GB2070176A - Pipe coupling - Google Patents

Abstract

A pipe coupling comprises a sleeve-like coupling body (10) which receives a grip seal (15), a lock washer (16) and an end cap (17). One end of the body (10) is closed by the end cap (17), which however has an aperture (23) through it, whilst the opposite end of the body has a bore (12) through it for insertion of a pipe. The pipe is tightly gripped by the seal (15) and washer (16) once it is inserted in the body (10) and its end abuts the end cap (17). The external surface of the body (10) has screw-threads (14) for engagement with matching internal screw-threads (31) on a socket portion (29, 34). The nature and arrangement of components in the coupling body (10) ensures a secure, efficient coupling of the pipe, whilst the engagement of the body (10) within the socket portion reduces the possibility of accidental unscrewing of the coupling body. <IMAGE>

Description

SPECIFICATION Pipe coupling This invention relates to pipe couplings, particularly for connecting copper piping and has as its object the provision of a pipe coupling in an efficient and convenient form.

According to the invention, a pipe coupling comprises a sleeve-like coupling body in which are disposed a lock washer and at least one sealing member, each having an aperture therethrough no greater in diameter than the external diameter of the pipe to be received in said coupling body, in use, one end of the coupling body being closed sufficiently to prevent said lock washer and said at least one sealing member passing therethrough but having a bore therethrough to allow passage of an end of said pipe into coupling body, and the exterior surface of said coupling body being adapted for engagement with a socket portion with which the pipe coupling is sealingly associated, in use.

According to a further aspect of the present invention, a pipe coupling comprises a socket portion at one end of a bore, there being an abutment between said bore and said socket portion, a sleeve-like coupling body in which are disposed a lock washer and at least one sealing member, each having an aperture therethrough no greater in diameter than the external diameter of the pipe to be received in the coupling body, in use, one end of the coupling body being closed sufficiently to prevent said lock washer and said at least one sealing member passing therethrough but having a bore therethrough to allow passage of an end of said pipe into the coupling body, which end of the pipe can bear, in use, against said abutment in the socket portion or an abutment at the other end of the coupling body, the exterior surface of the coupling body adapted for engagement with said socket portion, and the coupling body and the socket portion being sealingly engaged, in use.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded sectional view of parts of a pipe coupling of the present invention; Figure 2 shows the parts of Fig. 1 assembled for insertion into a socket portion into a socket portion at one end of a bore; Figure 3 is a part-sectional view showing the parts of Fig. 1 assembled together and received in a socket portion at one end of a further bore; Figure 4 is a top plan view, on an enlarged scale, of one of the parts of the coupling of Figs. 1 to 3; and Figure 5 is a cross-sectional view on the line 5-5 of Fig. 4.

Fig. 1 shows the parts,which make up a pipe coupling of one embodiment of the present invention. The coupling comprises a generally sleeve-like cylindrical coupling body 10 made of brass, but which alternatively could be made of plastics material or any, other suitable material. One end of the body 10 is open, whilst the other end is provided with an integral end wall 11 through which a circular bore 12 passes. The end wall 11 is, in this example, provided with a pair of diametrically opposed, radially extending slots 13 to allow the body 10 to be manipulated as will be described. Alternatively the external surface of the wall 11 could be of non-circular form, e.g.

hexagonal or octagonal, to allow rotation of the body 10 by suitable tool. A lower part of the external surface of the body 10, remote from the slotted end thereof, is provided with screw threads 14. The bore 12 has a diameter substantially equal to that of the external diameter of the pipe with which the coupling is intended to be used, so that an end of the pipe can pass through the bore 12 into the larger diameter of the body 10.

The coupling further comprises a grip seal 15, a lock washer 16 and an end cap 17.

The grip seal 15 is in the form of a resilient sealing grommet made of, for example rubber or plastics material. The seal is in the form of a generally square cross-section ring, but its underside, as shown in Fig. 1, is provided with an inverted generally V or U-shaped annular recess 19. An annular wall 20 of the seal at the side of the recess adjacent the aperture through the seal is inclined downwardly and outwardly towards the longitudinal axis of the seal. the external surface 18 of the grip seal is tapered so that the external diameter of the seal decreases towards the top of the seal, and moreover the interior surface 20a of the bore through the seal is tapered so that the diameter of the bore decreases towards the underside of the seal, the largest diameter of the bore matching the diameter of the bore 12.This inclination of the surface 20a ensures that the seal grips a pipe inserted therethrough, in use, as the minimum diameter of the aperture through the seal is smaller than that of the bore 12. Since the surface 18 is tapered, it assists reception into the body 10 and also enages the seal tightly therein.

