AU629307B2

AU629307B2 - A coupling arrangement

Info

Publication number: AU629307B2
Application number: AU50697/90A
Authority: AU
Inventors: Gian Lorenzo Ricci
Original assignee: PIPE COUPLINGS AUSTRALASIA Pty
Current assignee: PIPE COUPLINGS (AUSTRALASIA) Pty Ltd
Priority date: 1989-03-03
Filing date: 1990-03-05
Publication date: 1992-10-01
Anticipated expiration: 2010-03-05
Also published as: AU5069790A

Description

I I I I I II F I COMMONWEALTH OF AUSTRALIA Patents Act 1952 COMPLETE AFTER PROVIS I ONAL

SPECIFICATION

(ORIGINAL)

Class Int. Class 00 0 000 9000 00 @0 *0 .0 0 000 9 Application No Lodged Complete-After-Provisional Specification Lodged Accepted Published Priority Related Art Name of Applicant :PIPE COUPLINGS (AUSTRALASIA) PTY. LIMITED Address of Applicant Gasworks, Blacksmith's Shop, Tennyson Road, Mortlake, New South Wales 2137, Commonwealth of Australia Actual Inventor :Gian Lorenzo Ricci Address for Service H.R. HODGKINSON Co Patent Trade Mark Attorneys 26a Alfred Street MILSONS POINT N.S.W. 2061 Complete-After-Provisional Specification for the invention entitled: A COUPLING ARRANGEMENT The following statement is a full description of this invention including the best method of performing it known to me:- S013438 05/03/90 I I i I C*I~--XPL

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I I_ THIS INVENTION relates to a coupling arrangement and in particular to a coupling arrangement for allowing the connection of a metal fitting such as for example a valve constructed of a metal material, to one or more tubes or pipes constructed of an essentially plastic or semi-flexible material.

It is well known to provide valves and valve fittings constructed of a metal material. Such valves and fittings are often required to be constructed of a metal material in order to meet local utility and government regulations and requirements. It is however common to attach pipes or tubes 0* to said fittings, which pipes or tubes are constructed of a generally flexible and plastic material. This brings about certain problems, in that up until this time no means have e g.

been provided which allow for the efficient and straightforward connection of plastic pipes or tubes to a metal fitting such as a valve. In some cases, attempts have been made to bond or adhere the plastic pipes or tubes to the metal fitting, such as by using appropriate adhesives and glues, but while this has worked for a period of time, 0ooo such connections have not been sufficiently lasting, in that •0 the glue between the plastic material and the metal has been found to deteriorate with time. This results in the 0 deterioration and loosening of the connection between the plastic tube or pipe and the metal fitting, such as to cause leaking, inefficiencies and the like.

Other arrangements are also known whereby the ends of plastic pipes or tubes a n connected to metal fittings by compression fitting. One form of compression fitting has involved an end of the plastic tube or pipe or a plastic 2

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EI-

i I fitting connected thereto, being inserted into the bore of an inlet and/or outlet of a metal fitting (such as a valve), a metal nut then being passed over the connection and being secured over and relative to the connection. Such compression fitting involves the compression of the plastic minaterial from which the tube or pipe is formed, against and relative to the metal of the fitting, such that after the initial connection involving the compression of the plastic material, the plastic material may expand and move away from the metal material, thus resulting in leakage and general inefficiencies.

The above methods are known in connecting plastic tubes or pipes to metal fittings such as valves, for the passage and control of gas, water and other fluids and liquids. It will be appreciated therefore that the problems and inefficiencies experienced up until this time can result in the leakage and loss of gas, water and the like. Apart from being generally inefficient therefore, such known methods can result in substantial expense and danger resulting from 20 such leakage and loss.

It is an object of this invention to go at least some way towards overcoming or ameliorating the problems and disadvantages referred to hereinbefore.

Other objects of this invention will become apparent from S 25 the following description.

According to one aspect of this invention, there is provided a coupling arrangement between a metal fitting and one or more elongate plastic pipes or tubes, said fitting including one or more substantially tubular inlet or outlet I apl~s'i 4 ~el~ L- ~P ~FYmeans; wherein at least one of either an inner or outer end surface of said inlet or outlet means is coated or lined with a plastic material; an end of a plastic tube or pipe being located within said inner end or located over said outer end of said inlet or outlet means; adhesive being provided between adjacent surfaces of said plastic tube or pipe and said coated or lined inlet or outlet means, so as to adhere said plastic tube or pipe into or over said coated or lined said inlet or outlet means.

