GB2051994A - Pipe joint - Google Patents

Abstract

A pipe joint is provided by a socket end for receiving a male pipe part (not shown), a resilient sealing ring (18) and a locating collar therefor being located at the mouth of the socket end. The locating collar is provided at one end with a portion (30) for embracing and engaging around the socket end (10) and is provided at its other end with an inturned portion providing radially inner and radially outer walls defining an annular space (32) receiving a part of a radially outer locating portion (22) of the sealing ring (18). A sealing portion (24) of the ring (18) is connected integrally to the portion (22) and is provided with a plurality of annular enlargements (23) axially spaced apart along its radially inner surface for contacting the surface of the male pipe part (14) on assembly of the joint. In order to provide improved sealing, the sealing portion (24) of the sealing ring (18) is provided with a plurality of annular enlargements (25) axially spaced apart along its radially outer surface and oppositely disposed with respect to the enlargements (23) so that when the joint has been assembled there are bands of high concentrations of compression forming a series of fluid tight seals surrounding the inserted male pipe part. <IMAGE>

Description

SPECIFICATION Pipe joint The invention relates to pipe joints and has for its object to provide an improvement therein.

Pipe joints are known which comprise a female pipe part having a socket end for receiving a male pipe part, the joint 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. It is also known for the locating collar to be 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 reverse 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.Furthermore, it is known for the sealing ring to include a fluid sealing portion connected integrally to the locating portion at one end and having a plurality of annular 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.

However, the object of the invention is to provide a pipe joint of the kind described above which will have improved sealing.

According to the invention, there is provided a pipe joint comprising a female pipe part having a socket end for receiving a male pipe part, the joint 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 element of the sealing ring, the latter including a fluid sealing element connected integrally to said locating element at one end and having on radially inner and radially outer surfaces a series of oppositely located annular enlargements which in its free condition substantially thicken the fluid sealing element at axially spaced regions. The arrangement will preferably be such that when the joint is assembled the oppositely located annular enlargements are completely flattened so as to provide what are, in effect a plurality of separate seals produced by bands of high concentration of compression.A side surface of the locating element of the resilient sealing ring will preferably be provided with an annular ridge which when the joint as assembled is squashed flat against an end surface of the female pipe part, thus creating a further region in which there is a high concentration of compression. The side surface of the locating element of the resilient sealing ring may be provided with a tapering annular rim portion arranged to abut against a part of the socket end of the female pipe part. The socket will preferably be provided with a circumferential rib which prevents the locating collar from moving beyond its proper position on assembly of the joint and also prevents inadvertent dislodgement of the locating collar.

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. 1 is a side view, partly in section, of a pipe joint embodying the invention, Fig. 2 is a part-sectional view of a part of the joint, drawn to a much enlarged scale, shown in a partly assembled condition, and Fig. 3 is a view similar to Fig. 2 with the joint fully assembled.

Referring now to the drawings, the pipe joint illustrated in Fig. 1 includes a synthetic plastics socket part 10 with a cylindrical bore 12 for receiving an end length of a synthetic plastics 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 Figs. 2 and 3, it will be seen that the resilient sealing ring 18 has two main elements, namely a radially outer locating element 22 of generally rectangular cross section and a radially inner fluid sealing element 24 of somewhat hour-glass shape in cross section, that is to say, both the radially inner and radially outer surfaces of said fluid sealing element having a somewhat rippled configuration providing a series of annular ribs 23 along the inner surface of said sealing element and a pair of annular ribs 25 on the radially outer surface thereof. 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.When the joint has been fully assembled as in Fig. 3, a tapering annular rim portion 28 of the radially outer element of the sealing ring abuts an end surface of the circumferential ridge which is of complementary shape as shown. However, it will be seen that a side surface of the locating element in its free condition has an annular ridge 27 which is squashed flat against the end surface of the socket part when the joint is fully assembled.For holding the parts of the joint tightly together when the joint is fully assembled as shown in Fig. 3, the locating collar 20 has a radially inwardly turned circumferential lip 30 which can lie 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 ridged end of the socket part At its end remote from the circumferential lip 30, the locating collar is of inturned form providing a double walled portion defining an annular space 32 receiving a part of the radially outer locating element of the sealing ring and providing an abutment surface 34 bearings against a surface 35 of the ring.The arrangement is such that when the joint has been fully assembled, the abutment surface 34 bear against the surface 35 of the ring with a pressure sufficient to squash flat the annular ridge 27 and also to engage the projecting outer rim portion of the radially outer element of the sealing ring in the position which it is shown to occupy in Fig. 3 whereby the ring is locked in position and cannot become detached except by the removal of the locating element.

