MXPA97002374A - Coupling assembly that has resistance to increased axial latension and method of installation of the underground duct acopl - Google Patents

Abstract

The present invention provides a coupling assembly for a conduit or pipe, comprising a tubular component, a coupler, an annular clamping ring and an annular seal member, wherein the coupling assembly is assembled by the insertion of the tubular component. into the coupling and when the clamping ring is assembled estácolocado in a clamping position between the coupler and the tubular component and the seal member estácolocado in a position of seal between the engaged and the tubular component and a method for installing lengths coupled pipeline. The coupling assembly provides a coupling which can be installed by pulling through a substantially horizontal hole similar to a tunnel, without the use of any additional coupling or seal devices. PVC pipe of 10.16 cm / four inches) asíacoplada and installed remains clamped and sealed when subjected to an axial tensile force of at least 2,270 kg (5,000 pounds) during installation and the seal member maintains a seal, which can withstand a hydraulic pressure of at least 1.40 kg / cm2 (20 psi) without leakage. The installation method is simple and direct, requiring only the manual assembly of the coupling assemblies and without additional time, space or steps to increase the novel coupling described in the present

Description

COUPLING ASSEMBLY THAT HAS RESISTANCE TO INCREASED AXIAL TENSION AND METHOD OF INSTALLATION OF THE DUCT COUPLED UNDERGROUND DESCRIPTION OF THE INVENTION The present invention provides a coupling assembly for plastic pipe, in which the coupled pipe has increased axial stress resistance resulting in a pipe and coupling connection, which can withstand high axial loads in tension and which does not require additional means to maintain the coupling assembly in a coupled state. A coupling assembly utilizing this invention is particularly useful in applications that require multiple, coupled pipe lengths to be pulled long distances through underground pits without becoming disconnected and with the maintenance of a seal between the coupled lengths of the pipe. pipeline. A method of installing such a plastic pipe using the coupling assembly is provided. The present invention provides a cheap plastic coupling assembly for the conduit or pipe, comprising a tubular component, a coupler, an annular clamping ring and an annular seal member, the combination which is easy to assemble and which permits less 304 meters (1000 feet) of such pipe is pulled through an underground hole, without the use of additional fasteners to maintain the attached state and a method to perform this installation. Known coupling assemblies generally comprise a coupler and a tubular member, in which the tubular component is inserted into the coupler to form the coupling assembly. Metal coupling assemblies employing releasable fastening means and various seal devices are also known in the art. In such coupling assemblies, the overcurvature, the main interest is the maintenance of the seal to prevent leakage while in the coupled state. In such assemblies, the pressure which must be supported by the seal results only from the relatively static fluid pressure of the material carried by the coupled pipe. Such coupling assemblies are coupled in situ and are not required to withstand significant axial tension forces, resulting from the installation through underground pits or other conduits. Normally, the only axial tension force means that tends to disconnect the coupling assembly is a result of the internal pressure of the fluid that is transported by the pipe or conduit, which is only a few hundred kilograms / square centimeter (few hundred pounds per square inch ("psi") at most.) This force is much less than that of thousands of kilograms (thousands of pounds) of axial tension, which must be supported by the pipe or conduit during installation by In addition, this internal pressure is present only after the pipe and coupling have been placed in the location of the end use.Of course a metal conduit and coupling assembly would be prohibitively heavy and always subject to corrosion, even if it must be questionable to have enough resistance to withstand such axial tension forces, fiber optic transmission lines or cables have increasingly replaced the metallic, electrically conductive wires for the transmission of information.For various reasons, has been advantageous for fiber optic cables that are buried underground, such cables can be placed n a conduit or duct to protect the cables while they are underground. See, for example, U.S. Patent No. 5,027,864 to Conti, et al. The cables can be placed in an inner conduit, which in turn is pulled through a larger outer conduit. See also U.S. Patent No. 5,087,153 to Washburn. A preferred material for underground pipe applications is PVC pipe or pipe, which is normally supplied in lengths of 1.21 meters, 3.04 meters, or 6.08 meters (4, 10 or 20 feet), if they can not be supplied in other lengths. Each tube length must be coupled to adjacent lengths by means of a coupling assembly. A single length of 6.08 meters (20 feet) of PVC tube of 10.16 centimeters weighing approximately 20.43 kg (45 pounds). In this way, a tunnel 304 m (one thousand feet) long will require some of the coupling assemblies to carry an axial tensile force of at least several thousand kilograms, due to the combined effects of the weight of the tube and the drag friction due to contact with the walls of the hole through which the pipe is pulled or other obstructions. When these several thousand kilograms are applied over the surface area in contact with a clamping ring in a coupling assembly, the pressure carried by the clamping portion of the coupling assembly may be close to the tensile strength of PVC (ASTM D-638), or approximately 1,054.60 kg / cm2 (15,000 (psi)). Previously known PVC coupling assemblies, which have been attempted to be used in such applications, have been unable to withstand such additional loads or fasteners as required. Other materials were unsatisfactory for other reasons, such as weight, material limitations, such as propensity to corrosion of some metals (for example, aluminum or steel) or expensive (for example, stainless steel). Ducts made of a thermoplastic have been deployed underground to be used with other types of cable and other materials. Such conduits can be placed in a ditch or in a plowed trench. However, digging any ditch is expensive, making it through streets and roads is more expensive and doing so through the body of water is impossible. Likewise, plowing a trench generally only provides shallow underground placement of the cable and can not traverse a body of water. The processes to create a substantially horizontal tunnel or pit have become available and are generally referred to as "trenchless" excavation since an open trench is not required in such a process. In the present description, the term "hole" is generally used to indicate any type of substantially horizontal, small diameter underground conduit through which it may be necessary to pull plastic conduit and more generally include any underground conduit created by the " without trench ". Furthermore, the term "substantially horizontal" indicates that the holes of interest generally connect points on the surface of the earth by means of an underground tunnel running in a generally straight line between the points, but which may include portions, particularly in the ends of a section of the hole, which runs at an acute angle with respect to the surface. The holes described in the patents mentioned in the following, for example U.S. Patent 5,242,026, are included within the definition of relatively horizontal holes. In general, substantially vertical holes, drilling, such as that generally used for drilling a water or oil well, are not included. Two methods that have been employed to create the substantially horizontal underground pit within which such conduits can be inserted, are of particular interest here. The pneumatic drilling equipment as described, for example, in U.S. Patent No. 4,000,879, can be used to drill a horizontal tunnel in a straight line between two low-grade fasteners for the purpose of placing underground cables or conduit. . More recently, horizontal rotary auger type drilling equipment has become available, with which it is possible to drill downward first, then horizontally underground and then upwards to the surface, as described, for example, in U.S. Patent No. 5,242,026 to Deken and U.S. Patent No. 5,148,880 to Lee, et al and U.S. Patent 5,492,184 to Jene, for this purpose. Once a tunnel has been created, the conduit must be pulled through the tunnel, after which the optical fiber or other type of cable, with or without an inner conduit, can be pulled through the conduit which has been located in the tunnel. It has been known in the art to pull long lengths of plastic pipe or pipe, continuous through such underground drilling, but several constraints imposed by the materials have created difficulties making it more difficult or even avoiding the use of coupled lengths of plastic conduit in extended lengths of the tunnel. Previously known plastic pipe coupling assemblies have lacked sufficient strength to withstand the high axial stresses imposed on them, while being pulled through such tunnels and thus require additional fasteners to maintain the engaged state during such installation. The increase in such coupling assemblies of the prior art greatly increased the difficulty, expense and even danger of using coupled lengths of plastic tubing for such applications. A known type of underground conduit is plastic pipe normally deployed in continuous lengths. The method to install this type of duct in a horizontal hole is pulling for long lengths of the pipe from a reel through the hole. The most commonly used plastic tubing is polyethylene "PE" supplied in heavy, large reels that each contain about 121.6 m (400 ft) of tubing. Such a pipe generally has a wall thickness of 0.81 cm (0.320 inches) in a diameter of 10.16 cm (4 inches). Although cheap and widely available, PE pipe experiences several disadvantages. Adjacent lengths must be in full contact, sealed together by proper welding with a specialized device. Both of the tensile strength and crush resistance of the PE pipe are less than those of a material such as PVC pipe. Such a pipe frequently experiences increased ovality due to the flattening effect when rolled up on the spool. A contractor who installs the pipeline must feed each reel from a specially designed apparatus, on which each reel must be mounted in turn. When the end of the pipeline on the reel is released, it dangerously whips around, potentially causing serious injuries to workers and others. In a related effect, the PE has a considerable "memory" of the curvature that it has been forced to adopt, while it is on the reel as a result of which the PE pipe retains a strong tendency to wind up after it is removed from the reel . Finally, if the installation does not require a pipe length that corresponds to an integral number of reels, any remaining pipes must be treated and can be discarded. A second known type of underground conduit, and method for installing it in a horizontal hole is PVC pipe, coupled together and pulled into the pit. For such applications, the thermoplastic pipe of 5.08, 10.16 and sometimes 15.24 cm (two, four and four times times six inches) of lengths. Such a thermoplastic pipe can be supplied as the program 40 or the program 80. The lengths are coupled together as needed and then pulled through the hole. The most used thermoplastic for such applications is PVC. Although PVC is the preferred material herein for the tubing or tubular component, it is to be understood that the invention is not limited to the use of PVC tubing for the tubular component of the invention. The lengths of the PVC pipe have several advantages over the continuous lengths of rolled pipe. With PVC pipe, the exact number of lengths needed for a job can be stacked sufficiently together and delivered on an ordinary pallet truck, reducing time, labor, equipment and waste material, when compared to the use of continuous pipe lengths. polyethylene on the reels. PVC pipe has higher tensile strength and crushing resistance than polyethylene pipe and has better resistance to develop ovality. Since the lengths have not been forced to flex before use, they do not have problems that occur from a "memory" of such bending as with the PE pipe. The use of PVC pipe however has not been without disadvantages. The previously known PVC pipe couplings typically required an increase for use in applications such as those described herein. In this way, the assembly methods of the coupled lengths of the PVC pipe have numerous stages. The typical coupling for such PVC pipe is a bell-and-pin type coupling, in which each length of pipe has one end slightly flared outwardly (the coupler) and the other end is not flared (the tubular component). The flared end is enlarged to a sufficient degree to allow a non-flared end of an adjacent length to enter, forming a sealed engagement when properly cemented together. The cementing process includes all the known difficulties associated with PVC cement, including the use of hazardous, harmful solvents and the time required for cement (PVC) to cure. The most serious disadvantage of this type of coupling together with cement for use in applications requiring the installation by traction through a substantially horizontal hole, is the lack of resistance to the axially applied tension, when in the coupled state. This disadvantage has only been overcome previously by increasing the PVC cement with other fastening means, usually radially inserted screws. To securely join the lengths together, screws such as internally threaded metal screws are inserted radially into the coupling assembly. This constitutes another stage in the assembly, which requires additional equipment and personnel. However, even with this improvement, the adequate time for the glue to cure still, must be allowed in advance of the time when the pipe is going to be pulled through the tunnel. As a result, it is usually necessary to pre-assemble several hundred meters or the entire strip of PVC pipe together with screws and glued with the glue before the pulling process can be started. A further disadvantage of using the bell and spigot coupling assemblies results from the diameter of the bell end, which is larger than the rest of the pipe. This increased diameter results in additional difficulties during the installation of the pipeline through the underground hole when rocks, roots or other obstructions are encountered. The heads of the screws provide another source of difficulty as well, since they can extend radially outward from the bell, in addition to increasing the outside diameter of this portion of the pipe, in addition to providing a location for problem by obstructions. The present invention provides a coupling assembly that is simpler, stronger and easier to assemble than anything known up to now. A major difficulty, which must be overcome when any conduit is pulled through an underground hole or other conduit is the high axial stress that the conduit and its coupling assemblies must withstand. This is particularly true for conduit lengths maintained in the coupled state by known coupling assemblies. The present invention provides a plastic coupling assembly, inexpensive for the conduit or pipe, comprising a tubular component, a coupler, an annular clamping ring and an annular seal member. The combination is easy to assemble and allows at least 304 meters (1000 feet) of such a pipe to be pulled through an underground hole without the use of additional fasteners to maintain the engaged state. The coupling assembly can be assembled by hand, simply by manually inserting the tubular component into the coupler.

