GB1562797A

GB1562797A - Pipe couplings and joints

Info

Publication number: GB1562797A
Application number: GB5332575A
Authority: GB
Original assignee: British Steel Corp
Current assignee: British Steel Corp
Priority date: 1976-12-22
Filing date: 1976-12-22
Publication date: 1980-03-19

Description

(54) IMPROVEMENTS IN OR RELATING TO PIPE COUPLINGS AND JOINTS (71) We, BRITISH STEEL CORPORATION, a Corporation incorporated and existing under the Iron and Steel Act 1967 whose principal office is at 33 Grosvenor Place, London, S.W.1 do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to pipe couplings and joints and more particularly, although not exclusively, to couplings and joints for gas pipes.

According to the invention there is provided a pipe coupling comprising two insert members each intended for insertion into the end of one of the pipes to be coupled, at least one radially outwardly projecting member associated with each insert member for biting engagement with the internal wall of the end of its associated pipe when inserted therein, one end of each insert member being adapted for disengageable locking coupling, directly or through the intermediary of a linking member, with one end of the other insert member, and a sleeve assembly provided with annular sealing means for surrounding the pipe ends when coupled and effecting sealing thereof.

By the word "pipe" as used herein is included any pipe like member such as pipes, tubes and hoses, and hollow pipe fittings used in pipework such as elbows and 'T' junction members.

A plurality of radial projecting members may be provided in the form of outward projections of the insert members themselves.

Alternatively the radial projecting members may comprise separate elements located on the outer periphery of the insert members.

The insert members are preferably of a somewhat elongate annular form, and each may have such a configuration that the end thereof adapted for coupling is of greater external diameter than the remaining portion and is intended to protrude from the end of the associated pipe when the member is inserted therein.

The end of each insert member adapted for coupling may be provided with shoulders adapted for locking coupling with corresponding shoulders on the coupling end of the other member. Alternatively coupling of the shoulders of the two insert members may be by means of sets of co-operating shoulders on an intermediate linking member. The configuration of the shoulders may be such that coupling is achieved upon interengagement of the respective shoulders by moving the shoulders together transversely to the axes of the insert members. In this case, the positioning of the sleeve assembly about the coupled pipes, by preventing transverse movement of the insert members, retains the coupling locked.

The invention includes within its scope pipe joints incorporating a coupling as herein described.

In order that the invention may be more readily understood two embodiments thereof will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a sectional elevation of a joint incorporating the coupling according to the invention between two equal diameter polyethlene pipes; Fig. 2 is a sectional elevation of a joint incorporating a coupling according to the invention between a polyethylene and a metal pipe of different diameters; and Fig. 3 is an end elevation of part of the joint illustrated in figure 2.

Referring now to Figure 1 it will be seen that there are included two insert members 1 and 2 formed of light alloy material. The outer periphery of each insert is provided with annular projections 3 and 4 (constituting outwardly projecting members) which as can be seen have, in section, a saw tooth configuration. In the embodiment illustrated the projections 3 and 4 extend completely around the inserts. However the projections may be separated into separate bands spaced around the inserts. The insert members 1 and 2 are partially inserted into polyethylene pipes 5 and 6, the projections 3 and 4 biting into and firmly engaging the internal wall of the pipes 5 and 6. End portions of the members 1 and 2 project outside the ends of pipes 5 and 6 and have enlarged external diameters so as to conform to the diameters of the pipes. Diametrically opposed segments of the end portions of the insert members 1 and 2 are provided with inter-engaging shoulders 6 and 7 and 8 and 9 by means of which the insert members, and therefore their associated pipes, may be locked together.

Surrounding the pipe coupling is a sleeve assembly 10 which comprises a metal metal annular sleeve 11, annular resilient sealing members 12 and 13, metal pressure glands 14 and 15 and compressive nuts and bolts 16 and 17 respectively.

The joint illustrated is formed by pressing the insert members 1 and 2 into the respective pipes 5 and 6, whereupon the projections 3 and 4 bite into and lock with the internal walls of the pipes 5 and 6, interengaging the abutting shoulders 6 and 7 and 8 and 9 by a transverse movement of the insert members relative to their longitudinal axes, and then sliding the sleeve assembly (previously located about one of the pipes 5 or 6) over the coupled joint. The compressive nuts and bolts 16 and 17 are then tightened so as to press the sealing members 12 and 13 tightly upon the pipes 3 and 4 so as to provide sealing contact therewith, and at the same time by slightly compressing the pipes 5 and 6 to increase the engagement of projections 3 and 4 with the internal walls of pipes 5 and 6.

