GB2066399A

GB2066399A - A Ball and Socket Type Pipe Coupling

Info

Publication number: GB2066399A
Application number: GB8034527A
Authority: GB
Original assignee: Suiken KK
Current assignee: Suiken KK
Priority date: 1979-10-26
Filing date: 1980-10-27
Publication date: 1981-07-08
Also published as: JPS5666593U; JPS6329985Y2; FR2468824A1; FR2468824B1; DE3040117A1; CA1156286A; GB2066399B; DE3040117C2

Abstract

A ball and socket type pipe coupling comprises a pair of spaced socket housings (1a, 1b) each having a spherical concave surface (2), a pair of ball members at least one of which is in the form of an annular member (12b) having an outer spherical surface slidably engaged with the associated one of the concave surfaces and further having an internal, annular hollow space (14) defined by a pair of spaced annular walls (18', 19') which extend radially inwardly, and a single piece of joint pipe (11) which interconnects the pair of housings (1a, 1b) and is angularly movable with respect to each of the housings (1a, 1b) the annular member (12b) being mounted on one end section of the joint pipe (11) so as to slide back and forth on the pipe (11) until one of the spaced annular walls (18', 19') comes into contact against a stop member (15) which is fixedly mounted on the end section (11') of the pipe and positioned within the hollow space (14). <IMAGE>

Description

SPECIFICATION A Ball and Socket Type Pipe Coupling This invention relates to an improved ball and socket type pipe coupling, which is particularly advantageous when utilized in piping at a place where it is necessary to connect a pair of parallel pipe lines lying in two different planes or where it is expected that a pair of connected pipe lines might be subject to dislocation by an earthquake, subsidence of ground, or considerable weight, shocks or vibrations. The pipe coupling according to the invention is also very useful in repairing such pipe lines which have been misaligned or actually affected by dislocation or subsidence of ground.

Owing to subsidence of ground, caused for instance by lowering of the water table, or dislocation of ground caused by an earthquake or any other reason, one of a pair of fluid supplying pipe lines interconnected by a pipe coupling device is occasionally forced down to a new level lower than the level where the other pipe line lies, causing damage to the coupling device with a resulting leakage of fluid. However, the Applicant is not aware of any pipe coupling device which is advantageously designed for preventing the same from the above-mentioned damage caused by ground subsidence or some other catastrophe.

The conventional ball and socket type pipe coupling ad disclosed, for example, in Japanese Utility Model No. 76515/79 is of such a type that one of a pair of pipes interconnected by the coupling is capable of axial and angular movement relative to the other pipe but incapable of automatically establishing a new parallel relationship between the two centre lines thereof without losing the interconnection between the coupled pipes when one of the pipes is moved to a new different level or plane. The ball and socket type pipe couplings disclosed in U.S.A. Patent 2,918,313 and U.S.A.Patent 2,381,426 are capable of the aforementioned automatic establishment of a new centre line parallel relationship therebetween in response to a variation of the plane in which one of a pair of pipes is disposed, because they are designed so as to permit relative movement in all directions between the pair of coupled pipes.

However, the device of the first-mentioned U.S.A. patent has a specific construction such that a first half section of a socket housing mounted on a first pipe and a second half section thereof mounted on a second pipe are screwed together when assembled, and an axially and angularly movable joint pipe is not employed between the first and the second half sections of the socket housing. This invites the disadvantage that the freedom of axial and angular movement is so restricted that it is quite limited in utility and not applicable to piping in a place where a considerable difference between the pipe-lying levels may occur.

In the device of the second-mentioned U.S.A.

patent, a pair of joint pipes each having a spherical bulge formed integral with its one end are disposed between a pair of socket housings, this pair of joint pipes being different in diameter so as to be telescopic relative to each other. In other words, in the device of that U.S.A. patent, two kinds of non-interchangeable joint pipes which are specific in construction and different in diameter are necessary, resulting in an increase of manufacturing cost and inconvenience in application. Further, in this device of the U.S.A.

patent, no positive stopper means are provided for restricting the angular movement of the joint pipes and moreover the relative telescopic motion between the joint pipes, appears to invite easy breakage and less safety in the coupling.

Thus, the present invention consists in a ball and socket type pipe coupling comprising a pair of spaced socket housings each having an internally formed spherical concave surface, a pair of ball members each having a spherical outer surface disposed in spherically sliding contact with the associated concave surface, a single piece of joint pipe having at least one end section extended into the associated socket housing, at least one of said ball members being an annular member mounted on said end section of the joint pipe which is angularly movable in accordance with the spherically sliding movement of the annular member with respect to the associated socket housing, the annular member including a front end section formed with an annular projection extending radially inwardly and having an internal wall, a rear end section formed with an annular extension extending radially inwardly and having an internal wall, and an annular hollow space extending between said internal walls, said joint pipe being slidable back and forth relative to the annular member until one of said walls is in contact against a stop member which is fixedly mounted on said end section and positioned within said hollow space, preferably in its centre.

