AN END CONNECTOR

Abstract: The invention relates to an end connector system for a water or sewage pipe (2) and a liner (3), comprising means (4) adapted to seal the liner (3) and pipe (2) together from internally of the liner (3) whereby to obviate drawing back of the liner (3) and entry of material (water or sewage in the embodiments, though it could be gas, or powder) between the liner (3) and pipe (2). In the figure, the liner (3) terminates short of the end of the pipe (2) and is secured thereto by the means (4) which is in the form of a seal element or device (5) which is a flexible cylindrical element with internal reinforcement such as Kevlar and which has end profiles (6 and 7). The means (4) also includes a metal ring or union (8) with a groove (9) for receiving the end profile (6) and clamping device in the form of two tension bushes (9 and 10) which can be expanded radially to effect clamping.

Description: AN END CONNECTOR The invention relates to an end connector, particularly to such a connector for a pipe and liner. Pipe lines often have liners, to provide for a relatively simple yet efficient and inexpensive way of repairing a cracked or leaking pipe which would otherwise require to be replaced, which could be difficult in an underground pipe such as a water or gas pipe, or a sewage pipe. Such liners have the disadvantage that they have to allow the pipe to be connected with another, without drawing back into the pipe and without allowing material in the pipe to enter the annulus between the liner and pipe. It is an object of the invention to seek to mitigate this disadvantage. According to a first aspect of the invention there is provided an end connector system for a pipe and liner, comprising means adapted to clamp the liner in the pipe from internally of the liner whereby to obviate drawing back of the liner and entry of material carried by the pipe between the liner and pipe. The end connector system may comprise a seal element which is insertable between the liner and the pipe or internally of the liner. This helps to obviate entry of material into the annulus between liner and pipe. The seal element may comprise a flexible cylindrical seal device. This provides for ease of use and efficiency of operation. The seal device may have a surface profile at one end, whereby to provide a secure mounting of the seal device. There may be a surface profile at both ends of the seal device. The end profile(s) provide a means to grip the device. The seal device may comprise strengthening means, for example, integral reinforcing material or a reinforcing material bonded to the seal element. The reinforcing material may comprise a plurality of metal strips bonded to the seal device. The seal element may comprise a plurality of barb means projecting therefrom, whereby to grip the pipe or liner or the pipe and liner. This provides for additional security of mounting of the seal element. The seal device may comprise a plurality of separate parts and a connector therefor. The means may comprise a clamping device which is shiftable longitudinally of the pipe for clamping the liner to the pipe. The clamping device may comprise a wedge-configuration nose for engaging the liner and clamping same to the pipe. This provides a secure and progressive clamp as the device is drawn into the pipe. The means may comprise a clamping device which is expansible radially of the pipe for clamping the liner to the pipe, preferably a tension bush device, which itself may comprise an expansible body and means to maintain the body in an expanded condition. This provides for positive clamping, particularly where the body and means may have cooperable interengagement means for maintaining the body in an expanded condition. The cooperable interengagement means may comprise ratchet teeth and a pawl device. This provides a relatively simple yet efficient construction. The ratchet teeth may be on the body and the pawl device may be a free end of a member which is secured to a part of the body adjacent to the ratchet teeth whereby the pawl device overlies the ratchet teeth. According to a second aspect of the invention there is provided a clamping device, comprising an expansible body and means of the body to maintain the body in an expanded condition. The body may comprise a cylindrical body which is expansible radially. This provides a positive clamping action, particularly where the body and means may have cooperable interengagement means for maintaining the body in an expanded condition. The cooperable interengagement means may comprise ratchet teeth and a pawl device. This is a relatively simple yet effective construction. The ratchet teeth may be on the body and the pawl device may be a free end of a member which is secured to a part of the body adjacent to the ratchet teeth whereby the pawl device overlies the ratchet teeth. The member may comprise a metal strip element secured to the body, and a free end of the strip element may be turned out of the plane of the strip element to provide said pawl device. This is a relatively simple yet effective construction. The body may comprise metal and the member may be secured to the body by welding. The body may comprise a plurality of surface steps whereby to allow expansion of the body. The metal strip element may overlie the steps. This provides for a neat construction, particularly where the metal strip element and body may have substantially the same width. An end connector and clamping device for a water or sewage pipe with a liner are hereinafter described, by way of example, with reference to the accompanying drawings. Figs. 1 to 10 show respectively various embodiments of end connectors according to the invention; Figs. 11 to 16 show schematically an end connector, similar to Fig. 7, according to the invention; Figs. 17 to 20 show respectively stages in installation of an end connector