According to a further aspect of this invention there is provided a coupling arrangement between a metal fitting and one or more elongate plastic pipes or tubes, said fitting including one or more substantially tubular inlet or outlet means; an outer end surface of said inlet or outlet means being coated or lined with a plastic material; an end of said plastic tube or pipe being adapted to be located over said coated or lined outer end of said inlet or outlet means; adhesive being provided between the outer surface of said coated or lined inlet or outlet means and an inner S"surface of said plastic tube or pipe, so as to adhere said .plastic tube or pipe about the end of said coated or lined inlet or outlet means.

oeeo Accordin to a further aspect of this invention there is provided a coupling arrangement between a metal fitting and one or more elongate plastic pipes or tubes, said fitting i including one or more substantially tubular inlet or outlet means; an inner end surface of said inlet or outlet means being coated or lined with a plastic material; an end of a plastic tube or pipe being located within said coated or lined inner end of said inlet or outlet means; adhesive I I I _.11 9 111=_being provided between an outer surface of said plastic tube or pipe and the inner surface of said coated or lined inner end of said inlet or outlet means so as to adhere said plastic tube or pipe into said coated or lined inlet or outlet means.

According to a further aspect of this invention there is provided a metal pipe fitting including an inlet or outlet Smeans of a substantially elongate and tubular form; an inner or outer annular surface of said inlet or outlet means being lined or coated with a plastics material.

This invention will now be described by way of example only and with reference to the accompanying drawings, wherein: Fig. 1 is a partially exploded view of a metal fitting and an elongate tube or pipe according to one form of the present invention; Fig. 2 is a partially exploded view of a connection between a metal fitting and plastic tube or pipe according to another form of the present invention; and Figs. 3 4 are cross-sectional views of the inlet or outlet means of a metal fitting according to Figs. 1 and 2 of the drawings, respectively.

*i The present invention will be described by way of example i: ~only with reference to the accompanying draqings, wherein a metal fitting, such as a metal valve, is shown. The valve 1 has at least one inlet or outlet means 2, in the form of a substantially elongate tubular inlet or outlet 2. It should be appreciated however, that more than one inlet or outlet 2 can be provided. Further, it should be appreciated that the "q J t invention is described with reference to a valve, by way of example only. The invention has equal application to other fittings, constructed of metal, which are required to be connected in some way to plastic materials such as for example plastic tubes and pipes.

It should be appreciated that the present invention has equal application to the use of fittings and tubes and pipes when used in a variety of different areas, such as for the control and supply of water, air, gas, and other fluids and liquids.

As will be appreciated from the above, certain difficulties arise at this point in time when it is desired to attach or connect plastic pipes or tubes to metal fittings. As stated above, gluing the fittings together has not been successful in that the glue deteriorates after a period of time, thus resulting in a loosening of the connection and in leakage and the like. Compression fitting also has disadvantages, in that again the plastic tends to loosen after a period of time (after the initial compressive engagement) and this also causes leakage, inefficiencies and the like.

The valve 1 of the present invention includes the inlet or outlet means 2 in the form of a substantially tubular member which is adapted to be connected to an elongate tube or pipe 3, for example an elongate tube or pipe 3 constructed of a 5 plastics naterial.

In one form of the invention as illustrated in Figures 1 and 3, the substantially tubular inlet or outlet means 2 is formed with a lining or coating 13 of a plastic material on the inner end surface 8 thereof so that when the end 4 of a I I I I I ~g C r I eaa~-srr plastic tube or pipe 3 is inserted into the end of the bore 12 of the inlet or outlet means 2, there will be a plastic to plastic contact between the inner surface 5 of the lining 13 of the inlet or outlet means 2 and the outer annular surface 6 of end 4 of the plastic tube or pipe 3. The inner lining 13 is of a sufficient thickness to allow for sufficient contact. The lining 13 can be achieved by injection moulding (such as during formation of the fitting) or by coating; such as, for example, by hot dipping, wherein the metal would be hot dipped into a bath of plastic material. Other means of coating or lining, such as spraying and the like, can also be used.

Any appropriate plastic material can be utilized, although it is important that the material be such as to allow for a positive adhesive action between the material of the liner and the material of the pipe or tube which is to be connected to the metal fitting.

