MXPA00009795A - Connector for tubular members - Google Patents

Abstract

A connector (10) for joining together lengths of plastic tubing has a plurality of external annular barbs (28, 29) and an insertion end (20) portion having spaced apart first and second end edges (20a, 20b) with tapered edges (50, 60) extending therefrom to a cylindrical portion from which the annular barbs extend.

Description

CONNECTOR FOR TUBULAR MEMBERS BACKGROUND ART In duct systems that utilize a plurality of lengths of tubular tubes or conduits, connector means must be provided to join the various lengths of tubing. Although the connectors that link the outer surface of the pipe are well known, for some applications it is highly desirable to use a connector that connects the interior surfaces of the pipe lengths that are being joined. The outer connectors are bulky and have larger external diameters than the tubes. Additionally, for In some applications, it is desirable that the internal diameter of the passage defined by the interconnected lengths of pipe and the inner surface of the connector be substantially uniform. It is desirable to have a passage of uniform diameter for the The attached lengths of pipe and connector are particularly intense for connected pipes that are part of a fluid supply system or a system where wires or fiber optic bundles are passed through. Conduit systems of the state of the art that use the "inner surface bonding" type connector to join adjacent pipe lengths result in a constriction in the passage that restricts fluid flow.

A connector of the state of the art of inner surface bonding that does not restrict the internal diameter of the passage is disclosed in International Publication No. WO 97 47910, which teaches a connector that extends along an axis from a first end face to a second end face. Truncated areas are cut at the opposite end faces at an acute angle relative to the axis. Each of the truncated areas has a cross-sectional configuration normal to the axis that defines a partial circle. The truncated area is cut such that the remaining end face defines an arcuate surface, whose end points define a string that is smaller than the internal diameter of the connector and the internal diameter of the pipe. In this way, the end face and the truncated area can be inserted into the pipe, even though the outer diameter defined by the external threads in the connector is larger than the internal diameter of the pipe. In order to completely connect the connector to the pipe, the connector is rotated axially to screw the external threads on the inner surface of the pipe. Connectors of this type have encountered certain faults when subjected to strong axial pull forces for the reason that the truncated area is provided over such a large portion of the connector, thereby limiting the bonding of surface area between the outer surface of the connector and the interior surface of the pipe.

