NZ235487A - Extendible and retractable sleeve type pipe joint with integral seal and stops - Google Patents

Description

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,C' V- klr: i ZZ^Z'T*". .. *5.SfP.!S92— j P.O. Joure". >.%9. r 2 3 5 4 8 NEW ZEALAND PATENTS ACT. 1953 No.: Date: COMPLETE SPECIFICATJON PIPE JOINT s*T'v,e- STORK PLASTICS (SA) PTY LTD, a company incorporated under the laws of the State of South Australia; 99 Somerset Avenue,.Cumberland Park, South Australia, Australia hereby declare the invention for which we pray that a patent maybe granted to rpcjus, and the method by which it is to be performed, to be particularly described in and by the following statement: - (followed by page la) 2 3 5 4 8 7 This invention relates to a pipe joint, which can be used (a) to repair a break or other damage to a pipe (e.g. a storawater or sewer pipe) or SWV (soil, waste and vent) fitting or (b) to provide for expansion and contraction of 5 the pipe or SWV fitting, thereby compensating for earth movements and temperature changes.

Pipe joints incorporating "0"-ring seals are known. These have been suitable for use as expansion joints only, 10 and. have not been usable to repair damage to pipes.

Similarly, repair joints, wherein a bridging length of pipe is fixed between two sections of a broken pipe, are known. Such repair joints are not slidablv adjustable.

In areas such as South Australia, which are subject to significant earth movements caused by changes in temperature, drying out of the earth etc., there is a need for an expansion joint which can be used on drainage ana sewer pipes and SWV fittings. There is also a need for an expandable pipe 20 joint which can he used to repair breaks or other damage to drainage or sewer pipes or SWV fittings. The pipe joint of the present invention successfully addresses both these needs.

According to the invention, a pipe joint is provided which comprises: (a) an outer sleeve which is a first length of pipe of greater diameter than either of two pipes to be joined, 30 said outer sleeve having a pre-moulded or "0"-ring seal on its inner surface adjacent one end thereof and an annular stop on its inner surface adjacent the other end thereof; and (b) an inner sleeve which is a second length of pi-pe having an annular stop on its outer surface adjacent one^end - XX- # 2 3 5 4 8 7 thereof, the outer diameter of said second length of pipe being substantially identical to the inner diameter of said pre-moulded or uO"-ring seal; said inner and outer sleeves being slidably engageable, the limits of their relative movement being determined by the positioning of the stopped end of said inner sleeve within said outer sleeve.

The pipe joint of the invention is illustrated in the accompanying drawings: Fig. 1 is a cross-sectional view of the pipe joint., Fig. 2 is an end view of the pipe joint, Figs. 3 and 4 are perspective views of the pipe joint, Fig. 5 is a perspective view of the inner sleeve, Fig. 6 is a cut-away perspective view of the outer sleeve.

Figs. 7 and 8 are cross-sectional and cut-away views, 25 respectively, of another embodiment of the pipe joint.

Fig. 9 is a cross-sectional view of a further embodiment of the pipe joint, and Figs. 10 and 11 are cross-sectional views of the inner and outer sleeves, respectively, of the pipe joint of Fig. 9.

The pipe joint of Figs. 1-6 is suitable for use in relation to stormwater pipes. Pipe joint 10 comprises a 35 female member (outer sleeve) 11 and a male member (inner \ sleeve) 12. Suitably, female and male member 12 are each^ lengths of PVC pipe. /< c 3 5 4 87 Other suitable materials will be obvious to those skilled in the art. For example, other plastics and non-corroding metals may be used. Length "A", as marked on Fig. 1, may be varied to suit various applications. In Figs. 1-6, the seal 13 consists ox a pre-moulded or "0"-ring rubber seal 14 in a retainer 15, and is attached at one end of female member 11. Retainer 15 is preferably constructed as a two-piece plastic moulding. Stop 16, at the other end of female member 11, is preferably made of plastics or rubber. A similar stop 17 encircles one end of male member 12.

Stop 16 has -hree functions:- (a) It is a reducing bush (adaptor) to the diameter of the male member 12 (90 mm, in one embodiment; 110 mm in another embodiment). (b) It forms a positive stop for male member 12, due to interaction with the other stop 17, thereby limiting relative movement of the male and female members (12 and 11, respectively). (c) It can be used to directly mate with the end of a suitable sired (90 mm diameter or 110 mm diameter, respectively, in these embodiments) pipe.

The pre-moulded or "0"-ring seal 14 allows the male and female members to move relative to each other, whilst still ensuring a fluid-tight seal. Operation of the pipe joint is improved by the use of a suitable lubricant, which does not rot rubber, in conjunction with pre-moulded or "0"-ring seal 14 .

