GB2135415A

GB2135415A - Pipe coupler-plastic pipes

Info

Publication number: GB2135415A
Application number: GB08305059A
Authority: GB
Inventors: Pat Frawley
Original assignee: Plastiers Ltd
Current assignee: Plastiers Ltd
Priority date: 1983-02-23
Filing date: 1983-02-23
Publication date: 1984-08-30
Also published as: GB8305059D0; GB2135415B

Abstract

A pipe fitting for joining plastics pipe to a compression fitting for metal pipe of the type normally having a socket for a said metal pipe, an olive and a union nut, the pipe fitting comprises an adaptor 1 and a sealing member 3 for making a seal between the adaptor and the compression fitting. The adaptor has an external circumferential flange 11 adapted to cooperate with a union nut 5 of the compression fitting, the adaptor includes coupling means 2 for connecting the adaptor to a plastics pipe. The sealing member 3 is arranged to be located intermediate the flange 11 of the adaptor and the socket 60 of the compression fitting. The coupling means is preferably a separate coupler adapted respectively to mate with a said plastics pipe and with the adaptor, preferably by solvent-welding. <IMAGE>

Description

SPECIFICATION Pipe fitting This invention relates to a pipe fitting and more particularly to such a fitting for joining plastics tube to metal tube.

A flexible plastics tube can be joined to a copper tube quite easily by using a conventional compression fitting and sliding a metal support sleeve inside the bore of the plastics pipe so that when the olive is distorted by tightening the nut, the plastics pipe is compressed between the olive and the inner support sleeve. A watertight seal is thus obtained and the temperature of the assembly can be altered considerably without inducing 'creep' into the plastics material which might cause distortion and hence leaks.

This is not practicable with a rigid plastics pipe however as it is not possible to compress the wall of the pipe onto an internal support sleeve during the initial tightening, due to the pipe's inherent rigidity.

The task of producing a universal adaptor to connect rigid plastics pipes to all commercially available (copper) compression fittings is hampered by the fact that the thread of the nuts employed often varies widely, as does the configuration and shape of the olive and of the frustroconical part of the fittings on which the olive seats. In fact almost the only part of this type of fitting which is standardised is the internal diameter of the pipe-receiving part of the bore of the fitting which diameter is generally slightly greater than those of the standard sizes of copper pipe. Ideally therefore any adaptor should cooperate with this bore, and, if it is to be retained by a nut the nut from the fitting ought to be utilised as its thread will exactly match that of the fitting.

According to the present invention there is provided a pipe fitting for joining plastics pipe to a compression fitting for metal pipe of the type normally having a socket for a said metal pipe, an olive and a union nut which pipe fitting comprises an adaptor and a sealing means for making a seal between the adaptor and the compression fitting, the adaptor having an external circumferential flange adapted to cooperate with a said union nut of a said compression fitting, said adaptor further including means for connecting the adaptor to a plastics pipe, said sealing means being arranged in use to be located intermediate the flange of the adaptor and a said socket of a said compression fitting.

An embodiment of the pipe fitting of the present invention will now be defined by way of example only by reference to the accompanying drawings in which: Fig. 1 is a view in transverse section of an embodiment of a partially disassembled fitting according to the present invention.

Fig. 2 is a view in transverse section of the fitting of Fig. 1 in an assembled state; and Fig. 3 is an enlarged detail of the area ringed in Fig. 2.

Referring to the drawings the fitting comprises an adaptor 1 a coupler 2 and a sealing member 3.

The adaptor 1 comprises a hollow cylindrical socket 10 and an external circumferential flange 1 The coupler 2 includes a first hollow cylindrical section 20, an internal circumferential flange 21, and a second hollow cylindrical section 22. Said first hollow cylindrical section 20 of coupler 2 has an internal diameter such that it can receive as a push or sliding fit one end of the hollow cylindrical section 10 of adaptor 1 and said second hollow cylindrical section 22 of coupler 2 has an internal diameter such that it can receive the end of a plastics pipe 4 as a push or sliding fit.

Sealing member 3 has an internal diameter such that it fits snugly onto the outside of the other end of said hollow cylindrical section 10 of adaptor 1.

For use, adaptor 1 and coupler 2 are assembled with said hollow cylindrical section 10 of adaptor 1 passing through the bore of a union nut 5 which is retained on the assembly by virtue of appropriate selection of the diameter of flange 1 1 and cylindrical section 20.