The arrangement shown in figures 2 and 3 is generally similar to that of figures 1, but is intended to enable the connection of two pipes of different diameter. The requirement for this can occur, for example, when coupling new polyethylene pipe to greater diameter iron or steel pipe already present in a gas pipeline.

In this case the polyethylene pipe 18 and its associated light alloy insert member 19 are the same as the corresponding members illustrated in figure 1.

However, a somewhat different form of light alloy insert member 20 is provided for iron or steel pipe 21. The insert member 20 is provided with a helical thread-like groove 22 around its outer periphery, the groove being of V-shaped section and increasing in depth towards the end of the member 20. A spring steel circlip 23 of diamond cross-section is engaged in the groove 22. Locking of the insert member 20 in the pipe 21 is accomplished by locating the circlip 23 in the end of the pipe 21 and then inserting the member 20 into the pipe until the circlip is engaged at the extreme end of the groove 22. The insert 20 is then rotated so as to move the helical groove 22 within the circlip 23 causing the circlip to bite into the inner wall of the pipe 21 so that locking engagement is obtained. It will be seen that insert members 19 and 20 are of different diameters, and in order to obtain engagement between these two members, an intermediate light alloy linking member 24 is provided. As with the embodiment of figure 1 insert members 19 and 20 are provided on diametrically opposed segments with abutment shoulders 25 and 26 and 27 and 28. The linking member is similarly provided with abutment shoulders 29 and 30 and 31 and 32 on diametrically opposed segments which are intended to engage respectively with shoulders 25 and 26 and 27 and 28 of insert members 19 and 20. For convenience the radial disposition of the segmental abutment shoulders on the linking member 24 are illustrated in figure 2 as being in line. In practice, as illustrated in figure 3, shoulders 29 and 30 will be 90" removed from shoulders 31 and 32 around the linking member.

The embodiment of figure 2 is provided with a sleeve assembly 33 which although operating in an analogous manner to assembly 10 of figure 1 is of necessity of a stepped construction to accommodate the different diameter pipes. Thus it will be seen that a sleeve 34 of two generally different diameters is provided, and that a sealing gasket 35 is pressed into sealing engagement with pipe 21 by means of a pressure gland 36 and locking nut and bolt 37 and 38. Similarly a sealing gasket 39 is pressed into sealing engagement with pipe 18 by means of a pressure gland 40 and a locking screw and nut 41 and 42.

The embodiments of the invention illustrated constitute easily assembled and simply locked and sealed joints which we have found to be highly suitable for use with gas line pipework.

