GB2032030A

GB2032030A - Pipe joints

Info

Publication number: GB2032030A
Application number: GB7919832A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-10-19
Filing date: 1979-06-07
Publication date: 1980-04-30
Also published as: GB2032030B

Abstract

A pipe coupling comprises a pipe-receiving socket (10) made of plastics material, an annular shoulder (14) provided in the socket (10), a retaining ring (16), received in the socket (10) and defining with the shoulder (14) an annular channel which opens radially inwardly of the socket, and an annular seal (15) received in the channel for engagement with the outer periphery of a pipe when the latter is received by the socket. The retaining ring has latching engagement with recesses (18) taken through the internal wall of the socket and is releasable from externally of the socket by radially inward deformation of the retaining ring via the recesses (18). Various embodiments of retaining ring are described. <IMAGE>

Description

SPECIFICATION Pipe coupling This invention relates to a pipe coupling.

It is known to provide a pipe coupling having a pipe-receiving socket which is enlarged relative to the remainder of the coupling and which is provided with a circumferential groove in which a sealing ring, such as an O-ring, is accommodated.

When a pipe is received in the socket, the sealing ring engages sealingly with the outer periphery of the pipe in order to prevent leakage.

It is known to form the circumferential groove in the wall of the socket by machining, subsequent to the moulding of the socket. This has the evident disadvantage of involving an additional process step to the moulding step.

According to the invention there is provided a pipe coupling comprising a pipe-receiving socket made of plastics material, an annular shoulder provided in said socket, a retaining ring received in said socket and defining with said shoulder an annular channel which opens radially inwardly of the socket, and an annular seal received in said channel for engagement with the outer periphery of a pipe when the latter is received by said socket; in which the retaining ring has a latching engagement with the internal wall of the socket which is releasable from externally of the socket.

The latching engagement between the internal wall and the retaining ring may be provided by means of projections on one of these parts and corresponding recesses on the other of these parts. Preferably, the projections are provided on the retaining ring and the recesses are taken right through the internal wall. The retaining ring is made of resiliently deformable material so that it is capable of entering into the socket and latching in position as a snap-fit. To facilitate entry into the socket, the projections may be tapered. To provide satisfactory retention of the retaining ring, two or more recesses should be provided and preferably equally spaced around the periphery of the socket.

The annular seal may take any convenient shape, e.g. an O-ring, appropriate to the intended use of the coupling. Instead of providing a seal which is a separate item from the retaining ring, it is within the scope of the invention for the annular seal to be constituted by an integral portion of the retaining ring.

In order to provide improved resistance to unintentional withdrawal of a pipe from the socket, the retaining member may be provided with internal projections engageable with the outer surface of the pipe and preferably angled against the direction of withdrawal.

The internal projections may comprise a generally annular array of peripherally spaced and inwardly projecting teeth.

The recesses may formed during the moulding of the socket, or may be formed subsequently by a simple mechanical process such as stamping. The recesses may take any convenient shape, such as rectangular or triangular, or slot-shaped with the axis extending parallel to the longitudinal axis of the socket. The only requirement is that the recess should provide a holding surface which is engageable by the projections provided on the retaining ring to enable latching thereof.

In one preferred embodiment of the invention, the annular seal is received in said annular channel and adjacent to said annular shoulder. However, other preferred embodiments locate one or more additional components in the annular channel and between the annular seal and the annular shoulder.

Thus, an annular pipe-grabber may be arranged adjacent to the annular shoulder and having teeth angled so as to bite into the surface of a pipe to be received by the pipe coupling, so as to resist withdrawal of the pipe from the pipe coupling. If desired, a compression washer also may be located in the annular channel, between the pipegrabber and the annular seal. By locating the pipegrabber forwardly of the annular seal, with respect to the direction of entry of a pipe in the pipe coupling, the annular seal will engage with the surface of the pipe before the latter is engaged by the pipe-grabber so that, when the pipe reaches its fully inserted position, the seal can engage sealingly with an unmarked portion of the surface of the pipe.

In another preferred embodiment, the pipegrabber also constitutes said retaining ring, and the annular seal is located adjacent to the annular shoulder, optionally with a compression washer located between the annular seal and the pipegrabber.

Afternatively, the pipe-grabber and the compression washer may be arranged between the annular seal (located adjacent to the annular shoulder) and the retaining ring, with the pipegrabber adjacent to the retaining ring and the compression washer adjacent to the annular seal.

