GB2361272A

GB2361272A - Set of parts for a coupling

Info

Publication number: GB2361272A
Application number: GB0007759A
Authority: GB
Inventors: Malcolm Raymond Barfield
Original assignee: Polypipe PLC
Current assignee: Polypipe PLC
Priority date: 2000-03-30
Filing date: 2000-03-30
Publication date: 2001-10-17
Anticipated expiration: 2020-03-30
Also published as: GB2361272B; GB0007759D0

Abstract

A set of parts for assembly to provide a coupling for two elongate members, eg pipes, including first and second housings 1, 2 adapted for engagement, a split member 3 and a thrust member 5, 6. Preferably the spilt member comprises a substantially L-shaped body having a tapered external surface defined by a series of externally circumferentially alternating ribs and involutes (20, 21, fig 3). The thrust member may comprise a first body part and a separate end closer part. A sealing ring 7 may be provided which may be sealingly engaged with an inserted pipe when the split member is urged towards the thrust member by the threaded rotation of the second housing member. The coupling may be used to connect pipes having a varying range of diameters.

Description

1 2361272 1 A SET OF PARTS AND A COUPLER ASSEMBLED THEREFROM The invention

relates to a set of parts for assembly to provide a coupler for coupling of two elongate members such as pipes, and a coupler assembled therefrom.

The invention thus relates particularly to improvements in pipe fittings and to a combination of pipe fitting and transition means for a polymeric pipe to be joined with a wide range of pipe sizes and materials.

Pipe fittings or couplers in general, which are designed for use in conveying liquids or gases, must normally be capable of receiving a predetermined length of pipe, of sealing on said pipe surface and of securing said pipe against large pull-out forces. Pipe fittings are normally constructed in a wide range of sizes and designs to accommodate pipes of different diameters and materials or are designed in such a way as to incorporate additional components to facilitate the adaption of the pipe fitting to accommodate said different pipe diameters and materials.

It is an object of the invention to seek to provide a set of parts which on assembly provide an effective coupler for pipes in particular.

According to a first aspect of the invention there is provided a set of parts for assembly to provide a coupler for coupling of two elongate members, comprising first and second housings adapted for engagement, a split member and a thrust member, the last two members being adapted to be received in the first two members on assembly of the set and to be urged 2 together to provide a substantially fluid-tight couplet round two elongate members to be joined together.

There is preferably a seal ring associated in the assembled set with the thrust member and the first housing. Thus the seal ring is preferably a separate item, though it would be integral with a housing or the thrust member. The split member may comprise a substantially L-shaped body which may have a tapered external surface defined by a series of externally circumferentially alternating axially extending ribs and involutes. This provides a relatively simple construction that assists in radial compression.

An inner circumference of the body may have a radially inwardly projecting insert adapted on assembly of the set and in use to engage an external surface of an elongate member. This provides for additional gripping, particularly where there may be a plurality of said inserts which are radially inwardly projecting and circumferentially spaced one from another. The or each insert may be received in a seating in the body of the split member. This provides for a positive mounting, particularly when the or each seating and the or each insert may have a complementary configuration, which may advantageously be substantially of L-shape.

The or each insert may have a through bore whereby anchorage in its seating is enhanced. Anchorage of the or each insert in its respective seating may be by way of a welding, adhesive or snap-fit means or by a combination thereof. All these techniques are relatively effective.

The or each insert may comprise a relatively hard material as compared to 3 the material of the body of the split member.

The or each insert may comprise a series of barbs.

The split member may comprise a further plurality of barbs extending radially inwardly of the inner circumference.

The free ends of the body of the split member may be spaced apart sufficiently whereby to enable a wide range of diameter of elongate member to be received in, and gripped by, the split member.

The thrust member may comprise a first body part and a separate end closer body part.

The first body part may be substantially cylindrical.

The first body part may comprise a relatively large diameter bore for receiving an elongate member and a reduced thickness wall part including stiffener means.

The stiffener means may comprise longitudinally extending circumferentially arranged ribs.

The first body part and end closer body part may be secured together by securing means, suitably welding such as ultrasonic welding.

Alternatively the means may comprise mechanical grip means, or 4 complementary interengageable means such as spigot and socket means, which themselves may be securable as by being heat weldable.

The seal ring may comprise an 0-ring.

The first housing may comprise a plurality of internal ribs for gripping an elongate member.

Suitably, the ribs may be integral with the first housing or, alternatively, the ribs may be part of a separate cage device insertable in the first housing. This is suitable for bends and the like.

