MXPA99008686A - Transition connector from plastic to metal pipe - Google Patents

Abstract

The present invention relates to an improved transition connector of a metal pipe to a plastic pipe, characterized in that it comprises: a metal bushing, having first and second ends adapted to be joined to a pair of sections of metal pipe and which they have an annular groove formed within their interior, a first section of metal pipe attached to the first end of the metal bushing, a second section of metal pipe joined to the second end of the metal bushing, a plastic pipe disposed within the metal bushing and extends through the second metal section of the pipe having first and second ends, said portion of the first end of the plastic pipe having a plurality of spaced plastic retaining rings attached thereto and a snap ring Also connected by the aforementioned retaining rings adjusted snugly inside the cap and the snap ring fits within the annular groove, at least one O-ring seal disposed between the separate plastic retainer rings, in the plastic tubing in watertight engagement with the metal ferrule and tubing. mentioned plastic, and a metal reinforcement insert placed inside the first end portion of the plastic pipe.

Description

CONNECTOR TRANSITION FROM PLASTIC TO METALLIC PIPELINE ANTECEDENTS OF THE INVENTION 1. Field of the Invention The present invention relates to a transitional connector from plastic to metal pipe which can be used in various applications such as a vertical pipe of a gas meter. 2. Description of the Previous Technique The use of plastic pipe such as a polyethylene pipe in gas distribution systems has become common. As a result, there are many cases where the plastic pipe must be connected to the metal pipe. For example, gas meters above the ground are often connected by the metal pipe to the gas service pipe, plastic, below the ground. The metal pipe and the plastic pipe are joined together in a transition connector. A pipe REF .: 31225 vertical meter is frequently used to extend from below the ground to a gas meter above the ground. Such vertical pipes of the meter have heretofore been comprised of a metal pipe which is connected between the gas meter and a transition connector of plastic to metal pipe. The transition connector is connected in turn to a double-walled vertical pipe which is comprised of an external metal pipe and an internal plastic pipe. The internal plastic pipe extends through and out of the outer metal pipe. The outer metallic pipe provides protection to the inner plastic pipe and the plastic pipe is sealed to the metal pipe inside the transition fitting. Examples of such vertical meter pipes are described in U.S. Pat. Nos. 4,715,624 issued to Frye on December 29, 1987 and 5,326,137 issued to Lorenz et al. On July 5, 1994. The transition connectors of the plastic to metal pipe used as vertical pipes of the meter and in other applications have Until now relatively complicated and difficult to assemble. Accordingly, there is a continuing need for an improved transition connector from plastic to metal tubing which is relatively simple to handle and assemble and which is less expensive than comparable prior art transition connectors.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a transition connector from plastic to metal pipe, which meets the needs described above and overcomes the deficiencies of the prior art. The plastic-to-metal pipe transition connector of this invention is basically comprised of a metal sleeve or sleeve having first and second ends adapted to be fixed to a pair of metal pipe sections and having an annular groove formed within the interior Of the same. A first section of metal pipe is adapted to be connected to a complementary metal pipe or the connector is fixed to the first end of the metal sleeve or bushing. A second section of metal pipe is fixed to the second end of the metal sleeve or bushing, and the end portion of a plastic pipe which extends through the second metal pipe is placed inside the metal bushing or bushing. The end portion of the plastic tubing within the metal sleeve or sleeve includes a plurality of spaced plastic retaining rings and a plastic or metal retaining ring attached thereto whereby the retaining rings fit snugly or tightly. inside the sleeve or metal bushing and the retaining ring fits into the annular groove therein. At least one 0-ring seal is placed between the adjacent spaced plastic retaining rings on the plastic pipe and a metal reinforcing insert is placed within the end portion of the plastic pipe within the metal sleeve or bushing . In the assembly of the transition connector of the plastic to metal pipe of this invention, the first and second sections of the metal pipe are fixed to the metal sleeve or bushing such as by welding and the plastic retaining rings and the plastic clamping ring are fixed to an end portion of the plastic pipe. One or more O-rings are placed between the retaining rings, and the other end of the plastic tubing is passed through the inside of the sections of the welded metal sleeve or sleeve and of the pipe. After this, the plastic pipe is pulled through the sections of the metal bushing and the pipe until the metal ring snaps into the annular groove formed inside the metal sleeve and the plastic retaining rings and the rings in the metal sleeve. Or between them they fit snugly inside the sleeve or metal bushing. In mounting an alternative embodiment of the transitional connector of the plastic-to-metal pipe of this invention, the first and second sections of metal pipe are fixed to the metal sleeve or bushing and the plastic retaining rings are fixed to an end portion. of the plastic pipe. One or more rings at 0 are placed between some of the retaining rings and a plastic or metal clamping ring is placed between the other retaining rings. The end of the plastic pipe having the retaining rings, the O-rings and the fastening ring fixed thereto, is passed through the second section of metal pipe to the metal bushing. After this, the end of the plastic pipe having the retaining rings, the 0-rings and the fastening ring fixed thereto, is pushed towards the metal bushing until the clamping ring engages in the annular groove formed within the Metallic bushing and retaining rings and O-rings fit snugly inside the metal bushing. Therefore, it is a general object of the present invention to provide an improved transitional connector from the plastic to the metal pipe. These and other objects, features and additional advantages of the present invention will become apparent during a reading of the description of the preferred embodiments which are given below, when taken in conjunction with the drawings appended thereto.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration, partially in cross section, of a gas meter connected to a plastic service pipe by a transition connector of this invention in the form of a vertical pipe of the meter. Figure 2 is a side elevational view of the plastic pipe of the transition connector of this invention having spaced plastic retaining rings, 0 ring seals and a plastic fastening ring attached thereto and having a reinforcing insert metallic in it. Figure 3 is a side cross-sectional view of the metal bushing and the assembly of the pipe section of this invention. Figure 4 is a side elevational view of the metal reinforcement insert of this invention. Figure 5 is a cross-sectional view of the assembly of the pipe section and the metal bushing of Figure 3, having the plastic pipe of Figure 2 placed therein, prior to pulling the end portion of the pipe plastic that has plastic retaining rings, O-ring seals and plastic fastener ring, fixed to it in the metal sleeve. Figure 6 is a cross-sectional view similar to Figure 5 showing the plastic pipe in partial cross-section after the end portion thereof having the plastic retaining rings, the 0-ring seals and the fastening ring plastic attached to it, has been pulled towards the metal sleeve. Figure 7 is a cross-sectional view of an alternative embodiment of the transition connector of this invention after it has been assembled. Figure 8 is a side cross-sectional view of the metal bushing assembly and the pipe section of the second embodiment of the transition connector of this invention. Figure 9 is a side cross-sectional view of the plastic pipe of the second embodiment of this invention having plastic retaining rings, spaced, O-ring seals and a plastic or metal fastening ring attached thereto and It has a metallic reinforcement insert on it.