The external diameter of sealing member 3 selected to be such that it is a sealing fit within a pipe receiving part 60 of a conventional pipe fitting 6 for metal pipes (minus its olive).

The fitting of the invention, complete with captive union nut may then be assembled with the conventional fitting by screwing the union nut 5 onto the correspondingly threaded portion 61 on the conventional fitting 6.

The fitting of the invention is retained by entrapment of the flange 1 1 between union nut 5 and compression fitting 6.

Adaptor 1 and coupler 2 are preferably made of the same material e.g. a solvent-weldable rigid plastics, such as chlorinated polyvinyl chloride, polyvinyl chloride or a acrylonitrile/butadiene/styrene resin. Likewise pipe 4 is preferably of the same material so that solvent welding may be used to secure the joints.

The sealing member 3 is of an elastomeric material such as neoprene or natural or synthetic rubber; in the embodiment shown it is in the form of a sleeve 30 provided at one end with an external peripheral flange 31 and its other end with an internal peripheral flange 32. An intermediate external peripheral bead 33 assists in making the necessary seal.

Although the invention has been described by reference to the foregoing embodiment, a number of variations are within the scope of the invention.

For example, if a plastics pipe of suitable diameter is employed the coupler can be dispensed with and the adaptor inserted directly into the end of the pipe. Conversely if a plastics pipe of relatively small diameter is employed the pipe may be inserted directly into the end of the adaptor. Obviously in either case it must be possible for the adaptor to receive the nut of the conventional fitting as a collar therearound.

1. A pipe fitting for joining plastics pipe to a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Pipe fitting This invention relates to a pipe fitting and more particularly to such a fitting for joining plastics tube to metal tube. A flexible plastics tube can be joined to a copper tube quite easily by using a conventional compression fitting and sliding a metal support sleeve inside the bore of the plastics pipe so that when the olive is distorted by tightening the nut, the plastics pipe is compressed between the olive and the inner support sleeve. A watertight seal is thus obtained and the temperature of the assembly can be altered considerably without inducing 'creep' into the plastics material which might cause distortion and hence leaks. This is not practicable with a rigid plastics pipe however as it is not possible to compress the wall of the pipe onto an internal support sleeve during the initial tightening, due to the pipe's inherent rigidity. The task of producing a universal adaptor to connect rigid plastics pipes to all commercially available (copper) compression fittings is hampered by the fact that the thread of the nuts employed often varies widely, as does the configuration and shape of the olive and of the frustroconical part of the fittings on which the olive seats. In fact almost the only part of this type of fitting which is standardised is the internal diameter of the pipe-receiving part of the bore of the fitting which diameter is generally slightly greater than those of the standard sizes of copper pipe. Ideally therefore any adaptor should cooperate with this bore, and, if it is to be retained by a nut the nut from the fitting ought to be utilised as its thread will exactly match that of the fitting. According to the present invention there is provided a pipe fitting for joining plastics pipe to a compression fitting for metal pipe of the type normally having a socket for a said metal pipe, an olive and a union nut which pipe fitting comprises an adaptor and a sealing means for making a seal between the adaptor and the compression fitting, the adaptor having an external circumferential flange adapted to cooperate with a said union nut of a said compression fitting, said adaptor further including means for connecting the adaptor to a plastics pipe, said sealing means being arranged in use to be located intermediate the flange of the adaptor and a said socket of a said compression fitting. An embodiment of the pipe fitting of the present invention will now be defined by way of example only by reference to the accompanying drawings in which: Fig. 1 is a view in transverse section of an embodiment of a partially disassembled fitting according to the present invention. Fig. 2 is a view in transverse section of the fitting of Fig. 1 in an assembled state; and Fig. 3 is an enlarged detail of the area ringed in Fig. 2. Referring to the drawings the fitting comprises an adaptor 1 a coupler 2 and a sealing member 3. The adaptor 1 comprises a hollow cylindrical socket 10 and an external circumferential flange 1 The coupler 2 includes a first hollow cylindrical section 20, an internal circumferential flange 21, and a second hollow cylindrical section 22. Said first hollow cylindrical section 20 of coupler 2 has an internal diameter such that it can receive as a push or sliding fit one end of the hollow cylindrical section 10 of adaptor 1 and said second hollow cylindrical section 22 of coupler 2 has an internal diameter such that it can receive the end of a plastics pipe 4 as a push or sliding fit. Sealing member 3 has an internal diameter such that it fits snugly onto the outside of the other end of said hollow cylindrical section 10 of adaptor 1. For use, adaptor 1 and coupler 2 are assembled with said hollow cylindrical section 10 of adaptor 1 passing through the bore of a union nut 5 which is retained on the assembly by virtue of appropriate selection of the diameter of flange 1 1 and cylindrical section 20. The external diameter of sealing member 3 selected to be such that it is a sealing fit within a pipe receiving part 60 of a conventional pipe fitting 6 for metal pipes (minus its olive). The fitting of the invention, complete with captive union nut may then be assembled with the conventional fitting by screwing the union nut 5 onto the correspondingly threaded portion 61 on the conventional fitting 6. The fitting of the invention is retained by entrapment of the flange 1 1 between union nut 5 and compression fitting 6. Adaptor 1 and coupler 2 are preferably made of the same material e.g. a solvent-weldable rigid plastics, such as chlorinated polyvinyl chloride, polyvinyl chloride or a acrylonitrile/butadiene/styrene resin. Likewise pipe 4 is preferably of the same material so that solvent welding may be used to secure the joints. The sealing member 3 is of an elastomeric material such as neoprene or natural or synthetic rubber; in the embodiment shown it is in the form of a sleeve 30 provided at one end with an external peripheral flange 31 and its other end with an internal peripheral flange 32. An intermediate external peripheral bead 33 assists in making the necessary seal. Although the invention has been described by reference to the foregoing embodiment, a number of variations are within the scope of the invention. For example, if a plastics pipe of suitable diameter is employed the coupler can be dispensed with and the adaptor inserted directly into the end of the pipe. Conversely if a plastics pipe of relatively small diameter is employed the pipe may be inserted directly into the end of the adaptor. Obviously in either case it must be possible for the adaptor to receive the nut of the conventional fitting as a collar therearound. CLAIMS

