AU674316B2 - Demountable pipe and pipe fitting connections - Google Patents

Description

AUSTRALIA

Patent Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: .r o Names(s) of Applicant(s): LEHUNT ASSOCIATES PTY. LTD.

Actual Inventor(s): Robert J. LEHUNT Our Address for service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street MELBOURNE, Australia 3000 Complete Specification for the invention entitled: DEMOUNTABLE PIPE AND PIPE FITTING CONNECTIONS The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 1 0804N 2 DEMOUNTABLE PIPE AND PIPE FITTING CONNECTIONS This invention relates generally to demountable connecting or joining of pipes and pipe fittings, and in particular to an end connector for demountably connecting pipes and pipe fittings together as well as a pipe or pipe fitting incorporating the end connector. The end connector is applicable for interconnecting thin walled non-ferrous, and in particular thermoplastic, glass reinforced plastic and thermoset plastic, pipes and pipe fittings. It will be convenient to hereinafter disclose the invention in relation to that exemplary application, although it is to be appreciated that the invention is not limited to that application.

One approach for interconnecting thin walled plastic pipes and pipe fittings, in order to provide demountable connections or joints therebetween, is shown in Fig. 1 of the accompanying drawings and involves manufacture of the pipes and pipe fittings P with a radially thickened or flanged section S at ends E of the pipes P at which connection is to 26. occur. Those end sections S have sealing faces F, and are assembled together using a separate annular backing plate B positioned on each pipe or pipe fitting P behind the end sections S so that the sealing faces F are positioned in face-to-face relation between the spaced apart backing plates B. The backing plates B are fastened together, such as by rigid fastening bolts (not shown) extending through holes H in the backing plates B, with a sealing gasket (not shown) being compressed between the sealing faces F of the end sections S in order to achieve a fluid seal therebetween.

0. The thickened end sections have been provided by moulding, casting and tape winding.

In respect of moulded end sections, there are limitations to the thickness of moulding possible due to the thermal conductivity properties of plastic materials used for injection moulding. In that regard, the injected plastic material moulding cools progressively from the outside of the moulding, so that the material at the surface region is first to attain maximum stiffness. This effectively forms an outer shell and defines the outer geometry of the moulding. The internal material, however, remains hot due to poor thermal 3 conductivity of the surrounding material. As the internal material cools it progressively shrinks, but as restraint occurs from the previously cooled and now rigid surface region, this shrinkage tends to pull the material from the center of the moulding. This leads to the creation of voids within the moulding, which act as stress concentrations, causing an increase in localised stresses and leading to end connection failure in field operations.

Casting of the end section with reinforced resin materials, such as polyester and epoxy, also presents a shrinkage problem. That shrinkage occurs at curing of the resin material and necessitates machining of the section to ensure dimensional compliance. The machining usually exposes the reinforcement to moisture and leads to a progressive loss of bond between the reinforcement and resin matrix. Again, that produces a weakness which leads to field operation failure.

In the case of extruded tape wound thickened end sections, hot plastic material tapes are wound onto a former to build up a section of sufficient thickness for subsequent machining into the prescribed end section profile. Here, in addition to internal shrinkage, planes of weakness can occur at the overlapping tape faces due to inadequate bonding between those faces caused by either inadequate pressure applied during tape winding or contamination of the tape faces.

A further disadvantage of this pipe connection approach o. is that, in certain conditions, the backing plates are subject to corrosion leading to reduced operating lifetimes of the connections.

.3 An object of the present invention is to alleviate these disadvantages through the provision of an improved end connector for pipes and pipe fittigs.

A further object of the present invention is the provision of a relatively simple end connector for pipes and pipe fittings.

