AU782876B2 - Pipe joining method and apparatus - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "PIPE JOINING METHOD AND APPARATUS" The following statement is a full description of this invention, including the best method of performing it known to us:

TITLE:

1.

PIPE JOINING METHOD AND APPARATUS BACKGROUND OF THE INVENTION Field of the Invention THIS INVENTION relates to a pipe joining method and apparatus.

The invention is particularly suitable for, but not limited to, a method of, and apparatus for, joining sections of flexible pipe after removal of damaged sections (for repair), or to connect respective lengths of such pipe).

Throughout the specification, the term "pipe" shall include pipe, conduit, line and equivalents thereof.

The term "flexible pipe" shall include pipe manufactured of plastics material PVC, polyethylene, polypropylene, ABS); elastomeric materials natural rubber, synthetic rubber); relatively soft 15 (or deformable) metals; and combinations of same, which may or may not include reinforcing fibres, cords, layers or the like; and equivalents thereof.

2. Prior Art Polythene pipe (so-called "polypipe") has found ready acceptance especially in rural areas, for water distribution systems. As the pipes can be positioned in long lengths, drawn from reels and laid in trenches which are dug and filled as the pipe is laid, they are particularly suitable for connecting water sources, junctions and equipment (eg., animal watering troughs) which are spaced apart.

There are, however, a number of problems with such pipes: a) the free ends of adjacent lengths of pipe (which tend to curl) are difficult to join, as the ends must be cut to butt together; and the conventional joiners will not feed through the guide tubes of the pipe laying implements, so that the lengths cannot be laid continuously; b) the conventional joiners can only join adjacent ends of pipe sections at fixed distances apart, eg., 100mm. For example, if a small hole occurs in a pipe wall, a 100mm section must be cut from the pipe to enable a conventional joiner to be installed to effect a repair; and c) where a hole or split, eg., over 100mm long, occurs in a pipe wall, two joiners and a joining pipe section must be used with four potential leakage locations; d) the conventional joiners are expensive., eg., typically $35.00 each for a joiner 50mm diameter pipe.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for joining two pipe lengths or sections, where the adjacent pipe ends can be spaced apart within an allowable distance range.

It is a preferred object to provide such a method employing an internal joiner which causes minimal reduction to the flow capacity of the pipe(s).

It is a further preferred object to provide such a method 15 where the respective pipe ends are lockably, sealably clamped onto the S"pipe joiner.

It is a still further preferred object to provide a method wherein the respective clamps are formed in situ, using wire and a clamping tool.

0 20 It is a still further preferred object to provide apparatus to effect the method.

Other preferred objects will become apparent from the S. following description.

In one aspect, the present invention resides in a pipe joining apparatus for joining two pipe lengths or sections spaced apart within an allowable distance range, including: a pipe joiner, to be inserted into the pipe lengths or sections, having a tubular body divided into first and second ends by a peripheral flange intermediate its length, at least one peripheral groove about the first end, and a plurality of peripheral teeth or ridges, separated by respective valleys, about the second end; a first clamp means to sealably lock one of the pipe lengths or sections to the first end; and a second clamp means to sealably lock the other of the pipe lengths or sections to the second end.

Preferably, the joiner has at least two of the peripheral grooves, with adjacent grooves being separated by a peripheral wall flange about the one end.

Preferably, the face of the peripheral flange directed towards the first end, and at least one face of each of the wall flanges, is inclined relative to a respective plane radial to the longitudinal axis of the joiner.

Preferably, on the wall flanges, the inclined face is the face directed away from the peripheral flange.

Preferably, at least one of the peripheral grooves is also provided about the second end of the tubular body, adjacent the 15 peripheral flange.

Preferably, each of the teeth or ridges has a substantially saw tooth profile, with a first face (directed towards the peripheral flange) substantially radial to the longitudinal axis, and a second face inclined to a respective plane radial to the radial axis. Preferably, the second faces are inclined at an angle greater than 450 to the radial.

While the first and second clamp means may be screwoperated clamps of the "JUBILEE" trade mark type), it is preferred that they be wire clamps which are tensioned by a tensioning tool about the respective pipe lengths or sections and first and second ends of the pipe joiner. Suitable wire clamps include the wire clamps, tensioned by the "CLAMP-IT" (trade mark) tool sold by Super Drill Sales, Oakey, Queensland, Australia.

