AU2009202137A1

AU2009202137A1 - A Pipe Joint

Info

Publication number: AU2009202137A1
Application number: AU2009202137A
Authority: AU
Inventors: James Victor Henwood
Original assignee: Vinidex Pty Ltd
Current assignee: Vinidex Pty Ltd
Priority date: 2008-05-29
Filing date: 2009-05-28
Publication date: 2009-12-17

Description

I A PIPE JOINT BACKGROUND OF THE INVENTION 1. Field of the Invention 100011 The present invention relates to a pipe joint for joining and sealing a smaller pipe to a larger pipe. 2. Description of the Art [00021 A pipe joint between a larger pipe and a smaller pipe is commonly made in a manner that does not involve the extra effort of cutting the larger pipe into two sections and inserting a suitable "T" fitting for joining the two sections of the larger pipe with the smaller pipe. The typical approach is to bore a hole into the wall of the larger pipe and then join the end of the smaller pipe to the hole in the wall of the larger pipe. [00031 Joining techniques that may be employed either singularly or in combination include welding, applied adhesives, mortar, sealant, grommets or sealing sleeves, encapsulation in concrete and those that a person skilled in the art of plumbing may employ. [00041 Some pipe joining applications involve a larger pipe that is additionally strengthened by wall corrugations, ribs or other structures within or applied to the pipe wall. The additional strengthening being used to complement the flexibility of the materials used in the larger pipe. The larger pipe being required to have some flexibility as well as the required strength to cope with the static and dynamic loads applied to and within it. In such pipe joining applications the pipe joint may be required to have a degree of flexibility whilst still maintaining a seal between the larger pipe and the smaller pipe. [00051 None of the prior art pipe joints provides an entirely satisfactory solution to the provision of a pipe joint between a smaller pipe and a larger pipe as described nor to the ease of installation of the pipe joint.

2 SUMMARY OF THE INVENTION 100061 The present invention aims to provide an alternative pipe joint arrangement which overcomes or ameliorates the disadvantages of the prior art, or at least provides a useful choice. [0007] In one form, the invention provides a pipe joint for joining and sealing a smaller pipe to a larger pipe comprising: a flexible sleeve body adapted to make a sealing engagement between a smaller pipe and a hole in a wall of a larger pipe, where the sleeve body includes: one or more first formations on the sleeve body adapted to engage with one or more second formations on a wall of the larger pipe and one or more third formations to resist withdrawal of the smaller pipe from the larger pipe. [00081 Preferably the first formation is one or more lugs or pins, the second formation is one or more corrugations or ribs and the third formation is a flange or one or more projections. Optionally the third formation may be further adapted to engage with an inner surface of the larger pipe. [0009] Preferably the one or more first formations provide rotational location in engagement with one or more second formations. [00101 Preferably the first formation or third formation prevents a withdrawal of the pipe joint from the hole in the wall of the larger pipe. [0011] The pipe joint may be use with larger pipes of outside diameter up to 2500 mm whilst the smaller pipe has an outside diameter of up to half the outside diameter of the larger pipe. Preferably the pipe joint may be adapted to join a smaller pipe of 100 mm or 150 mm diameter to a larger pipe of diameter of 225, 300, 375, 450, 525, 600, 750, 900 mm or more. Optionally the pipe joint in part at least may be made up of one or more of a synthetic rubber, a natural rubber or a EPDM rubber [00121 Optionally the pipe joint may further include one or more sealing ribs upon an inner wall of the flexible sleeve. In addition the pipe joint may be further adapted to join and seal either a larger pipe or a smaller pipe of non-circular cross section. 100131 Preferably the adaptation for the sealing engagement between the smaller pipe and the hole in the wall of the larger pipe is a radial expansion of the flexible sleeve body of the pipe joint when the smaller pipe is inserted into the pipe joint.

3 [0014] In an alternate form the invention provides a method for joining a larger pipe to a smaller pipe using a pipe joint. The steps of the method may be: providing a suitable hole in a larger pipe, deforming and inserting the pipe joint into the hole, engaging one or more first formations of the pipe joint with one or more second formations on a wall of the larger pipe and inserting an end of the smaller pipe into the pipe joint. [00151 In a further form of the invention, a pipe joint being substantially as herein described. [0016] In yet another form the invention provides a method for joining a larger pipe to a smaller pipe using a pipe joint substantially as herein described. [00171 Further forms of the invention are as set out in the appended claims and as apparent from the description.

