GB1597525A - Pipe joints - Google Patents

Description

(54) AN IMPROVEMENT IN OR RELATING TO PIPE JOINTS (71) We, PARAGON PLASTICS LIMITED, a British Company, of Broomhouse Lane, Edlington. Doncaster 12, 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: The invention relates to pipe joints and has for its object to provide an improvement therein. In particular, the invention relates to pipe joints for use in rainwater and effluent drainage systems and in sanitary plumbing systems.

According to the invention, there is provided a pipe joint for use in particular in rainwater and effluent drainage systems and in sanitary plumbing systems, the joint comprising a female pipe part having a socket end for receiving a male pipe part, and also comprising a resilient sealing ring and a locating collar at the mouth of the socket end of the female pipe part for retaining the sealing ring in position at said mouth of said socket end, the locating collar being provided at one end with a portion for embracing and engaging an outer end portion of the socket part and being at its other end of an inturned form, that is to say, being inturned so that the end extends in a reversed axial direction to that of the adjoining part, providing a portion having a radially inner and a radially outer wall defining an annular space receiving a part of a radially outer locating portion of the sealing ring, the latter including a fluid sealing portion connected integrally to said locating portion at one end and having a plurality of annular stepped lands axially spaced apart along its radially inner surface, the arrangement being such that when the male pipe part is entered into the female pipe part the fluid sealing portion of the resilient sealing ring is gradually deflected radially outwards as the end of the said male pipe part contacts the annular stepped lands in turn and such that as the resilient sealing ring becomes fully deflected an endmost region of said ring, that is to say the endmost annular land, becomes radially compressed between the periphery of the male pipe part and the radially inner surface of the socket end of the female pipe part. The fluid sealing portion of the resilient sealing ring may be of gradually widening cross section and in this case its integral connection to the radially outer locating portion of the sealing ring will be at its wider end. Preferably, the arrangement will be such that when the locating collar is engaged with the end portion of the socket part to locate the resilient sealing ring at the mouth of said socket part, a portion of said ring will be compressed between an end surface of the socket part and an abutment surface of the inturned portion of the locating collar. Preferably, also, the locating portion of the sealing ring will be formed with a projecting outer rim portion adapted to embrace the outer surface of the end portion of the socket part, so that when the sealing ring has been secured at the mouth of the socket part it is locked in position and cannot become detached except by the removal of the locating collar. The plurality of lands spaced apart along the radially inner surface of the sealing ring will preferably be undercut so that when the joint is in use each land functions as a separate sealing element independently of its neighbour. An endmost one of the lands, that is to say the land at the end of the resilient sealing ring which finally becomes radially compressed as the ring becomes fully deflected, may be axially less extensive than the other lands. The locating collar will preferably be capable of engaging the end portion of the socket part by means of a snap-fit connection.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which: Fig. I is a side view, partly in section, of a pipe joint embodying the invention, Fig. 2 is a sectional view, drawn to a much enlarged scale, which will presently be referred, to, and Fig. 3 is a further sectional view which will be referred to in connection with a modification which will presently be described.

Referring now to the drawings, the pipe joint illustrated in Fig. I includes a synthetic plastics material socket part 10 with a cylindrical bore 12 receiving an end length of a synthetic plastics material pipe 14 shown in chain-dotted lines. (The socket part is provided with an annular abutment surface 16 which limits the maximum extent by which the pipe 14 can be entered into said socket part although in practice the pipe 14 need not extend that far into the socket part). The pipe joint also includes a resilient sealing ring generally indicated 18, for providing a fluid tight seal between the pipe 14 and the socket, and a locating collar 20 by means of which the sealing ring is retained in position at the mouth of the socket part 10.

Referring now in particular to Fig. 2, it will be seen that the resilient sealing ring 18 has two main portions, namely a radially outer locating portion 22 of generally rectangular cross section and a radially inner fluid sealing portion 24 of generally triangular cross section connected integrally at its wider end to said locating portion. The outside diameter of the sealing ring is substantially the same as that of a circumferential ridge 26 which is formed around the socket part adjacent its mouth. A tapering annular rim portion 28 of the radially outer portion of the sealing ring abuts against an end surface of the circumferential ridge which is of complementary shape as shown. It will also be seen that the locating collar 20 has a radially inwardly turned circumferential lip 30 which when the pipe joint is assembled lies behind the ridge 26 of the socket part, the cross sectional shape of the lip being such that the locating collar has a tapering mouth portion which facilitates the snap fitment of the collar over the ridge 26 of the socket part.