of Figs. 11 to 16; Figs. 21 and 22 show a modified clamping device that could be used for example with a system like that shown in Fig. 7; and Fig. 23 shows part of the end connector of Figs. 1 to 22, in the form of a clamping device according to the invention. Referring to the drawings, in which like parts are referred to by like reference numerals, Fig. l shows an end connector system 1 for a water or sewage pipe 2 and a liner 3. comprising means 4 adapted to seal the liner 3 and pipe 2 together from internally of the liner 3 whereby to obviate drawing back of the liner 3 and entry of material (water or sewage in the embodiments, though it could be gas, or powder) between the liner 3 and pipe 2. In Fig. 1, the liner 3 terminates short of the end of the pipe 2 and is secured thereto by the means 4 which is in the form of a seal element or device 5 which is a flexible cylindrical element with internal reinforcement such as Kevlar and which has end profiles 6 and 7. The means 4 also includes a metal ring or union 8 with a groove 9 for receiving the end profile 6 and clamping device in the form of two tension bushes 9 and 10 which can be expanded radially to effect clamping. The end profile 7 of the sealing device 5 is a bulbous nose and it is inserted into the annular space between the liner 3 and the pipe 2, to form a "blip" or ridge adjacent which the tension bush 9 is mounted, the tension bush 10 being positioned to force the end profile 6 into the groove 9 of the ring 8. Thus on expansion of the tension bushes 9, 10 the liner is securely clamped to the pipe 2, via the sealing element 5, and is prevented from withdrawing into, or contracting along, the pipe 2. The sealing device 5 also obviates entry of water into the annulus between the liner and pipe. The end connector 1 can be used to provide an end termination joint for retrofitting. The sealing device 5 can have any desired diameter to suit a particular pipe 2. The pipe 2 has a flange which has an adaptor for connection with another pipe (not shown) the end connector 4 providing for a leak free connector between pipes in line. Referring to Fig. 2, the end connector 20 shown has a clamping means 4 which comprises a grooved ring 8, as before, a single radially expansible clamping device 21 and a relatively short sealing element or device 22 which has a bull nose 23 for insertion between the liner 3 and the pipe 2, and a plurality of surface profiles or rings 24 for reception in facing grooves of the ring 8. The liner 3 is longer than the pipe 2 in this embodiment, and there is the usual standard flange 11 and adaptor 12. The embodiment of end connector 30 of Figs. 3 and 4 has a liner 3 which extends beyond the end of the pipe 2 and which is clamped thereto by clamping means in the form of a bodily shiftable device 31 which is in the form of a ring of ' configuration (in section) wall having a wedge configuration which extends into the liner. There is a ring 32 with a profiled inner surface with serrations 33 and a seat for an 'O'-ring 34, this ring being connected to the flange 35 of the 'T' by a device which is shown as a screw-threaded stud 36 (but which could be a hydraulic or other device). The ring 32 is secured to the pipe by suitable means, not shown. When the nut 37 or the stud is rotated, the clamping device 31 is progressively drawn into the liner 3, which is forced into the serrations 33 and thus firmly clamped in place, and is prevented from withdrawal into the pipe by the serrations 33, which are "stepped" radially as shown, and against the 'O' ring so that entry of water between the liner 3 and pipe 2 is prevented. The end connector 40 shown in Fig. 5 is similar to that of Figs. 3 and 4, Fig. 5 showing the clamped condition similar to Fig. 4. In the end connector, the clamping device shown (which could be replaced by a clamping device in the form of a tension ring) is secured and drawn into the pipe by a usual V.J. joint 41 for connecting pipes between end flanges, a depending lug 42 acting on the clamping device 31 via its flange 35. Fig. 6 shows another embodiment of end connector 50 which has a toothed wedge-configuration clamping device for gripping the liner 3, there being a T- section end cap 52 which is expanded radially by a tension bush (not shown) for clamping the liner and wedge together. The end connector 60 of Fig. 7 has a seal element device 61 which is cylindrical with an end flange 62 and which is inserted between the pipe 2 and the liner 3 and which has reinforcement such as a plurality of metal members which could be stainless steel strips 63. bonded to the seal and an expansible clamping device 64 which forces the liner 3 against the seal element 61. there being barbs 65, 66 on the seal element which respectively grip the liner 3 and the pipe 2 for secure clamping and which as before prevent the liner 3 from being able to withdraw into the pipe, the direction of the barbs 65 hooking into the liner 3 preventing such an occurrence, the sealing element 61, also as before, preventing entry of water between the liner and pipe. An annular clamping device 64 holds the liner 3 and seal element device against the pipe 2. Fig. 8 shows an embodiment of end connector 70 similar to that of Fig. 7, the seal element 71 having barbs 72 on only one side, for gripping the liner 3 and prevention of withdrawal thereof into the pipe 2. There is an end ring or clamping device 73 which can be expanded to clamp the liner 3, which extends beyond the end of the pipe, against a clamp ring 74 with an 'O' ring seal 75. Fig. 9 shows an embodiment of end connector 80 in which the seal element or device 81 is in two parts, namely a radially outer seal 83 (which can be provided in a range of diameters) and a radially inner seal 82, the two parts 82, 83 being held together by a connecting ring 84 having an end lip 85 and a tooth or ring 86 for engaging in a groove