Preferably, the first clamp means deforms or constricts an end of one of the pipe lengths or sections into one of the peripheral grooves about the first end of the pipe joiner.

Preferably, the second clamp means deforms or constricts an adjacent end of the other of the pipe lengths or sections into at least one of the valleys, or the peripheral groove, about the second end of the pipe joiner.

Preferably, the first and second wire clamps are formed from at least one length of wire of high tensile strength, preferably stainless steel.

Preferably, the tensioning tool is operable to tension the wire of the wire clamps and to deform free ends of the wire to lock the clamps against release.

In a second aspect, the present invention resides in a method for joining two pipe lengths or sections spaced apart within an allowable distance, the method employing the apparatus as hereinbefore described including the steps of: S. inserting the first or second end of the pipe joiner into one of the pipe lengths or sections so that the peripheral flange substantially abuts a free end of the one pipe length or section; S"inserting the pipe joiner into the other of the pipe lengths or sections; and applying the first and second clamp means to sealably lock the pipe lengths or sections to the pipe joiner.

20 Preferably, the pipe joiner is adjusted so that the peripheral flange is substantially equidistant from the free ends of the first and ~second pipe lengths or sections.

Preferably, the pipe joiner is adjusted relative to the one pipe length or section so that the free end of the one pipe length or section abuts, or is supported by, the inclined face of the peripheral flange or an inclined face on the, or one of the, wall flange(s).

In third and fourth aspects, the present invention resides in a joint between two pipe lengths or sections incorporating the pipe joining apparatus, and the joint effected by the pipe joining method, respectively, as hereinbefore described.

BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which: FIG. 1 is a schematic side view of the pipe joiner, of the present invention, and of the two pipe lengths prior to joining; FIG. 2 is a part-sectional side view showing the pipe lengths joined by the pipe joining apparatus in a first configuration; FIG. 3 corresponds to FIG. 1; FIG. 4 corresponds to FIG. 2 with the pipe lengths joined in a second configuration; FIG. 5 is a perspective view of one of the wire clamps as installed about a pipe length; :FIG. 6 is a side view showing one of the wire clamps about a pipe length, mounted on the tensioning tool; and FIGS. 7 to 9 show progressive stages of the application of 1° 5 the wire clamp to the pipe length.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 4, the pipe joining apparatus incorporates a pipe joiner 20 and a pair of wire clamps 40, 41, shown in more detail in FIGS. 5 to 9, to join together two lengths of flexible pipe 51, eg., 50mm diameter polyethylene pipe used for water distribution on farms. As shown in FIGS. 2 and 4, the pipe lengths 50,. 51 can be joined with their free ends 52, 53 spaced apart over an allowable range of, eg., D= 5 to 150mm by the joining apparatus 10 of the present invention.

The pipe joiner 20 has a tubular body 21 (preferably) moulded of suitable plastics material polyethylene, PVC or the like) which is stiffer than the material of the pipe lengths 50, 51. (The material of the pipe joiner body 21 may be reinforced, eg., with glass fibres.) A peripheral flange 22, substantially centrally of the tubular body 21% (but more preferably slightly offset, eg., by 5-20% from the centre) divides the tubular body into a first end 23 and a second end 24.

The first end 23 has a pair of peripheral grooves 25 and 26 defined by the peripheral flange 22 and a wall flange 23, and by wall flanges 27, 28, respectively. It will be noted that the side face 22a of the peripheral flange 22 directed to the first end 23, and the side face 27a of the wall flange 27 directed to the free end of the one end 23, are frusto-conical, ie., inclined relative to a respective plane radial to the longitudinal axis of the tubular body 21.

The second end 24 of the tubular body 21 has a peripheral groove 29 defined by the frusto-conical (or inclined) face 22b of the peripheral flange 22 and by an inner face 20a of the innermost of a plurality of saw-tooth profile peripheral teeth 30. The second end is terminated by an end flange 31.

Each tooth 30 has an inner face 30a lying on a respective plane radial to the longitudinal axis of the tubular body 21 and an outer frusto-conical face 30b inclined to such a plane, with an inclined angle of, eg., 150 to 750, more preferably 300 to 600, relative to the longitudinal S"axis.