At its end remote from the circumferential lip 30, the locating collar is of inturned form, as shown, providing a double walled portion defining an annular space 32 receiving a part df the radially outer portion of the sealing ring and providing an abutment surface 34 bearing against the wider end of the fluid sealing portion which is of gradually widen ing cross section. The proportions of the various parts are such that when the locating collar has been engaged with the end portion of the socket part to locate the resilient sealing ring at the mouth of said socket part, the locating portion is compressed between an end surface of the socket part and the abutment surface 34 of the locating collar.

The arrangement is also such that, by virtue of the projecting outer rim portion of the sealing ring embracing an end portion of the socket part. when the sealing ring has been secured at its mouth it is locked in position and cannot become detached except by the removal of the locating collar 20.

The fluid sealing portion 24 of the resilient sealing ring is provided. as shown, with four stepped lands 36, 38, 40 and 42 along its radially inner surface, and before the entry of the male pipe part into the female pipe part the trailing portion of the sealing ring (that is to say that part of the ring which projects in an axial direction away from its region of attachment to the locating portion 22) is surrounded by an annular space within a bell mouthed portion of the socket part. The arrangement is such that, as shown by the chain-dotted lines in Fig. 2, when the pipe 14 has been received within the socket part 10, the fluid sealing portion of the resilient sealing ring has been gradually deflected outwards as the generously tapered end of the pipe has contacted the stepped lands 36, 38, 40 and 42 in turn. In addition, as the fluid sealing portion has become fully deflected, an endmost region of the trailing portion (as defined above) has been radially compressed between the periphery of the pipe and the bell mouthed portion of the socket so that the land 42, which is relatively narrow, that is to say narrow in relation to the width of the other three lands, is pressed against the surface of the pipe with a pressure greater than the pressure produced by the outward stretching of the ring.

It has been found that the pipe joint just described can be assembled very easily and provides a consistently leak proof connection, this being though to result from the fact that it is constituted by a plurality of separate seals produced by the respective stepped lands, from the fact that an endmost region of the fluid sealing portion has been radially compressed as described above, and from the fact that an auxiliary seal has been formed, acting to prevent the ingress of moisture, by the axial compression of the ring between the end surface of the socket part and the abutment surface 34 of the locating collar.

The assembly of the joint has been found to be facilitated if the resilient sealing ring is first positioned within the locating collar instead of simply being trapped between the end of the socket part and said collar. The collar and sealing ring assembly can then be mounted on the socket part in readiness for the pipe being pressed into position within the socket. The joint can be used with equal facility for rainwater and effluent drainage systems and in sanitary plumbing systems.

Referring now to Fig. 3, this illustrates a resilient sealing ring of somewhat modified cross sectional shape, having only three stepped lands 36, 38 and 40. It will also be seen that, in its unstressed condition as drawn, each land is somewhat undercut instead of being of parallel form as in the ring previously described. This is so that when the joint is in use each land is able to function as a separate sealing element almost independently of its neighbour. The proportions of the ring are of course still such that as the fluid sealing portion becomes fully deflected an endmost region of the ring becomes radially compressed between the periphery of the male part and the mouth of the socket end of the female part.

Various other modifications may be made without departing from the scope of the invention. For example, the number of the stepped lands may be less than or greater than three or four. Furthermore, the manner in which the locating collar is secured on the socket part may be varied; for example, the spap-fitting could be replaced by an insert and twist (i.e. a cam-type lock) arrangement.

WHAT WE CLAIM IS: 1. A pipe joint for use in particular in rainwater and effluent drainage systems and in sanitary plumbing systems, the joint comprising a female pipe part having a socket end for receiving a male pipe part, and also comprising a resilient sealing ring and a locating collar at the mouth of the socket end of the female pipe part for retaining the sealing ring in position at said mouth of said socket end, the locating collar being provided at one end with a portion for embracing and engaging an outer end portion of the socket part and being at its other end of an inturned form, that is to say, being inturned so that the end extends in a reversed axial direction to that of the adjoining part, providing a portion having a radially inner and a radially outer wall defining an annular space receiving a part of a radially outer locating portion of the sealing ring, the latter including a fluid sealing portion connected integrally to said locating portion at one end and having a plurality of annular stepped lands axially spaced apart along its radially inner surface, the arrangement being such that when the male pipe part is entered into the female pipe part the fluid sealing portion of the resilient sealing ring is gradually deflected radially outwards as the end of the said male pipe part contacts the annular stepped lands in turn and such that as the resilient sealing ring becomes fully deflected an endmost region of said ring, that is to say the endmost annular land, becomes radially compressed between the periphery of the male pipe part and the radially inner surface of the socket end of the female pipe part.

2. A pipe joint according to claim 1, in which the fluid sealing portion of the resilient sealing ring is of gradually widening cross section and its integral connection to the radially outer locating portion of the sealing ring is at its wider end.