It is important that the connector or coupler in combination with attached lengths of pipe meets certain minimum pull resistance requirements. For some applications, such as joined pipe lengths having fiber optic bundles passed therethrough using high velocity air blowing system, it is desirable that the attached lengths of pipe be capable of supporting a predetermined amount of pressure without loss of pressure meaningful The present invention improves a connector of the type shown in WO 97 47910 in that when it is connected, the combination of the outer surface of the connector and the inner surface of the linked pipe length is able to withstand, without significant leakage, the high internal pressures developed through the use of the connector and the attached pipe lengths. Additionally, the combination can withstand significant axial pulling forces without the connector separating from the length or lengths of pipe. Disclosure of the Invention The present invention is directed to a connector or coupler for joining two lengths of plastic pipe by means of a straight axial movement of the coupler relative to the length of pipe to be bonded to effect bonding of the inner wall surface of the pipe. the pipe with the outer end portion of the connector. The connector has a cylindrical internal surface that defines a passage that extends along an axis. The internal diameter of the passage is not less than the requirements of the internal diameter of the pipe length. When it connects, the combination of the connector and the pipe length is able to withstand, without significant fluid leakage, the internal pressures developed by the rapid flow of fluid required to pass the fiber optic bundles through the connector and attached lengths of pipe. Additionally, the combination can withstand a significant axial pulling force without the connector separating from the length or lengths of pipe. The present invention is also directed to the combination of a connector and pipe and to a method for forming such a combination. The pipe, before its connection by the connector, has a substantially uniform internal diameter all the way through except at the ends to be joined by the connector. Preferably, the inner surface of the pipe is beveled or thinned at the ends by being joined by the connector. The pipe is formed of a material that has some resilience and the ability to be expanded. For example, the pipe is desirably manufactured from a plastic material such as high density polyethylene. In contrast, the connector is manufactured from a more rigid material such as metal, stainless steel or brass, for example, or a plastic material that has considerably more rigidity than the material from which the pipe is manufactured. The connector extends along an axis from a first end to a second end and has a plurality of spaced annular beards extending outwardly from its outer wall surface. The end portion of the connector intended to be inserted into the end of a length of pipe to be connected thereto is formed or cut to define a pair of recesses extending rearwardly of a pair of truncated end edges. The recesses are located on opposite sides of the shaft with each other. The truncated end edges are also located on opposite sides of the shaft from each other. A line drawn between the centers of the truncated end edges will pass through the axis. When viewed in elevation with the connector oriented such that the eyes of the observer are aligned with a line passing through the centers of the truncated end edges and the axis, each of the cut edges extending from an edge of end to the opposite end edge will appear as a substantially straight line disposed at an angle of 40 to 60 ° with respect to the axis. When the connector is rotated about the axis 90 'from such orientation, each of the cut edges will be seen as an arc extending between each of said end edges. The beards are separated from one another by means of sections of a substantially cylindrical external wall surface. Each beard has (1) a first surface tapering outward in a direction away from the end that is being inserted into the pipe, (2) an apex and (3) a second surface extending from the apex to the surface of the pipe. external cylindrical wall. In a preferred embodiment, the beard closest to the end edges extends outwards a first distance such that its apex defines a first diameter and the beard more spaced from such end edges extends outward a greater distance such that its apex defines a second diameter greater than the first diameter. In a preferred embodiment, the external wall surfaces of the connector in the areas between the annular beards are substantially cylindrical and of uniform diameter slightly larger than the inner cylindrical diameter of the length of pipe to be connected. However, as a result of the thinning or inner bevel at the connecting end of the pipe length, the inner diameter in such a pipe end bevel is slightly larger than the outer diameter of the outer wall surface of the connector. Such size ratio, together with the connector end configuration, allows the connector to be easily inserted into such a pipe end with a straight axial thrust of sufficient force to cause the pipe end and an adjacent portion to expand as it moves through the pipe. they the connector. In another embodiment, it is possible to link the connector with a length of pipe that does not have a thinning or internal bevel at its binding end. As a result of the truncated end edges defining the end to be inserted, it is possible to begin inserting the connector to the end of the length of such a pipe without thinning by simply tightening and temporarily deforming the open end of the pipe to approximate an oval shape, with this by increasing the size of the opening along the long axis of the oval to a larger size than the outer cylindrical surface of the connector and orienting the connector such that the opposite truncated end edges have their centers oriented with said long axis, thereby allowing that such end edges fit in the ovally enlarged portions of the pipe linking end. In the Drawings; Figure 1 is a perspective view of the connector of the present invention. Figure 2 is a side elevational view showing the connector with the end portion of a pipe length about to be fixed thereto. Figure 3 is a view similar to Figure 2, but showing the connector and tubing rotated 90 ° about the axis and with the connector closest to the connection with the end of the pipe length. Figure 4 is an enlarged sectional view taken through line 4-4 of Figure 3. Figure 5 is a sectional view taken through two lengths of pipe attached to the connector of Figures 1-4. . Figure 6 is a top plan view of a T-shaped connector. Figure 7 is a perspective view showing a length of pipe having three integral tubular sections, each of which can be joined with the connector of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, there is shown a connector 10 and a pair of tubular members 12 and 13, which are components of a global tubular system (not shown). The tubular system, for example, may be a system for controlling the flow of fluids or a system that forms a portion of an optical fiber duct insert. Various types of fiber optic duct inserts are disclosed in the patents of the United States Nos. 4,582,093 