GB1578743A

GB1578743A - Pipe coupling sockets

Info

Publication number: GB1578743A
Application number: GB2123376A
Authority: GB
Original assignee: Wavin BV
Current assignee: Wavin BV
Priority date: 1977-03-18
Filing date: 1977-03-18
Publication date: 1980-11-12

Description

4) IMPROVEMENTS RELATING TO PIPE COUPLING SOCKETS (71) We, WAVIN B.V., a Dutch corporate body, of Handellaan 251, Zwolle, Holland, 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 more particularly to sockets thereof having a radially inwardly opening annular groove for receiving a sealing member for making sealing contact around a spigot.

The groove for the sealing ring may be provided, without using collapsible cores when moulding the socket and without machining after moulding, by a socket assembly in which a member extends within the socket and defines with the socket the groove. This member may comprise an endcap, which, for example, may be snap-fitted to the socket by means of snap engagement formations on the cap and on the outside of the socket; or it may be an insert which may be disposed totally or only partially within the socket, and which, for example, may be snap-fitted to the socket by means of snap engagement formations on the insert and the inside of the socket, the latter being mouldable without using collapsible cores.

The present invention provides a socket assembly comprising a socket and a member extending within a radially inwardly and axially outwardly opening annular recess in the socket and having an axially inner portion defining with the socket a radially inwardly opening annular groove, the axially inner portion of the member contacting the inner surface of the socket and having a radially inwardly facing surface against which, in use, a sealing member is compressed thereby causing a radially outwardly directed force to be exerted on the axially inner portion of the member.

As will be appreciated the above-mentioned force is able to act to increase frictional contact between the inner portion of the member and the socket thereby reducing any tendency for axial relative movement between the member and the socket due to operational conditions. This is particularly beneficial where, as in the presently preferred embodiments of the invention, which are described hereinafter, the members are inserts which are snap-fitted into the sockets, with snap engagement formations of the sockets limited to a radial depth which is mouldable without using collapsible cores.

Hence the radially outwardly directed force assists the snap engagement formations to retain the insert in position within the socket.

In order that the invention will be well understood, the presently preferred embodiments thereof, which are given by way of example only, will now be described in more detail, reference being made to the accompanying drawings, in which: Figure 1 is an axial sectional view of a socket assembly; Figure 2 is an enlarged view of a detail of Figure 1; and Figure 3 is a similar view to Figure 2 of another socket assembly.

Referring to Figures 1 and 2, there is shown a socket assembly 1 for a pipe coupling, which assembly comprises a plastics socket 2 and a member in the form of a plastics insert 3 disposed totally within the socket and snap-fitted therein by means of snap engagement formations 4, 5 on the insert and the inside of the socket. The insert 3 is located within a radially inwardly and axially outwardly opening annular recess 6 in the socket such that an axially inner portion 7 of the insert defines with the socket a radially inwardly opening annular groove 8 for accommodating a sealing member 9. The inner portion 7 of the insert is provided with a radially inwardly and axially outwardly opening recess. 10 and the groove is formed between the axially inner ends 11, 12 of the recess 6 and 10 respectively. A radially inwardly facing surface 13 of the recess 10 in the inner portion of the insert also delimits the groove, and, in use, insertion of a spigot (not shown) into the socket assembly to form a pipe coupling therewith causes the sealing member to be compressed against the surface 13 thereby causing a radially outwardly directed force to be exerted on the inner portion 7 of the insert, which is in contact with the inner surface of the socket, to increase the frictional contact between the inner portion 7 of the insert and the socket. As explained previously, this assists the snap-engagement formations in retaining the insert within the socket during operation, and this is particularly beneficial where the effectiveness of the snap-fit is limited because the formations on the sockets are limited to a radial depth which is mouldable without using collapsible cores.

in the socket assembly 1 the snap engagement formation 4 is provided on an axially outer portion of the insert and comprises an annular rib, and the formation 5 on the socket is a groove of such a radial depth that it can be moulded without a collapsible core.