or aperture in the inner seal. The outer seal 83 has a metal core 87, suitably of stainless steel, for strength and barbs 88 as in for example Fig. 7. There is also an elastomeric seal 89' which is compressed when the liner (not shown) is clamped. The end connector 90 of Fig. 10 is similar to those of the other embodiments, there being a seal element or device 91 in the form of a metal cylinder with an end flange 92, barbs 93 for gripping the liner 3 and seals such as elastomeric seals 94 which prevent entry of water into the annulus between the liner and pipe (as in Fig. 9). The elastomeric material passes through holes 95 for firm keying. There is a clamping device 96 such as a tension bush which is radially expansible for forcing the liner 3 towards the pipe 2. Figs. 11 - 22, show an embodiment of end connector 100 which is similar in principle to that of Fig. 7. The end connector 100 is particularly suited for use in end termination of thin wall liners 3 in small cast iron pipes, which are generally prone to vary greatly in their degree of ovality and range of actual diameters for each nominal diameter. The end connection 100 comprises a perforated sheet of suitable material 101, for example stainless steel. The perforations 102 in the embodiment are formed by turning out punched out parts of the sheet to form barbs 103, though it will be understood that the sheet 101 may merely be perforated. Fig. 12 is a view on arrow 'X' of Fig. 11 showing barbs 103 which are directed to one side of the sheet 101. A sheet of suitable material such as butyl rubber 104 is then secured by any suitable method to each side of the sheet 101, and is extended beyond each end of the perforated sheet, each extended end being tapered as shown at "e" in Fig. 15, which itself is a view on arrow 'Y' of Fig. 14 which shows a plan view of the element 100. A release or masking agent such as a strip of release or masking paper is then adhered to each outer surface of the butyl material 104, 104. The strip 101 , 104 is then folded to form substantially a circle, Fig. 16, having the nominal inner diameter of a host pipe to be lined, the tapered ends 'c' providing that there is no step or discontinuity. The barbs 103 (not shown in Fig. 17 for clarity) fall inwardly i.e. towards the centre of the now circular device 100. The device 100 is then offered up to and inserted in an end of the pipe 2 after the release paper is removed from the outer butyl surface, so exposing a tacky or sticky surface which is secured to the inner surface of the host pipe. The thin wall liner 3 is then installed, and is temporarily lifted off or pulled away from the release paper 105 on the inner (as viewed) butyl surface, so allowing the "inner" release paper 105 to be removed. The thin wall liner 3 is then applied to the "tacky" butyl inner surface, where it is maintained in position by application of a clamping device which is an expansion device which is used to expand the whole assembly thereby to provide a sealed joint to prevent ingress of foreign bodies between the thin wall liner 3 and the host pipe 2. During this expansion process the barbs 103 of the perforated sheet 101 penetrate through the inner butyl layer 104, thus to provide a firm grip to the outer surface of the liner 3. As shown in Fig. 21, there could be used a plurality of connectors 100, 100' , which are each folded to form part of a curve so that they form a circle when placed together. In use there could be a gap 'G' between the edges of the connectors 100, 100' , as shown in Fig. 22 although the butyl extensions 'e' overlap. The system could be held in place by a clamping device 200 of Fig. 23 which can be used to clamp all the end connectors described, though in Figs. 11 to 22 an additional end restraint is achieved. Thus referring now to Fig. 23, there is shown a clamping device 200 which can be used with the end connectors previously described, though it could find other applications, for example in patch repairs for sewers. The clamping device 200 is a metal bush 201 which has a body which is expansible radially by having a longitudinal slot or step 202 running the length thereof. Part of the surface of the body of the bush adjacent (in the embodiment) steps of the bush has a set of ratchet teeth 203. Secured to a part of the body on the other side of the step from the ratchet teeth 203 is a member in the form of a metal strip member 204, an end 205 of which is secured as by welding to the body of the bush 201 at 'W. The opposite end ot the member 204 is bent out of the plane of the member to form a downwardly (as viewed) directed pawl device 206. The pawl device 206 forms an edge of the strip 204 which itself is the same length as the bush 201 and which extends over the step, or slot 202, to provide a neat appearance. In use, the device 200 is inserted within the item to be clamped, such as the liner 3 of Figs. 1 - 22, and expanded radially to the required diameter by any suitable means. During the expansion the pawl device 206 rides over the ratchet teeth 203. Once the required diameter is reached, the pawl device 206 rests against a tooth 203, and the ratchet tooth and pawl device thus hold the body in that position, so that no residual spring tension has to be relied upon. The ratchet teeth and pawl device thus provide cooperable interengagement means. By incorporating the ratchet system, a thinner wall of the body can be used, with consequent saving on weight, cost, and a greater general applicability as the device can be used in relatively small diameter orifices. It will be understood from the foregoing that all the end connectors described herein with reference to the drawings provide for positive clamping of a liner 3 without withdrawal thereof into a pipe 2, or entry of material such as water into the annulus between the liner and a host pipe, the liners 3 being thin wall liners.