When the clamping ring is assembled, it is placed in a clamping position between the coupler and the tubular component and the annular seal member is placed in a seal position between the coupler and the tubular component. The coupling assembly can be installed by pulling through an underground hole and remains clamped and sealed when subjected to an axial tensile force of at least 2,270 kg (5000 pounds) during the installation of a 10.16 cm PVC pipe ( 4 inches) and longer. For 5.08 cm (2 inch) PVC, the corresponding axial tensile force is at least 885.30 kg (1950 pounds) when similarly installed through a hole. The seal member maintains a seal, which can withstand an externally applied static hydraulic pressure of at least 1.40 kg / cm2 (20 psi) without leakage and can withstand an internal transient pressure of at least 8.43 kg / cm2 (120 psi) without significant pressure loss. The coupling assembly of the present invention does not require an increase for its strength for axial tension, the clamping ring providing sufficient strength when in its clamped position, that fasteners or additional glue are no longer needed to keep the coupling assembly in place. the coupled state. The coupling assembly of the present invention further provides an interior surface without obstruction, uniform and a relatively uniform outer surface. The outer surface is generally convex, although it preferably has a constant, central diameter portion. The outside diameter of the coupler is only slightly larger than the diameter of the pipe or tubular component, and the outside diameter of the coupler is tilted to a smaller diameter towards each end of the coupler. This inclined or chamfered outer surface of the coupler ends forms portions of the outer surface of the coupling assembly which have a frusto-conical shape. Therefore, the coupling is relatively uniform and avoids the possibility of problems or excessive frictional interactions with the walls of or obstructions within the hole through which the pipe is installed. The preferred coupler has an inner surface which includes a cavity used to hold the coupling assembly together and a retainer surface used to prevent over-insertion of the tubular component and in some embodiments to carry an annular seal ring. The preferred coupler further includes at least one open end for receiving the tubular component. The preferred coupler is made of a fiber reinforced thermoplastic. More preferably, the coupler is made of thermoplastic reinforced with glass fiber and the preferred thermoplastic is a polyester. More preferably, the coupler is made of a reinforced glass fiber reinforced polyester which has been manufactured by a compression molding process. The present invention further provides a method of installing such a plastic conduit in an underground pit using the coupling assembly. The method provided for the assembly and insertion by traction of a plastic conduit through a hole in which, neither the pre-assembly, nor cement bonding and waiting, nor supplementary clamping stages are required. The method provides for the installation of such plastic conduit through an underground hole, which may be in excess of 304 m long (1000 feet) and in which the coupled state is maintained by only the coupling assembly described, without any increase in fasteners required or required. The method provided is simpler, easier, faster and requires less working space than the prior art method for installing the plastic conduit in similar applications. The method allows assembly of the coupling assembly by hand, and allows assembly on a length-by-length basis instead of requiring the entire chain of lengths to be placed outside and assembled in advance of the pulling process. The coupling assembly of the present invention, overcomes the difficulties of the prior art apparatus and the methods for installing the plastic conduit through an underground pit. The coupling assembly of the present invention also provides high resistance against the side walls which tend to flex the coupling assembly and result in the breaking of either the clamping or sealing function. This resistance is derived from the insertion depth of the tubular component within the coupler and from the strength of the coupler construction materials and the relative positions of the clamping ring and seal member. The method of the invention is simpler than previously known methods, due to the advantages of the present invention. In describing the present invention, it is expressly contemplated that the seal needs to be maintained by the various annular seal members described herein, means that the coupling assembly, when in the coupled state and installed in a hole, at least provides a seal which will not allow the surrounding groundwater to leak into the duct or duct and at least allows a "missile" or plug to be "ignited" through the conduit installed for the purpose of the wire lines to pull the wires through the conduit, without loss of pressure resulting in the part that stops the "missile" on the way through the conduit.

