GB2510223A

GB2510223A - Improvements in and relating to pipe connectors

Info

Publication number: GB2510223A
Application number: GB1319663.9A
Authority: GB
Inventors: Vicki Jane Johansen; Gary James
Original assignee: ATLANTIC PLASTICS Ltd
Current assignee: ATLANTIC PLASTICS Ltd
Priority date: 2012-11-13
Filing date: 2013-11-07
Publication date: 2014-07-30
Anticipated expiration: 2033-11-07
Also published as: EP2920500A1; WO2014076472A1; GB201319663D0; GB201220412D0; GB2510223B; AU2013346578A1

Abstract

A connector system and associated connecting method in the system including a plurality of sets of connectors (1), each set comprising or including a tubular connector fitting (2) and respective pipe end spigot(s) (3), each spigot having a first end (4) for fitting into and supporting the end of a pipe (5) and a second and (6) for fitting into a correspondingly shaped bore (7) in the connector fitting, an 'O' ring seal (12) within the connector for sealing the outside of the pipe end spigot and/or the pipe, the first end of the spigot including one or more continuous teeth (9) .for gripping and sealing the inside of the pipe end, a radially expandable split collar (11) having an outer taper corresponding to a correspondingly shaped tapered chamber (10) in the connector fitting whereby upon positive pressure being applied from the inside of the pipe tending to force the pipe out of the connector the tapered collar slides towards the narrower and of the tapered chamber to thereby grip the pipe end and hence the toothed first end of the spigot to thereby collectively prevent or inhibit the pipe end from delaminating as a consequence of water ingress due to high internal water pressure.

Description

I

ants in tmd S atir jäpe cc nnecto rs This invention relates to pipe connectors, auch as. plastics pipe connectors of the type typically used to connect pipes underground, such as water pipes supplying water to buildings.

S A common method of conneothig plastIcs water pipes of the type described above Is by the use of compression fittings in which the tubular connector has. threaded ends onto which respectively opposite threaded compression collars may be received, the collars themselves being rotatable with respect to the connector to capture the end of the pipe to both mechanically secure It to the connector fitting as well as sealing the connection therebetween by, typically, an ring or similar compressible seal. Given that the typical wpddng pressure is 1t bar, requfring the application of considerable turning forces it will be understood that installing such compression fittings below ground can be time consuming and difficult. This problem is exacerbated where the free ends of the pipe have to be cut or otherwise prepared but are already below ground and hence difficult to access. In the case of contamInated ground pipeworic, where the pipe itself is sheathed with a, typically, wound aluminium cover to prevent the ingress of chemical contaminants into the plastics piping and hence Into the water itself, this problem is compounded because ofthe need to ensure that there i no gap between the compressIon seal and the outside of the pipe where the connection is made.

The foregoing disadvantages are largely overcome by the use of push-fit fittings the type described In 0B2266569 to a connector fitting having a tapered chamber within which is disposed a radially expandable corresppndlngty tapered collar; and associated 4(Y ring, the collar acting to grip the pipe with increasing force fri. response to positive pressure within the pipe tending to force the pipe out of the fitting, in a manner similar to a Chinese fingerlock. To prevent the pipe from buckling under the qompressive load of the collar as It Is squeezed against the outside of the pipe, the end of the pipe. Is provided with an Internal ferrule and associated flange for ensuring that the position of the feitule (a maintained relative to the connec,,, fitting. However, whilst this general S arrangement is an Improvement on compression fittings in terms of ease of installation and accessibility, it exposes the cut end of the pipe to the Internal water pressure, and where the pipe is of laminate construction, such as in the case of contaminated ground water piping, It allows the Ingress of water between and along the laminated layers, even though the outside of the pipe is 10' securely held by the push-fit coupling.

The present invention is derived from the realisation that there is a need for an alternative approach to couplings required for laminated pipework in which the foregoing disadvantages are obviated.

According to a first aspect of the invention there is pri,vided' onrtector system for connectIng, laminated pipes, such as contaminated ground plastics pipes, the connector system including a plurality of sets of connectors, each set camprfsing or Including a tubular connector fitting and respective pipe-end spigot(s), each spigot having a first end for fitting into and supporting the end of a pipe and a second, end for fitting into a correspondingly shaped bore in the cgnpector fitting, an "D' ring seal within the connector for eeallng the outside of the pipe end spigot and/or the pipe, the first end of the spigot including one or more continuous teeth for gripping and, seaiipg the inside' of the pipe end, a radially expandable split collar having an outer taper corresponding to a correspondingly shaped tapered chamber In the connector fitting whereby upon positive pressure being applied from the inside of the pipe tending to force the pipe out of the connector the tapered collar slides towards the narrower end of the tapered chamber to thereby grip the pipe end and hence the toothed first end of the spigot to thereby collectively prevent or inhibit the pipe end from delaminating as a consequence of water ingress due to high internal water pressure.