4 DISCLOSURE OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS 100181 The description is made with reference to the accompanying drawings; of which: [00191 FIG I is a schematic perspective view from the top of a pipe joint in an embodiment of the present invention. 10020] FIG 2 is a bottom view of the pipe joint in FIG 1. [00211 FIG 3 is a schematic perspective view of a larger pipe with a hole in the pipe wall. [00221 FIG 4 schematically illustrates the installation of a pipe joint to the larger pipe of FIG 3. 100231 FIG 5 is a transverse cross sectional view from FIG 4 along the line 5 5. 100241 FIG 6 schematically illustrates the installation of the smaller pipe to the pipe joint and larger pipe of FIG 5. [00251 FIG 7 is an alternate embodiment of FIG 1. 100261 FIG 8 is a transverse cross sectional view from FIG 4 along the line 8 8. [00271 FIG 9 is a longitudinal cross sectional view from FIG 4 along the line 9-9 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 100281 FIGs 1 and 2 schematically illustrate perspective views of a pipe joint 110 or a grommet seal used for joining a larger pipe to a smaller pipe. The larger pipe is described with respect to FIG 3 and further, whilst the smaller pipe is described with respect to FIG 6 and further. FIG 1 is a perspective view of the pipe joint 110 from the top or the outer of the pipe joint 110 when in use. FIG 2 is a perspective view from the underside or the inner of the pipe joint 110 when installed. [00291 The pipe joint 110 may have a sleeve body 112 with two lugs 114 on opposing sides of the sleeve body's 112 outer wall. The two lugs 114 are examples of 5 first formations 114 that are shaped and positioned to interact or engage with second formations (not shown) which are described below with reference to FIGs 3 and 4. The flange 116 located at the bottom end of the sleeve body 112 is an example of a third formation 116 which is described below with reference to FIGs 5 and 6. The inner wall of the sleeve body 112 may have a number of optional sealing ribs 118. One end of the sleeve body 112 may have a chamfer 120 to aid in insertion of the smaller pipe (not shown) into the pipe joint 110. [0030] FIG 3 schematically shows a perspective view of a section of an example of a larger pipe 310. The larger pipe 310 is of a typical twin skin variety. An inner skin 312 of the larger pipe 310 is commonly a pipe or conduit of polypropylene, PVC or other suitable material for carrying liquids. The inner skin 312 has a smooth inner wall so as to present minimal flow resistance to the liquids carried. An outer skin 314 of the larger pipe 310 is commonly in the form of a corrugated pipe featuring through thickness corrugations 316. In an alternative embodiment the outer skin 314 may have instead of a corrugated form, a series of stiffening ribs applied to the outer and/or inner walls of the outer skin 314. The purpose of the corrugations, stiffening ribs or any other suitable stiffening technique that a person skilled in the art may employ, is to improve the structural support provided by the outer skin 314 to the inner skin 312 of the larger pipe 310. The corrugations 316, stiffening ribs or the like are examples of second formations 316 that the lugs 114 or first formations 114 may engage with. [00311 A hole 318 may be bored through the twin skins 312, 314 of the larger pipe 310. The dimensions of the hole 318 corresponds to those of the sleeve body 112 of the pipe joint 110, between the lug 114 and the flange 116. [0032] FIGs 4 and 5 schematically illustrate the installation of the pipe joint 110 into the hole 318 of the larger pipe 310. FIG 5 is a transverse cross sectional view from FIG 4 along the line 5-5. The pipe joint 110 is made of a material which is sufficiently flexible such that the sleeve body 112 and/or the flange 116 may be deformed so that the flange 116 end of the pipe joint 110 may be inserted wholly into the hole 318 in the wall of the larger pipe 310. FIG 5 shows the flange 116 inside the inner skin 312 of the larger pipe 310.

6 100331 FIG 4 illustrates the location of the lug 114 with respect to the corrugations 316 of the larger pipe 310. Simultaneously with the insertion of the flange 116 into the hole 318, the lower portion 410 of the lug 114 (opposing the flange 116) engages with a valley 412 of the corrugations 316 of the outer skin 314 of the larger pipe 310. 100341 The locating of the lug 114 with respect to the corrugations 316 and consequently the inside curvature of the inner skin 312 of the larger pipe 310 allows the curvature 510 of the flange 116 to conform wholly or in part to that of the inner wall of the inner skin 312 of the larger pipe 310 as shown in FIG 5. The relative locations of the lugs 114, the corrugations 316, the curvature 510 of the flange 116 and the inner wall curvature of the inner skin 312 so as to allow for the correct operation of the pipe joint 110 as described below with reference to FIG 6. [00351 FIG 6 schematically illustrates the next step to FIG 5 in joining a smaller pipe 610 to the larger pipe 310 via the pipe joint 110. An end 612 of the smaller pipe 610 is pushed into the pipe joint 110 until the end 612 of the smaller pipe 610 projects beyond the flange 116. The dimensions of the inside of the sleeve body 112 and any optional sealing ribs 118 may be slightly less than the outer dimensions of the smaller pipe 610. This arrangement of dimensions for the sleeve body 112, the smaller pipe 610 and those for the hole 318, as described above with reference to FIG 3, together with the flexible material of the sleeve body 112 allow the sleeve body 112 to expand radially outwards on insertion of the smaller pipe 610. The radial expansion of the sleeve body 112 being sufficient to form a liquid proof seal between the smaller pipe's 610 outer wall, the sleeve body 112 and the edges of the hole 318. [0036] An example of typical installation instructions may be as follows: (a) Cut a suitable hole 318 into a larger pipe 310 using a suitable trepanning / hole saw. (b) Squash the pipe joint 110 / grommet seal into a "C" shape and offer it to the prepared hole 318, inserting the flange 116 into the hole 318. (c) Position the lugs 114 into a valley of a corrugation 316 of the large pipe 310. (d) Optionally apply a suitable lubricant to the inside of the sleeve body 112 of the pipe joint 110.

