1210are formed within a lubricant conduit housing1218. As shown, the lubricant conduit housing1218forms a portion of the side wall of the lubricant distributor1004. By forming the lubricant conduit1208and lubricant discharge1210in the side wall of the lubricant distributor1004the lubricant conduit1208is moved substantially away from the center portion of the lubricant distributor thereby providing a large open cavity in the pneumatic lumen1206for provision of a pneumatic line for coupling with the pneumatic hammer102.

As shown inFIG.12C, the lubricant conduit1208further includes a lubricant line connector1220. The lubricant line connector1220is sized and shaped to engage with and fix a lubricant line connected with the lubricant distributor1004. For example, a quick connect connector is threaded into the lubricant line connector1220and a lubricant line is coupled with the quick connector and provides a sealed delivery path from the lubricant line through the lubricant conduit1208and lubricant discharge1210to deliver lubricating fluid to the exterior of the distributor body1200.

Referring again toFIGS.12A-C, the distributor body1200includes a lubricant groove1212extending around the distributor body. The lubricant groove1212is substantially aligned with the lubricant discharge1210and is sized and shaped to distribute lubricating fluid from the lubricant discharge1210around the distributor body1200for discharge through the lubricant passages1100of the pipe puller1002as shown inFIG.11. The lubricant conduit1208, the lubricant discharge1210, the lubricant groove1212and the lubricant passages1100are part of a lubricant system formed by the lubricant distributor1004and the pipe puller1002.

In one example, the distributor body1200includes O-ring grooves1214,1216positioned distally and proximally relative to the lubricant discharge1210. The O-ring grooves1214,1216are sized and shaped to receive O-rings. The O-rings coupled between the lubricant distributor1004and the pipe puller1002provide a continuous sealed channel extending around the distributor body1200and the interior of the pipe puller1002. Pressurized lubricating fluid delivered to the lubricant discharge1210is thereby correspondingly delivered through the lubricant passages1100aligned with the lubricant groove1212without appreciable leaking between the pipe puller and the lubricant distributor.

FIG.13shows the lubricant distributor1004assembled with the pipe puller1002and the replacement pipe108. As shown, the lubricant discharge1210and the lubricant groove1212are aligned with the lubricant passages1100extending through the pipe puller1002. Lubricating fluid is delivered through the lubricant discharge1210to the lubricant groove1212. The lubricating fluid is distributed around the lubricant distributor1004according to the length of the lubricant groove1212. Stated another way, where the lubricant groove1212extends over a portion of the distributor body1200the lubricant within the groove will only be distributed to that portion of the distributor body exterior. Correspondingly, lubricant passages1100aligned with the lubricant groove1212extending over the limited portion of the distributor body1200will receive lubricating fluid. In one example where the pipe puller1104includes one or a few lubricant passages1100presented over only a portion of a perimeter of the pipe puller1004the lubricant groove1212and the distributor body1200is formed with a length substantially corresponding to the positioning of the lubricant passages1100on the pipe puller1002. Optionally, the O-ring grooves1214,1216positioned proximally and distally to the lubricant groove1212include O-rings1300positioned therein. The O-rings1300extend between the distributor body1200and the pipe puller1002and form a sealed area between the O-rings1300. The sealed area substantially prevents the passage of lubricating fluid from outside the lubricant groove1212and forces any pressurized lubricating fluid out of the groove1212and into the lubricant passages1100of the pipe puller1002.

In operation, where lubricating fluid is delivered to the lubricant conduit1208the lubricating fluid is under pressure and is delivered through the lubricant discharge1210into the lubricant groove1212. Lubricating fluid is delivered from the lubricant groove1212through the lubricant passages1100of the pipe puller1002. The lubricating fluid passes over the pipe puller exterior surface1104. As the pipe pulling assembly1000(FIG.10) is pulled though an existing pipe, soil and rock the lubricating fluid on the pipe puller exterior surface1104is distributed along the pipe puller exterior surface and onto the replacement pipe exterior surface1302. The lubricating fluid substantially minimizes the skin friction of the pipe puller1002and the replacement pipe108. Forces needed to pull the pipe pulling assembly1000through the existing pipe are thereby correspondingly minimized as well. Lodging and snagging of the pipe pulling assembly1000and a pipe splitting assembly coupled with the pipe pulling assembly are thereby substantially minimized.

Conclusion

The pulling lubrication systems described herein provide systems and methods for applying lubricant to portions of the pipe pulling or splitting assemblies and the replacement piping pulled behind such assemblies. Lubricating of one of the replacement piping decreases the skin friction of the replacement pipe and decreases forces needed to pull the replacement piping through the existing piping and the surrounding soil and rock. Additionally, the lubricating systems minimize seizing of the replacement piping, the splitting assembly or pulling assembly within the surrounding existing pipe and soil. Costly excavation to retrieve the lodged assemblies and delays in the pipe replacement process are correspondingly minimized. Moreover, the lubricating systems apply lubricating fluids to the exteriors of one or more of the pipe splitting assembly or the pipe pulling assembly to further minimize the skin friction of the entire system and further minimize seizing of the system.

The lubrication systems and methods described herein distribute lubricating fluids over the perimeter of at least one of the pipe pulling assembly or pipe splitting assembly. The lubrication systems accomplish the distribution by using a array of lubricant passages, grooves and the like that extend around at least one component of an assembly and correspondingly deliver the lubricant fluid over the perimeter of the component. Optionally, the lubricant passages direct the lubricant fluid into lubricant jets that deliver lubricating fluid to the surrounding existing piping, soil and rock as well as the replacement pipe and the assembly to minimize friction between the components and facilitate the splitting operation.

Although the present invention has been described in reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. It should be noted that embodiments discussed in different portions of the description or referred to in different drawings can be combined to form additional embodiments of the present application. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.