In use, an end 4 of a plastic pipe or tube 3 that is to be e connected to the metal fitting 1 is inserted into the bore 12 of the inlet or outlet means 2, having an internal annular coating 13 of plastic. Appropriate adhesive O rO agent(s) 16 are applied to one or both of the inner surface 5 of the lining 13 or the outer surface 6 of the end 4 of the pipe or tube 3, so that once the end 4 of the pipe or tube 3 is inserted into the bore 2 of the inlet or outlet 2, the adhesive 16 will act between the two plastic surfaces m and there will be a positive location and bonding by adhesion therebetween. In this way a positive location of the pipe or tube 3, relative to the metal fitting I, is achieved.

_1 Ir II I la laa~auassl In use, it should be appreciated that any appropriate adhesive can be utilized, for example, contact adhesives.

This is by way of example only and any adhesive which acts to bond, hold and adhere the end of the pipe or tube in position relative to the coated or lined end of the inlet or outlet means is appropriate.

In a further form of the invention as shown in Figures 2 and 4 of the accompanying drawings, a coating or lining 7 of plastic material can be provided over the outer end surface 9 of the inlet or outlet means 2 of the metal fitting 1.

The plastic coating 7 can be applied by spraying, hot dipping, injection moulding or the like. The plastic coating or lining 7 about the outer surface 9 of the end of the inlet or outlet means 2 allows for the end 15 of a plastic tube or pipe 3, of a greater diameter than the inlet or outlet means 2, to be placed over the end of the inlet or outlet means 2 and for glue 11 to be inserted therebetween so that the inner surface 10 of the end 15 of the tube or S pipe 3 and the outer annular surface 14 of the lining 7 on the outer surface 9 of the inlet or outlet means 2 are glued one to the other and held in position relative one to the other. In such a form of the invention it may be necessary to utilize some additional clip (not illustrated), around the outer surface of the pipe or tube 3, to apply additional pressure or compression to the connection.

If desired, and as shown by way of example in Figure 2 of the accompanying drawings, the inlet or outlet means 2 of the metal fitting 1 can be formed with a plastic lining or o o coating 13 and 7 on both the inner surface 8 thereof and on the outer surface 9 thereof respectively, so that the I IIIBllgLeC1C~~~fitting 1 can be used to engage with the end 4 of a plastic tube or pipe 3 inserted into the bore 12 of the inlet or outlet means 2 or over the end of the inlet or outlet means 2. In other forms of the invention, and depending upon the desires of users, the inlet or outlet means can be formed or provided with a plastic lining or coating on the outer surface of the inlet or outlet means, or on the inner annular surface thereof.

As will be appreciated, the above provides a straightforward and efficient means of connecting plastic pipes or tubes to metal fittings, which overcomes or goes at least some way towards ameliorating the problems that have been brought about by such connections up until this time. The connection described herein avoid;s; or substantially minimises leakages and inefficiencies.

The invention is described by way of example only with reference to the lining being of a plastic material. Any appropriate plastic material can be utilized, although in i one form of the invention a nylon material can be utilized.

*g It should be appreciated that modifications and improvements may be made to this invention without departing from the scope or spirit thereof.

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Claims

1. A coupling arrangement between a metal fitting and one Sor more elongate plastic pipes or tubes, said fitting including one or more substantially tubular inlet or outlet means; wherein at least one of either an inner or outer end surface of said inlet or outlet means is coated or lined with a plastic material; an end of a plastic tube or pipe being located within said inner end or located over said outer end of said inlet or outlet means; adhesive being provided between adjacent surfaces of said plastic tube or pipe and said coated or lined inlet or outlet means, so as to adhere said plastic tube or pipe into or over said coated or lined said inlet or outlet means.

2. A coupling arrangement according to claim 1 in which the coating or lining of plastics material is achieved by injection moulding, coating by hot dipping or spraying.

3. A coupling arrangement according to any one of the preceding claims in which the adhesive agent is a contact adhesive.

4. A metal pipe fitting including an inlet or outlet I means of a substantially elongate and tubular form; an inner or outer annular surface of said inlet or outlet means being lined or coated with a plastics material.

5. A metal pipe fitting according to Claim 4, in which the coating or lining of plastics material is S•achieved by injection moulding, coating by hot dipping ,...au.,rnLu,~EmIUUULkk or spraying.

6. A coupling arrangement substantially as disclosed herein in conjunction with either figuress 1 and 3 or figures 2 and 4. Dated this 22nd day of July 1992 PIPE COUPLINGS (AUSTRALASIA) PTY. LIMITED by: I4 U I) 7 its Patent Attorney