Figure 3 shows a socket assembly 14, which is substantially the same as socket assembly 1, like part being given like ref- erence numerals, wherein the snap engagement formation-on the insert comprises a groove 15 and the co-operable snap engagement formation on the socket is a rib 16 which can be moulded without a collapsible core. Further similar snap engagement formations may be provided, and advantageously these may comprise a formation on the inner portion 7 of the insert and a cooperable formation on the socket, since, as will be appreciated, the radially outwardly directed force exerted on the inner portion 7 on compression of the sealing member will enhance the engagement of the formations. Thus, in the socket assembly 1 a further groove 17 in the socket and rib 18 on the insert (shown in dotted line in Fig urge 2) may be provided. Figure 3 shows in dotted line how a further groove 19 in the insert and rib 20 on the socket may be provided in assembly 14. It is desirable for the radial depth of the further formations 17, 18 'and 19, 20 to be less than the radial depth of the other formations, as shown, (i) t6 reduce the amount of inward deflection of the inner portion 7 of the insert during assembly, pårticularly if, as would be the case in the illustrated embodiments, the seal ing member is located in the recess 10 of the' insèr prior tò insertion of the insert into the socket; and (ii) in the case where a groove is provided in the inner portion 7 of the insert, to reduce any weakening of the inner portion.

It is also possible to provide reverse formations, that is to provide the insert with a groove and rib, as illustrated, for example, in Figure 3 by the provosion of a rib 21 (shown in dotted line) on the inner portion 7 of the insert in addition to the groove 15.

However, in such a case the overall radial depths of the corresponding rib and groove on the socket must be such as to allow moulding without a collapsible core.

In the illustrated embodiments, it will be noted that the inserted 3 is arranged to extend axially the entire length of the recess 6 in the socket to abut the radially inner end 11 thereof. This prevents accidental insertion (or subsequent movement) of the snap fit formation of the inserted past the corresponding formation of the socket.

The ends 11 and 12 of the recesses 6 and 10 converge radially inwardly in both of the embodiments. This assists retention of the illustrated sealing member 9, which is preferably compressed between the ends 11 and 12, in position in the groove formed between the ends 11 and 12. However, it is to be understood that the ends 11 and 12 need not converge radially inwardly and furthermore neither they nor the surface 13 need be plane surfaces as illustrated.

It is also to be understood - that whilst the snap-engagement formations have been shown as semi-circular in cross-section other cross-sections may be utilised.

WHAT WE CLAIM IS: 1. A socket assembly comprising a socket and a member extending within a radially inwardly and axially outwardly opening annular recess in the socket and having an axially inner portion defining with the socket a radially inwardly opening annular groove, the axially inner portion of the member contacting the inner surface of the socket and having a radially inwardly facing surface against which, in use, a sealing member is compressed thereby causing radially outwardly directed force to be exterted on the axially inner portion of the member.

2. A socket assembly as claimed in claim 1, wherein the member extends the entire axial length of the recess in the socket to abut the radially inner end thereof.

3. A socket assembly as claimed in claim 1 or 2, wherein the member is provided with a radially inwardly and axially outwardly opening recess, and said groove is formed between the axially inner ends of the recesses in the member and socket.