With these objects in mind, the p r e sen provides, in one aspect, an end connector fo ipe or pipe fitting, including: a molde ast body having a flange S4AL, portion extend wardly from a pipe or pipe fitting when cposition at an end -e 3a- With these objects in mind, the present invention provides, in one aspect, an end connector for a pipe or pipe fitting, including: a molded or cast one-piece body having a tubular stub portion through which the end connector is applied to an end of the pipe or pipe fitting, and a flange portion projecting outwardly from the stub portion so as to extend outwardly from a pipe or pipe fitting when the end connector is applied to the end thereof, the flange portion being directly or indirectly connectable to a flange portion of another end connector thereby to interconnect those end connectors and the pipes or pipe fittings associated therewith; and, a reinforcing insert within the body for reinforcing the end connector, the body being molded or cast about all sides of the reinforcing insert so that the reinforcing insert is wholly contained within the body and extends into the flange portion, whereby when the end connector is applied to the end of the pipe or pipe fitting the body is free of any reinforcement extending from the pipe or pipe fitting.

a *e V'NfVlCRP (ATE'SPEI4219G33 4 pipe or pipe fitting, the flange portion being directly or indirectly connectable to a flange portion of another end connector thereby to interconnect those end connectors and the pipes or pipe fittings associated therewith; and, a reinforcing insert within the body and extending into the flange portion so as to reinforce the end connector.

In another aspect, the present invention includes a pipe or pipe fitting having the above end connector at an end thereof.

The body preferably has a stub portion through which t-he end- connenctor- is applied te the end of he pipe pi-pe fitting. The flange portion is carried by and projeets pu!t-wardly from the stutb- por Li-on-r,---ad he reinforcing insert preferably extends into both the stub and flange portions.

More.ver ,the reinforcing insert is preferably of a shape substantially the same as or generally consistent with the shape of the body.

Preferably, the stub portion is tubular and forms a tubular extension to the pipe or pipe fitting. Moreover, the reinforcing insert preferably has a tubular stub portion extending coaxially within the stub portion of the body. The stub portion of the reinforcing insert may be annular and extend substantially throughout the axial extent of the stub portion of the body.

Preferably, the flange portion projects radially from the body stub portion entirely about that stub portion. The reinforcing insert preferably has a flange portion extending radially within the flange portion of the body. The flange portion of the reinforcing insert may be annular and project substantially throughout the radial extent of the flange portion of the body.

The bedy is preferably molded orcast in onee pice about the :reinforcing insertso ethat the insert is wholly cen-ta-i--ed within t4 he.by. The reinforcing insert is preferably of one piece, solid construction.

The following description refers to a preferred embodiment of the end connector of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the end connector is illustrated in that preferred embodiment. It -0 is to be understood that the apparatus is not limited to the 5 preferred embodiment as hereinafter described and as illustrated in the drawings.

In the drawings: Fig. 1 is a cross sectional elevation of a pipe end with a prior art end connector as discussed above; and Fig. 2 is a cross sectional elevation of a pipe end with an end connector according to a preferred embodiment of the present invention.

Referring to Fig. 2 of the drawings, there is generally shown an end connector 1 applied to an end of a pipe P. The connector 1 has a molded or cast body 2, with a stub portion 3 through which the connector 1 is applied to the pipe P and a flange portion 4 carried by an extending outwardly therefrom.

The coiinector also has a reinforcing insert 5 contained within the body 2, and extending into the stub portion 3 and flange portion 4 of the body 2.

The body 2 is moulded or cast in one piece about the reinforcing insert 5 so that the insert 5 is wholly contained within the body 2.

The stub portion 3 is shaped and sized relative to the pipe or pipe fitting P so as to form an axial extension of the end thereof (as shown). Thus, the stub portion 3 is of a tubular shape and size so as to provide a tubular extension to the pipe or pipe fitting end. In this embodiment, the stub portion 3 is of the same cross sectional shape as the end of the pipe or pipe fitting. Moreover, the stub portion 3 has inside and outside surfaces 6,7, and is sized so that those surfaces 6,7, merge smoothly with corresponding surfaces of the pipe or pipe fitting P at the end thereof. The stub 0. portion 3 has a cross sectional size the same as that of the end of the pipe or pipe fitting, in this embodiment. To that end, the stub portion 3 has an end face 8 which meets the end of the pipe or pipe fitting P face-to-face.