During the installation process, in some methods, the axial tension source to pull the pipeline through the hole is provided using high pressure to "ignite" a "missile" with a line attached through the hole. When the missile reaches the far end, the line is attached to a cable or other source of axial tension to pull the pipe through and the cable or other means is pulled back through the time hole in which it joins the first length of the pipe that is going to be pulled through the hole. The seal of the present invention should be adequate to avoid substantial loss of transient internal pressure associated with the ignition of the missile through the hole. The seal is also suitable to prevent the incursion of underground water into the interior of the pipe or duct. Although the foregoing provides a summary of the invention, other aspects of the present invention will become apparent in the following. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is an elevation view of a clamping ring according to the present invention. FIGURE 2 is a schematic diagram of a cross-sectional plan view of a coupling assembly assembled in a clamping position, according to a first preferred embodiment of the invention, when an axial tension has been applied. FIGURES 3 and 4 are schematic diagrams similar to FIGURE 2, showing the steps of inserting the tubular component into the coupler of the present invention. FIGURES 5a, 5b and 5c are schematic diagrams of an elevation view, a cross-sectional view and an enlarged cross-sectional view, respectively, of a coupler according to a preferred embodiment of the invention. FIGURES 6a and 6b are schematic diagrams of an elevational view and a cross-sectional view, respectively, of a tubular component according to a preferred embodiment of the invention. FIGURES 7 and 8 are schematic diagrams of a cross-sectional view of the coupling assembly and the coupler, respectively, according to a second preferred embodiment of the invention, incorporating an annular seal member of the O-ring type. FIGURE 9 is a schematic diagram of an enlarged cross-sectional view of the coupling assembly according to a preferred embodiment of the invention, using an annular seal member of the joint type.

FIGURE 10 is a schematic diagram of an enlarged cross-sectional view of the coupling assembly according to a preferred embodiment of the invention, using an annular seal member of the O-ring type. Figure 11 is a schematic diagram of an enlarged cross-sectional view of the coupling assembly according to a preferred embodiment of the invention, using an annular ring-like member of a V-ring type. FIGURE 12 is a schematic diagram of an enlarged cross-sectional view of the coupling according to a preferred embodiment of the invention, using an annular seal member of the chevron type. FIGURE 13 is a schematic diagram of a cross-sectional view of an assembled coupling assembly according to the third preferred embodiment of the invention, when an axial tension has been applied. FIGURE 13a shows additional details of a possible shape of the annular seal member in this embodiment. FIGURE 14 is a schematic diagram of a cross-sectional view of an assembled coupling assembly according to a fourth preferred embodiment of the invention, when an axial tension has been applied.

FIGURES 14a and 14b show additional details of the possible shapes of the annular seal member in this embodiment. The present invention generally describes and is drawn for the use of a thermoplastic tube or pipe as the tubular component of the invention. The preferred thermoplastic material for this component is rigid PVC. Other suitable materials are also contemplated, such as PE filling or polypropylene. The following description is not intended to limit the invention to the embodiments described, which are exemplary in nature. The present invention generally describes and is written for the use of a fiber reinforced thermoplastic coupler as the coupler component of the invention. The most preferred material is polyester reinforced with glass fiber, oriented. Other suitable materials are also contemplated, such as carbon fibers and epoxy materials. The following description is not intended to limit the invention to the embodiments described, which are exemplary in nature. The following description is with reference to the drawings. As shown in FIGURE 2, the coupling assembly 10 of the present invention includes a coupler 40 and a tubular component 20. The coupling assembly 10 further includes an annular clamping ring 60, which is preferably a clamping ring of metal (FIGURE 1) and an annular seal member, such as an annular seal 80 (FIGURES 2-4) or an annular seal ring O-ring 90 (FIGURES 7-8), or an annular chevron ring 100 (FIGURES 12 and 14), or an annular ring V of ring 110 (FIGURES 11 and 13). Sealing or additional sealing rings similar to those described herein, may be used without departing from the scope of the invention. The coupling assembly 10 is designed to be easily coupled, and with the hand, but to strongly resist both the high axial tension and the high lateral tension. The most preferred clamping ring 60 is a C-shaped piece of stainless steel. The C shape allows the ring to be expanded and compressed radially. The cross section of the ring 60 is more preferably round. The clamping ring 60 is preferably the hardest and strongest element of the coupling assembly. Other corrosion resistant materials that have similar strength can be used. As shown in FIGURE 1, the fastening ring 60 of the present invention is preferably a split metal ring that is made of stainless steel and has a C shape. The C shape is preferably defined by the nature generally circular ring, which is not a complete circle without breaking, but has a space between the two ends 62 and 62 M In the cross section, the fixing ring 60 is preferably round, but can also be more or less oval in the cross section. It is to be understood that the references herein to the substantially circular cross section include the cross sections, which are ovoid as well as completely round. Further, when reference is made herein to the width of the cross section of the fixation ring, variations in the diameter of the cross section or radius resulting from the ovoid shape are expressly included within the scope included by this term. An ovoid clamping ring can provide a larger surface area on which the axial tension forces are applied, thus reducing the pressure on the load carrying portions of the coupling assembly. The preferred fastening ring 60 is round in cross section and preferably has a cross sectional diameter or width of 0.38 cm (0.150 inches) for PVC of 10.16 cm (4 inches). Other diameters of the ring can be used. In the preferred embodiment, the fixing position comprises a slot 28 on the outer surface 22 of the tubular component 20 and a portion of the cavity 64 on the inner surface 42 of the coupler 40. The cavity 64 preferably includes a fixing projection 66 and a groove 68 relatively deeper, adjacent. The attachment boss 66 preferably includes a portion configured to more closely conform and engage with the locking ring, when in the fixation position. The fixing projection 66 preferably has a depth substantially equal to a quarter of the cross section of the width of the fastening ring 60. The groove 68 preferably has a depth substantially equal to the cross-sectional width of the fastening ring 60. The slot 28 is preferably formed intimately to the shape of the fixing ring 60 and has a depth substantially equal to one half of the width of the cross section of the fixing ring 60. The fixing ring therefore, preferably it fits into a portion of the slot when in the clamped position. In the most preferred embodiment of the coupling assembly 10, the slot 28, placed on the outer surface 22 of the tubular component 20, has a depth equal to approximately one half of the cross section of the width of the fastening ring 60, or 0.19. cm (0.75 inches) for PVC of 10.16 cm (4 inches).