1. A pipe fitting for joining plastics pipe to a compression fitting for metal pipe of the type normally having a socket for a said metal pipe, an olive and a union nut, which pipe fitting comprises an adaptor and a sealing means for making a seal between the adaptor and the compression fitting, the adaptor having an external circumferential flange adapted to cooperate with a said union nut of a said compression fitting, said adaptor further including means for connecting the adaptor to a plastics pipe, said sealing means being arranged in use to be located intermediate the flange of the adaptor and a said socket of a said compression fitting.

2. A pipe fitting as claimed in Claim 1, wherein the connecting means comprises a separate coupler adapted to mate with the adaptor and with a said plastics pipe.

3. A pipe fitting as claimed in claim 1, wherein the connecting means comprises a part of the adaptor, in the form of a bore adapted to receive the end portion of said plastics pipe.

4. A pipe fitting as claimed in claim 1, wherein the connecting means comprises a part of the adaptor, in the form of a spigot adapted to be received within the end portion of a said plastics pipe.

5. A pipe fitting as claimed in any one of the preceding claims, wherein the adaptor, and the -coupler if present, is composed of a solvent weldabie rigid plastics material.

6. A pipe fitting as claimed in claim 5, wherein the adaptor, and the coupler if present, is composed of chlorinated polyvinyl chloride, polyvinyl chloride or an acrylonitrile/butadiene/styrene resin.

7. A pipe fitting as claimed in any one of the preceding claims, wherein the sealing means is composed of an elastomeric material.

8. A pipe fitting as claimed in claim 7, wherein the sealing means is composed of neoprene or of natural or synthetic rubber.

9. A pipe fitting as claimed in any one of the preceding claims, wherein the sealing means is in the form of a sleeve provided at one end with an external peripheral flange and at its other end with an internal peripheral flange.

10. A pipe fitting for joining plastics pipe to a compression fitting for metal pipe, substantially as hereinbefore described with reference to the accompanying drawing.

11. The combination of a pipe fitting according to any one of the preceding claims, and a compression fitting for metal pipe of the type normally having a socket for a said metal pipe, an olive and a union nut.

12. A combination as claimed in claim 11 and substantially as hereinbefore described with reference to the accompanying drawing.

13. The features hereinbefore disclosed, or their equivalents, in any novel selection.