The first and second housing may be assembled together by screwengagement.

The split member and thrust member may be adapted to be urged together by complementary tapering surfaces of the split member and second housing.

According to a second aspect of the invention there is provided a coupler, whenever assembled from a set as hereinbefore defined.

According to a third aspect of the invention there is provided a coupler, as hereinbefore defined, in combination with two elongate members, suitably pipes or tubes.

According to a fourth aspect of the invention there is provided a split member comprising a substantially L-shaped body which has a tapered external surface defined by a series of externally circumferentially alternating axially extending ribs and involutes.

According to a fifth aspect of the invention there is provided a thrust member comprising a first body part and a separate end closer body part.

A set of parts and a coupler embodying the invention are hereinafter described, by way of example only, with reference to the accompanying drawings.

Figure 1 is an exploded two-dimensional view illustrating the main components of the set of parts for assembly to provide a coupler, or pipe fitting, in accordance with the present invention; Figure 2 is a sectional view of the pipe fitting of Figure 1 in the assembled condition; Figure 3 is a view of a split member of ring prior to an insert being located into position; Figure 4 is a transverse sectional view of the split ring; Figure 5 is an enlarged view of one of hard teeth inserts in the split ring; Figure 6 is a sectional view of the main body of a thrust member or carrier; 6 Figure 7 is a sectional view of the thrust carrier end-closure prior to being joined with the main body shown in Figure 6; Figure 8 is a cross sectional view of the main body of the thrust carrier taken on the line A-A in Figure 6; Figures 9 and 10 are respectively a sectional and elevational view of the sealing ring of the pipe fitting of Figures 1 and 2; Figure 11 is a cross sectional view of a separate rib-cage; and Figure 12 is an end view of the separate rib-cage.

The drawings illustrate a coupler or pipe fitting in accordance with the present invention that is shown in the form of an end-to-end connector for joining the end of a pipe to be joined to polymeric pipe (details not shown). The pipe fitting illustrated in the drawings is an example only as the invention is applicable to pipe fittings other than end-to-end connectors.

The pipe fitting comprises five components:

A first housing member 1 in the form of a body member, which is formed with a large diameter outer bore 8 for receiving the pipe to be joined which is connected to a smaller diameter bore 9 via an angled surface 10 which engages with the sealing ring 7. The surface of the smaller diameter bore is typically formed with a plurality of deformable ribs 11, 7 leading edge 12 to guide the inward movement of the pipe to be joined when inserted into the body, said ribs may also be formed as an additional rib-cage component for use on a housing section on fittings other than end to end connectors, typically bends and the like, see Figures 11 and 12. External threads 13 are formed at one end of the body member to receive a nut 2 threadedly.

B. A second housing or member in the form of the nut 2, formed with a large diameter bore, having internal threads 14 at one end to receive threadedly the body member 1. The opposite end of the nut 2 is reduced in diameter via an inner conical surface 15 which cooperates with the split ring 3 for clamping the split ring onto the pipe to be joined, and terminating in a bore 16 for receiving said pipe. The outer surface of the but 2 is formed with a plurality of longitudinal ribs 17 to facilitate assembly of the pipe fitting.

A split member or ring 3 for clamping the pipe to be joined, illustrated in Figures 3 and 4, wherein the split ring is constructed in a conventional form having the opposite ends 18 of the split ring 3, defining the split in the ring, being of sufficient dimensional gap as to accommodate compression of the ring such that the internal diameter 19 of the split ring can be varied between predetermined limits to accept the varying extremes of the outer diameter of the pipe to be joined.

8 The split ring 3 is formed on its outer surface with a plurality of axially extending circumferentially spaced involutes 20 and ribs 28 having an outer tapered surface 22 that defines the outer conical face of the split ring engageable with the conical surface 15 of the but 2.

The inner surface of the split ring 19 is formed with a plurality of circumferentially spaced recesses 23 centrally located in the thick section of the ribs 21. The recesses 23 are designed to receive inserts Figure 5, manufactured of a hard material, such as metal, which serve as hard teeth projecting radially inwardly, flush with or projecting above the inner surface of the split ring 3 to become embedded in the outer face of the pipe to be joined when enclosed and clamped by the split ring and are intended firmly to grip pipes of hard material.