Finally, as best shown in FIGS. 9-12, in the preferred embodiment, substantially three-quarters of the cross-sectional width of the clamping ring engages with and conforms to the slot 28 and clamping projection 66. The portion The remaining one, about a quarter of the cross-sectional width of the clamping ring 60 does not extend into either the slot 28 or the clamping projection 66. This portion or space is a space or gap that provides a space between the tubular component 20. and coupler 40. Ideally, this space is approximately 0.09 cm (0.0375 inches) uniform in 10.16 cm (4 inches) PVC, but since the purpose for space is to allow ovality defects, which can occur In the PVC pipe or the coupler, this space can vary in size. Another purpose is to compensate for other defects in the thickness of the wall, the outer diameter of the tube or the inner diameter of the coupler, in such a way that this space is variable. For 5.08 cm (2 inch) PVC, the most preferred clamping ring 60 is round and has a cross section diameter of 0.30 cm (0.120 inches). Other diameters of the ring can be used. The corresponding preferred depths are 0.15 cm for slot 28 and 0.07 cm (0.030 inches) for clamping projection 66. As with the preferred clamping ring for PVC of 10.16 inches, the clamping ring of 5.08 cm (2 inches) it is preferably round in cross-section, C-shaped and made of metal, preferably of stainless steel. Since manufacturing tolerances are narrower with the 5.08 cm (2 inch) tube, the allowable clearance between the outer surface of the tubular component and the inner surface of the coupler may be reduced, allowing the depth of the retaining flange the slot are increased proportionally. As best shown in FIGS. 6a and 6b, the slot 28, although generally round, preferably has a flat central section 30 and its deepest point. Thus, when in the clamping position, the clamping ring 60 is in contact and engages with one side of the slot 28. As shown in FIGURE 6b, in the clamping position under an axial tension tending to pull tubular component 20 outwardly of the coupler 40, the clamping ring 60 will be shaped and will engage the portion 28a of the slot 28. The depths of the slot 28 and clamping projection 66 may vary somewhat, but are selected to increase the maximum resistance of the resulting coupling assembly 10. It has been discovered that a PVC pipe of program 40 of 5.08 cm and 10.16 cm (2 inches and 4 inches), the diameter of the inner clamping ring and the groove and the depths of the clamping protrusion maximize the resistance of the The resulting coupling assembly, when the coupler is made of a polyester material reinforced with glass fiber and the tubular component is made of rigid PVC. As detailed in the above, the cross-sectional width of the clamping ring 60, will vary depending on the size and weight of the pipe used in a particular application, for example, the PVC of 15.24 cm (6 inches) must require a ring that has a larger cross section width. An important consideration in selecting the diameter is the depth of the groove, which houses the ring compared to the thickness of the wall of the tubular component. More preferably, the slot has a depth equal to one half of the cross-sectional diameter of the clamping ring. This depth may be greater if wall thickness considerations allow it. Another source of variation in those depths and widths is the shape of the cross section of the clamping ring. If an ovoid clamping ring is used, the depth and width of the slot 28, the recess 68 and the clamping protrusion 66 will vary to retain the conformity and clamping capacity with the clamping ring 60. An ovoid clamping ring would provide a surface area carrying more load, but such a ring would be more expensive to manufacture and would have to be further selected radially outward during the insertion of the tubular component into the coupler and would require a deeper groove and a deeper cavity. In addition, the cavity 64 can not include a retaining projection. The clamping ring in such a mode would be adapted for snap fit in the slot 28, without any assistance from the clamping projection, which should be provided if that feature were present. The preferred tubular component 20 is rigid thermoplastic material (preferably PVC). As shown in FIGS. 6a and 6b, the tubular component 20 includes a tube end 24, an inclined or chamfered surface 26 adjacent the end of the tube 24 and a segment of the constant outside diameter 22. The constant outside diameter segment 22, it preferably extends over the entire length of the tube to the next coupling assembly. The tubular component preferably includes an annular groove 28 substantially semi-round. The slot 28 includes a flat area 30 in its lower part. Preferably the flat area is about 0.05 cm wide (0.020 inches), when the preferred total width of the slot 28 is about 0.43 cm (0.170 inches) and the clamping ring 60 has a preferred cross sectional diameter of 0.38. cm (0.150 inches). The preferred coupler is made of a fiber reinforced thermoplastic. The most preferred coupler is formed of a polyester material reinforced with glass fiber. The most preferred coupler is made by compression molding process, which includes directionally oriented fibers. As best shown in FIGS. 5a, 5b and 5c, the coupling assembly 10 of the present invention preferably includes a "double" coupler, which is axially symmetrical, in which each side is a single coupler 40 which is the mirror image of the other coupler 40. Accordingly, the following description of the coupler 40 (one side of the "double" coupler) will describe both sides of the "double" coupler. It is further apparent that the coupler 40 can be manufactured as an integral part of a single tube length, which would thus consist of both a tubular component 20 and a coupler 40. As described above, in such embodiment, the coupler corresponds to the bell-shaped end of such a tube and the coupler 40 will be joined to the rest of the tube instead of an image to the mirror thereof. The preferred embodiment of the present invention is a double coupler 50, which comprises 2 mirror image couplers 40, as shown in FIGS. 5a, 5b and 5c. As shown in FIGS. 5a, 5b and 5c the coupler 40 includes an outer surface 44, an inner surface 42, an open end 46 and an inner detent surface 48, which extend radially inwardly from the inner surface. The retaining surface 48 extends radially inwardly a distance, such that the opening defined by its margin radially inwardly has substantially the same diameter as the inner diameter the tubular component of the coupling assembly. In this way, the interior surface of the duct is continuous, uniform and free of obstructions that extend inwards. As shown in FIGS. 5a, 5b and 5c, the outer surface 44 of the preferred coupler is generally convex, and may include a portion having a constant outside diameter. The outer diameter of the coupler gradually decreases near the open end, such that at the open end the coupler is almost level with the outside of the tubular component. Thus, the outer surface 44 can generally include a portion having a truncated cone shape, as shown in FIGS. 5a, 5b and 5c. This provides the outer surface of the coupling assembly with a relatively uniform, unobstructed surface having a minimum increase in outside diameter in the coupling assembly and substantially reducing the locations in which problems must occur later during installation. The surface 42 of the coupler is generally cylindrical and includes a first annular cavity 64, which has a first recess 68 having a depth substantially equal to the width of the cross section of the clamping ring 60. The cavity 64 includes a second recess, or a clamping projection 66, having a maximum depth equal to one fourth of the cross-sectional width of the clamping ring 60. The clamping projection 66 is shaped as a projection and is positioned on the side of the cavity 64 closest of the open end of the coupler. When radial force is not applied to the clamping ring 60, it has a general outer diameter that is larger than the inner diameter of the coupler 40 and approximately equal to the diameter of the clamping projection 66. Thus, in the coupler 40, the ring 60 is retained in the cavity 64, because the clamping ring can only be inserted or removed by first pressing it radially in a slight manner to decrease its outer diameter. As the axial tension is applied to the coupling assembly in the engaged state, the clamping ring gradually becomes seated and engages with the portions of the clamping projection and the slot, which is forced against the, consequently, in the most preferred embodiment, the coupler 40 is supplied with the clamping ring 60 in place in the cavity 64. The foregoing description of the clamping ring and its operation together with the groove and clamping projection the preferred embodiment of the invention. A clamping ring with a larger diameter should be preferred, particularly with the thermoplastic tube having a thick wall. A clamping ring having a larger cross-sectional diameter would be expected to increase the surface area over which the pressure due to axial tension would be diffused. In such an embodiment, the groove on the tubular component would be proportionally deeper than the modality described in the foregoing. The projection would have a depth less than the proportion of the clamping ring of cross section diameter described in the above. In the preferred embodiment, the coupler 40 includes a retaining surface 48, generally positioned inwardly of the open end at a depth slightly deeper than the deepest possible penetration of a tubular component. The retaining surface 48 has an inner diameter that is substantially the same as the inner diameter of the tubular component. The substantial identity of these diameters provides an interior surface without obstruction, uniform for the coupling assembly, which is important for the subsequent installation of internal cables or conduits within the tube for which the present invention is written.