DESCRIPTION OF THE PREFERRED MODALITIES Referring now to the drawings and particularly to Figure 1, a transition connector of the present invention in the form of a vertical pipe of the meter is schematically illustrated and designated generally by the numeral 10. The transition connector 10 is shown connected to a gas meter 12 by a metal pipe assembly 14. The plastic pipe of the transition connector 10 is connected underground to a service pipe 16 by a plastic coupling or adapter 18. As described hereinafter additionally, the connector Transition 10 is comprised of a metal sleeve or bushing 20 having first and second metal pipe sections 22 and 24, respectively, attached thereto and a plastic pipe 26 sealingly connected within the metal bushing 20. The plastic pipe 26 is placed inside the metal bushing 20 and the second section 24 of the metal pipe ica of the transition connector 10 and the end 30 extends outside the section 24 of the metal pipe a distance by which it can be connected to a complementary plastic pipe or connector, for example, the connector 18. Referring now to Figure 2, the plastic pipe 26 of the transition connector 10 without the 90 ° elbow, is illustrated in detail. The plastic pipe 26, which may be formed of polyethylene or other suitable plastic material, has a first end 28 and a second end 30. The portion of the plastic pipe 26 adjacent the first end 28 thereof includes three rings of plastic retainer 32 spaced apart and a plastic fastener ring 34 fixed thereto. Although the retaining rings 32 and the fastening ring 34 can be fixed to the pipe 26 in various ways, they are preferably fixed because they are injection molded on the pipe 26. Placed within the adjacent retaining rings 32 are a pair of conventional O-ring seals 36. A cylindrical metal reinforcing insert 70 which will be described hereinafter hereinafter, is positioned within the first end portion of the plastic pipe 26. Referring now to Figure 3, the metal bushing 20 of the transition connector 10 and the first and second sections 22 and 24 of the metal pipe, are illustrated in a welded assembly designated generally by number 40. The first section of metal pipe 22 has a first end 42 and a second end 44. The portion of the section 22 of metal pipe adjacent the first end 42 thereof, is preferably threaded for connection to a complementary pipe connector (not shown). The portion of the pipe section 22 adjacent the second end 44 thereof is fixed to the first end 46 of the metal bushing 20, preferably by a sealing weld 48. The second end 50 of the metal bushing 20 is fixed to the portion of the second section of metal pipe 24 adjacent the first end 52 thereof, preferably by a sealing weld 54. As will be understood by those skilled in the art, the second end 56 of the metal pipe section 24 may be at a distance relatively short of the first end 52 thereof, or it may be a relatively long distance from the first end 52 and may include a 90 ° elbow as illustrated in Figure 1. The metallic bushing 20 includes a first recessed hole 60 formed in the same and a second larger reamed hole 62 formed therein. A metal ring or washer 64 is placed in the second recessed hole 62 adjacent the first end 52 of the second metal pipe section 24. The recessed hole 60 and the metal ring 64 form an internal annular groove 66 within the second end portion of the pipe. metallic cap 20. As will be understood by those skilled in the art, the notch 66 can be internally machined optionally within the second end portion of the metal cap 20 whereby the use of the ring 64 is unnecessary. In another alternative technique, the thickness of the walls of the second section of metallic pipe 24 can be increased to avoid by this the need for the ring 24. However, the use of the ring 24 is currently preferred because it is more economical .