As shown in Figure 4, each recess 23 is generally of an Lshaped rectangular configuration having flat sides and formed with internal abutments 24 which are of a narrower slotted cross section than the insert Figure 5 and being typically deformable by the insert during the action of the entry of the insert into the recess and more particularly by the action of the assembly process e.g. ultrasonic, heat weld or mechanical. The insert is formed typically with holes 26 or slots which receive material released from the abutments 24 during the assembly process thereby locking the inserts into the body of 9 the split ring which is particularly useful in preventing dislodgement of the inserts during handling and entry of the pipe to be joined into the body of the fitting. Alternatively the insert could be bonded into position using a propriety adhesive.

The split ring is additionally formed on its inner surface 19 with a plurality of annular locking barbs 25 which become embedded in the outer surface of the pipe to be joined when said pipe is manufactured from a softer material.

D. A thrust member or carrier that is comprises of an assembly of two individual components, a thrust carrier main body 5 and a thrust carrier end-closure 6. The main body of the thrust carrier (Figure 6) is in the form of a cylinder and is formed with a large diameter bore 27 for receiving the pipe to be joined and a plurality of internal ribs 28 for the purpose of reducing the wall section and material weight of the thrust carrier body whilst maintaining mechanical body stiffness.

The thrust carrier assembly is completed by the end closure 6 (Figure 7) which is also formed with a large diameter bore 29 for receiving the pipe to be joined and is secured to the thrust carrier main body utilising either ultrasonic mechanical grip or alternative heat weldable techniques illustrated by the socket 30 and spigot 31 arrangement in Figures 6 and 7.

The completed assembly thus has two outer facing surfaces 32 and 33 and is interposed between the split ring 3 and the scaling ring 7 and transfers the axial force produced by tightening the nut 3, from the split ring to the sealing ring to press the sealing ring into firm sealing engagement with the angled surface 10 of the body member 1.

E. A seal member or sealing ring 7 for sealing the pipe within the pipe fitting, which is of a toroidal configuration formed with a central opening for receiving the pipe insert.

The illustrated pipe fitting is utilised in the following manner:

The split ring 3, thrust carrier 5 and 6 and sealing ring 7 are assembled in the order illustrated in Figures 1 and 2 and contained within the complete housing of the pipe fitting as defmed by the first housing body 1 and the nut 2, with the threads of the body housing 13 being loosely engaged with the threads of the nut 14. The pipe to be joined is then inserted through the opening 16 of the nut 2 until the end of the pipe engages the internal ribs 11 of the body housing 1. The nut is then rotated which in turn causes the split ring 3 to be compressed thus reducing its internal diameter until it firmly grips the surface of the pipe to be joined. Further tightening of the nut creates an axial movement of the split ring 3 thrust carrier 5 and 6 into the body housing 1, thus creating a compressive force onto the sealing ring, which by virtue of the angled surface 10, is formed into intimate contact with the end face of the thrust carrier 33, the angled surface 10 and the outer surface of the pipe to be joined, thereby producing a pressure tight 11 seal with respect to the pipe to be joined.

Thus there is provided: a pipe fitting comprising a threaded housing formed with a bore for receiving the pipe to be joined and a threaded nut, attachable to the threaded housing and moveable axially to effect compression of the split ring contained within the nut, having an outer conical face engageable with an inner conical face, such as to decrease its internal diameter thereby causing the split ring to effect a firm grip onto the pipe to be joined, and to effect an inward axial movement of the thrust carrier into the bore of the housing which in turn effects an inward axial movement of the sealing ring which is compressed against the angled, in one sense or another, sealing face of the housing and against the outer surface of the pipe to be joined; a pipe fitting as described above, characterised in that the split ring is dimensioned such as to permit the split ring to be compressed substantially thereby decreasing its internal diameter aided by the flexural action of the outer involuted surface of the split ring thereby enabling the split ring onto pipes having a wide range of outer diameters; a pipe fitting as described above characterised in that the split ring includes a plurality of hard inserts circumferentially spaced around the inner surface of the split ring with said inserts having a plurality of inwardly projecting teeth, said teeth lying flush with or projecting above the inner surface of the split ring and which become imbedded in the outer surface of the pipe to be joined when compressed and clamped by the split ring, said inserts being locked into position using ultrasonic, snap-fit, adhesive or weldable techniques, thus preventing the inserts from being dislodged during storage, handling and assembly with the pipe to be joined, said split ring also 12 includes a plurality of annular barbs which extend radially inwardly to additionally engage the outer surface of the pipe to be joined when said pipe is of a material having a surface hardness equal to or less than that of the split ring; a pipe fitting as described above characterised in that the thrust carrier is comprised of a double-ended hollow body comprised of two individual components with the longer component of the two being internally relieved in section with a plurality of internal spines such that the component material requirement is reduced whilst body stiffness is maintained, said components being locked together using ultrasonic, weldable or mechanical techniques to minimise the component inventory requirements and material costs, said double-ended hollow body having one end dimensioned such that the end load exerted by the split ring over its entire compressible diameter is transferred directly into the hollow body, and with the opposite end of the hollow body being angled in one sense or the other to the axis of the hollow body, dimensioned such that the said load is transferred onto the sealing ring over the range of pipe diameters for which the pipe fitting is designed; a pipe fitting as described above characterised in that the threaded housing typically contains an internal sealing face being angled in one sense or another to provide both a sealing surface for the sealing ring over the range of pipe diameters for which the pipe fitting is designed, and at the same time a means by which the load required to effect the seal is reduced by the redirection of the resultant forces acting on the scaling ring.