The annular seal member can be any of at least 3 types. In each case, the seal member is transported within the coupler prior to the assembly of the coupling assembly in the coupled state. First, as shown in FIGS. 7, 8 and 10, the seal member may be a rubber O-ring 90, preferably placed in a second cavity in the coupler in such a way as to form a seal between the coupler and a outer surface of constant diameter of the tubular component. The second cavity is disposed at a small distance from the first cavity of the clamping ring to provide maximum sealing capacity and is positioned between the first cavity and the retaining surface on the inner surface of the coupler. The O-ring may also be placed in an O-ring cavity on the outer surface of the tubular component. The 90-in-O ring is preferably composed of butadiene or silicone rubber. Second, as shown in FIGURES 2-4 and 9, the annular seal member can be generally flat, a washer-type seal 80 made of foam rubber material, placed against the retainer surface in the coupler prior to use. When used in the coupling assembly, the annular seal of the joint type provides a seal between the end of the tube of the tubular component and the retainer surface of the coupler. The foam rubber material is preferably a material, which is sufficiently elastic, to rebound and maintain a seal even after being compressed approximately 80% during the insertion of the tubular component into the coupler to a sufficient depth to allow the ring to clamping, the cavity and the recess are aligned. The preferred material for the seal ring similar to a board is viniip rilo. Third, as shown in FIGS. 13 and 14, the annular seal member may be an annular rubber ring 100, positioned near the open end of the coupler, which includes chevrons or fins 102 extending inward from the Seal Ring. As best shown in FIGURE 14a, the chevrons or fins 102 are long enough to make contact and provide a seal against the outer surface of the tubular component, when it has been inserted into the coupler. This chevron seal member provides a seal between the open end of the coupler and the constant outer diameter portion of the tubular component outside the region of the fastening ring. Although preferably the chevron seal member is positioned on the inner surface of the coupler, between the open end and the cavity, it can likewise be placed on the outer surface of the tubular component in a seal member groove. The preferred material for the chevron seal member is EPDM. Configurations other than chevrons such as those shown in FIGURE 14b having rounded, raised rings 104 may be replaced by chevrons 102 in other embodiments. Fourth, as shown in FIGURES 11 and 13, the annular seal member may be a 110 seal of anille in V, annular placed near retainer surface 46; coupler. This V-ring seal includes a V-shaped portion 112 which extends radially inwardly from the lateral portion of the V-ring seal. The V-shaped portion is 1 long enough to make contact and provide a seal against the chamfered surface of the tubular component and against the inner surface of the coupler, when the tubular component has been inserted into the coupler. This V-ring seal member is preferably made of EPDM. The ring seal member V can be formed in an alternative embodiment also shown in FIGURE 13. In this embodiment, a double seal V-ring seal member 120 is transported on the inner surface of the coupler and provides a means of Seal for both sides of the coupler at the same time.