It should be appreciated that, in an alternative embodiment (not shown), the stub portion 3 may be shaped and sized relative to the pipe or pipe fitting P so as to extend at least partially coaxially with the end thereof. Thus, the stub portion 3 may be of a tubular shape and size so as to form a sleeve about the pipe or pipe fitting end. That sleeve may project beyond the pipe or pipe fitting end.

6 The stub portion 3 is of an annular cross sectional shape in common with the pipe or pipe fitting end, in this embodiment. Moreover, the cross sectional shape and size of the stub portion 3 is constant throughout its axial extent.

However, it should be appreciated that other shapes are equally suitable.

The flange portion 4 projects radially from the tubular stub portion 3 entirely about that stub portion 3. That projection is perpendicular to the axial extent of the stub portion 3.

The flange portion 4 is of any suitable shape and, in this embodiment, is generally of the same shape as the cross sectional shape of the stub portion 3. Thus, an annular stub portion 3 is provided with an annular flange portion 4 in this particular embodiment.

The body 2 has a connecting face 9 at which the end connector 1 connects to another end connector in face-to-face relation. That connecting face 9 is at an end of the connector 1 opposite the stub portion end face 8, and extends 2.Q perpendicular to the axial extent of the stub portion 3.

Moreover, the connecting face 9 is provided by the flange portion 4 either alone or together with the stub portion 3.

The connecting face 9 is at least substantially planar, although may be configured (not shown) to seat one or more sealing elements between the face-to-face connecting faces 9 of opposed end connectors i.

The flange portion 4 projects from the stub portion 3 a distance sufficient to enable the flange portions 4 of opposed connectors 1 to be connected together.

.I :That connection may be directly through one or more fastening elements (not shown), such as bolts. In that embodiment, the flange portion 4 has a radial extent sufficient to accommodate those elements passing through holes (not shown) provided in the flange portion 4. Alternatively, the connection may be indirect through the use of backing plates (as shown in the prior art end connector of Fig. i), and fastening elements, such as bolts, extending between those backing plates. In that embodiment, the flange portion 4 has a radial extent sufficient to retain the backing plate under force of the fastening elements.

7 A single reinforcing insert 5 is provided. That insert may be of any suitable shape and size for containing within the body 2 although, in this embodiment, is of a shape substantially the same as or at least generally consistent with the shape of the body 2. Moreover, the insert 5 extends substantially throughout the axial extent of the stub portion 3 and the radial extent of the flange portion 4. The insert also extends at least generally centrally within the stub and flange portions 3,4 so as to be entirely surrounded by the body 2. Thus, in this embodiment, the insert 5 has an L-shaped cross-sectional profile providing an annular stub portion 10 extending coaxially within the stub portion 3 of the body 2 and a flange portion 11 extending radially within the flange portion 4 of the body 2.

The insert 5 extends radially within the flange portion 4 to provide sufficient rigidity in the flange portion 4 for direct connection between opposed end connectors 1. In that regard, the reinforcing insert 5 is positioned so that S fastening elements can extend through the flange portion 11 of 2* the reinforcing insert The reinforcing insert 5 is of a one-piece, solid construction.

The body 2 is moulded or cast in plastic materials, such as thermoplastic materials. The reinforcing insert 5 is manufactured from any suitable material using any suitable manufacturing process and, by way of example, may be composed of metal, plastics or resin matrix materials.

In one embodiment, the end connector 1 is manufactured as a separate piece and connected to a pipe or pipe fitting end. That connection may be achieved in any suitable manner, such as by welding or with adhesive or other fastenings.