A coupler as hereinbefore described with reference to the drawings has the following advantages- 13 A pipe fitting which is universal in the range of diameters of member which can be coupled, comprising a first housing section with a bore for receiving the pipe to be joined and a second housing section threadedly attachable to the first housing section and moveable axially to effect compression of a split ring contained within the second housing causing the split ring to effect a firm grip onto the pipe to be joined, and to effect an inward axial movement of a thrust carrier into the bore of the first housing effecting an inward axial movement of a sealing ring which is compressed against an angled, in one sense or the other, sealing face of the first housing and against the outer surface of the pipe to be joined.

2.

A split ring wherein the split ring contains a plurality of hard inserts circumferentially spaced around the inner surface of the split and being locked into position using ultrasonic snap-fit, adhesive or weldable techniques, extending radially inwardly to engage the outer surface of the pipe to be joined when said pipe is of a material having a surface hardness equal to or greater than that of the split ring.

3. A split ring wherein the split ring includes a plurality of annular barbs extending radially inwardly to additionally engage the outer surface of the pipe to be joined when said pipe is of a material having a surface hardness equal to or less than that of the split ring.

14 4. A split ring wherein the opposite end portions of said split ring are separated sufficiently such as to permit the split ring to be compressed substantially enabling the split ring to grip onto pipes over a wide range of diameters.

5.

A thrust carrier wherein the body section of said thrust carrier is internally relieved such that the body stiffness is maintained and the body material requirement is reduced.

6. A thrust carrier wherein the end faces of said thrust carrier are angular, in one sense or another, in nature thereby maximising the efficient transfer of end load from the split ring to the sealing ring.

A combination of sealing ring and angular, in one sense or another, sealing face in the first housing section wherein the end load transferred from the thrust carrier required to compress the scaling ring against the angled sealing face and against the outer surface of the pipe to be joined is reduced as a consequence of resultant forces.

Claims

CLAIMS:

1. A set of parts for assembly to provide a coupler for coupling of two elongate members, comprising first and second housings adapted for engagement, a split member and a thrust member, the last two members being adapted to be received in the first two members on assembly of the set and to be urged together to provide a substantially fluid-tight coupler round two elongate members to be joined together.

2. A set according to claim 1, including a seal ring associated in the assembled set with the thrust member and the first housing.

A set according to claim 2, the split member comprising a substantially Lshaped body which has a tapered external surface defined by a series of externally circumferentially alternating axially extending ribs and involutes.

4. A set according to claim 3, an inner circumference of the body having a radially inwardly projecting insert adapted on assembly of the set and in use to engage an external surface of an elongate member.

5. A set according to claim 4, there being a plurality of said inserts which are radially inwardly projecting and circumferentially spaced one from another.

6. A set according to claim 5, the or each insert being received in a seating in the body of the split member.

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7. A set according to claim 6, the or each seating and the or each insert having a complementary configuration.

8. A set according to claim 7, the configuration being substantially of Lshape.

9. A set according to claim 8, the or each insert having a through bore whereby anchorage in its seating is enhanced.

10. A set according to claim 9, anchorage of the or each user in its respective sealing being by any of a welding, adhesive or snap-fit means, or any combination thereof.

11. A set according to any of claims 4 to 10, the or each insert comprising a relatively hard material as compared to the material of the body of the split member.

12. A split member according to claim 11, the or each insert comprising a series of barbs.

13. A set according to any of claims 4 to 12, the split member comprising a further plurality of barbs extending radially inwardly of the inner circumference.