With this arrangement, the split tapered collar (which may have one or several splits) and tapered charnber'collectjvely act lIke a Chinese finger lock as the collar grips the end of the pipe in that the more force exerted from without or within to disconnect the pipe from the connector fitting the tighter is the grip between the fitting' and the pipe by' virtue of the split dngtcollar sliding to the natrower open, end of the connector fltflng However, more importantly the tapered coliar squeezes the end' of the pipe' against the one or more continuous teeth on the first end of the spigot which, In' turn, seals Land thereby prevents delamination of the pipe caused by internal water' pressure such that the higher the pressure the greater the seal integrity.

With this arrangement the connection of e.g. underground water pipes 16 simply requires that for each such connection the end of the pipe is cut off generally at 90 degrees to the major axis of the pipe, whereafter the first end of the spigot Is then pushed or tapped Into the pipe end, the second end Is inserted all the way into the bore of t' connector fitting beyond the split collar and C? ring, thereby completing the connection.

A ftirther significant advantage is that the spigot effectively acts as extension piece for the pipe which, by vitlue of having a smooth outer surface can be completely sealed by the 10* ring against the ingress of water or other contaminants entering, through the open end, of the connector fitting.

According to a second aspect of the invention there is provided a connector for connecting laminated pipes, such as contaminated' greund plastics pipes, the connector including a tubular connector fitting and respective pipe-end spigot, the spigot having a first end fOr fitting into and suppqding the end of a pipe and a second end for fitting into a correspondingly shaped bore itt the connector fitting, an 0' rIng seal within the connector for seang the outsIde of the pipe end spigot andlor the pipe, the first end of the spigot including one or more continuous teeth for gripping and sealing the inside of the pipe end, a radially expandable split collar having an outer taper corresponding to a ccnrespondlngly shaped tapered chamber in the connector fitting whereby upon positive pressure being applied from the inside of the pipe tending to force the pipe out of the connector the tapered collar slides towards the narrower end of the tapered chamber to thereby grip the pipe end and hence the toothed first end of the spigot to thereby collectively prevent or inhibit the pipe end from detaminating as a consequence at water ingress due to high Internal water pressure.

According to a third aspect of the invention them Is provided a method of connecting pipes blow ground Including the steps of cutting the end of each pipe to be connected to a connector fitting substantially normal to the major aids of' the or each pipe, Inserting into the or each pipe the first end of a spigot according to the first aspect of the invention and thereafter push fittIng the second end of the or each spigot into the open end of the connector titUng beyond the 0' ring in the fitting to thereby seal the end *1 the pipe and locking and sealing the pipe in position via the split collar and spigot system according to the first aspect of the Invention.

The invention in all its aspects will now be described, with reference to the accompanying drawings, in which: Figure 1 is an, exploded halfcut out perspectIve view of a connector set adjacent a pipe to, be connected thereto, Figure 2 is a cc ss$ectlona! skis elevation of Figure 1, Figure 3 is a partly cut out perspective view of the connector set and pipe of Figure 1 shown in their connected condition, and Figure 4 is a cross-sectional view of Figure 3.

Referring firstly to Figures 1 and 2, a connector set, shown generally at I comprises a tubular connector fitting 2 (only part of which is shown) and a pipe-end spigot 3, the latter having a first pipe-connecting' end 4 for fitting within the cut end of a laminated pIpe 5 and a second connection end 6 for fitting within and through the open end 7 of the connector fitting 2, whIch second end 6 is itself receivable within a bore 8 at the other end of' the connector fitting 2. The outside of the first end at the spIgot 4 Includes a number of circular rIbs or teeth 9 which, ii; use, act as seals in a manner to be described.