In use, the first end 23 of the pipe joiner 20 is inserted into the free end 52 of the first pipe 50 until the peripheral flange 22 is adjacent, or abutting, the free end 52.

20 The second end 24 is then inserted into the free end 53 of the second pipe 51 and the position of the pipe joiner 22 relative to the free ends 52, 53 is adjusted so that the free end 52 of the first pipe 50 is S. supported by the frusto-conical (or inclined) face 22a of the peripheral flange 22 or by the frusto-conical (or inclined) face 27a of the wall flange 27, so that the first pipe 50 spans one, or both, of the peripheral grooves 26 on the pipe joiner 20. The saw-tooth profile of the teeth 30 about the second end 24 of the pipe joiner 20 assists in the latter being inserted into the free end 53 of the second pipe 51.

As shown in FIGS. 2 and 4, the joiner 20 can join the first and second pipe lengths 50, 51 together when their free ends 52, 53 are spaced apart, eg,. D 5 to 150mm.

The first wire clamp 40 sealably locks the first pipe 50 to the first end 23 of the pipe joiner 20, constricting the first pipe into the 8 peripheral groove 26 (see FIG. 2) or the peripheral groove 25 (see FIG.

4).

The second wire clamp 41 sealably locks the second pipe 51 to the second end 24 of the pipe joiner 20, constricting the second pipe 51 into the peripheral groove 29 of the pipe joiner 20 (see FIG. 4) or into one (or two) of the "valleys" defined by the adjacent faces 30a, 30b of adjacent peripheral teeth 30 (see FIG. 2).

It will be readily apparent to the skilled addressee that the frusto-conical (or inclined faces) 22a, 22b, 27a, 30b "deflect" the free ends 52 and 53 of the first and second pipes 50, 51 outwardly so that the free ends 52, 53 are "locked" against being pulled free of the wire clamps 40, 41.

Referring now to FIGS. 5 to 9, the wire clamps 40, 41 are formed from a length of stainless steel (or other high-tensile-strength wire) with arms 42, 42a having loops 43, 44 at the respective ends, the S"wire length being bent into substantially a U-shape about a mid-point and "wrapped" into at least one pair of coils 46, 47.

A tensioning tool 60, of the type sold under the "CLAMP-IT" trade mark by Super Drill Sales, is used to tension each wire clamp 41.

The tensioning tool 60 has a tool body 61 with a slotted nose 62 to engage the mid-point 45 of the wire clamps 40, 41; and a pair of tensioning pins 63, 64 carried on a travelling nut (not shown) within the tool body 61, the travelling nut being engaged with a screw (also not shown) in the tool body 61 rotated by a handle 65. The wire clamp "arms" 42, 42a pass under the mid-section 45 and over guide pins 66, 67 on the tool body 61.

The wire clamp 40, 41 is located on the first and second pipe 50, 51 at the desired location, adjacent a free end 52, 53, and the tensioning tool 60 is engaged as shown in FIG. 6.

The handle 65 is operated to move the tensioning pins 63, 64 away from the nose 62, ie., in the direction opposite to the arrows in FIG. 7.

When the desired tension is achieved, the tensioning tool is inverted, ie., moved in a clockwise direction, as per arrow A in FIG.

6, about the nose 62. The guide pins 66, 67 bend the arms 42, 42a about the mid-section 45 to form "hooks" 48, 49 as shown in FIG. 5. NB: As the material of the "hooks" 48, 49, at the point of bending, is stretched on the outside and compressed on the inside, the "hooks" are very stable and are not likely to release the clamps 40, 41.

As shown in FIG. 7, the handle 65 is rotated in the opposite direction to move the tensioning pins 63, 64 to release the tension on the arms 42, 42a, which are then cut free by cutters 70 see FIG. 8.

As hereinbefore described, the invention provides a simple, relatively inexpensive, yet highly efficient method and apparatus for S. joining pipe lengths or sections where the free ends are spaced a range ~of distances apart. In addition, the "low profile" of the wire clamps 40, 41, in the constricted portions of the free ends 52, 53 of the pipes 50, 51 allow the pipe joint apparatus 10 to pass through the guide tube of a pipelaying machine, enabling the pipes 50, 51 to be joined before the pipes S: are laid. This enables, eg., farm water reticulation pipes between junctions/junctions and equipment, to be laid in lengths greater than the lengths of the pile reels/coils as supplied.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.

