GB2198798A

GB2198798A - Disconnectable pipe joints

Info

Publication number: GB2198798A
Application number: GB08719124A
Authority: GB
Inventors: Willem Kiezebrink; Jan Aert Van Nes
Original assignee: Wavin BV
Current assignee: Wavin BV
Priority date: 1986-08-15
Filing date: 1987-08-12
Publication date: 1988-06-22
Anticipated expiration: 2007-08-12
Also published as: NL193118B; GB2198798B; NL8602082A; NL193118C; GB8719124D0

Abstract

A disconnectable pipe joint comprises a male pipe part with an outer shoulder and a female pipe part with an internal recess. The two pipe parts are coupled in a tensile resistant way by means of a radially resiliently expansible coupling ring member being retained in a groove in the female pipe part due to expansion by means of a locking member pushed below said coupling member. A snap fit connection between a rib on the locking member and a groove on the outer side of the male pipe part ensures a good fastening between said male pipe part and said locking member. The coupling member is sufficiently loosely retained in said groove and is provided with a flexible cord for easily pulling coupling member out of the groove and for controlling the presence of coupling member. The male pipe part bears a check ridge indicating the distance to which the locking member must be pushed inwards for expanding the coupling member. The outer shoulder, the groove and check ridge may be formed on a sleeve which can be connected with the male pipe part by means of an adhesive. The male pipe part together with the sleeve and/or coupling member may be presented to a customer in a shrink film surrounding these parts. <IMAGE>

Description

DISCONNECTABLE PIPE JOINTS The invention relates to a disconnectable pipe joint comprising at least a male pipe part provided with an outside shoulder, a female pipe part provided with an internal recess, a radially resiliently expansible coupling member for the tensile resis- fastening of the male and female pipe parts, said member being adapted to cooperate with an outer stop edge of the recess and with said shoulder, a sealing member, and also an axially slidable locking member cooperating with the coupling member.

A disconnectable tensile resistant pipe joint of this kind is known from Dutch Patent Application No. 271155, in which å radially resiliently expansible coupling member, in the form of a rigid split polyvinyl chloride ring, clampingly disposed on the male pipe part is adapted to cooperate with a stop edge of a groove in the female pipe part, and on the other hand with a shoulder provided on the male pipe part.

For the uncoupling of the pipe parts forming the pipe joint, a sleeve-like locking member slidable in the axial direction is disposed on the outer side of the male pipe part and is adapted to be pushed under the coupling member in order to expand the latter to an inner diameter such that the external shoulder provided on the end of the male pipe part can pass over the coupling member on the removal of the male pipe part.

This known disconnectable pipe joint presents the disadvantage that the outer side of the male pipe part must be provided with a stop ring gripping around it in order to limit the axial movement of the sleevelike locking member, after its installation, to outward clamping cooperation with the coupling member.

The fitting of a stop ring of this kind gives rise in practice to numerous difficulties, since this stop ring must be pushed either over the shoulder extending on the outer side of the male pipe part or, if a male pipe part is provided at one end with a shoulder and at the other end with a socket end, over the latter.

In order to avoid problems which may arise because of particles of sand finding their way during assembly into the groove in the female pipe part, and in order to apply resilient pressure to the coupling member in the finished pipe joint, it is also necessary to fit in the groove a compressible rubber ring before the coupling member is installed. This makes assembly difficult and increases costs.

In addition, problems frequently occur because of particles of sand, which are always entrained during the inward movement of the locking member and may subsequently make their way between the coupling member and the outer side of the male pipe part.

The invention now seeks to provide a disconnectable pipe joint in which these disadvantages do not occur because in the finished pipe joint the locking member continues to cooperate clampingly with the coupling member radially resiliently expanded by the locking member, while particles of sand introduced during the insertion of the coupling member cause no problems.

According to the invention this feature is achieved in that the coupling member is expanded by and cooperates resiliently with the locking member in such a manner that in this expanded state the coupling member can cooperate with said shoulder and said stop edge.

Through the clamping cooperation between the expanded coupling member and the locking member, the latter is held in place without special fastening means. Furthermore, the clamping force between the coupling member and the locking member can be varied within determined limits by appropriate selection of the dimensions of the coupling member and the locking member, whereas variation of this kind is not possible with the known pipe joint mentioned above.