and 4,674,167, both assigned to the assignee of the present application. Although such multiple chamber duct inserts or fiber optic inserts of the state of the art are shown with sections of pipe having non-circular cross sections, the connector of the present invention is preferably used with tubing and tubular sections having an internal configuration circular. As shown, the tubular member 12 has an internal surface 14 and the tubular member 13 has an internal surface 15, each of which internal surfaces 14 and 15 has a circular cross-sectional configuration of predetermined diameter DI. The connector of the present invention is particularly well suited for use with plastic tubing having an internal diameter of the order of 0.5 to 4 inches; however, it can be used with tubing that has a larger or smaller diameter. The tubular member 12, the connector 10 and the tubular member 13 are shown aligned along the axis A. The tubular member 12 has an end face 16 which preferably lies in a plane substantially perpendicular to the axis A and the tubular member 13 has an end face 17 that also preferably lies in a plane substantially perpendicular to the axis A. The connector 10 extends from a first end 20 to a second end 21 and has a passage 22 extending therethrough. The passage 22 is defined by an inward facing wall surface 23 that lies in a cylinder having a diameter substantially equal to the diameter DI of the inner surface 14 and the inner surface 15 of the tubular members. 12 and 13, respectively. Externally, the connector 10 has a cylindrical wall surface 24 with a central collar 25 extending outwardly thereof. The collar 25 has a first shoulder 36 and a second shoulder 46. Between the first end 20 and the collar 25 there is a first pair of annular beards 28 and a second pair of annular beards 29. Between the second end 21 and the collar 25 there is a third pair of annular beards 128 and a fourth pair of annular beards 129. Each of the first pair of annular beards 28 includes a first taper surface 28A tapering outward from the cylindrical wall surface 24 in a direction away from the end 20 and a second wall surface 28B attached to the taper wall surface 28A at an apex 28C. The second wall surface 28B extends radially inward from the apex 28C to the cylindrical wall surface 24. The taper wall surfaces 28A are disposed at an angle in the range of 10 to 20 ° relative to the A axis. similarly, the second pair of beards 29 each has a first tapering wall surface 29A tapering outward in a direction away from the first end 20 and a second wall surface 29B attached thereto at an apex 29C. The second wall surface extends radially inward from the apex 29C to the cylindrical wall surface 24. The taper wall surfaces 29A are disposed at an angle of 10 to 20 ° relative to the axis A. The apex 29C extends outward of the axis A a greater distance than the apex 28C and, therefore, it works to deform the inner surface 14 or 15 of the respective tubular member 12 or 13 linked thereto outwardly by a greater amount than the first pair of annular beards 28 Each of the apices 28C and 29C is sharpened so that any tendency of the connector 10 to be pulled out of the tubular member 12 or 13 will cause the apices 28C and 29C to cut or dig into the inner surface 14 or 15 of the tubular member. respective 12 or 13 and prevent the removal of any of the tubular members, except when a pulling force occurs in excess of that anticipated for the conditions of use planned. For example, as can be seen in Tables 1-4, connectors attached to a 1-inch internal duct plastic tubular member successfully withheld pulling forces greater than 900 lire while connectors attached to a tubular internal duct member of 1.25 inches successfully withheld pulling forces greater than 1500 pounds The third pair of annular beards 128 and the fourth pair of annular beards 129, positioned between the second end 21 and the collar 25, are tapered in a reverse direction of the first and second pairs of annular beards 28 and 29 so as to have surfaces taper wall 128A and 128B tapering outward in a direction away from the second end 21. Except for such an inversion, the third pair of annular beards 128 and the fourth pair of annular beards 129 are similar to the first pair of annular beards 28 and the second pair of annular beards 29 and will not be described further. As an example, for a connector 10 in which the outer cylindrical wall surface 24 has a diameter of the order of 1.41 inches, the apex 28C may have a diameter of 1.47 inches and the apex 29C may have a diameter slightly greater than 1.5 inches. The portion of the connector 10 between the first end 20 and the nearest beard of the first pair of annular beards 28 will now be described. At a slightly spaced point of the annular beard 28 closest to the first end 20, a tapered edge 50 is formed or cut off which, when viewed in elevation in the orientation shown in Figure 2, appears as a straight line extending from a point of origin 50A on the cylindrical wall surface 24 at two intersecting points spaced 50B, 50B at the end 20. When viewed in elevation with the connector 10 rotated 90 'about the axis A, as shown in figure 3 , the edge appears as a bow. A second cut edge 60 extends from the cylindrical surface 24 starting at an extreme external origin point 60A disposed 180 ° from the point 50A and extending to substantially the same angular arrangement to the A axis as the first edge 50 to a pair of points 60B intersecting with the first end 20. As can be seen in the drawings, the respective intersection points 50B and 60B at the end 20 define first and second spaced apart end edges 20A and 20B. Similar edges 150 and 160 are formed or cut in the area of the second end 21 and extend from origin points 150A and 160A. Their respective intersection points 150B and 160B with the end 21 define the first and second spaced end edges 21A and 2IB. The end edges 20A and 20B have a slight bevel on the outer wall surface disposed at an angle of approximately 15 ° with the axis A and extending a distance of the order of 0.05 inches from the ends 20 and 21, respectively. Except for the slight size reduction resulting from the 15 ° bevel, the distance between the end edges 20A and 20B is equal to the diameter of the cylindrical outer surface 24 and is greater than the internal diameter DI of the internal surfaces 14 and 15 of the respective tubular members 12 and 13. Preferably, each of the end edges 20A and 20B lies in a first plane disposed perpendicular to the axis A. Similarly, the edges 21A and 21B lie in a second plane which is also perpendicular to axis A but it is spaced from the foreground. In a preferred embodiment, the tubular member 12 is provided with a thinning or bevel 18 extending from its end face 16 at an angle to intersect the inner surface 14. The tubular member 13 is provided with a thinning or bevel 19 extending from its end face 17 at an angle relative to the axis A to intersect the inner surface 15. The intersection of the bevel 18 with the end face 16 defines a circle having a diameter D2 that is not only greater than the diameter DI, but also is larger than the diameter of the outer cylindrical wall surface 24. The intersection of the bevel 19 with the end face 17 also defines a circle having a diameter D2.