Instead of the grip seal 15, an O-ring could be used to provide the required seal.

The lock washer 16 is in the form of a conventional star lock washer with slits to enable it to open to facilitate insertion of a pipe and then to grip the inserted pipe and prevent its removal, in use. The aperture defined through the lock washer 16 in its initial state, before pipe insertion, is smaller in diameter than the external diameter of the pipe The lock washer 16 is made of stainless steel or any other suitable hard material which will not rust.

The end cap 17, which, in this example, is made of plastics material, is in the form of a cylindrical plug having a hollow cylindrical body portion 21 and, at one of its ends, an end wall 22. An aperture 23 extends through the end wall 22, so that the portion of the end wall 22 remaining around the aperture 23 inwardly of the portion 21 provides an annular abutment surface 27 for the end of the tube inserted into the body 10, in use.

Thus the diameter of the aperture 23 is less than the external diameter of the pipe. The end wall 22 extends outside the portion 21, as shown in the Figs. to provide an external annular flange 24 at the end of the cap.

Figs. 4 and 5 show the end cap in detail, on an enlarged scale. As can be seen an external surface 25 of the body portion 21 is tapered, so that the external diameter of the body portion 21 decreases in a direction away from the end wall 22. As with the grip seal 15, this tapering assists insertion into the body 10.

As is also evident from Figs. 4 and 5, an internal surface 26 of the body portion 21 is tapered so that the diameter of the opening through the body portion 21 decreases towards the end wall 22. This taper of the surface 26 ensures that the surface tightly engages the end of a pipe which is inserted into the pipe coupling, in use. The engagement may, in fact, be so tight that the pipe is secured against the surface 26, without it bearing against the surface 27. This tight engagement prevents movement of the pipe out of alignment with the longitudinal coupling axis in use, which movement might weaken the grip of the teeth of the lock washer on the pipe.

Extending through the body portion 21 and end wall 22 of the end cap parallel to the central end cap axis, are six grooves 28 of part-circular cross-section, as seen in Fig. 4.

The grooves 28, which communicate with the open interior of the body portion 21 and the bore 23 are equi-angularly disposed and serve to allow resilience of the end cap, as well as destroying any seal between the end cap and the pipe, in use.

Fig. 2 shows the body 10 with the various parts of the coupling assembled together. As can be seen from Fig.2, the grip seal 15 is disposed within the body 10 in contact with the end wall 11 with the lock washer being disposed next to and in contact with the grip seal 1 5, the body portion of the end cap 17 being finally received into the open end of the body 10. The body portion 21 of the end cap 17 bears against the lock washer 16, whilst the flange 24 bears against the annular end surface of the body 10. The end cap thus acts as a plug to hold the seal 15 and lock washer 16 in the body 10.

As can be seen from Fig. 2, the body 10 is intended to be received into a sleeve member 29, which has a pair of socket portions 30, each of which is internally threaded, as indicated at 31, so as to engage with the complementary threads 14 on the body 10. The member 29 has an internal annular flange 32, which defines the two separate socket portions 30. The flange 32 has a bore 32a therethrough, the diameter of which is smaller than the diameter of the bore 12 in the end wall 11 of the body 10.

The arrangement is such that, in use, the elements 15 to 17 are assembled together with the body 10, as shown in Fig. 2, and the body 10 is then screwed into one of the socket portions 30 by means, in this example, of a special tool engaged in the slots 13. The body 10 is screwed into the socket portion 25 until the flange 24 tightly engages the flange 32.

With the body 10 thus engaged in the socket portion 30, the end of the pipe to be coupled is inserted through the bore 12 and into the body 10 until the end of the pipe contacts, the tapered surface 26 or the abutment surface 27 provided by the end cap 17.