Ir. addition, the assembly of the pipe joint is simple because after the coupling member has been fitted, it only has to be expanded by axial movement of the locking member, while particles of sand entrained by the inward axial movement of the locking member, or any particles which have gained access in some other way to the interior, will be forced away when the coupling member is expanded to the state necessary for coupling.

For optimum safety the locking member can be provided with a fastening part, for example in the form of a projection extending around it, which can cooperate with a fastening member disposed on the female and/or male pipe part, more particularly in the form of a groove in the male pipe part. A groove of this kind zan be formed Very easily.

It is particularly advantageous for the coupling member to be provided with a preferably flexible pull means extending out of the joint, for example in the form of a cord. In this way it can always be determined after assembly that the coupling member has actually been fitted, while the coupling member can also easily be pulled out of the pipe joint after removal of the locking member.

Finally, the invention also relates to a male pipe part provided with an external shoulder, together with a locking member and/or coupling member disposed thereon and surrounded on the outer side by a covering suitable for use in a pipe joint according to the invention. This makes it possible to provide for the user a male pipe part with a locking member and/or coupling member surrounded by a closed shrink film, so that after removal of the shrink film the joint can easily be made to a female pipe part, such as for example a socket or hub.

The invention further relates to a sleeve provided with an external shoulder, together with a locking member and/or coupling member surrounded on the outer side by a covering, such as for example a shrink film, thus raking it possible for the sleeve to be adhesive bonded on the male pipe part, whereupon, after removal of the shrink film, a pipe joint according to the invention can be made with the aid of a female pipe part.

The invention will now be explained with the aid of one example of embodiment and with reference to the accompanying drawings, in which: Figure 1 is a section through a finished pipe joint according to the invention; Figure 2 shows the pipe parts which are to be joined together to form a pipe joint according to the invention; Figure 3 shows a male pipe part provided with an external shoulder, together with a locking member and coupling member mounted on it and surrounded by a closed covering, and Figure 4 shows a sleeve which is to be connected to a male pipe part and which is provided with an external shoulder, a locking member and a coupling member surrounded by a closed covering in the form of a shrink film.

Figure 1 shows a finished pipe joint according to the invention, comprising a male pipe part 1 and a female pipe part 2 in the form of a socket end.

The inner side of the female pipe part 2 is provided with a collar seal 12 which cooperates with the male pipe part 1 and whose head is retained in a groove 26 by means of a retaining ring 24.

On the male pipe part, which is for example of polyvinyl chloride, a polyvinyl chloride sleeve 18 is secured by adhesive bonding and carries at the free inserted end a shoulder 3 provided with a top edge 17, which merges by way of a wall 16 and a'roun- ded portion 16a into a wall 14 which extends conically and is connected on the outer side to said sleeve 18.

It is obvious that if use is made of a male pipe part of glass fibre reinforced thermosetting resins, the sleeve 18 with the shoulder 3 can be formed during the winding of a male pipe part of this kind, so that a male pipe part 1 will be obtained which is integral with the sleeve 18 and the shoulder 3.

A recess in the form of a groove 4 is provided in the female pipe part 2 and has a bottom 22 and an outer stop edge 5. The stop edge 5 merges into a wall part 23 which is located at the free end of the female pipe part 2 and has an inside diameter which is always smaller than the outer diameter of the coupling member 6 in the non-expanded state, in order to enable the coupling member to be moved into and out of the region of the groove 4.

In order to obtain a tensile resistant coupling a ring 6 is provided which is split at one point in the longitudinal direction and which will also be made of hard polyvinyl chloride when use is made of a female pipe part 2 and a male pipe part 1, together with its sleeve 18 and shoulder 3, which are made of polyvinyl chloride.

It is expedient to ensure that the E modulus of the material of the coupling member 6 is substantially equal to that of the pipe parts with which the coupling member 6 cooperates.

The coupling member 6 is preferably provided with a preferably flexible pull means 7, generally in the form of a flexible cord, which passes out of the joint.