As can be seen from Figure 3, by virtue of the bevel 18 and its intersection with the end face 16 having a diameter D2 greater than the diameter of the outer cylindrical wall surface 24, the end edges 20A and 20B will contact with the bevel 18 upon insertion of the connector 10 towards the end 16 of the tubular member 12. The movement of the connector 10 along the axis A under whatever force is required to deform and expand the end portion of the tubular member 12 It will continue until the end face 16 links the collar 25, in which case the connector 10 is fully and sealingly linked with the tubular member 12. A similar axial movement of the connector 10 towards the tubular member 13 will similarly effect the bonding of the second tubular member 13 to the connector 10, as shown in Figure 5. The connector 10 can also be inserted into a tubular member that is not provided with a bevel such as the bevel 18, even if the tubular member has the same dimensions relative to the connector 10 as the inner surface 14 of the tubular member 12. In that case, when it is desired to insert the end 20 of the connector 10 to the tubular member, it is necessary simply to tighten the tubular member 12 in the area of its end 16 to deform the tubular member in the end area to approximate an oval, such that the maximum distance through the inner surface 14 (ie, along the length of the oval), is greater than the distance between the end edges 20A and 20B.

This will allow the connector 10 to have an inlet towards the tubular member so that the connector can continue to be pushed into it with the inner surface of the pipe adjacent to the end face being ramped outwardly by the edges 50 and 60 and, as the connector 10 continues inwardly, ramp outwardly over the tapered surfaces 28A and the tapered surfaces 29A. Referring now to Figure 6, a modified connector assembly 70 with individual connectors 72 extending therefrom is shown. The connectors 72 can be formed integrally with the housing 71, each being a unitary part thereof. Alternatively, the individual connectors may be formed and welded separately, or otherwise secured to the housing 71. The housing 71 has a T-shaped passage 74 communicating with the passage of each of the connectors 72. Each connector 72 extends from a guide end 75 intended for insertion into a length of plastic tubing shown in phantom lines and designated 80A, 80B and 80C. Each connector 72 has a passage similar to the passage described with respect to the embodiment of Figures 1 to 5. Additionally, the portion of each connector 72 adjacent the end 75 is similar to the ends 20 and 21 described with respect to the shape of embodiment of Figures 1 to 5. Each of the connectors 72 has first and second annular beards 76 having an apex 76C of substantially the same diameter as described with respect to the apex 28C for the embodiment of Figures 1 to 5 Additionally, the connector has a third annular beard 78 having an apex 78C that has a larger diameter than the apex 76C of the other two beards. This particular connector 72 is described below as a three-ring connector, in contrast to the four-ring connector of the embodiment shown in Figures 1 to 5. Except for the difference in the number of annular beards, each connector 72 is substantially as described with respect to the embodiment of Figure 2 for those portions between the collar 25 and the respective ends 20 and 21. The connector of the present invention can withstand a minimum pull-out resistance of 7,000 pounds for an internal one-inch duct and a minimum pull load of 1,100 pounds for an internal SDR 13.5 of 1.25 inches. Tables 1 to 4 show the amount of movement between the connectors and the tubing linked in inches when subjected to varying degrees of pulling load for various sizes, including an internal one-inch duct with a three-ring connector (Table 1), one-inch internal duct with a four-ring connector (Table 2), 1.25-inch internal duct with a three-ring connector (Table 3) , and an internal duct of 1.25 inches with a four-ring connector (Table 4). Additionally, each of the connectors retains pressures substantially in excess of the required 100 psi target to 23 ° C + 5 ° C. Tables 5, 6, 7 and 8 show the results of the various connectors and sizes when tested at pressures up to 300 psi. As can be seen from the tables, the combination of the connectors with the tubular segment successfully exceeded the desired objectives. Table 1 Internal 1 Inch Duct with 3-Rings Connector (3 Bends) Mov. Total Duct / Force Peak Pass / Sample Connector (inches) (pounds) Fault 1 0.009 1055 Pass 2 0.006 960 Pass 3 0.006 980 Pass 4 0.002 1040 Pass 0.006 980 Pass Table 2 Internal 1 Inch Pipe with 4 Rings Connector (4 Bends) Mov. Total Duct / Force Peak Pass / Sample Connector (inches) (pounds) Fail 1 0.004 1038 Pass 2 0.001 1000 Pass 3 0.003 950 Pass 4 0.002 980 Pass 0.003 980 Pass Table 3 1.25"Internal Pipe with 3-Rings Connector (3 Beats) Pipeline / Force Pivot Pass / Sample Conec r (inches) (pounds) Fault 1 0, .02 1600 Pass 2 0, .018 1600 Pass 3 0. .007 1550 Pass 4 0, .012 1560 Pass 0, .011 1675 Pass Table 4 1.25"Internal Pipe with 4 Rings Connector (4 Barb) tell Pipe / Force Peak Pass / Sample r (inches) (pounds) Fail 1 0. .009 1610 Pass 2 0. .017 1620 Pass 3 0, .008 1640 Pass 4 0. .005 1620 Pass 5 0. .004 1595 Pass Table 5 1-Inch Internal Pipe with 3-Rings Connector (3-Barb) Max. Pressure Pass/ Sample Achieved (psi) Comments Falla 1 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 2 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 3 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 4 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi Table 6 1 Inch Internal Pipe with 4 Rings Connector (4 Beards) Max. Pressure Pass/ Sample Achieved (psi) Comments Failure 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 3 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 4 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 5 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi Table 7 1.25"Internal Pipe with 3-Rings (3-Bends) Connector Max.

