GB2273537A

GB2273537A - Sealing ring for spigot and socket pipe joints

Info

Publication number: GB2273537A
Application number: GB9305985A
Authority: GB
Inventors: Yong Goo Shin
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-12-17
Filing date: 1993-03-23
Publication date: 1994-06-22
Anticipated expiration: 2013-03-23
Also published as: CN2165289Y; JPH0678665U; GB9305985D0; GB2273537B

Abstract

A water-expandable ring packing 10 of synthetic rubber comprises a retaining part 17 with outer and inner sealing parts 12, 13 projecting therefrom. The sum of thicknesses of the outer and inner sealing parts 12, 13 is substantially equal to the gap (L, Fig. 2) the ring fills between the outer surface of a male pipe and the inner surface of a collar of a female pipe. One or both of the outer and inner sealing parts 12, 13 may be provided with a water-expandable rubber piece (16, Fig. 3)at an inner surface thereof and/or the ring packing may be made of a material of water-expandable rubber as a whole. In another embodiment (Fig. 5B) a single sealing part (11) has an inner diameter which decreases towards its free end. <IMAGE>

Description

RING PACKING The present invention relates to a rubber ring packing, more particularly to a ring packing which can be waterexpandable and which is used to be fitted in the connection of a male end of a pipe within a female collar of a pipe, such as a PVC water pipe, in order to connect them tightly and sealably.

Referring to Fig. 5A, there is shown a known ring packing. The ring packing 10, which is fitted between male 20 (see Fig. 2) and female pipes 30, is generally constructed in an annular shape, having a retaining ring part 17 and a seal part 11 projecting toward its free end, and serves to prevent water leakage from a joint portion of the pipes.

The conventional ring packing 10 is made of a material of synthetic rubber, having a strength sufficient to resist a water pressure and an elasticity sufficient to prove a seal effect.

The above-mentioned conventional ring packing 10 serves to prevent a water leakage from a joint portion of water pipes, to align the two pipes, and to absorb external impact so as to prevent occurrence of cracks in the joint portion of the pipes.

As shown in the drawing, the ring packing 10 for water pipes has the sealing part 11 which is increased toward the female pipe 30 in thickness to form a thickened free end.

Otherwise stated, the sealing part 11 of ring packing 10 is reduced toward the female pipe 30 in inner diameter.

Therefore, when the male pipe 20 is inserted into the collar part of female pipe 30 after the ring packing 10 has been disposed in the collar part of female pipe 30, an insertion resistance is increased considerably.

Hence, it is difficult to insert the male pipe 20 into the female pipe 30 due to the increase of insertion resistance, thereby decreasing an operational efficiency.

However, since a sealing effect is increased in proportion to the increase of insertion resistance, user must willingly submit to the decrease of operational efficiency.

The present invention has been made in view of the abovedescribed prior art problems and an object of the invention is to provide a water-expandable ring packing which is capable to minimize an insertion resistance and to improve a sealing effect in connection of pipes.

In accordance with the present invention, there is provided a ring packing for sealing a gap between an outer surface of a male end of a pipe and an inner surface of a female collar of an end of a pipe, said ring packing comprising a retaining part with a sealing part projecting therefrom, wherein said sealing part comprises an outer sealing member and an inner sealing member with a groove formed therebetween and the sum of thicknesses of the outer and inner sealing members is substantially equal to or less than the gap for which it is intended.

One or both of the outer and inner sealing members can be provided with a water-expandable rubber piece within the groove.

Alternatively, the sealing part may comprise a single sealing member with the inner diameter of the member becoming smaller toward its free end.