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:~ Figure 1 is a side view of a first embodiment of pipe coupling according to the invention; Figure 2 is a longitudinal sectional view of the pipe coupling; Figure 3 is a transverse cross-sectional view of the pipe coupling; Figure 4 is a longitudinal sectional view of a first construction of retaining ring for use in the pipe coupling; Figure 5 is a longitudinal sectional view of a second construction of retaining ring; Figure 6 is a detail view of a third construction of retaining ring; Figure 7 is a longitudinal sectional view of a second embodiment of pipe coupling according to the invention; Figure 8 is a longitudinal sectional view of a third embodiment of pipe coupling according to the invention; and Figure 9 is a longitudinal sectional view of a fourth embodiment of pipe coupling according to the invention.

Referring now to Figures 1 to 3 of the drawing, there is shown a pipe coupling comprising a socket made of plastics material and designated generally by reference to numeral 10. The socket 10 has a pipe receiving portion 1 1 provided with an internal shoulder 12 which limits the insertion of a pipe into portion 1 The socket 10 also has an enlarged entry portion 13, which comprises a cyclindrical wall which is joined to the portion 11 via an annular shoulder 14.

A seal 15 is accommodated within the portion 13 and is located adjacent to the shoulder 14. As illustrated, the seal comprises an O-ring, and the purpose of the seal 1 5 is to engage sealingly with the outer surface of a pipe which is received by the socket 10. The type of seal provided is not critical, and will depend on the intended use of the pipe coupling.# In order to retain the seal 1 5 in position against the shoulder 14, a retaining ring 16 is provided which is receivable in the portion 13 and holds the seal 15 in position against the shoulder 14. Thus, the retaining ring 16 and the shoulder 14 together define an annular channel which opens radially inwardly of the sockert and in which the seal 15 is accommodated.The retaining ring 16 is made of resiliently deformable material and is capable of moving into latching engagement with the internal wall of the socket as it enters the portion 13. As will be described in more detail below, the latching engagement with the internal wall of the socket is of such a nature as to be releasable from externally of the socket.

Referring in particular to Figure 2, one means is illustrated for providing latching engagement between the retaining ring 16 and the internal wall of the socket. Thus, the retaining ring 1 6 is provided with a pair of tapered tooth-like projections 17 which are capable of latching in corresponding recesses 18 formed right through the wall of the portion 1 3. One of the recesses 1 8 is shown in Figure 1 in the form of a square aperture, though any other convenient shape may be adopted which is capable of having a snapfitting engagement with the projections provided on the retaining ring 16.

The retaining ring 16 will be provided with at least two projections 17, and the projections are preferably spaced equidistantly about the periphery of the retaining ring 1 6. The recesses 1 8 which cooperate with the projections 17 will be similarly spaced about the periphery of the entry portion 13 of the socket 10. By providing recesses 18 which are taken right through the cylindrical wall of portion 13, access can be had to the projections 17 from externally of the socket, whereby the latching engagement between the projections 17 and recesses 18 can be released from externally of the socket.

The socket 10 is molded in plastics material, and the recesses 1 8 can be readily formed during the initial moulding of the socket. However, the recesses 18 may be post-formed, if desired, e.g.

by stamping subsequent to the moulding operation.

The retaining ring illustated in Figure 2 is shown in more detail in figure 4, from which it will be noted that an annular rib portion 19 projects axially outwardly from the projections 1 7.

This enables the retaining ring 16 to be flush with the end face 20 (Figure 2) of the entry portion 13 of the socket. In Figure 5, a retaining ring is illustrated in which the annular rib 19 is absent, and in this case the retaining ring will be located wholly within the entry portion 13.

The retaining ring 16 illustrated in Figures 1 to 5 is preferably made of plastics material so as to provide the requisite resiliently deformable properties therefore, whereby the retaining ring 1 6 can be moved into snap fitting latching engagement with the internal wall of the socket.

However, any other suitable resiliently deformable material may be adopted. In particular, with reference to Figure 6, there is illustrated in longitudinal section a detail of part of a retaining ring 21 made of metal such as spring steel. The retaining ring 21 has a central cylindrical portion 22, outwardly extending projections 23 and inwardly extending projections 24. The projections 23 are intended to function in similar manner to the projections 17, so as to snap-fit into corresponding recesses formed in the cylindrical wall portion 13. However, the inward projections 24 are intended to engage with the outer periphery of a pipe received by the socket so as to resist unintentional withdrawal thereof.Thus, the prujections 24 may comprise an annular array of peripherally spaced teeth which are angled against the direction of withdrawal of a pipe and which are capable of biting into the surface of the pipe. At the same time, the retaining ring 21 is capable of holding the seal 15 in position against the shoulder 14.

Referring now to Figure 7 of the drawings, there is shown a second embodiment of pipe coupling according to the invention, and parts corresponding with the first embodiment are designated by the same reference numerals and will not be described in detail again. In Figure 7, the annular seal 15 remains received in the annular channel defined between the annular shoulder 14 and a retaining ring 25, but the annular seal 15 is not located adjacent to the annular shoulder 14.