This cord 7 makes it possible and easy to pull the coupling member 6 out of the region of the groove 4 and to the outer side for the disconnection of the pipe joint, while in this way it can also be checked, after assembly, that the coupling member 6 has been fitted.

In order to obtain a tensile resistant coupling the coupling member 6 is expanded by the locking mem ber 8 whichhas a collar ~9 which can be struck in order to push the sleeve 8 under the coupling member, and thus to expand the coupling member 6. It will be clear that the radially resiliently expanded coupling member 6, in the state illustrated in Figure 1, cooperates clampingly with the sleeve-like part of the locking member 8. In Figure 2 it is indicated that the locking member or ring 8, in the non-deformed state, cooperates preferably clampingly with the outer -de of the sleeve 18 and shoulder 3.Assembly is rhus facilitated, because after the ring 8 has befn fitted it remains in position until ex pansio starts, although this is not indispensable.

In order to give the specialist assembling the joint 2n indication of the distance to which the locking member 8 must be driven inwards, a check ridge 11 is advantageously provided on the outer side of the sleeve 18.

It may be advisable, after the pipe joint has been made, for the locking member 8 to be additionally fastened for the sake of safety, for which purpose te locking member is provided with a rib 28 extending around it and adapted to snap into a groove 10 in the sleeve 18.

In order to prevent tilting on the expansion of the coupling member 6 when the latter is much smaller than te recess 4, it is advisable for the outer side 15 of the sleeve 18 to merge by way of the frustoconical wall 14 and a rounding wall 16a into a vertical wall 16 which is connected to the top part 17 of the shoulder. On the movement of the locking member 8 under the couplingmember 6, the tipping of the coupling member can then be avoided.

For the same reasons the bottom 22 of the groove 4 merges by way of a rounded portion 5a into a vertical wall which is connected to the inner wall 23 of the female pipe part 2.

It is advisable for the annular end partion 8' of the locking member 8 to merge by way of a frustoconical wall 19 into a cylindrical wall 27, extending in the direction of the collar 9, of the locking member 8.

This frustoconical wall 19 is desirable in order to for: an open space 21 to receive particles of sand wich are always entrained by the locking member during the assembly of the pipe joint and which could hinder the correct positioning of the locking member.

Through the provision of the frustoconical wall 19 the locking member can during its inward movement push these sand particles into the space 21 bounded by the locking member 8 and the groove 4.

Because of possible problems with the particles of sand entrained by the introduction of the locking member, it is also particularly advisable for the coupling member 6 always to be sufficiently loose in said space 21 to leave room to receive sand particles.

In order to achieve good resistance to tensile stress the couplingmember 6 preferably has a lengthto-height ratio of at least 2:1 so as to limit forces in the radial direction.

In most cases occurring in practice a sleeve 18 having a shoulder 3 will be secured by adhesive bonding, effected at the factory, to the outer side of the male pipe part, particularly when the latter is of thermoplastic synthetic material, such as polyvinyl chloride.

In certain cases, however, it is necessary for a male pipe part to be able to be secured by adhesive bonding to a sleeve 18 having a shoulder 3, at the assembly site itself. In such cases the sleeve 18 provided with the shoulder 3 and carrying the locking member 8, together with the coupling member 6 clampingly cooperating with the outer side of the sleeve 18 and in the form of a plastics ring split at one point in the longitudinal direction, is expediently supplied as an assembly which on the outer side is surrounded by a shrink film 20. At the point where the joint is to be made the sleeve 18 is then bonded to the male pipe part, whereupon the shrink film is removed so that the coupling member 6 and the locking member 9 are freed.It is obviously also possible to supply an assembly enclosed in a shrink film and consisting solely of the sleeve 18 and the locking member 9, or an assembly consisting of the sleeve 18 and the coupling member 6.

It may also be advisable for the male pipe part 1 to be fastened at the factory to the sleeve 18 together with the shoulder 3 and for the locking member 8 and coupling member 6 to be mounted on the outer side, whereupon these last-mentioned parts are enclosed in a shrink film 20. At the place where the joint is to be made it is then very easy to free the locking member 8 and the coupling member 6 by removing the shrink film.