Finally, any of the stamps described can be used together with any other and various combinations of stamps are possible. In addition to the four embodiments described in detail, other known sealing devices can be replaced by or added to the described seal members. The following description is specifically worded for the ring seal member modality similar to a board. A similar description is applicable to other tr? Odality of the annular seal member described in the foregoing, with appropriate changes for each particular embodiment. The differences are described in the following with respect to each modality of seal member described. In the first preferred embodiment, the annular seal 80, by which the seal between the coupler 40 and the tubular component 20 is maintained, is a foam rubber ring placed between the retainer surface 48 and the end of the tube 24. of the tubular component 20. This ring is preferably of a joint-like material, ie, an annular ring cut of a substantially flat supply. The replacement for the preferred foam rubber ring can be made by a foam rubber or other type of O-ring, placed in the same location and can be replaced by a seal member having another known configuration. The material similar to a joint can be elastic material apart from foam rubber. When the tubular component 20 is inserted into the coupler 40, the coupler first interacts with the end tube 24 of the tubular component 20. The tubular component 20 is inclined or chamfered at the leading edge to provide a chamfered surface 26 adjacent to the end of the tube. 24 and has a semi-round circumferential groove 28 on its outer surface 22. The slot 28 is the engagement area for the clamping ring € :, which is normally installed and retained in the recess 68 of the inner surface 42 of the coupler 40, before the insertion of the tubular component. The slot 28 has a curvature, which is intimately coupled to that of the clamping ring 60, allowing the clamping ring 60 to be hermetically sealed in the slot 28 and have a depth equal to a maximum of one half the width of the cross section of the clamping ring 60. The depth of the clamping protrusion 66 is substantially equal to one half of the depth of the groove 28 on the tubular component 20 and substantially equal to a quarter of the width of the cross section of the clamping ring 60. When the tubular component 20 is inserted into the coupler 40, the chamfered surface 26 adjacent the end of the tube 24 encounters the clamping ring 60 and forces it to expand radially outwardly. This forces the clamping ring 60 to expand within the first deepest recess 68, creating the space required for the tube to pass. As the constant outer diameter segment 22 of the tubular component 20 passes through the clamping ring 60, the clamping ring remains radially outwardly within the first recess 66 to the fullest extent. As the tubular component 20 of the preferred vertex is inserted deeper into the coupler 40, the end of the tube 24 of the tubular component encounters the seal member 80 placed on the retainer surface 48 of the coupler 40. As the component tucular 20 is further inserted, the seal member 80 is further compressed by a preferred maximum amount of about 80%, or a compressed thickness of about 20% of its original, uncompressed thickness. This characteristic applies particularly for this modality. When the slot 28 of the tubular component reaches the depth of insertion within the coupler 40, which is opposite to the position of the clamping ring 60 radially expanded outwardly, the clamping ring snaps or snaps radially inwardly of the slot 28. The diameter and shape of the clamping ring allow it to snap into the slot 28. Then, the clamping ring 60 is held in this position on the tubular component by the slot 28. The slot 28 holds the clamping ring 60 in this same shape whether or not the coupling assembly 10 is in the clamped position. When the insertion of the tubular component 20 within the coupler 40 reaches the depth at which the clamping ring 60 snaps into the slot 28, the seal member 80 is compressed to its maximum extent. It will be noted that although the clamping ring 60 is primarily intended to prevent withdrawal of the tubular component 20 from the coupler 40, the clamping ring will also act to prevent over-insertion of the tubular component 20 into the coupler 40 during assembly. of the coupling assembly 10. When an axial tension is placed on the assembled coupling assembly 10, ie tends to pull the tubular component out of the coupler, the clamping ring 60 is thereby forced into the clamping boss 66 of the coupling assembly. The cavity. Since the clamping ring 60 has substantially the same curvature of cross section and diameter of the inside diameter of the clamping projection 66, the clamping ring 60 is held in place partially by the clamping projection 66 particularly by the fourth round portion. of the clamping projection against which the clamping ring 60 is pressed and engaged by the applied axial tension. Under axial tension, the clamping ring 60 snaps in and in substantial conformation, which engages with the fourth round portion of the clamping projection 66. As discussed above, the clamping ring 60 likewise engages with and substantially conforms to the semi-round slot 28. This position constitutes the holding position, in which the clamping ring 60 is held by the slot 28 and the clamping projection 66, as best shown in Figures 10 and 11. As the drawings clearly show, the ring at this point, it has no contact with the first recess 68. In this way, the clamping ring 60 is held in the clamping position only by the groove 28 and by the clamping projection 66 of the cavity 64, when it is low. an axial tension force. The clamping ring engages in the slot 28 and clamping projection 66, when the coupling assembly 10 is in its clamped position. It should be understood that when the tubular component 20 has been inserted into the coupler 40, the clamping ring 60 is in place in the slot 28 and the cavity 64 and the seal is formed, the coupling assembly can be said to be in the condition coupled. The clamping ring 60 moves completely within the clamping protrusion 66 and therefore completely within the clamping position, when an axial tension force is applied in the direction, in which it would result in the disengagement of the coupling assembly. , but for the clamping ring 60. When the axial tension force is applied in this direction the clamping ring 60 moves within the clamping projection 66, which thereby constitutes the clamping position of the coupling assembly, in wherein the clamping ring 60 is held in its clamped position by the slot 28 and the clamping projection 66. The axial tension force required to bring the assembly into engagement coupled to the coupled state, provided when the coupling is assembled, can be be made by hand. The force required to bring the clamping ring fully into the clamping position, generally comes from the axial tension forces applied during the installation of the tube coupled through a hole. Due to the relative configuration of the tubular component 20, the coupler 40, the clamping ring 60 and the seal member 80, the seal is held every time, if the clamping ring is in its initial position (axial decoupling force is not applied) or its clamped position (during or after the application of the axial force), or when a lateral force is applied to the coupling assembly. The seal member 80 is always partially compressed to maintain the seal.