Additional components are received in the annular channel and located between the annular shoulder 14 and the annular seal 15, the additional components comprising an annular pipe-grabber 26, and a compression washer 27.

The pipe-grabber 26 has inclined teeth 28 which are arranged to bite into the surface of a pipe 29 so as to resist withdrawal of the pipe 29 from the pipe coupling 10. By locating the pipe-grabber 26 forwardly of the annular seal 1 5 with respect to the direction of entry of the pipe 29, the annular seal 15 will always engage an unmarked surface of the pipe 29, whereby the risk of leakage, which might be caused by marking of the surface of the pipe 29 by the pipe-grabber 26 can be avoided.

Referring now to Figure 8 of the drawing, the annular seal 15 is located adjacent to the annular shoulder 14, but the pipe-grabber 26 and the compression washer 27 are arraged differently.

Thus, in this embodiment, the pipe-grabber 26 also functions as a retaining ring, equivalent to the retaining ring 25 or 16, in that it has outwardly projecting lugs which are arranged to snap into recesses 1 8 taken through the wall of the entry portion 13. The compression washer 27 is located, as indicated, between the annular seal 1 5 and the pipe-grabber 26.

Referring now to Figure 9 of the drawings, the fourth embodiment also locates the annular seal 15 adjacent to the annular shoulder 14, but a compression washer 30 and pipe-grabber 26 are located between the annular seal 1 5 and a retaining ring 31 which is latched in the recesses 18. As illustrated, the compression washer 30 and the pipe grabber 26 are located, respectively, adjacent to the annular seal 1 5 and the retaining ring 31.

Claims

1. A pipe coupling comprising a pipe-receiving socket made of plastics material, an annular shoulder provided in said socket, a retaining ring received in said socket and defining with said shoulder an annular channel which opens radially inwardly of the socket, and an annular seal received in said channel for engagement with the outer periphery of a pipe when the latter is received by said socket; in which the retaining ring has a latching engagement with the internal wall of the socket which is releasable from externally of the socket.

2. A pipe coupling according to claim 1, in which the latching engagement between the internal wall of the socket and the retaining ring is provided by means of projections on one of these parts and corresponding recesses on the other of these parts.

3. A pipe coupling according to claim 2, in which the projections are provided on the retaining ring and the recesses are taken right through the internal wall.

4. A pipe coupling according to claim 2 or 3, in which the projections are tapered so as to facilitate entry of the retaining ring into the socket.

5. A pipe coupling according to any one of claims 2 to 4, in which recesses are equally spaced around the periphery of the socket.

6. A pipe coupling according to any one of the preceding claims, in which the annular seal is constituted by an integral portion of the retaining ring.

7. A pipe coupling according to any one of the preceding claims, in which the retaining member is provided with internal projections engageable with the outer surface of the pipe and angled against the direction of withdrawal of the pipe.

8. A pipe coupling according to claim 7, in which the internal projections comprise a generally annular array of peripherally spaced and inwardly projecting teeth.

9. A pipe coupling according to claim 3, in which the recesses provided in the internal wall are formed during the moulding of the socket, or by a mechanical process subsequent to the moulding of the socket.

10. A pipe coupling according to claim 3, or any one of claims 4 to 9 when appended to claim 3, in which the recesses are rectangular, triangular, or slot-shaped with the axis of each slot extending parallel to the longitudinal axis of the socket.

11. A pipe coupling according to any one of the preceding claims, in which the annular seal is received in said annular channel and adjacent to said annular shoulder.

12. A pipe coupling according to any one of claims 1 to 10, in which one or more additional annular components are received in the annular channel and located between the annular seal and the annular shoulder.

13. A pipe coupling according to claim 12, in which an annular pipe-grabber is arranged adjacent to the annular shoulder and has teeth angled so as to bite into the surface of a pipe to be received by the pipe coupling so as to resist withdrawal of the pipe from the pipe coupling.

14. A pipe coupling according to claim 13, in which a compression washer is located in the annular channel between the pipe-grabber and the annular seal.

15. A pipe coupling according to claim 11, in which an annular pipe-grabber constitutes said retaining ring and has teeth angled so as to bite into the surface of a pipe to be received by the pipe coupling, so as to resist withdrawal of the pipe from the pipe coupling.

16. A pipe coupling according to claim 15, in which a compression washer is arranged in the annular channel between the annular seal and the pipe-grabber.

17. A pipe coupling according to claim 11, in which a compression washer is arranged in the annular channel adjacent to the annular seal, and an annular pipe-grabber is arranged between the compression washer and the retaining ring and has teeth angled so as to bite into the surface of a pipe to be received by the pipe coupling, so as to resist withdrawal of the pipe from the pipe coupling.

18. A pipe coupling according to claim 1 and substantially as hereinbefore described with reference to, and as shown in any one of the embodiments illustrated in the accompanying drawings.