As already stated, the male pipe part 1 may be made of a thermoplastic synthetic material, such as polyvinylchloride, on which a sleeve 18. with a shoulder 3, likewise of thermoplastic synthetic material, is then bonded. It is however also possible for the male pipe part 1 and the sleeve 18 with shoulder 3 to be made as a unitfrtm a fibre reinforced thermosetting resin.

When use is made of a male pipe part 1 of thermoplastic systhetic material, the female pipe part 2 will also be of a thermoplastic synthetic material.

When use is made of a male pipe part 1 of fibre reinforced thermosetting resin, the female pipe part 2 will advantageously also be made of fibre reinforced thermosetting resin.

The coupling member is advantageously made of a thermoplastic synthetic material.

Claims

CLAIMS 1. -Disconnectable pipe joint comprising at east a male pipe part provided with an out~--side shoul der, a female pipe part provided with an internal recess, a radially resiliently expansible coupling member for the tensile Pastening of the male and female pipe parts, said member being adapted to cooperate with an outer stop edge of the recess and with said shoulder, a sealing member, and also an axially slidable locking member cooperating with said coupling member, characterized in that the coupling member 9 is expanded by and cooperates resiliently with the locking member h~8,4 in such a manner that #in this expanded state the coupling member I#J./ can cooperate with said shoulder 9 and said szop edge
2. Disconnectable pipe joint according to Claim 1, characterized in that the locking member is provi ded with a fastening part adapted to cooperate with a fastening member disposed on the female and/or male pipe part.
3. Disconnectable pipe joint according to Claim 2, characterized in that the locking member h is fas tened by means of a snap connection .
4. Disconnectable pipe joint according to one or more of the preceding claims, characterized in that the locking member t is provided with a rib which extends around it and which, at least over a part of the periphery of the locking member, is adap ted to snap into a recess in one of the pipe parts.
5. Disconnectable pipe joint according to one or more of the preceding claims, characterized in that one of the pipe parts carries a check member
6. aisconnectable pipe joint according to one or more of the preceding claims, characterized in that the locking member H is provided with a wall extending conically and lying opposite the recess #I.
7. Disconrectable pipe joint according to one or more of th- preceding claims, characterized in that the space cccupied by the coupling member is smal ler than t space bounded by the locking member and that portion of the female pipe part < which lies around it.
8. Disconnectable pipe joint according to one or more of the preceding claims, characterized in that the shoulder W on the male pipe part has a frus- toconical mall which is disposed at some distance from the top of the shoulder and which merges by way of a rounded portion < into a wall W 1 which is connected to the top 9 of the shoulder
9. Disconnectable pipe joint according to one or more of the preceding claims, characterized in that said stop edge H #merges by way of a rounded por tion into the bottom 9 #of the recess and on the other hand into an adjoining internal end wall extending towards the outer side of the male pipe part.
10. Discornectable pipe joint according to one or more of the preceding claims, characterized in that the coupling member is provided with a preferably flexible Full means extending out of the joint.
11. Disconnectable pipe joint, characterized in that the E modulus of the coupling member is substantial ly equal to that of the pipe parts with which the coupling ember cooperates.
12. Disconnectable pipe joint according to Claims 1 to 11, characterized in that the shoulder on the male pipe part 9 is formed by a sleeve provi ded with such a shoulder and secured by adhesive bonding to and/or integral with the male pipe part
13. Locking member suitable for use in a disconnec table pipe joint according to one or more of the preceding claims.
14. Male pipe part provided with an external shoul der 7 and with a locking member and/or a c#u- pling member mounted on it and surrounded on the

outer side by a covering \ , suitable for use in a pipe joint according to one or more of Claims 1 to 12.
15. Sleeve provided with an external shoulder j(+j, together with a locking member W and/or a coupling member surrounded on the outer side by a cove ring H #, suitable for use in a pipe joint according to one or more of Claims 1 to 12.
16. A disconnectable pipe joint substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.
17. A male pipe part for a disconnectable pipe joint, substantially as hereinbefore ' described with reference to Figure 3 of the accompanying drawings.
18. A sleeve for a male pipe part of a disconnectable pipe joint substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.
19. A locking member for use in a disconnectable pipe joint and substantially as herein described with reference to the accompanying drawings.