Unlike previously known expansion joints, the present pipe joint cannot come apart in use. Stop 17 on male member 12 cannot be moved past the pre-moulded or "0"-ring seal 3 <■ m ■•—a*' 2 3 5 4 8 7 retainer 15, and therefore inhibits over-extension.

For use as a repair joint, pipe joint 10 is contracted; i.e. the end of male member 12 which is encircled by stop 17 is moved towards stop 16 of the female member 11. Pipe joint 10 is then positioned between the ends of two sections of pipe to be joined. Next, pipe joint 10 is expanded to fit the gap between the two sections of pipe. Stop 16 is firmly attached, e.g. by gluing, to one section of pipe. If that pipe section is of smaller diameter than the inner diameter of stop 16, an appropriately sized reducing bush is used.

Male member 12 is attached to the other section of pipe by conventional means (e.g. T-piece junction or socket).

For use as an expansion joint, pipe joint 10 is similarly inserted into a pipe line. The relative positions of the male and female members, at the time of inserting the joint, will be dependent on prevailing environmental conditions, e.g. reactivity of the soil and/or temperature. At moderate reactivity and/or temperature, the pipe joint should be inserted in a median condition, with stop 17 approximately midway between pre-moulded or "0"-ring seal retainer 15 and stop 16. This will allow for either expansion or contraction of the joint.

At high reactivity and/or temperature, the pipe line will be approaching maximum expansion. The pipe joint should be inserted in a contracted condition, with stop 17 located in the vicinity of stop 16. The pipe joint is then able to expand, to compensate for the contraction of pipes as reactivity and/or temperature falls. Conversely, at low reactivity and/or temperature, the pipe joint should be inserted in an expanded condition, with stop 17 located in the vicinity of pre-moulded or "0"-ring seal retainer 15. The pipe joint is joined into the pipe line as described abov^v^ with respect to repair joints. \ 235 4 87 The male and female members of the pipe joint together form a sealed unit which, as stated above, cannot be physically pulled apart. According to one embodiment of the invention, the pipe joint in fully contracted condition has a length of about 60 cm expandable to a length of about 90 cm.

An alternative embodiment, which may be used in relation to either stormwater or sewer pipes, or SWV fittings, is depicted in Figs. 7 and 8. The facing edges 18 and 19 of annular stops 16' and 17', respectively, are tapered. Therefore, solids suspended in liquid flowing through the pipe joint are unlikely to be trapped between the stops.

The inner sleeve 12' is otherwise substantially the same as that depicted in Fig. 5, whereas stepped outer sleeve 11' also differs from that shown in Fig. 6 in having a different configuration for the seal retainer 15'. Seal 14' is pre-moulded and, in order to comply with Australian standards, has an approximately 8 mm face. This seal has been found to be more effective than an "0"-ring seal.

A further embodiment, also suitable for use in relation to either stormwater or sewer pipes, or SWV fittings, is depicted in Figs. 9, 10 and 11. This embodiment differs from the pipe joint illustrated in Figs. 7 and 8 in the following respects: (a) annular stop 17", at the end of inner sleeve 12", has a ribbed configuration, for extra strength; (b) on the outer sleeve 11", the retainer 15" for pre-moulded seal 14' has a different configuration which provides greater strength; and (c) annular ridges 20 encircling outer sleeve 11" add to the strength of the pipe joint, and also provide added grip for the plumber etc. handling the pipe joint. 235 4 87 In an alternative embodiment, the pre-moulded or "0"-ring seal retainer 15, 15' or 15" is attached to the outer surface of male member 12, 12' or 12" (in place of stop 17, 17' or 17") instead of to the inner surface of female member Dimensions of the pipe joint can be varied, depending on the application, and the requirements and standards of the country in which it is being used.

For use in relation to stormwater pipes, the outer diameter of the outer sleeve is preferably 100-190 mm. The inner sleeve will then have an internal diameter of 70-155 mm and an outer diameter of 75-160 mm.

For use in relation to sewer pipes, the outer diameter of the outer sleeve is preferably 130-190 mm. The inner sleeve will then have an internal diameter of 100-150 mm and an outer diameter of 110-160 mm.

Pipe joints of widely varying thicknesses may be used in relation to SWV fittings. For example, the outer diameter of the outer sleeve may be 40-190 mm. The inner sleeve will then have an internal diameter of 30-150 mm and an outer diameter 25 of 35-160 mm. ^ 5 11, 11' or 11".