4. A socket assembly as claimed in claim 3, wherein said axially inner ends converge radially inwardly.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. groove is formed between the axially inner ends 11, 12 of the recess 6 and 10 respectively. A radially inwardly facing surface 13 of the recess 10 in the inner portion of the insert also delimits the groove, and, in use, insertion of a spigot (not shown) into the socket assembly to form a pipe coupling therewith causes the sealing member to be compressed against the surface 13 thereby causing a radially outwardly directed force to be exerted on the inner portion 7 of the insert, which is in contact with the inner surface of the socket, to increase the frictional contact between the inner portion 7 of the insert and the socket. As explained previously, this assists the snap-engagement formations in retaining the insert within the socket during operation, and this is particularly beneficial where the effectiveness of the snap-fit is limited because the formations on the sockets are limited to a radial depth which is mouldable without using collapsible cores. in the socket assembly 1 the snap engagement formation 4 is provided on an axially outer portion of the insert and comprises an annular rib, and the formation 5 on the socket is a groove of such a radial depth that it can be moulded without a collapsible core. Figure 3 shows a socket assembly 14, which is substantially the same as socket assembly 1, like part being given like ref- erence numerals, wherein the snap engagement formation-on the insert comprises a groove 15 and the co-operable snap engagement formation on the socket is a rib 16 which can be moulded without a collapsible core. Further similar snap engagement formations may be provided, and advantageously these may comprise a formation on the inner portion 7 of the insert and a cooperable formation on the socket, since, as will be appreciated, the radially outwardly directed force exerted on the inner portion 7 on compression of the sealing member will enhance the engagement of the formations. Thus, in the socket assembly 1 a further groove 17 in the socket and rib 18 on the insert (shown in dotted line in Fig urge 2) may be provided. Figure 3 shows in dotted line how a further groove 19 in the insert and rib 20 on the socket may be provided in assembly 14. It is desirable for the radial depth of the further formations 17, 18 'and 19, 20 to be less than the radial depth of the other formations, as shown, (i) t6 reduce the amount of inward deflection of the inner portion 7 of the insert during assembly, pårticularly if, as would be the case in the illustrated embodiments, the seal ing member is located in the recess 10 of the' insèr prior tò insertion of the insert into the socket; and (ii) in the case where a groove is provided in the inner portion 7 of the insert, to reduce any weakening of the inner portion. It is also possible to provide reverse formations, that is to provide the insert with a groove and rib, as illustrated, for example, in Figure 3 by the provosion of a rib 21 (shown in dotted line) on the inner portion 7 of the insert in addition to the groove 15. However, in such a case the overall radial depths of the corresponding rib and groove on the socket must be such as to allow moulding without a collapsible core. In the illustrated embodiments, it will be noted that the inserted 3 is arranged to extend axially the entire length of the recess 6 in the socket to abut the radially inner end 11 thereof. This prevents accidental insertion (or subsequent movement) of the snap fit formation of the inserted past the corresponding formation of the socket. The ends 11 and 12 of the recesses 6 and 10 converge radially inwardly in both of the embodiments. This assists retention of the illustrated sealing member 9, which is preferably compressed between the ends 11 and 12, in position in the groove formed between the ends 11 and 12. However, it is to be understood that the ends 11 and 12 need not converge radially inwardly and furthermore neither they nor the surface 13 need be plane surfaces as illustrated. It is also to be understood - that whilst the snap-engagement formations have been shown as semi-circular in cross-section other cross-sections may be utilised. WHAT WE CLAIM IS:

1. A socket assembly comprising a socket and a member extending within a radially inwardly and axially outwardly opening annular recess in the socket and having an axially inner portion defining with the socket a radially inwardly opening annular groove, the axially inner portion of the member contacting the inner surface of the socket and having a radially inwardly facing surface against which, in use, a sealing member is compressed thereby causing radially outwardly directed force to be exterted on the axially inner portion of the member.

5. A socket assembly as claimed in any

one of the preceding claims, wherein said member comprises an insert which is disposed totally or partially within the socket.

6. A socket assembly as claimed in any one of the preceding claims, wherein the member is snap-fitted within the socket by means of snap engagement formations on the insert and the inside of the socket, the latter being mouldable from a plastics material without the use of collapsible cores.

7. A socket assembly as claimed in claim 6, wherein said snap engagement formations comprise a rib on or groove in an axially outer portion of said member and a corresponding groove in or rib on said socket.

8. A socket as claimed in claim 7, wherein said snap engagement formations comprise a further rib or groove provided on or in said axially inner portion of the member and a corresponding groove in or rib on the socket.

9. A socket assembly as claimed in claim 8, wherein the radial depth of said further snap engagement formations is less than the radial depth of said first mentioned snap engagement formations.

10. A socket assembly as claimed in any one of the preceding claims, and having a sealing member accommodated in the groove which the axially inner portion of the member defines with the socket.

11. A pipe coupling comprising a socket assembly as claimed in claim 10, and a spigot insert therein, the sealing member making sealing contact around the spigot and being compressed thereby to cause a radially outwardly directed force to be exerted on the axially inner portion of the member of the socket assembly.

12. A socket assembly substantially as herein described with reference to Figure 1 and Figure 2 or 3 of the accompanying drawings.