Referring now to Figure 4, the cylindrical metal reinforcing insert 70, referred to above, is illustrated. The insert 70 is used to reinforce the first end portion 28 of the plastic pipe 26 within the metal bushing 20. The insert 70 includes an outer annular groove 73 formed thereon and an end 72 thereof preferably is flared outwardly as is. shown The insert 70 is positioned within the interior of the first end portion of the plastic pipe 26 with the flared end 72 thereof adjacent the first end 28 of the pipe 26 as shown in Figure 2. Preferably, the insert 70 is placed inside the plastic pipe 26 prior to when the retaining rings 32 and the fastening ring 34 are fixed to the plastic pipe 26. The outer groove 73 in the insert 70 functions to retain the insert within the plastic pipe 26. When the retaining rings 32 and the clamping ring 34 are molded onto the plastic pipe 26, the heat causes the plastic material forming the pipe 26 to expand or flow towards the outer groove 73 of the insert 70 whereby it is retained in a rigid way in it. Referring now to Figures 5 and 6, the assembly of the plastic pipe 26 within the metal bushing assembly and the pipe section 40 is illustrated. As shown in Figure 5, the end 30 of the pipe 26 is inserted into the first end 42 of the first section of metal pipe 22 and pushed into and through the assembly of the pipe section and metal bush 40 until the end 30 of the plastic pipe 26 extends outwardly from, and at a distance once the end 56 of the second section 24 of the metal pipe has been passed. As best shown in Figure 6, the spaced plastic retaining rings 32 are rectangular in cross-section and have a thickness such that the retaining rings 32 snap shut tightly within the cylindrical interior 74 of the metallic cap 20. The plastic fastening ring 34 is of a cross-sectional shape, whereby at least a portion of the outer surface thereof is inclined outwardly in a direction towards the second end 30 of the plastic pipe 26. The size of the fastener ring 34 is such that its portion 35 of the trailing edge will fit into the annular groove 66. The assembly of the transition connector 10 is complemented by pulling the plastic pipe 26 through the assembly of the pipe section and ferrule. metallic 40 until the plastic fastener ring 34 reaches it and its portion 35 of the trailing edge fits into the annular groove 66 inside the hood. metallic ring 20 and the plastic retaining rings 32 and the O-rings 36 are moved inwardly 74 of the metal sleeve 20, all as shown in Figure 6. When the threaded end portion 42 of the first section of metal pipe 22 is sealingly connected to a metal pipe and the end portion 30 of the plastic pipe 26 is sealingly connected to a plastic pipe, the fluid pressure within the resulting plastic and metal pipes and within the transition connection 10, it is prevented from escaping into the atmosphere by means of the open end 56 of the pipe section 24 by the O-ring seals 36. Furthermore, if the plastic pipe 26 elongates or contracts within the metal bush 20 and the section 24 of the pipe, the portion of the pipe 26 adjacent the end 28 thereof can move within the interior 74 of the metal bush 20 without breaking the seal produced by the pipe. The O-rings 36. That is, the fastening ring 34 fixed to the plastic pipe 26 can move longitudinally within the annular groove 66 in the metal bushing 20 as can the plastic retaining rings 32 and the ring seals. at 0 36 inside the interior 74 of the metal bushing 20. Referring now to Figures 7-9, a second embodiment of the transition connector of the present invention is illustrated and generally designated by the number 80. The transition connector 80 is similar to the transition connector 10 described above, except that it is assembled differently, ie the first The end of the plastic pipe is inserted directly into the assembly of the pipe section and the metal bushing. Referring specifically to Figure 7, the transition connector 80 is comprised of a metal bushing 82 having first and second metal pipe sections 84 and 86, respectively, attached thereto. The assembly consisting of the metal bushing 82 and the metallic pipe sections 84 and 86 is designated by the numeral 87. The plastic pipe 88 having a first end 90 and a second end 92 is located inside the metal bushing 82 and the second one. metal pipe section 86. The portion of the plastic pipe 88 adjacent the end 90 is sealingly retained within the metal bushing 82 and the other end 92 extends out of the section 86 of the metal pipe a distance by which it can be connected to a complementary plastic pipe or connector. Referring now to Figure 8, the metal bushing assembly 87 and the pipe section is illustrated. The first metal pipe section 84 has a first end 94 and a second end 96. The portion of the metal pipe section 84 adjacent the first end 94 thereof is threaded for connection to a complementary pipe connector (not shown) . The second end 96 of the pipe section 84 is fixed to the first end 98 of the metal bushing 82, preferably by a sealing weld 100. The second end 102 of the metal bushing 82 is fixed to the first end 104 of the second section of metal pipe 86, preferably by a seal weld 106. The metal sleeve 20 includes a first counterbore 108 formed therein and an internal annular groove 110 formed within the bore hole 108. The side 112 of the annular groove 110 closest to the first end 98 of the metal bushing 82 is bevelled. The other side of the internal annular groove 110 is perpendicular to the bottom of the groove and a second rebore hole 116 beveled intersects the side 114 of the annular groove 110.