When the pipe, which is preferably of copper or like metal, is inserted into the body 10, it is a close sliding fit through the bore 12 and compresses the grip seal 15 so that the tapered surface 20a of the seal 15 tightly sealingly grips the pipe. The lock washer 16 also tightly grips the external surface of the pipe to prevent its removal, while the pipe is also a close sliding fit in the end cap 17, against the surface 26, and/or against the abutment surface 27, as already described.

Thus, by this arrangement a tight seal is obtained both between the pipe and the body 10, and also between the body 10 and the socket portion 30. Both the grip seal 15 and the lock washer 16 tightly grip the exterior surface of the tube, and by way of the lock washer 16, removal of the pipe from the body 10 is effectively prevented.

The body 10 and the sleeve member 29 are relatively easy to produce. Moreover a coupling of the invention is advantageous in that it can be used with stainless steel pipes as well as with copper or plastics pipes. Some known couplings cannot be used with stainless steel pipes as such a pipe would be insufficiently gripped. A further advantage of the coupling of the invention is that since the body 10 screws into the socket portion 30, rather than onto its exterior, there is less chance of the body being accidentally unscrewed.

If required, it would be possible in an emergency to remove the pipe from the body 10, by unscrewing the body from the socket portion 30, removing the end cap 17, and prizing the lock washer off the pipe. On reassembly, a fresh lock washer would naturally be required.

An alternative embodiment of the invention would be the replacement of the grip seal by an O-ring and a disc seal, the apertures through these members being smaller in diameter of the pipe, so as tightly to engage the pipe, in use. With this alternative arrangement, the O-ring would be disposed against the end wall 11 of the body 10.

With the arrangement shown in Fig. 2, a.

pair of pipes can be coupled together, by way of a pair of coupling bodies 10 engaging in the socket portions 30 respectively. This arrangement gives a linear connection between the two pipes. However, alternatively, the body 10 could engage in a socket portion formed integrally at the end of the pipe, valve, tap or like member. All that is required is that the socket portion has an internal screw-thread to match the external screwthread 14 on the body 10, with the socket portion also providing an abutment flange, such as the flange 32 of the sleeve member 29 shown in Fig. 2, against which the flange 24 bears when the body 10 is fully screwed into the socket portion.As a development of the member 29 shown in Fig. 2, the socket portion need not of course be a straight sleeve but could instead by a right-angled sleeve with socket portions at its ends disposed at 90 to one another. As a further alternative, the sleeve could be in the form of a T-piece-to allow three tubes to be coupled together, the three ends of the T-piece being internally threaded, each to receive a body 10. Instead of the screw-threaded arrangement shown, an alternative means of engagement between the body 10 and a socket portion can be employed, but any alternative means must be able to provide the necessary tight sealing engagement between the two members which is necessary to prevent leakage or even disengagement.

The arrangement shown in Fig. 3 is quite similar to that shown in Figs. 1 and 2, in that the coupling shown therein comprises a coupling body 10 of identical form to that shown in Figs. 1 and 2. Similarly, the body 10 contains, in the assembled form of the coupling, a grip seal 1 5, lock washer 16 and end cap 17. When the seal 15. washer 16 and end cap 17 are assembled, the assembled body unit 10 is then screwed into an associated socket portion 34.

As shown in Fig. 3, the socket portion is integrally provided at the end of a pipe 33 and has internal screw threads complementary to the threads 14 on the body. The body 10 is screwed into the socket portion 34 using, in this example, a special tool engaged in the slots 13, and when fully engaged, the flange 24 of the end cap 17 engages against an annular flange 35 between the pipe 33 and socket portion 34, the flange 35 thus acting as a seal. The flange 35 has a bore therethrough of a diameter less than the diameter of the bore 12.

In use, the copper or other material pipe is inserted through the bore 12, the pipe passing through the seal 15 and the lock washer 16, into the end cap 17, until the end of the tube engages against the surface 26 or the abutment surface 27 of the end cap 17, in a similar manner to the arrangements shown in Figs. 1 and 2. Again, if necessary in an emergency, the body 10 can be unscrewed and the various parts of the coupling removed from the pipe.

In an alternative arrangement, the end cap 17 could be provided with an annular recess extending axially into the portion 21 of the end cap from its end remote from that through which the aperture 23 extends. With this arrangement the end of the inserted pipe would engage in this annular recess, instead of merely bearing against the surface 26 or the surface 27 of the end wall.