14. A set according to any of claims 3 to 13, the free ends of the body of the split member being spaced apart sufficiently whereby to enable a wide range of diameter of elongate member to be received in, and gripped 17 by, the split member.

15. A set according to any of claims 3 to 14, the thrust member comprising a first body part and a separate end closer body part.

16. A set according to claim 15, the first body part being substantially cylindrical.

17. A set according to claim 16, the first body part comprising a relatively large diameter bore for receiving an elongate member and a reduced thickness wall part including stiffener means.

18. A set according to claim 17, the stiffener means comprising longitudinally extending circumferentially arranged ribs.

19. A set according to claim 18, the first body part and end closer body part being secured together by securing means.

20. A set according to claim 19, the securing means comprising welding.

21. A set according to claim 20, the securing means comprising ultrasonic welding.

22. A set according to claim 20, the means comprising mechanical grip means.

23. A set according to claim 20, the means comprising complementary 18 interengageable means.

24. A set according to claim 17, the said means comprising spigot and socket means.

25. A set according to claim 24 weldable.

spigot and socket means being heat

26. A set according to any of claims 3 to 25, the seal ring comprising an 0-ring.

27. A set according to any preceding claims, the first housing comprising a plurality of internal ribs for gripping an elongate member.

28. A set according to claim 27, the ribs being integral with housing.

first

29. A set according to claim 28, the ribs being part of a separate cage device insertable in the first housing.

30. A set according to any preceding claim, the first and second housings being assembled together by screw-engagement.

31. A set according to any preceding claim, the split member and thrust member being adapted to be urged together by complementary tapering surfaces of the split member and second housing.

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32. A set of parts for assembly to provide a coupler for coupling of two elongate members, substantially as hereinbefore described with reference to the accompanying drawings.

33. A coupler, whenever assembled from a set according to any preceding claim.

34. A coupler according to claim 33, in combination with two elongate members.

35. A coupler according to claim 34, the two elongate members comprising pipes or tubes.

36. A coupler, according to claim 33, substantially as hereinbefore described with reference to Figure 2.

37. A split member, comprising a substantially L-shaped body which has a tapered external surface defined by a series of externally circumferentially alternating axially extending ribs and involutes.

38. A split member according to claim 37, an inner circumferential of the body having a radially inwardly projecting insert adapted on assembly of the set and in use to engage an external surface of an elongate member.

39. A split member according to claim 38, there being a plurality of said inserts which are radially inwardly projecting and circumferentially spaced one from another.

40. A split member according to claim 39, the or each insert being received in a seating in the body of the split member.

41. A split member according to claim 40, the or each sealing and the or each insert having a complementary configuration.

42. A split member according to claim 41, the configuration being substantially of L-shape.

43. A split member according to claim 42, the or each insert having a through bore whereby anchorage in its seating is enhanced.

44. A split member according to claim 43, the or each anchorage in its respective seating being by any of a welding, adhesive or snap-fit means, or any combination thereof.

45. A split member according to any of claims 38 to 44, the or each insert comprising a relatively hard material as compared to the material of the body of the split member.

46. A split member according to claim 45, the or each insert comprising a series of barbs.

47. A split member according to any of claims 38 to 46, comprising a further plurality of barbs extending radially inwardly of the inner circumference.

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48. A split member according to any of claims 37 to 47, the free ends of the body of the split member being spaced apart sufficiently whereby to enable a wide range of diameter of elongate member to be received in, and gripped by, the split member.

49. A split member, substantially as hereinbefore described with reference to the accompanying drawings.

50. A thrust member, comprising a first body part and a separate end closer body part.

51. A thrust member according to claim 50, the first body part being substantially cylindrical.

52. A thrust member according to claim 51, the first body part comprising a relatively large diameter bore for receiving an elongate member and a reduced thickness wall part including stiffener means.

53. A thrust member according to claim 52, the stiffener means comprising longitudinally extending circumferentially arranged ribs.

54. A thrust member according to claim 53, the first body part and end closer body part being secured together by securing means.

55. A thrust member according to claim 54, the securing means comprising welding.

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56. A thrust member according to claim 55, the securing means comprising ultrasonic welding.

57. A thrust member according to claim 55, the means comprising mechanical grip means.

58. A thrust member according to claim 55, the means comprising complementary interengagement.

59. A thrust member according to claim 58, the said means comprising spigot and socket means.

60. A thrust member according to claim 59, the spigot and socket means being heat weldable.

61. A thrust member, substantially as hereinbefore described with reference to the accompanying drawings.