The present invention will be further described by way of non-limitative example, with reference to the accompanying drawings, in which: Fig. 1 is a partly sectioned perspective view of a water-expandable ring packing according to the present invention; Fig. 2 is a sectional view of a connected portion of male and female pipes; Fig. 3A is a sectional view of a water-expandable ring packing according to an embodiment of the invention; Fig. 3B is a view similar to Fig. 3A showing another embodiment of the invention; Fig. 3C is a view similar to Fig. 3A showing still another embodiment of thr invention; Fig. 4A is a sectional view of the water-expandable ring packing of the invention which is disposed in a collar of a female pipe;; Fig. 4B is a view similar to Fig. 4A in which a male pipe inserted into the collar via the ring packing; Fig. 4C is a view similar to Fig. 4A in which the ring packing is expanded by being contacted with water; Fig. EA is a sectional view of a conventional ring packing; and Fig. 5B is a sectional view of the simplest waterexpandable ring packing of the invention.

Referring first to Fig. 1, there is shown a waterexpandable ring packing of the present invention which is sectioned partly for a better understanding. As shown in the drawing, the ring packing 10 comprises a retaining part 17, an outer sealing part 12 projecting therefrom and an inner sealing part 13 projecting therefrom such that an annular valley 14 is provided between the outer and inner sealing parts 12 and 13.

Referring to Fig. 5B there is shown the simplest ring packing of the invention which is disposed in a collar of a female pipe. The ring packing 10 comprises a retaining part 10 and a sealing part 11 projecting therefrom. The sealing part 11 is increased toward a female pipe 30 in thickness.

Referring to Fig. 2, there is shown female and male pipes which are connected each other. The female pipe 30 is formed with an enlarged collar 40 at its end and the collar 40 is formed with an annular groove 50 at its middle position. The male pipe 20 is inserted into the collar 40 at its end.

The ring packing 10 is disposed in the annular groove 50 of the collar 40. A thickness of the sealing part 11 or a sum of thicknesses of the outer and inner sealing parts 12 and 13 of the ring packing 10 is equal to a gap "L" between an outer surface of the male pipe 20 and an inner surface of the collar 50 of the female pipe 30. The ring packing 10 is more preferable to have a pair or more of divided sealing parts rather than a single sealing part so as to enlarge an area contacting with water.

When the ring packing 10 has the outer sealing part 12 and the inner sealing part 13, it is preferable that the inner sealing part 13 is reduced toward its free end in inner diameter. Accordingly, the male pipe 20 is fixedly fitted in the female pipe 30 because the reduced inner sealing part 13 tightly grips the male pipe 20 by its elasticity.

On the other hand, the ring packing 10 shown in Fig. 58 has a strength unsuitable to resist high water pressure and also has a lower expansion effect due to its smaller area contacting with water.

Since a water-expandable rubber is lower than an usual synthetic rubber in strength, the ring packing 10 made of a single material of water-expandable rubber as shown in Fig. 5B is suitable to a condition of lower water pressure.

Referring to Figs. 3a to 3B, there are shown various embodiments of the present invention for overcome the disadvantage of the ring packing of Fig. 5B. As shown in the drawings, the ring packing 10 has a sealing part divided into the outer and inner sealing parts 12 and 13. The ring packing 10 of the invention is made of a synthetic rubber (see Fig.

3A). Further, a water expandable rubber pièce 16 may be attached to the ring packing 10,@on one or both of surfaces of the outer and inner sealing parts 12 and 43 which face each other (see Figs. 3B and 3C).

The annular valley 14 is ~~- open toward the female pipe 30 such that water is easily introduced into the annular valley 14 and easily contacted to the surfaces of the outer and inner sealing parts 12 and 13.

The ring packing 10 shown in Fig. SA Is made of only a water-expandable rubber as a whole and thus suitable to a condition of water pressure of up to or roughly 5Kgf/cm.

The ring packing 10 shown in Fig. 3B is made of a synthetic rubber and provided with a water-expandable rubber piece 16 at one facing surface of the outer and inner sealing parts 12 and 13. The ring packing it is suitable to a condition of water pressure of 6 - 9 Kgf/c#.

The ring packing 10 shown in Fig. 3B is made of a synthetic rubber and provides with a water-expandable rubber piece 16 at both facing surfaces of the outer and inner sealing parts 12 and 13. The ring packing 10 is suitable to a condition of water pressure of roughly 10Kgf:cm or more.