Sample Achieved (psi) Comments Falla 1 200 Maintained at 125 psi x 5 Pass min. Escaped at 200 psi 2 '255 Maintained at 125 psi x 5 Pass min. He escaped at 255 psi 3 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 4 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 5 250 Maintained at 125 psi x 5 Pass min. Connector flew at 250 psi Table 8 Internal 1.25"Pipe with 4-Rings Connector (4 Bends) Max.

Sample Achieved (psi) Comments Falla 1 275 Maintained at 125 psi x 5 Pass min. Maintained at 275 psi 0 2 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 3 300 Maintained at 125 psi x 5 Spend 5 min. Maintained at 300 psi • 4 300 Maintained at 125 psi x 5 Pass min. Maintained at 300 psi 0"5 300 Maintained at 125 psi x 5 Min Pass Maintained at 300 psi Referring now to Figure 7, there is shown a further embodiment of pipe 90 having three separate passages 91, 92 and 93 of three tubular portions unitarily and integrally formed 94, 95 and 96 forming the tubular member of multiple cells. Each of the portions ^ tubular 94, 95 and 96 has a bevel 97 at the end 98 to which each of the connectors is to be inserted. These tubular portions can be connected to them (1) three individual connectors or (2) a connector type three multiple units or (3) a single connector and a two-unit multiple connector. Many modifications will be evident to the technicians in the 5 subject. For example, it is within the contemplated objects of the present invention that at least some of the annular beards may be intermittent with grooves extending axially rather than continuously, as shown. However, all test results in the above tables are for connectors that have continuous annular beards. Accordingly, the scope of the present invention should be limited only by the scope of the claims.