In the second preferred embodiment, the coupler 40 includes a second annular cavity 92, which accepts an annular seal member, preferably a rubber O-ring 90, to create a watertight and air tight seal between the coupler 40 and the tubular component 20. In this embodiment, a seal on the retainer surface is not necessary, although if desired such a seal can be provided at that location in addition to the O-ring seal. Such a coupling assembly, comprising two members of Annular seal, could be expected to provide a stronger seal, resistant to higher pressures. In the O-ring seal embodiment, when the tubular component 20 is inserted into the coupler 40 the chamfered surface 26 contacts the O-ring 90 first, compressing it gradually. When the uniform diameter segment 22 between the inclination or bevel and the groove of the tubular component 20 meets the O-ring 90, it is compressed to its maximum extent. A seal of this shape is created between the coupler 40 and the constant outer diameter portion 22 of the tubular component 20. The slot 28 is spaced a sufficient distance from the end of the tube 24 to allow the constant outer diameter segment of the tubular component 20 Create and maintain a seal with the 90 rubber O ring. Due to the relative configuration of the tubular component 20, the coupler 40, the clamping ring 60 and the O-ring 90, the seal formed by the assembly is maintained every time, whether the clamping ring is in its initial position (without applied force of axial decoupling) or in the clamped position (during or after an application of axial force), or when an axial force is applied to the coupling assembly. Another embodiment of the present invention provides a tubular component that carries the clamping ring before insertion into the coupler. Although this embodiment is less preferred, it is within the scope of the present invention. With respect to the ability of the coupling assembly of the present invention to maintain a seal, the depth at which the tubular component 20 is inserted into the coupler 40 and the strength of the fiber reinforced plastic of the coupler 40 are of particular help. in keeping the seal. The depth of insertion, together with the closeness of the space between the tubular component and the coupler, prevents any very small angle from developing between these parts under the lateral force, which in other way would allow the seal to break. The fiber reinforcement in the coupler provides it with enough strength to withstand extreme lateral forces, which in any other way would allow the seal to be broken by deformation of the coupler body. The preferred fiber is glass fiber, used to preferably reinforce the polyester material. Other useful fibers may include carbon fibers, used as reinforcement for an epoxy-based resin, for example. The most preferred manufacturing process of the coupler includes a step of placing the molding material impregnated with glass fiber resin, oriented in a compression mold in an oriented manner, followed by compression molding in the shape of the coupler. Preferably the cavity and the O-ring or the chevron ring or other grooves are cut in a subsequent, separate step to reduce molding costs. The preferred orientation of the glass fibers are parallel to and perpendicular to the axial direction of the coupler. It is considered that this orientation provides the highest resistance for the coupler. The process of inserting the tubular component 20 into the coupler 40 is essentially the same for all embodiments of the present invention, as described in detail for the first preferred embodiment. A difference between the V-type and joint-type seals on the one hand and the O-ring and the chevron-type seals on the other, is that once the O-ring or chevron seal comes into contact with the constant outside diameter portion 22 of the tubular component, in the degree of compression of the ring or the resistance of the seal changes significantly by the insertion of the tubular component 20 inside the coupler 40. In the V-ring seals and the seal type, another insert further compresses the seal member. Some compression of the annular seal member remains in all modes when in the fastened position. The present invention provides a cheap plastic coupling assembly for a conduit or tube, comprising a tubular component, a coupler, an annular clamping ring, an annular seal member, the combination that is easy to assemble and allow for at least three hundred four meters (one thousand feet) of such a tube is pulled through an underground hole without the use of additional fasteners to maintain the engaged state. The present invention provides a method for installing coupled lengths of plastic conduit in a substantially horizontal underground pit. The method is provided for the installation of coupled lengths of the conduit, each length comprises a tubular component and a coupler in coupled relation. The preferred method includes the steps of: a) providing a substantially horizontal underground pit, b) providing an axial stress source for pulling the lengths of the plastic conduit through the hole, c) joining the source to a first end of a plastic duct, d) pulling the first end into the hole, whereby a second end of the duct remains outwardly extending from the hole, the second end comprises a tubular component having a circumferential, annular groove on its outer surface, and ) fastening a first open end of a coupler to the second end, the first open end comprises an inner surface, the inner surface includes at least one annular cavity, at least one annular cavity having a retaining projection and carrying a ring of clamping, by inserting the second end into the first open end until the clamping ring comes to be placed in the slot in addition to being placed in the cavity, f) holding a first end of a next plastic conduit inside a second open end of the coupler, the first end comprises a tubular component having a circumferential, annular groove on its outer surface, the second open end comprises an inner surface, the inner surface includes at least one annular cavity, at least one annular cavity having a retaining projection and carrying a clamping ring, inserting the first end at the second open end until the clamping ring comes to be placed in the groove, in addition to being placed in the cavity, g) pull the length of the conduit coupled within the hole, h) repeat the stages d. e ', f) and g) until the entire length of the coupled duct has been installed in the underground hole and in which the clamping stages are only the clamping steps necessary for the installation of the duct. Although each stage of the method has been fully described in the description of the apparatus, some additional details are given in the following. Providing the hole that includes a cable or other apparatus within the hole, which provides a source of axial tension for traction, is suitably described in the references cited therein. Various devices are known for attaching the traction apparatus to a first end of a plastic conduit. The connection can be made directly, by use of a flexible clamping device, such as a "mesh clamping" device which works by exerting a radially inward force on an object within the mesh material, when the mesh material is subjected to an axial tension, which functions as a "Chinese finger lock". Such a device is available from CARLON Telecom Systems, Cleveland Ohio, and from other sources in the industry. The connection can be indirect in which a modified coupler or other device is used as the interface between the first end of the first plastic conduit. The modified coupler can be made of the same material as the coupler of this invention, or of some other material, such as steel, but could preferably be attached to the first end of the first plastic conduit in the manner described herein for the coupling assembly . Step d) of the method establishes that the conduit is partially pulled into the hole with a sufficient portion of the second end that remains outside the hole to allow placement of the coupler and insertion of the next length of conduit into the coupler in the next step. Steps e) and f) are essentially mirror images of each other, since the method described herein contemplates the use of both of a length of plastic conduit of a coupler which are each mirror images of themselves. In other words, both the tube and the coupler are symmetrical end-to-end. One end of each can be designated the first end, the other designated the second end. In this way, in one step the second end of the conduit is inserted into the first end of the coupler and in the next stage, the second end of the coupler receives the first end of the next conduit. Step g) is essentially the same as step d), and represents the end of a cycle of the method. In addition, it will be apparent that instead of alternating steps e) and f / in each method cycle, the couplers can be installed at one end of the length of the conduit before the time in which the conduits are to be coupled together and pulled inside. of the hole. The anterior connection of a coupler to a length of the conduit can be carried out in the factory, by an intermediary supplier or by the contractor in the field. Such a prior binding, however, follows the steps of the method, since all the steps are carried out only in a different sequence. In addition, steps (e) and (f) can be alternated for the full number of tube lengths to be pulled through the hole, before starting to pull the tube. The traction process would then consist of steps (d) and (d) repeated on a continuous, alternating base until the entire tube chain is pulled into the hole. In this way, steps (d), (e), (f) and (g) can be juxtaposed in various ways without departing from the scope of the invention. EXAMPLES To provide a basis for comparing the known couplings for the PVC conduit to the coupling assembly of the present invention, the following test results are pertinent. In a series of tests, the coupling assemblies of a 10.16 cm (4 inch) PVC duct C conduit coupled only with glue and with both glue and screws were tested to determine the amount of axial tensile force, which A coupling assembly can support before it is separated by the traction Note that although the conduit C has a wall thickness smaller than the PVC pipe program 40, the contact that holds the coupling together is cemented together and the thickness of the The wall is not an important factor in determining the coupling capacity to support an axial tension.When screws are used, six 10x16x1 / 2 screws of internal self-tapping hex head are inserted in the bell and spigot type couplings, which have been glued together with cement and allowed to cure for the indicated times, three pairs of screws were inserted at 120 ° C intervals around the circumference of l Coupling assembly. The following table presents the results of the test.

TABLE I Glue, Was it used? Time used for pulling force and screws that the glue is axial to pull heals out All Weather NO 20 1606 All Weather NO 10 1039 R RSH NO? 664 R RSH NC 10 731 All Weather SI 10 1300 R RSH SI 20 2413 R RSH Yes 10 1288 Note: 3C minutes is the best cure time, but 10 minutes is the standard used in the field for All Weather glue. The glue "All Weather" is a PVC cement resistant to moisture, fast comprising PVC resin, rahydrofuran, acetone, cyclohexanone, metiletxlcetopa and amorphous silicon. "R RSH" is another fast moisture resistant PVC cement comprising PVC resin, tetrahydrofuran, cyclohexanone and amorphous silica. The results in Table I show that the use of screws and PVC cement together, greatly increase the strength of a coupling that is to be pulled apart by axially applied tensile forces compared with either PVC cement alone or with screws. Table II shows the results of a series of tests using 10.16 cm (four inches) PVC with coupling mounts joined with cement and with screws.

In these tests, three pairs of 10x16x1 / 2 hexagonal, self-tapping screws were inserted into the bell and spigot type couplings at intervals of 120 °, which have been cemented together and allowed to heal during the indicated times. TABLE II Conduit Cement Time used to force the glue to a; for Jal cure hacsi outside T-40 R RSH 10 -11 6690 T- 40 R RSH 10 - 11 7399 T-40 All Weather 10 - 11 7922 T-40 All Weather -30 3TC4 T- 40 Without Cement- 1939 Only Screws T- 80 R RSH 10 6215 T- 80 R RSH 10 5243 T- 80 Ail Weather 10 487S T- 80 All Weather 10 5332 T- 80 Without Cement- 2099 Only Screws In a single reported measurement, the coupling assembly of the present invention is shown as eig-e.