Claims (15)

1. A pipe joining apparatus for joining two pipe lengths or sections spaced apart within an allowable distance, including: a pipe joiner, to be inserted into the pipe lengths or sections, having a tubular body divided into first and second ends by a peripheral flange intermediate its length, at least one peripheral groove about the first end, and a plurality of peripheral teeth or ridges, separated by respective valleys, about the second end; a first clamp means to sealably lock one of the pipe lengths or sections to the first end; and a second clamp means to sealably lock the other of the pipe lengths or sections to the second end.

2. Apparatus as claimed in Claim 1 wherein: the joiner has at least two of the peripheral grooves, with 15 adjacent grooves being separated by a peripheral wall flange about the one end.

3. Apparatus as claimed in Claim 2, wherein: the face of the peripheral flange directed towards the first end, and at least one face of each of the wall flanges, is frusto-conical or inclined relative to a respective plane radial to the longitudinal axis of the joiner.

4. Apparatus as claimed in Claim 3 wherein: on the wall flanges, the frusto-conical or inclined face is the face directed away from the peripheral flange.

5. Apparatus as claimed in any one of Claims 1 to 4 wherein: at least one of the peripheral grooves is also provided about the second end of the tubular body, adjacent the peripheral flange.

6. Apparatus as claimed in Claim 5 wherein: each of the teeth or ridges has a substantially saw tooth profile, with a first face (directed towards the peripheral flange) substantially radial to the longitudinal axis, and a second face frusto- conical or inclined to a respective plane radial to the radial axis. Preferably, the second faces are inclined at an angle greater than 150 to 11 the radial planes.

7. Apparatus as claimed in any one of Claims 1 to 6 wherein: the first and second clamp means are screw-operated clamps, or wire clamps which are tensioned by a tensioning tool about the respective pipe lengths or sections and first and second ends of the pipe joiner.

8. Apparatus as claimed in any one of Claims 1 to 7 wherein: the first clamp means deforms or constricts an end of one of the pipe lengths or sections into one of the peripheral grooves about the first end of the pipe joiner; and the second clamp means deforms or constricts an adjacent end of the other of the pipe lengths or sections into at least one of the valleys, or the peripheral groove, about the second end of the pipe joiner.

9. Apparatus as claimed in Claim 7, or Claim 8, when 15 dependent on Claim 7, wherein: the first and second wire clamps are formed from at least one length of wire of high tensile strength, optionally stainless steel. Apparatus as claimed in Claim 7 wherein: the tensioning tool is operable to tension the wire of the wire D 20 clamps and to deform free ends of the wire to lock the clamps against release.

11. A method for joining two pipe lengths or sections spaced apart within an allowable distance, the method employing the apparatus as claimed in any one of Claims 1 to 10, the method including the steps of: inserting the first or second end of the pipe joiner into one of the pipe lengths or sections so that the peripheral flange substantially abuts a free end of the one pipe length or section; inserting a pipe joiner into the other of the pipe lengths or sections; and applying the first and second clamp means to sealably lock the pipe lengths or sections to the pipe joiner.

12. The method of Claim 11 wherein: the pipe joiner is adjusted so that the peripheral flange is substantially equidistant from the free ends of the first and second pipe lengths or sections.

13. The method of Claim 12 wherein: the pipe joiner is adjusted relative to the one pipe length or section so that the free end of the one pipe length or section abuts, or is supported by, the inclined face of the peripheral flange or an inclined face on the, or one of the, wall flange(s).

14. A joint between two pipe lengths or sections incorporating the pipe forming apparatus of any one of Claims 1 to A joint between two pipe lengths or sections effected by the method of any one of Claims 11 to 13.

16. A pipe joining apparatus substantially as hereinbefore described with reference to the accompanying drawings. 15 17. A method for joining two pipe lengths or sections substantially as hereinbefore described with reference to the accompanying drawings.

18. A joint between two pipe lengths or sections substantially as hereinbefore described with reference to the accompanying drawings. DATED this twentieth day of March 2001. S. LLOYD LINSON-SMITH trading as PRACTOOL PRODUCTS By his Patent Attorneys FISHER ADAMS KELLY