Referring now to Figure 9, the plastic pipe 88 having a first end 90 and a second end 92, is illustrated in detail. The portion of the plastic pipe 88 adjacent the first end 90 thereof includes three spaced plastic retaining rings 120 which form a pair of spaced annular grooves having O-rings 124 disposed thereon. Two additional spaced detent rings 126 are attached to the first end portion of the plastic pipe 88 which provides a notch for receiving a fastener ring 128. The fastener ring 128 can be formed of either plastic or metal and is a type which expands out of, or is flattened or compressed within the notch formed by the retaining rings 126 depending on the diameter of the surface adjacent thereto. Preferably, the fastening ring 128 is a metal fastening ring having a C-shaped cross section. Although the retaining rings 120 and 126 can be fixed to the pipe 88 in various ways, they are preferably fixed because they are injection molded. on the pipe 88. A cylindrical metal reinforcement insert 130, similar to the insert 70 described above with respect to the transition connector 10, is positioned within the interior of the first end portion of the plastic pipe 88. The insert 130 includes a external annular groove 132 formed therein whereby when the retaining rings 120 and 126 are injection molded onto the pipe 88, the plastic material forming the pipe 88 expands or flows into the outer groove 132 of the bushing 130 by which is rigidly retained in it. In the assembly of the plastic pipe 88 within the assembly of the metal bushing and pipe section 87, the first end portion of the plastic pipe 88 is inserted through the interior of the section 86 of the metal pipe, into the interior of the pipe. metallic bushing 82. When the plastic pipe 88 is inserted, the beveled surfaces 114 and 112 of the metal bushing 82 compress the rings in 0124 and the clamping ring 28 so that the 0-rings slide to and fit snugly within the interior of the counterbore 108 within the metal bushing 82 and provide a seal thereon, and so that the clamping ring 128 is compressed and then expanded or snapped to the annular groove 110, all as shown in FIG. Figure 7. Accordingly, the present invention is well adapted to carry out the objects and achieve the purposes and advantages mentioned as well as those which are inherent. in the same. Although numerous changes may be suggested by themselves to those skilled in the art, such changes are encompassed within the spirit of this invention as defined by the appended claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having described the invention as above, property is claimed as contained in the following