3. A pipe joint according to either one of the preceding claims, in which the arrangement is such that when the locating collar is engaged with the end portion of the socket part to locate the resilient sealing ring at the mouth of said socket part, a portion of said ring is compressed between an end surface of the socket part and an abutment surface of the inturned portion of the locating collar.

4. A pipe joint according to any one of the preceding claims, in which the locating portion of the sealing ring is formed with a projecting outer rim portion adapted to embrace the outer surface of the end portion of the socket part, so that when the sealing ring has been secured at the mouth of the socket part it is locked in position and cannot become detached except by the removal of the locating collar.

5. A pipe joint according to any one of the preceding claims, in which the plurality of lands spaced apart along the radially inner surface of the sealing ring are undercut so that when the joint is in use each land functions as a separate sealing element independently of its neighbour.

6. A pipe joint according to any one of the preceding claims, in which an endmost one of the lands, that is to say the land at the end of the resilient sealing ring which finally becomes radially compressed as the ring becomes fully deflected, is axially less extensive than the other lands.

7. A pipe joint according to any one of the preceding claims, in which the locating collar is capable of engaging the end portion of the socket part by means of a snap-fit connection.

8. A pipe joint constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated by Figs. 1 and 2 of the accompanying drawings or with reference to Figs. 1 and 2 and modified as illustrated by Fig. 3 of the accompanying drawings.

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

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. as the fluid sealing portion becomes fully deflected an endmost region of the ring becomes radially compressed between the periphery of the male part and the mouth of the socket end of the female part. Various other modifications may be made without departing from the scope of the invention. For example, the number of the stepped lands may be less than or greater than three or four. Furthermore, the manner in which the locating collar is secured on the socket part may be varied; for example, the spap-fitting could be replaced by an insert and twist (i.e. a cam-type lock) arrangement. WHAT WE CLAIM IS:

1. A pipe joint for use in particular in rainwater and effluent drainage systems and in sanitary plumbing systems, the joint comprising a female pipe part having a socket end for receiving a male pipe part, and also comprising a resilient sealing ring and a locating collar at the mouth of the socket end of the female pipe part for retaining the sealing ring in position at said mouth of said socket end, the locating collar being provided at one end with a portion for embracing and engaging an outer end portion of the socket part and being at its other end of an inturned form, that is to say, being inturned so that the end extends in a reversed axial direction to that of the adjoining part, providing a portion having a radially inner and a radially outer wall defining an annular space receiving a part of a radially outer locating portion of the sealing ring, the latter including a fluid sealing portion connected integrally to said locating portion at one end and having a plurality of annular stepped lands axially spaced apart along its radially inner surface, the arrangement being such that when the male pipe part is entered into the female pipe part the fluid sealing portion of the resilient sealing ring is gradually deflected radially outwards as the end of the said male pipe part contacts the annular stepped lands in turn and such that as the resilient sealing ring becomes fully deflected an endmost region of said ring, that is to say the endmost annular land, becomes radially compressed between the periphery of the male pipe part and the radially inner surface of the socket end of the female pipe part.

2. A pipe joint according to claim 1, in which the fluid sealing portion of the resilient sealing ring is of gradually widening cross section and its integral connection to the radially outer locating portion of the sealing ring is at its wider end.

3. A pipe joint according to either one of the preceding claims, in which the arrangement is such that when the locating collar is engaged with the end portion of the socket part to locate the resilient sealing ring at the mouth of said socket part, a portion of said ring is compressed between an end surface of the socket part and an abutment surface of the inturned portion of the locating collar.

4. A pipe joint according to any one of the preceding claims, in which the locating portion of the sealing ring is formed with a projecting outer rim portion adapted to embrace the outer surface of the end portion of the socket part, so that when the sealing ring has been secured at the mouth of the socket part it is locked in position and cannot become detached except by the removal of the locating collar.

5. A pipe joint according to any one of the preceding claims, in which the plurality of lands spaced apart along the radially inner surface of the sealing ring are undercut so that when the joint is in use each land functions as a separate sealing element independently of its neighbour.

6. A pipe joint according to any one of the preceding claims, in which an endmost one of the lands, that is to say the land at the end of the resilient sealing ring which finally becomes radially compressed as the ring becomes fully deflected, is axially less extensive than the other lands.

7. A pipe joint according to any one of the preceding claims, in which the locating collar is capable of engaging the end portion of the socket part by means of a snap-fit connection.

8. A pipe joint constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated by Figs. 1 and 2 of the accompanying drawings or with reference to Figs. 1 and 2 and modified as illustrated by Fig. 3 of the accompanying drawings.