7 (e) Cut a lead-in chamfer to the smaller pipe 610 that is to be inserted into the pipe joint 110. (f) Mark a line on the outside of the smaller pipe 610 to indicate the required insertion depth into the pipe joint 110 and/or larger pipe 310. (g) Apply a suitable lubricant to the outside of the smaller pipe 610. (h) Insert the smaller pipe 610 into the pipe joint 110 to the required insertion depth. [00371 If the smaller pipe 610 is pulled upon in the direction to withdraw it from the pipe joint 110, the flange 116 (or third formations) either in part or wholly may contact the inside wall of the inner skin 312 of the larger pipe 310, such that the withdrawal of the pipe joint 110 from the larger pipe 310 is resisted. Such a situation may occur in stormwater applications when the larger pipe 310 is at a full carrying capacity and sinks slightly into its bedding. In another application area of pumped sewers piping, both the larger 310 and smaller 610 pipes may be at an internal pressure less than ambient such that the smaller pipe 610 and/or the pipe joint 110 may experience an inwards pressure towards the larger pipe 310. In this situation the lugs 114 (or first formations) may prevent the sleeve body 112 from further insertion into the larger pipe 310 which may result in loss of the liquid seal. In the sewer application an adhesive may be used between the pipe joint either or both of the larger 310 and smaller 610 pipes to improve the seal for liquids and gases. [00381 The arrangement of the flexible sleeve body 112, with the flange 116 and lugs 114 enables a flexible and durable join to be maintained between the larger pipe 310 and a smaller pipe 610 under static and dynamic loads experienced in liquids transport. In addition the joining and sealing between the larger pipe 310 and smaller pipe 610 is maintained during relative movements between the two pipes 310, 610 which may occur during their service life. For example such relative movements may due to ground movements or during dynamic loading of the pipes. [00391 FIG 7 schematically illustrates an example alternative embodiment of the pipe joint 110. The alternative pipe joint 710 features alternative first formations 714 which are one or more pins 714 rather than lugs 114. In addition the flange 116 is absent; instead the alternative third formations 716 are a number of projections 716 8 from the sleeve body 112 in the prior location of the flange 116. The performance of the alternative pipe joint 710 is as per that described above for the first embodiment. For example a projection 716 may still prevent withdrawal of the pipe joint 710 from the larger pipe 310. [00401 In yet another embodiment the first formations upon the sleeve body 112 may be formed in a different manner to engage with an alternative embodiment of the third formations upon the outer skin 314 of the larger pipe 310. For example the first formation may be in the form of a slot (not shown) which engages with a ridge of a series of stiffening ribs located on the outer wall of the larger pipe 310. [00411 It will be appreciated that a person skilled in the art of pipe fitting and plumbing, may design and employ any number of forms for the first, second and third formations and still be an equivalent embodiment of the invention. Materials [00421 The flexible material to form the pipe joint is in a preferred embodiment an industrial grade, synthetic (silicone etc) or natural rubber with a durability suitable for stormwater or sewer applications. Where the durability refers to both chemical and physical properties. The flexibility or hardness of the material of the pipe joint is preferably a single Shore A Hardness of 45. In alternative embodiments it may be desirable to vary the flexibility or hardness of the rubber used either overall or for various parts of the pipe joint 110, 710. For example for the alternative pipe joint 710 the pins 714 and/or projections 716 may be of an increased Shore A Hardness, for example 85. [00431 The properties and the dimensions of the material used to form the pipe joint 110, 710 may be also varied to change the pressure rating of the seal formed by the pipe joint. For example the properties of flexibility, cohesiveness and slip to the pipes 310, 610. [00441 An example of a suitable material form the pipe joint for stormwater applications is EPDM rubber (ethylene propylene diene M-class).