X \ 6 £35 4 87 Preferred, figures within these ranges are: Nominal diameter Outer diameter Outer diameter of inner sleeve of inner sleeve of outer sleeve (in mm) (in mm) (in mm) SWV FITTINGS Example A 32 36.2 Example B 40 42 . 8 Example C 50 55.7 Example 0 65 68.7 Example E 80 82. 3 Example F 100 110 Example G 150 160 STORMWATER PIPES Example H 75 75 Example I 90 90 110 Example J 100 110 128 Example K. 150 160 $SWEK PIPES Example L 100 110 130 Example M 150 160 190 Those skilled in the art will appreciate that the invention described herein is susceptible to variations modifications other than those specifically described. It is 30 to be understood that the invention includes all such variations and modifications which fall within its spirit and scope. \ /'

Claims (5)

235 4 87 WHATJfWE CLAIM IS:

1. A pipe joint comprising: 10 15 20 25 (a) an outer sleeve which is a first length of pipe of greater diameter than either of two pipes to be joined, said outer sleeve having an B0"-ring seal on its inner surface adjacent one end thereof and an annular stop on its inner surface adjacent the other end thereof; and (b) an inner sleeve which is a second length of pipe having an annular stop on its outer surface adjacent one end thereof, the outer diameter of said second length of pipe being substantially identical to the inner diameter of said MOu-ring seal; said inner and outer sleeves being slidable engageable, the limits of their relative movement being determined by the positioning of the stopped end of said inner sleeve within said outer sleeve.

2. A pipe joint comprising: (a) an outer sleeve which is a first length of pipe of greater diameter than either of two pipes to be joined, said outer sleeve having an annular stop on its inner surface adjacent each end thereof; and (b) an inner sleeve which is a second length of pipe having an "0"-ring seal on its outer surface adjacent one end thereof, the outer diameter of said second length of pipe being substantially identical to the inner diameter of said annular stops; said inner and outer sleeves being slidably engageable, the \ \ 8 25 30 23548 limits of their relative movement being determined by the positioning of the "0"-ring seal of said inner sleeve within said outer sleeve. 5

3. A pipe joint comprising: (a) an outer sleeve which is a first length of pipe of greater diameter than either of two pipes to be joined, said outer sleeve having a pre-moulded seal on its inner 10 surface adjacent one end thereof and an annular stop on its inner surface adjacent the other end thereof; and (b) an inner sleeve which is a second length of pipe having an annular stop on its outer surface adjacent one end 15 thereof, the outer diameter of said second length of pipe being substantially identical to the inner diameter of said pre-moulded seal; said inner and outer sleeves being slidably engageable, the 20 limits of their relative movement being determined by the positioning of the stopped end of said inner sleeve within said outer sleeve.

4. A pipe joint comprising: (a) an outer sleeve which is a first length of pipe of greater diameter than either of two pipes to be joined, said outer sleeve having an annular stop on its inner surface adjacent each end thereof; and (b) an inner sleeve which is a second length of pipe having a pre-moulded seal on its outer surface adjacent one end thereof, the outer diameter of said second length of pipe being substantially identical to the inneifMiameter *^t;35 of said annular stops;;- 9 -;said inner and outer sleeves being slidably engageable, the limits of their relative movement being determined by the positioning of the pre-moulded seal of said inner sleeve within said outer sleeve.;

5. A pipe joint according to claim 1 or claim 3, wherein the annular stop on the inner sleeve has a ribbed configuration.;o. A pipe joint according to any one of the preceding claims, wherein each of said annular stops is made of plastics or rubber.;7. A pipe joint according to any one of the preceding claims, wherein said "0"-ring or pre-moulded seal is made of rubber.;8. A pipe joint according to claim 1 or claim 3, wherein the facing edges of the annular stops on said inner and outer sleeves are tapered.;9. A pipe joint according to any one of the preceding claims, wherein annular ridges encircle the outer sleeve.;10. A pipe joint according to any one of claims 1 to 9, wherein the outer sleeve has an outer diameter of 40-190 mm and the dimensions of the inner sleeve are 30-150 mm (internal diameter) and 35-160 mm (outer diameter).;11. A pipe joint according to any one of claims I to 9, wherein the outer sleeve has an outer diameter of 100-190 mm and the dimensions of the inner sleeve are 70-155 mm (internal diameter), 75-160 mm (outer diameter).;12. A pipe joint according to any one of claims 1 to 9, wherein the outer sleeve has an outer diameter of 130-190 mm;235 4 87;and the dimensions of the inner sleeve are 100-150 mm (internal diameter), 110-160 mm (outer diameter).;13. A pipe joint according to any one of the preceding claims, substantially as described herein with reference to the accompanying drawings.;. P-lbdiCii j)l) P-k^;*cr