As with the arrangement shown in Figs. 1 and 2, the body 10 shown in Fig. 3 can be engaged with any convenient socket portion at one end of a bore. In the embodiments illustrated, the socket portion 34 is at the end of a bore through a pipe 33, whilst in the Fig.

2 embodiment, it can be considered that each socket portion is at the end of a bore provided by the other socket portion, or alternatively each socket portion can be considered to be at the end of the bore 32a enclosed by the flange 32.

As an alternative arrangement from that shown in the drawings, the internal diameter of the pipe 33 itself could be the same as the diameter of the bore through the flange 35, i.e. smaller than the external pipe diameter.

Claims (13)

1. A pipe coupling comprising a sleevelike coupling body in which are disposed a lock washer and at least one sealing member, each having an aperture therethrough no greater in diameter than the external diameter of the pipe to be received in said coupling body in use, one end of the coupling body being closed sufficiently to prevent said lock washer and said at least one sealing member passing therethrough but having a bore therethrough to allow passage of an end of said pipe into the coupling body, and the exterior surface of said coupling body being adapted for engagement with a socket portion with which the pipe coupling is sealingly associated, in use.

2 A pipe coupling comprising a socket portion at one end of a bore, there being an abutment between said bore and said socket portion. a sleeve-like coupling body in which are disposed a lock washer and at least one sealing member, each having an aperture no greater in diameter than the external diameter of the pipe to be received in the coupling body, in use. one end of the coupling body being closed sufficiently to prevent said lock washer and said at least one seallng member passing therethrough but having a bore therethrough to allow passage of an end of said pipe into the coupling body, which end of the pipe can bear, in use, against said abutment in the socket portion or an abutment at the other end of the coupling body, the exterior surface of the coupling body being adapted for engagement with said socket portion, and the coupling body and the socket portion being sealingly engaged, in use.

3. A coupling as claimed in claim 1, wherein the other end of the coupling body is provided with an abutment for said end of the pipe.

4. A coupling as claimed in claim 2 or claim 3, wherein said abutment at said other end of the coupling body is provided by an end cap which is received in said other end of the coupling body, the end cap having a bore therethrough, the diameter of which is less than the external diameter of said pipe to be received in said coupling body.

5. A coupling as claimed in claim 4, wherein said end cap comprises a hollow cylindrical body portion which is open at one end and has at its other end wall through which said bore extends, said bore having a diameter less than the internal diameter of said cylindrical body portion of the end cap at said other end so as to produce an annular abutment surface inwardly of said body portion and around said bore.

6. A coupling as claimed in claim 5, in which the interior surface of said cylindrical body portion is tapered outwardly away from said end wall, said end of the pipe, in use, engaging against either said annular abutment surface or said tapered internal surface.

7. A coupling as claimed in claim 5 or claim 6, in which a plurality of grooves extend through said annular abutment surface and the interior surface of said body portion, thereby destroying any seal between the end cap and the pipe, in use.

8. A coupling as claimed in claim 7, wherein a multiplicity of equi-angularly spaced grooves extending parallel to a central axis of the end cap are provided.

9. A coupling as claimed in claim 2 or claim 3, wherein an end cap received in said other end of the coupling body has an annular recess therein, into which recess said end of the pipe is received, in use, so as to abut against the end cap which thus defines said abutment.

10. A coupling as claimed in any one of the preceding claims, wherein said at least one sealing member is a grip seal in the form of a generally square cross-section ring having a generally V or U-shaped recess in one of its end surfaces.

11. A coupling as claimed in claim 10, wherein the interior surface of the seal is tapered so that the bore defined through the seal decreases in diameter in a direction towards the end surface in which said recess is formed, the maximum diameter of said bore through the seal being substantially equal to the diameter of said bore in said one end of the coupling body.

12. A coupling as claimed in any one of the preceding claims, wherein said exterior surface of said coupling body is internally screw-threaded to engage, in use, with a complementarily internally screw-threaded part of said socket portion.

13. A pipe coupling substantially as here.

inbefore described, with reference to, and as shown in Figs. 1, 2, 4 and 5 or Fig. 3 of the accompanying drawings.