Claims: CLAIMS 1. An end connector system for a pipe and liner, comprising means adapted to clamp the line in the pipe from internally of the liner whereby to obviate drawing back of the liner and entry of material carried by the pipe between the liner and pipe. 2. An end connector system according to Claim 1, comprising a seal element which is insertable between the liner and the pipe or internally of the liner. 3. An end connector system according to Claim 2, the seal element comprising a flexible cylindrical seal device. 4. An end connector system according to Claim 3, the seal device having a surface profile at one end, whereby to provide a secure mounting of the seal device. 5. An end connector system according to Claim 4, there being a surface profile at both ends of the seal device. 6. An end connector system according to Claim 3, the seal device comprising strengthening means. 7. An end connector system according to Claim 6, the strengthening means comprising integral reinforcing material. 8. An end connector system according to Claim 6, the strengthening means comprising a reinforcing material bonded to the seal element. 9. An end connector system according to Claim 8, the reinforcing material comprising a plurality of metal strips bonded to the seal device. 10. An end connector system according to any of Claims 3 to 9. the seal element comprising a plurality of barb means projecting therefrom, whereby to grip the pipe or liner or the pipe and liner. 11. An end connector system according to Claim 3, the seal device comprising a plurality of separate parts and a connector therefor. 12. An end connector system according to any of Claims 2 to 11 , the means comprising a clamping device which is shiftable longitudinally of the pipe for clamping the liner to the pipe. 13. An end connector system according to Claim 12, the clamping device comprising a wedge-configuration nose for engaging the liner and clamping same to the pipe. 14. An end connector system according to any of Claims 2 to 11 , the means comprising a clamping device which is expansible radially of the pipe for clamping the liner to the pipe. 15. An end connector system according to Claim 14, the clamping device comprising a tension bush device. 16. An end connector system according to Claim 15, the tension bush device comprising an expansible body and means to maintain the body in an expanded condition. 17. An end connector system according to Claim 16, the body and means having cooperable interengagement means for maintaining the body in an expanded condition. 18. An end connector system according to Claim 17, the cooperable interengagement means comprising ratchet teeth and a pawl device. 19. An end connector system according to Claim 18, the ratchet teeth being on the body and the pawl device being a free end of a member which is secured to a part of the body adjacent to the ratchet teeth whereby the pawl device overlies the ratchet teeth. 20. An end connector system according to any of Claims 2 to 19, the seal element comprising a perforated sheet material with an adhesive covering. 21. An end connector system according to Claim 20, the perforated sheet comprising barbs. 22. A clamping device, comprising an expansible body and means of the body to maintain the body in an expanded condition. 23. A clamping device according to Claim 22, the body comprising a cylindrical body which is expansible radially. 24. A clamping device according to Claim 23, the body and means having cooperable interengagement means for maintaining the body in an expanded condition. 25. A clamping device according to Claim 24, the cooperable interengagement means comprising ratchet teeth and a pawl device. 26. A clamping device according to Claim 25. the ratchet teeth being on the body and the pawl device being a free end of a member which is secured to a part of the body adjacent to the ratchet teeth whereby the pawl device overlies the ratchet teeth. 27. A clamping device according to Claim 26, the member comprising a metal strip element secured to the body, a free end of the strip element being turned out of the plane of the strip element to provide said pawl device. 28. A clamping device according to Claim 27, the body comprising metal and the member being secured to the body by welding. 29. A clamping device according to Claim 28, the body comprising a plurality of surface steps whereby to allow expansion of the body. 30. A clamping device according to Claim 29, the metal strip element overlying the steps. 31. A clamping device according to Claim 30, the metal strip element and body having substantially the same width. 32. A seal element for insertion between a pipe and a liner therefor, comprising means adapted to secure the liner in position.

Inventors: SANDERS TREVOR GEORGE, SANDERS, TREVOR, GEORGE
Applicants: SANDERS TREVOR GEORGE, THAMES WATER UTILITIES, SANDERS, TREVOR, GEORGE, THAMES WATER UTILITIES LIMITED
Application year: 1998
Main classification: F16L55
IPC codes: F16L55