The socket part 10 is provided with a circumferential rib 29 which is spaced from the circumferential ridge 26 such that there is formed a deep groove into which the radially inwardly turned circumferential lip 30 of the locating collar can snap. The rib 29 prevents the locating collar from movin#g beyond its proper position on assembly of the joint, and also prevents inadvertent dislodgement of the locating collar, for example if the assembled fitting is accidentally dropped.

As shown in Fig. 2, the radially inner fluid sealing element of the resilient sealing ring, in its free condition, that is to say before the pipe 14 has been entered into the socket part, projects in an axial direction away from its region of attachment to the integral locating element 22 but is surrounded by an annular space within a bell mouthed portion of the socket part. The arrangement is such that when the pipe 14 has been received within the socket part 10, the fluid sealing element of the resilient ring has been deflected radially outwards as the generously tapered end of the pipe has contacted the annular ribs 23 in turn, the extent of the radially outwards deflection being such that the annular ribs 23 and the ribs 25 have been completely flattened as shown in Fig. 3.The effect of this is that in those regions in which the annular ribs have been flattened there are bands of high concentration of stress and it has been found that this produces excellent fluid sealing.

It has been found that the pipe joint just described can be assembled very easily and provides a consistently leak proof connection, this being thought to result partly from the fact that it is constituted by what are, in effect, a plurality of separate seals produced by the bands of high concentration of compression of the sealing ring, and to a lesser extent to the provision of the annular ridge 27 which in being squashed flat against the end surface of the socket part produces a similar concentration of compression in that region.

The assembly of the joint has been found to be facilitated if the resilient sealing ring is first positioned within the locating 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.

Various modifications may be made without departing from the scope of the invention. For example, the number of annular ribs providing the region of high concentration of compression when the joint is assembled may be different.

Furthermore, the manner in which the locating collar is secured on the socket part may be varied; for example, the snap-fitting could be replaced by an insert and twist (i.e. a cam-type lock or bayonet fitting) arrangement.

Claims (6)

1. A pipe joint comprising a female pipe part having a socket end for receiving a male pipe part, the joint 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 element of the sealing ring, the latter including a fluid sealing element connected integrally to said locating element at one end and having on radially inner and radially outer surfaces a series of oppositely located annular enlargements which in its free condition substantially thicken the fluid sealing element at axially spaced regions.

2. A pipe joint according to claim 1, in which the arrangement is such that when the joint is assembled the oppositely located annular enlargements are completely flattened so as to provide what are, in effect, a plurality of separate seals produced by bands of high concentration of compression.

3. A pipe joint according to either one of the preceding claims, in which a side surface of the locating element of the resilient sealing ring is provided with an annular ridge which when the joint as assembled is squashed flat against an end surface of the female pipe part, thus creating a further region in which there is a high concentration of compression.

4. A pipe joint according to any one of the preceding claims, in which the side surface of the locating element of the resilient sealing ring is provided with a tapering annular rim portion arranged to abut against a part of the socket end of the female pipe part.

5. A pipe joint according to any one of the preceding claims, in which the socket is provided with a circumferential rib which prevents the locating collar from moving beyond its proper position on assembly of the joint and also prevents inadvertent dislodgement of the locating collar.

6. A pipe joint constructed and arranged and adapted to be used substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.