WHAT WE CLAIM IS: 1. A pipe coupling comprising two insert members each intended for insertion into the end of one of the pipes to be coupled, at least one radially outwardly projecting member associated with each insert member for biting engagement with the internal wall of the end of its associated pipe when inserted therein, one end of each insert member being adapted for disengageable locking coupling, directly or through the intermediary of a linking member, with one end of the other insert member, and a sleeve assembly provided with annular sealing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. can be seen have, in section, a saw tooth configuration. In the embodiment illustrated the projections 3 and 4 extend completely around the inserts. However the projections may be separated into separate bands spaced around the inserts. The insert members 1 and 2 are partially inserted into polyethylene pipes 5 and 6, the projections 3 and 4 biting into and firmly engaging the internal wall of the pipes 5 and 6. End portions of the members 1 and 2 project outside the ends of pipes 5 and 6 and have enlarged external diameters so as to conform to the diameters of the pipes. Diametrically opposed segments of the end portions of the insert members 1 and 2 are provided with inter-engaging shoulders 6 and 7 and 8 and 9 by means of which the insert members, and therefore their associated pipes, may be locked together. Surrounding the pipe coupling is a sleeve assembly 10 which comprises a metal metal annular sleeve 11, annular resilient sealing members 12 and 13, metal pressure glands 14 and 15 and compressive nuts and bolts 16 and 17 respectively. The joint illustrated is formed by pressing the insert members 1 and 2 into the respective pipes 5 and 6, whereupon the projections 3 and 4 bite into and lock with the internal walls of the pipes 5 and 6, interengaging the abutting shoulders 6 and 7 and 8 and 9 by a transverse movement of the insert members relative to their longitudinal axes, and then sliding the sleeve assembly (previously located about one of the pipes 5 or 6) over the coupled joint. The compressive nuts and bolts 16 and 17 are then tightened so as to press the sealing members 12 and 13 tightly upon the pipes 3 and 4 so as to provide sealing contact therewith, and at the same time by slightly compressing the pipes 5 and 6 to increase the engagement of projections 3 and 4 with the internal walls of pipes 5 and 6. The arrangement shown in figures 2 and 3 is generally similar to that of figures 1, but is intended to enable the connection of two pipes of different diameter. The requirement for this can occur, for example, when coupling new polyethylene pipe to greater diameter iron or steel pipe already present in a gas pipeline. In this case the polyethylene pipe 18 and its associated light alloy insert member 19 are the same as the corresponding members illustrated in figure 1. However, a somewhat different form of light alloy insert member 20 is provided for iron or steel pipe 21. The insert member 20 is provided with a helical thread-like groove 22 around its outer periphery, the groove being of V-shaped section and increasing in depth towards the end of the member 20. A spring steel circlip 23 of diamond cross-section is engaged in the groove 22. Locking of the insert member 20 in the pipe 21 is accomplished by locating the circlip 23 in the end of the pipe 21 and then inserting the member 20 into the pipe until the circlip is engaged at the extreme end of the groove 22. The insert 20 is then rotated so as to move the helical groove 22 within the circlip 23 causing the circlip to bite into the inner wall of the pipe 21 so that locking engagement is obtained. It will be seen that insert members 19 and 20 are of different diameters, and in order to obtain engagement between these two members, an intermediate light alloy linking member 24 is provided. As with the embodiment of figure 1 insert members 19 and 20 are provided on diametrically opposed segments with abutment shoulders 25 and 26 and 27 and 28. The linking member is similarly provided with abutment shoulders 29 and 30 and 31 and 32 on diametrically opposed segments which are intended to engage respectively with shoulders 25 and 26 and 27 and 28 of insert members 19 and 20. For convenience the radial disposition of the segmental abutment shoulders on the linking member 24 are illustrated in figure 2 as being in line. In practice, as illustrated in figure 3, shoulders 29 and 30 will be 90" removed from shoulders 31 and 32 around the linking member. The embodiment of figure 2 is provided with a sleeve assembly 33 which although operating in an analogous manner to assembly 10 of figure 1 is of necessity of a stepped construction to accommodate the different diameter pipes. Thus it will be seen that a sleeve 34 of two generally different diameters is provided, and that a sealing gasket 35 is pressed into sealing engagement with pipe 21 by means of a pressure gland 36 and locking nut and bolt 37 and 38. Similarly a sealing gasket 39 is pressed into sealing engagement with pipe 18 by means of a pressure gland 40 and a locking screw and nut 41 and 42. The embodiments of the invention illustrated constitute easily assembled and simply locked and sealed joints which we have found to be highly suitable for use with gas line pipework. WHAT WE CLAIM IS:

1. A pipe coupling comprising two insert members each intended for insertion into the end of one of the pipes to be coupled, at least one radially outwardly projecting member associated with each insert member for biting engagement with the internal wall of the end of its associated pipe when inserted therein, one end of each insert member being adapted for disengageable locking coupling, directly or through the intermediary of a linking member, with one end of the other insert member, and a sleeve assembly provided with annular sealing

means for surrounding the pipe ends when coupled and effecting sealing thereof.

2. A pipe coupling according to Claim I wherein the insert members are of an elongate annular form.

3. A pipe coupling according to Claim 2 including a plurality of radial projecting members in the form of outward projections of the insert members.

4. A pipe coupling acording to Claim 3 wherein the projections have a saw-tooth form and extend at least partially around each insert member.

5. A pipe coupling according to any one of Claims 2 to 4 wherein the end of each insert member adapted for disengageable locking coupling is of greater external diameter than the remaining portion of the insert member and is intended to protrude from the end of the associated pipe when the member is inserted therein.

6. A pipe coupling according to any one of Claims 1 to 5 wherein the insert members are adapted for disengageable locking coupling together through the intermediary of an annular linking member.

7. A pipe coupling according to Claim 5 or 6 wherein the end of each insert member adapted for coupling is provided with shoulders adapted for locking coupling with corresponding shoulders on the coupling end of the other insert member or the linking member as the case may be.

8. A pipe coupling according to Claim 7 wherein the configuration of the shoulders is such that coupling is achieved upon interengagement of the respective shoulders by moving the shoulders together transversely to the axes of the insert members.

9. A pipe joint including a pipe coupling according to any one of the preceding claims.

10. A pipe joint substantially as shown in and as hereinbefore described with reference to Figure 1 or Figures 2 and 3 of the accompanying drawings.