The connector fItting 2 has a tapered or frusta-conical chanter 10 between the open end 7 and the. bore 8 for containing an annular but split collar 11 andanto'ringseat IZ As can be seen mare clearly with reference to Figure 2 the collar 11 has a smooth outwardly tapering outer surface corresponding to the inside of the tapered chamber 10 whereas on the inside of the coRer 11 there are circular gripping surfaces in the form of' ribs or teeth 13 by which the collar 11 can both radially grip the pipeS in a manner to be described, and slide along and against the inner surface of the tapered chamber 10 in response to axkal pressure on the pipe in a direction towards the open end 7 of the fitting 2, or in response to water prössure within the pipe 5, FIgure 3 shows the fully assembled condition of the cortnect r set I and pipe S in which it will be seen that the second end of spigot S is fully' received within the bore 8 of the connector fittIng 2, in which condition the 0' ring 12 operates to seal the assembly from the ingress of water or other contaminants through the opening 7 whereas, as it is more, dearly seen with reference to Figure 4, the annular split collar 11 has radially expanded to accommodate the diameter of the pipe 5 to the e*ent that its smooth but tapered outer surface bears against the smooth and correspondingly tapered inner surface of the tapered chamber 9. In the position shown, correspond irig to no, or negative pressure being applied to the Joint, the 0' ring 12 serves to seat the joint against the ingress of contaminants, such as groundwater, as weli as stopping water leakIng out. However, in the event of positive pressure being applied to the contents of the pipe & the C ring seal 12 pushes against the thick end of the collar 11, forcing ft. and the pipe 5 and sptgQt $ towards the open and 7 of the fitting 2, but in so doing is increasingly resisted by the gradually narrowing, space within the tapered chamber 10, which both reçls$ further axial movement of the colbr 11 and increases the grip at' the collar on the pipe 5, thereby collectively preventing with increasing force the tendency of the pipe 5 to be ejected from the opening 7. ThIs is countered by the circular teeth 9 pressIng into the inside of the pipe 5 to thereby collectively form a watertight seal In this region such that, in particular,, water under high pressure cannot travel alOng the laminations ofthepipeii.

In this description the term connector fitting' Is Intended to Include aft types' of pipe fittings including, without limitation, straight couplings, elbow couplings and T-shaped couplings. CIa

Claims

1) A connector system for connecting laminated pipes, such as contamlnate4 ground plastics pipes, the connector system including a plurality of sets of connectors (1), each set comprising or including a tubular connector fittIng (2) and, respective pipe-and sptgot(s (3)), each spigot having a first end (4) for fitting into and supporting the end cit a pipe (5) arid, a second end (6) for fitting into a correspondingly shaped bore (7) in the connector fitting, en CY ring seal (12) within the connector for sealing the outside of the pipe end spigot and/or the pipe, the first end at the spigot including one or more continuous teeth (9) for It) gripping, and sealing the Inside of the pipe end, a radially expandable split collar (11) havIng an outer taper corresponding to a correspondingly shaped tapered chamber (10) In the connector fitting whereby upon poltlve pressure being applied, fnm the inside of the pipe tending to force the pipe out of the connector the tapered collar slides towards the narrower end of the tapered chamber to thereby grip the pipe end and hence. the toothed first end of the spigot to thereby coflecthSy prevent or inhibit the pipe end from: delamn'ating as a consequence of water ingress due to high internal water pressure.

2) A connector (1) for connecting laminated pipes (5), such as contaminated ground plastics' pipes, the connector including a. tubular connector fitting (2) and respective pipe-end spigot (3), the spigot having a first end (4) for fitting into and supporting the end of a pipe and a second end (8) for fitting into a correspondingly shaped bore (7) In the connector fitting, an O' ring seal (12) within the connector for sealing the outside of the pipe end spigot and/or the pipe, the first end of the spigot including one or more continuous teeth (9) for grIpping and sealing the inside of the pipe end, a radially expandable split collar (II) having an, outer taper corresponding to a correspondingly shaped tapered chamber (10) in the connector fitting whereby upon positive pressure being applied from the insIde of the pipe tending to force the pipe out of the. connector the tapered colLar slides towards the narrower end of the tapered chamber to thereby grIp the pIpe end and hence the toothed first end of the spigot to thetby collectively prevent or inhibit the pipe end from delaminating as a consequence of water ingress due to high internal water pressure.

8) A, connector according to claim 2 further characterised In that the cac$ially expandable split collar Includes a plurality of split segments which collectively define the collar.

4) A connector according to claim 2 or claim 3 further characterised in that the split collar (11) has inwardly facing gripping surfaces in the form of ribs or teeth (13).

5) A method of connecting pipes below ground Including the steps, in any convenient order, of cutting the end of each pipe (5) to be connected to a connector fitting (2) substantially normal to the major axis of the or each pipe, inserting into the or each pipe the first cr4 (4) of a spigot (3) accordIng to the second aspect of the invention and thereafter push fitting the second end (6) of the or each sp$got' Into the open end of' the connector fitting beyond the 0" ring (12) in the fitting to thereby seat thØ end of the pipe and locking and sealing the pipe in position via the split collar and spigot according to the second aspect of the Invention.