Two conduit ends, each having a half-round, 0.19 cm (0.075 inch) deep groove machined as previously described, was inserted and clamped in a coupler having a clamping ring with a cross-sectional diameter of 0.38 cm (0.150 cm). inches), with the clamping ring in the clamping position as described herein. Cement and screws were not used with the coupling assembly as described above in the present invention. The ends of the conduit were attached to a Ins test machine, which was adjusted for a 1.27 cm per minute T.500 inch per minute traction. The test runs until the union fails. The joint failed to 3628.36 kg (7992 pounds) of axially applied tensile load. As shown by this experiment compared to previous measurements, the coupling assembly of the present invention, without the use of either glue or glue and screws, provides a high strength coupling, which is particularly useful for traction to through the extended lengths of substantially horizontal, underground holes. Although the particular embodiments of the invention have been shown and described, various modifications will be apparent to those skilled in the art and therefore it is not intended that the invention be limited to the described embodiments or the details thereof and the separations can be made from it within the spirit and scope of the invention.

Claims (24)

1. CLAIMS 1. A coupling assembly constructed to allow coupled lengths of conduit or thermoplastic tubing to be pulled through a substantially horizontal, underground pit, characterized in that it comprises: a tubular component having an outer surface, an end tube and a surface chamfered adjacent to the end of the tube; a coupler which extends the interior surface which includes a surface of an outer surface, an open end for receiving the tube end of the tubular component, the inner surface of the coupler further includes an annular cavity, the cavity has a relatively deep recess and an adjacent clamping projection; an annular clamping ring partially positioned within the cavity, the ring being substantially circular in cross section and having a cross-sectional width; and an annular sealing member, - in which the coupling assembly is assembled into a state coupled by the insertion of the end of the tubular component tube to the open end of the coupler and when in the engaged state, the clamping ring it may be placed in a clamping position between the coupler and the tubular component, when axial pulling force is applied and the annular sealing member is placed in a seal position between the coupler and the tubular component; and wherein the assembled coupling assembly with the clamping ring in the clamping position, which is the only means to maintain the engaged state, when installed by pulling through the hole which remains in the engaged and sealed state when it is pulled for installation. The coupling assembly according to claim 1, characterized in that the clamping position comprises a groove on the outer surface of the tubular component and a cavity on the inner surface of the coupler. The coupling assembly according to claim 2, characterized in that the cavity includes a clamping projection and an adjacent recess and a portion of the clamping projection is configured to conform to and engage with the clamping ring. The coupling assembly according to claim 3, characterized in that the clamping protrusion has a depth substantially equal to one fourth of the cross-sectional width of the clamping ring and the recess has a depth substantially equal to the section width. cross section of the clamping ring. The coupling assembly according to claim 4, characterized in that the groove conforms to the shape of the clamping ring and has a depth substantially equivalent to one-half the width of the cross section of the clamping ring. The coupling assembly according to claim 1, characterized in that the annular seal member is positioned between the end of the tube of the tubular component and the retainer surface of the coupler. The coupling assembly according to claim 6, characterized in that the annular seal member can be compressed approximately 80% during the insertion of the tubular component into the coupler to a depth sufficient to allow the clamping ring, the cavity and the recess are aligned. The coupling assembly according to claim 1, characterized in that the annular seal member is an O-ring placed in an O-ring groove, located between the groove and the tube end of the tubular component. The coupling assembly according to claim 1, characterized in that the annular seal member is an O-ring placed in an O-ring cavity located between the cavity and the retainer surface on the inner surface of the coupler. 10. The coupling assembly according to claim 1, characterized in that the annular seal member is an annular seal ring, having at least two rows of chevrons, the ring being placed in a cavity located on the inner surface of the coupler between the cavity and the open end. The coupling assembly according to claim 1, characterized in that the annular seal member is an annular seal ring having at least two rows of chevrons, the ring which is placed in a seal ring groove on the outer surface of the tubular component. The coupling assembly according to claim 1, characterized in that when assembled, the outer surface of the tubular component and the inner surface of the coupler are separated by a distance substantially equivalent to a quarter of the width of the cross section of the ring. subjection. The coupling assembly according to claim 1, characterized in that the clamping ring is metal and C-shaped. 14. The coupling assembly according to claim 1, characterized in that the coupler is reinforced with fiber. The coupling assembly according to claim 14, characterized in that the coupler is a polyester reinforced with glass fiber. 16. The coupling assembly according to claim 1, characterized in that the annular seal member is foam rubber. The coupling assembly according to claim 1, characterized in that the outer surface of the coupler is inclined toward the open end. 18. A method for installing coupled lengths of plastic conduit in a substantially horizontal underground pit, the coupled lengths comprising tubular components and couplers in coupled relation, characterized in that it comprises the steps of: (providing a substantially horizontal underground pit, b) providing a source of axial tension for pulling the lengths of the plastic conduit through the hole, c) joining the source to a first end of a plastic conduit, d) pulling the first end into the hole, whereby a second end of the the duct remains outwardly extending from the hole, the second end has a circumferential, annular groove on its outer surface, e) holds a first open end of a coupler to the second end, the first open end comprises an interior surface, the interior surface includes at least one annular cavity, at least one annular cavity that has a seal When holding and holding a clamping ring, the clamping is performed by inserting the second end into the first open end until the clamping ring becomes placed in the groove, f) holding a first end of a following conduit of plastic at a second open end of the coupler, the first end having an annular groove, circumferential on its outer surface, the second open end comprises an inner surface, the inner surface includes at least one annular cavity, at least one cavity annular having a clamping projection and carrying a clamping ring, inserting the first end into the second open end, until the clamping ring becomes placed in the groove, g) pulling the length of the attached conduit into the hole , h) repeating steps d), e), f) and g) until the full length of the coupled duct has been installed in the underground hole and in the The clamping stages are the only clamping steps necessary for the installation of the conduit. 19. The method according to the claim 18, characterized in that the clamping steps include a clamping ring that is moved to the clamping position, when an axial tension has been applied to pull the conduit through the hole. 20. The method of compliance with the claim 19, characterized in that the clamping steps include the clamping ring which is held in the clamping position by the groove and the clamping projection. 21. The method according to the claim 18, characterized in that the clamping steps include forming a seal between the tubular component and the coupler, the seal provided by an annular seal member. 22. The method according to claim 21, characterized in that the annular seal member is a rubber 0-ring. 23. The method according to claim 21, characterized in that the annular seal member is a seal similar to a rubber seal. 24. The method according to claim 21, characterized in that the annular seal member is a rubber seal having seal chevrons. SUMMARY The present invention provides a coupling assembly for a conduit or pipe, comprising a tubular component, a coupler, an annular clamping ring and an annular seal member., in which the coupling assembly is assembled by the insertion of the tubular component into the coupler and when assembled the clamping ring is placed in a clamping position between the coupler and the tubular component and the seal member is placed in a seal position between the coupler and the tubular component and a method for installing coupled lengths of pipe. The coupling assembly provides a coupling which can be installed by pulling through a substantially horizontal hole similar to a tunnel, without the use of any additional coupling or seal devices. The 10.16 cm (four inch) PVC pipe thus coupled and installed remains clamped and sealed when subjected to an axial tensile force of at least 2,270 kg (5,000 pounds) during installation and the seal member maintains a seal, the which can withstand a hydraulic pressure of at least 1.40 kg / cm2 (20 psi) without leakage. The installation method is simple and direct, requiring only the manual assembly of the coupling assemblies and without additional time, space or steps to increase the novel coupling described herein.