Claims (14)

1. CLAIMS 1. A connector for holding a length of pipe having an internal surface of predetermined size and an open end, said connector comprising a tubular portion having an inner surface extending along an axis, a contoured exterior and a insert end portion, the invention characterized in that: (a) said insert portion including (i) first and second end edges, said end edges being spaced from each other, each said end edges extending from a point of origin to a terminus point and each of said end edges defining a plane perpendicular to said axis; (ii) a first tapered edge disposed at an angle with said axis extending from the point of origin of said first end edge to the point of origin of said second end edge; (iii) a second tapered edge disposed at an angle with said axis extending from the terminating point of said first end edge to the terminating point of said second end edge, said first and second tapered edges being spaced apart by said end edges; and (b) said contoured exterior including (i) a smooth outer surface for bonding the inner surface of said pipe length, said outer surface defining a plurality of annular beards that are being axially spaced from said end edges on said surface outside and extending outward therefrom, each of said beards including: (1) a first surface that tapers outwardly from said outer surface in a direction away from said insertion end, (2) a second surface extending toward inward to said outer surface, and (3) an apex between said first surface and said second surface. The connector according to claim 1, wherein said first and second end edges are combined to define a plane perpendicular to said axis. The connector according to claim 1, wherein said inner surface of said tubular portion of said connector is of the same predetermined size as said inner surface of said length of pipe. The connector according to claim 1, wherein each of said annular beards continuously extends around said outer surface. The connector according to claim 1, wherein each of said annular beards extends intermittently around said outer surface. The connector according to claim 1, wherein the beard positioned close to said end edges defines an apex of a first predetermined height from said smooth outer surface and each of the remaining barbs is axially spaced further from said end edges that said first beard, each one defines an apex that has a height from said smooth outer surface that is dimensioned respectively to increase more and more than said first height. The connector according to claim 1, wherein each of said first and second tapered edges defines an arcuate path. The connector of claim 1, wherein said insertion end links a flexible tubular member having an open end and an inner surface and said annular barbs deform said inner surface outward, and wherein said tubular member has a bevel extending at an angle from said open end with said cylindrical internal surface, the intersection of said bevel with said open end defining a circle having a diameter greater than the diameter of said inner surface of said connector, whereby, upon the occurrence of axial insertion of said connector to said tubular open end, said first and second end edges initially bond said bevel and expand said open end and the axially continued insertion additionally causes all the portions of said tubular member connected by said connector to be deformed to a size larger . 9. The combination according to claim 8, wherein the diameter of said inner surface of the tubular member before insertion of said connector is substantially equal to the diameter of said cylindrical internal surface of said connector. 10. A method for assembling a connector to a deformable tubular member having an internal surface of a predetermined diameter and an open end, said connector having a tubular portion with an internal surface extending along an axis, a contoured exterior and an insert end portion, the method characterized in that: (a) said insert end portion including (i) first and second end edges, said end edges being spaced from each other, each said end edge extending from a point of origin to a point of end and each of said end edges defining a plane perpendicular to said axis; (ii) a first tapered edge disposed at an angle with said axis extending from the point of origin of said first end edge to the point of origin of said second end edge; (iii) a second tapered edge disposed at an angle with said axis extending from the terminating point of said first end edge to the terminating point of said second end edge, said first and second tapered edges being spaced apart by said end edges; and (b) said contoured exterior including (i) a smooth outer surface for bonding the inner surface of said pipe length, said outer surface defining a plurality of annular beards that are being axially spaced from said end edges on said outer surface and extending outward therefrom, each of said beards including: (1) a first surface tapering outward from said outer surface in a direction away from said insertion end, (2) a second surface extending inwardly towards said outer surface; and (3) an apex between said first surface and said second surface; and (c) linking said first and second end edges to said length of pipe at said open end and moving said connector axially towards said tubular member to a point at which said annular beards are linked to said inner surface, said connector expanding the portions of said tubular member contacted by him. The method according to claim 10, further comprising the step of providing a bevel tapering in and away from said open end of said tubular member and linking said first and second end edges to said bevel. The method according to claim 10, wherein said predetermined diameter of the tubular member is substantially equal to the diameter of said internal diameter of the internal surface of the connector. The method according to claim 0, further comprising the step of providing a bevel tapering toward and far from said open end of said tubular member and linking said first and second end edges to said bevel. The method according to claim 10, further comprising the step of deforming said open end of the tubular member to enlarge its size in one direction while reducing its size in a second direction perpendicular to said first mentioned direction and inserting said end edges at said open end by aligning said end edges with said first mentioned direction.