The water-expandable rubber is composed of synthetic rubber material added with hydrophilic high-molecular compound such as polyvinyl alcohol, polyethylene oxide, polyurethane and used as a corking material for plugging a gap between cement structures.

Referring to Figs. 4A to 4C, there are shown serial operations of the ring packing made of water-expandable rubber which is fitted between the outer and Inner pipes 20 and 30.

In use, the ring packing 10 is first disposed in the collar portion 40 of the outer pipe 3D1 as shown in Fig. 4A.

Thereafter, the male pipe 20 is inserted into the collar portion 40 via the ring packing ID, As shown Fig. 4B. At this time, since the sum of thicknesses of the outer and inner sealing parts 12 and 13 is equal to a gap between the outer surface of the male pipe 20 and the inner surface of collar 40, the male pipe 20 is easily inserted into the ring packing 10. As the water-expandable ring packing 10 comes into contact with water, the ring packing 10 is progressively expanded to tightly grip the male pipe 20 so that the male pipe 20 is fixedly fitted in the female pipe 30, as shown in Fig. 4C.

As apparent from the above description, the present invention is a ring packing for a water pipe utilizing a physical property of water-expandable rubber. The waterexpandable ring packing of the invention is also modified in a structure of sealing part thereof such that a male pipe is easily inserted into a female pipe without insertion resistance. Therefore, the water-expandable can prevent breakage and deformation of a water pipe caused by forcible insertion of a male pipe by strike and provide connected pipes with a sufficient sealing effect.- Also, the present invention allows pipes to be connected easily-each other.* - -# - Although the preferred embodiments of the invention have been disclosed for illustrative purpose, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope of the invention as disclosed in the'accompanying claims.

Claims

1. A ring packing for sealing a gap between an outer surface of a male end of a pipe and an inner surface of a female collar of an end of a pipe, said ring packing comprising a retaining part with a sealing part projecting therefrom, wherein said sealing part comprises an outer sealing member and an inner sealing member with a groove formed therebetween and the sum of thicknesses of the outer and inner sealing members is substantially equal to or less than the gap for which it is intended.

2. A ring packing according to claim 1 wherein said groove is annular.

3. A ring packing according to claim 1 or 2 wherein the inner face of the groove of at least one of said outer and inner sealing members is formed with a recess of a predetermined depth, said at least one recess being provided with a water-expandable rubber piece, corresponding to the recess therein.

4. A ring packing according to claim 3, wherein recesses are formed on the inner faces of the groove of both said outer and inner sealing members and are provided with said rubber pieces.

5. A ring packing according to any one of the preceding claims wherein the inner diameter of the sealing part decreases towards its free end, away from the retaining part.

6. A ring packing for sealing a gap between an outer surface of a male end of a pipe and an inner surface of a female collar of an end of a pipe, said ring packing comprising a retaining part with a sealing part projecting therefrom, the thickness of which is substantially equal to or less than the gap for which it is intended and wherein the inner diameter of said sealing part decreases towards its free end, away from the retaining part.

7. A ring packing according to any one of the preceding claims wherein the thickness of the sealing part decreases away from the retaining part.

8. A ring packing according to any one of the preceding claims wherein the retaining part is shaped to fit in a recess on the inner surface of the female collar.

9. A ring packing according to any one of the preceding claims wherein said ring packing is made of at least one synthetic rubber material.

10. A ring packing according to any one of the preceding claims wherein the majority of the ring packing is made of water-expandable rubber material.

11. A ring packing according to claim 10 wherein the majority is substantially the whole.

12. A ring packing according to any one of claims 1 to 9 which is water-expandable.

13. A ring packing substantially as hereinbefore described with reference to and as illustrated in accompanying drawings Figures 1 - 4 and SB.

14. A pipe connection comprising a male end of a pipe, a female collar of a pipe, and a ring packing according to any one of the preceding claims.