9 Applications 100451 For applications to stormwater plumbing the pipe joint may be applied to a larger pipe 310 of up to 2500 mm outside diameter with a smaller pipe 610 outside diameter of up to half or more that of the larger pipe. A single size pipe joint 110, 710 may be applied across a large range of larger pipe 310 diameters since the sleeve body 112 and third formation 116, 716 may be sufficiently flexible to conform to the varying radius of curvatures for a range of different diameter larger pipes 310. [00461 In one stormwater plumbing application the larger pipe size may be from 225 to 300 mm internal diameter and the smaller pipe of 100 mm nominal sized (110mm outside diameter). For this application the pipe joint 110 may have a sleeve body 112 of height 65 mm, outside diameter 140 mm and an internal diameter of 103 mm with a wall thickness of 12 mm. The dimensions of the first formation 114, 714 and third formation 116, 716 may be as appropriate for the pipe joint 110 to perform as described above. [00471 An example of a product range of pipe joints 110 to suit the joining of smaller pipes to larger pipes is as follows: 100 or 150 mm service connection diameter smaller pipe may be connected using suitable pipe joints to larger pipes of nominal diameter of 225, 300, 375, 450, 525, 600, 750, 900 mm or more. [0048] As described above the pipe joint 110 may also be applied to sewer or other plumbing applications where lower than ambient pressures may be present in the larger and smaller pipes 310, 610. [0049] The pipe joint may also be applied to joining larger and smaller pipes of non-circular cross-section. [00501 FIG 8 is a transverse cross sectional view from FIG 4 along the line 8 8. FIG 8 schematically illustrates another view of the pipe joint 110 installed within the larger pipe 310, but before the insertion of the smaller pipe 610 into the installed pipe joint 110. [0051] FIG 9 is a longitudinal cross sectional view from FIG 4 along the line 9-9. FIG 9 also schematically illustrates another view of the pipe joint 110 installed within the larger pipe 310, but before the insertion of the smaller pipe 610 into the installed pipe joint 110.

10 [00521 Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiments, it is recognized that departures can be made within the scope of the invention, which is not to be limited to the details described herein but is to be accorded the full scope of the appended claims so as to embrace any and all equivalent assemblies, devices and apparatus. [0053] In this specification, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of". A corresponding meaning is to be attributed to the corresponding words "comprise, comprised and comprises" where they appear. [0054] It will further be understood that any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates.

Claims

1. A pipe joint for joining and sealing a smaller pipe to a larger pipe comprising: a flexible sleeve adapted to make a sealing engagement between a smaller pipe and a hole in a wall of a larger pipe; where the sleeve includes: one or more first formations on the sleeve adapted to engage with one or more second formations on a wall of the larger pipe; and one or more third formations to resist withdrawal of the smaller pipe from the larger pipe.

2. A pipe joint according to claim 1 wherein the first formation is one or more lugs or pins.

3. A pipe joint according to any preceding claim, wherein the second formation is one or more corrugations or ribs.

4. A pipe joint according to any preceding claim, wherein the third formation is a flange or one or more projections.

5. A pipe joint according to claim 4 where the third formation is further adapted to engage with an inner surface of the larger pipe.

6. A pipe joint according to any preceding claim, wherein the one or more first formations provide rotational location in engagement with one or more second formations.

7. A pipe joint according to any preceding claim, wherein the first formation or the third formation prevents a withdrawal of the pipe joint from the hole in the wall of the larger pipe. 12

8. A pipe joint according to any preceding claim, wherein the larger pipe has an outside diameter of up to 2500 mm.

9. A pipe joint according to claim 8, wherein the smaller pipe has an outside diameter of up to half the outside diameter of the larger pipe.

10. A pipe joint according to any one of claims I to 7 adapted to join a smaller pipe of 100 mm or 150 mm diameter to a larger pipe of diameter of 225, 300, 375, 450, 525, 600, 750, 900 mm or more

11. A pipe joint according to any preceding claim where the pipe joint in part at least comprises one or more of a synthetic rubber, a natural rubber or a EPDM rubber

12. A pipe joint according to any preceding claim further including one or more sealing ribs upon an inner wall of the flexible sleeve.

13. A pipe joint according to any preceding claim adapted to join and seal either a larger pipe or a smaller pipe of non-circular cross-section.

14. A pipe joint according to any preceding claim, wherein the adaptation for the sealing engagement between the smaller pipe and the hole in a wall of the larger pipe is a radial expansion of the flexible sleeve when the smaller pipe is inserted into the pipe joint.

15. A method for joining a larger pipe to a smaller pipe using a pipe joint comprising the steps of: providing a suitable hole in a larger pipe; deforming and inserting the pipe joint into the hole; engaging one or more first formations of the pipe joint with one or more second formations on a wall of the larger pipe; and inserting an end of the smaller pipe into the pipe joint. 13

16. A pipe joint being substantially as herein described.

17. A method for joining a larger pipe to a smaller pipe using a pipe joint substantially as herein described.