However, in an alternative embodiment, the end connector 1 is formed integral with the pipe or pipe fitting end during manufacture thereof. Thus, the pipe or pipe fitting end will merge with the stub portion 3.

The present invention enables the manufacture of relatively large end connectors, particularly with heavy flange portions, without shrinkage voids or faults, as occurs with previous connection arrangements.

In addition, the inclusion of a reinforcing insert in 8 the end connector provides the connection between pipes and pipe fittings with sufficient stiffness to achieve a satisfactory connection without the need for an external backing plate. This in turn improves the corrosion resistance of the connector and completed pipe connection. Moreover, mechanical damage to the pipe or pipe fitting caused by a loose backing plate during pipe and pipe fitting transportation can be avoided, Finally, it will be appreciated that various modifications and/or additions may be made to the end connector without departing from the ambit of the invention as defined in the claims appended hereto.

ioe

Claims (11)

1. An end connector for a pipe or pipe fitting, including: a molded or cast one-piece body having a tubular stub portion through which the end connector is applied to an end of the pipe or pipe fitting, and a flange portion projecting outwardly from the stub portion so as to extend outwardly from a pipe or pipe fitting when the end connector is applied to the end thereof, the flange portion being directly or indirectly connectable to a flange portion of another end connector thereby to interconnect those end connectors and the pipes or pipe fittings associated therewith; and, a reinforcing insert within the body for reinforcing the end connector, the body being molded or cast about all sides of the reinforcing iir:sert so that the reinforcing insert is wholly contained within the body and extends into the flange portion, whereby when the end connector is applied to the end of the pipe or pipe fitting the body is free of any reinforcement extending from the pipe or pipe fitting.

2. An end connector as claimed in claim 1, wherein the reinforcing insert extends into both the stub and flange portions.

3. An end connector as claimed in claim 2, wherein the reinforcing insert is of a shape substantially the same as or generally consistent with the shape of the body.

4 An end connector as claimed in claim 2 or 3, wherein the stub portion is tubular for providing a tubular extension to the pipe or pipe fitting, and the reinforcing insert has a tubular stub portion extending coaxially within the stub portion of the body.

5. An end connector as claimed in claim 4, wherein the stub portion of the 25 reinforcing insert is annular and extends substantially throughout the axial extent o a of the stub portion of the body.

6. An end connector as claimed in any one of claims 2 to 5, wherein the flange portion projects radially from the body stub portion entirely about that stub portion, and the reinforcing insert has a flange portion extending radially within the flange portion of the body.

7. An end connector as claimed in claim 6, wherein the flange portion of the reinforcing insert is annular and projects substantially throughout the radial extent k of the flange portion of the body. pL yA K'~~Enn, C~Z r9

8. An end connector as claimed in any preceding claim, wherein the reinforcing insert is of one piece, solid construction.

9. An end connector as claimed in any preceding claim, wherein the end connector is formed separate from the pipe or pipe fitting for subsequent application thereto.

An end connector as claimed in any one of claims 1 to 8, wherein the and connector is formed integral with the pipe or pipe fitting during manufactu-e thereof.

11. An end connector for a pipe or pipe fitting, substantially as hereinbefore described with reference to what is shown in Fig. 2 of the accompanying drawings. DATED: 16 October, 1996 PHILLIPS ORMONDE FITZPATRICK Attorneys for: LEHUNT ASSOGIATES PTY. LTD. *e a* a a S e I I ABSTRACT An end connector for a pipe or pipe fitting The connector has a molded or cast body with a flange portion extending outwardly from the pipe or pipe fitting when the end connector is in a cornecting position at an end of the pipe or pipe fitting The flange portion is directly or indirectly connectable to a flange portion of another end connector so as to interconnect those end conne:-ors and the associated pipes or pipe fittings A reinforcing insert is positioned within the body and extends into the flange portion so as to reinforce the end connector fly. f S 9 0 **a ao a o a#