Claims (15)

1. An improved transition connector from a plastic pipe to a metal pipe, the improvement is characterized in that it comprises: a metal bushing having first and second ends adapted to be fixed to a pair of metal pipe sections and having an annular groove formed inside of it; a first section of metal pipe fixed to the first end of the metal bushing; a second section of metal pipe fixed to the second end of the metal bushing; a plastic pipe placed inside the metal bushing and extending through the second section of metal pipe having first and second ends, the first end portion of the plastic pipe having a plurality of spaced plastic retaining rings and a a fastener ring fixed thereto, whereby the retaining rings fit snugly within the interior of the metal bushing and the fastener ring engages within the annular groove therein; at least one 0-ring seal placed between the plastic retaining rings spaced over the plastic pipe; and a metal reinforcement insert positioned within the first end portion of the plastic pipe.

2. The transition connector according to claim 1, characterized in that the spaced plastic retaining rings are injection molded onto the plastic pipe.

3. The transition connector according to claim 1 or 2, characterized in that the plastic pipe includes three or more spaced plastic retaining rings, fixed thereto.

4. The transitional connector according to claims 1, 2 or 3, characterized in that the plastic retaining rings are of rectangular cross-sectional shape.

5. The transition connector according to claim 3, characterized in that at least two 0-ring seals are placed between the plastic retaining rings spaced over the plastic pipe.

6. The transition connector according to any of claims 1 to 5, characterized in that the fastening ring is formed of plastic or metal.

7. The transition connector according to any of the preceding claims, characterized in that the first and second metal pipe sections are welded to the metal bushing.

8. The transition connector according to any of the preceding claims, characterized in that the first metal pipe section is threaded at the end thereof opposite the metal bushing.

9. The transition connector according to any of the preceding claims, characterized in that the second section of metal pipe is elongated and includes an elbow therein, whereby the connector can be used as a vertical pipe of the gas meter.

10. An improved connector of transition from a plastic pipe to a metal pipe, the improvement is characterized in that it comprises: a metal bushing having first and second ends adapted to be fixed to a pair of metal pipe sections and having an annular groove formed inside of it; a first section of metal pipe fixed to the first end of the metal bushing having threads or threads formed on the end thereof opposite the metal bushing, for the threaded connection to a complementary metal pipe or connector; a second section of metal pipe fixed to the second end of the metal bushing; a plastic pipe placed inside the metal bushing and extending through the second section of metal pipe having first and second ends, the first end portion of the plastic pipe having spaced plastic retaining rings and a fixed fastening ring thereto, whereby the retaining rings fit snugly within the interior of the metal bushing and the fastener ring engages within the annular groove therein; at least one 0-ring seal placed between the plastic retaining rings spaced over the plastic pipe; and a metallic cylindrical insert positioned within the first end portion of the plastic pipe to provide rigidity to the plastic pipe.

11. The transition connector according to claim 10, characterized in that the spaced plastic retaining rings and the clamping ring are injection molded onto the plastic pipe.

12. The transition connector according to claim 10 or 11, characterized in that the plastic retaining rings are of a rectangular cross-sectional shape.

13. The transition connector according to claim 10, 11 or 12, characterized in that the plastic fastening ring is of a cross-sectional shape, whereby the external surface thereof is tilted downwards in a direction towards the second end of the plastic pipe.

14. The transition connector according to claims 10, 11, 12 or 13, characterized in that the first and second metal pipe sections are welded to the metal bushing.

15. The transition connector according to any of claims 10 to 14, characterized in that the second section of metal pipe is elongated and includes a 90 ° elbow thereon, whereby the connector can be used as a vertical pipe of the meter Of gas.