Both of the pair of socket housings as well as both of the pair of ball members are preferably structurally identical so as to be interchangeable.

However, none of the pair of ball members may be a spherical bulge formed at one end of the joint pipe. Each of the socket housings may preferably consist of a first half section and a second half section coupled together, so that the first half section can easily be removed for inspection or replacement of the parts disposed internally of the housing. Each of the socket housings may preferably be formed at its free end with a stopper surface which is engageable with the periphery of the joint pipe for preventing excessive angular movement of the joint pipe.

The pipe coupling is preferably provided with a suitable sealing member between the socket housing and the associated ball member and/or between the joint pipe and the associated ball member in the form of an annular member. The pipe coupling may also preferably be provided with a suitable indication means for giving a visible warning when the joint pipe is excessively pulled out of the socket housing.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a fragmentary side elevation of one embodiment of the ball and socket type pipe coupling according to the present invention; Figure 2 is an enlarged view showing a part of Figure 1; Figure 3 is a fragmentary side elevation showing a centre line offset position of the coupled pipes of Figure 1; Figure 4 is a similar view to Figure 3, but showing a centreline offset and axially extended position of the coupled pipes of Figure 1; Figure 5 is a similar view to Figure 1, showing a modification of the invention; Figure 6 is a fragmentary side elevation showing another embodiment of the present invention Figure 7 is a fragmentary side elevation, showing a centreline offset position of the coupled pipes of Figure 6; and Figure 8 is a similar view to Figure 7, but showing a centreline offset and axially extended position of the coupled pipes of Figure 6.

The ball and socket type pipe coupling of the invention comprises a pair of axially spaced socket housings 1 a, 1 b each of which is preferably a cup or bell-shaped member having open ends and formed internally with a spherical concave surface 2.

In the first embodiment as illustrated in Figures 1 to 4, one end of the first housing 1 a is formed with a flange 3a for connection with a first pipe line 4a by means of a cooperating flange 5a formed at the opposed end of the pipe line 4a, while the second housing 1 b is also formed with a flange 3b for connection with a second pipe line 4b by means of a cooperating flange Sb formed at the opposed end of the pipe line 4b. However, in a case where the diameter of the employed pipes is sufficient or a maximum fluid pressure to be applied to the pipe lines is so limited that safety is well maintained, the connection between the first pipe line 4a and the first housing 1 a as well as the connection between the second pipe line 4b and the second housing 1 b may be achieved by screwing as indicated at 3 in Figure 5.

The socket housings 1 a, 1 b may be a unitary structure; however, for the convenience of easy manufacture and dis-assembly, each of the housings 1 a, 1 b is preferably comprised of two separate pieces, that is, a first half section 6 and a second half section 7 which are coupled together when in use, for example, by means of bolts 8 and nuts 9 as illustrated in Figures 1 to 4 or by screwing as indicated at 8' in Figure 5. In maintenance, by removing the bolts 8 or by unscrewing at 8', the first half section 6 of the housing can be easily removed for inspection or replacement of the sealing members 22, 23, 25 and/or the stop ring 15. A free end 10 of each of the first half sections 6 is formed wi#h a surface 10' serving as a stopper for a purpose to be hereinafter described.Both of the housings 1 a, 1 b may be structurally symmetrical, but preferably are structurally identical for interchangeability.

In the embodiments shown in Figures 1 and 5, a single piece of joint pipe 1 1 is telescopically interposed between the pair of axially spaced housings 1 a, 1 b with each of its opposite end sections 11' extending into the housings, respectively. The meaning of the term "a single piece of joint pipe" herein used should not be limited so strictly but includes in its scope such a pair of pipes when made separately and then connected together by welding, screwing, or other conventional method.

Ball members in the form of annular members 1 2a, 1 2b, each having a spherical outer surface 13, are respectively mounted on the opposite end sections 11' of the joint pipe 1 The spherical radius of the surface 13 should be equal to that of the surface 2, so that both surfaces 13, 2 are in spherically sliding contact with each other. Thus, the ball members are independently rockable or angularly movable with respect to the associated housings. Each of the annular members 12a, 1 2b is internally formed with an annular hollow space 14 extending between its front and rear end sections.Within the hollow space 14, a stop member 15, preferably a split stop ring, is disposed and fixedly mounted on each of the end sections 11' of the joint pipe 1 The stop rings 15 should be prevented from axial dislocation. For this purpose, as best shown in Figure 2, it is preferable to form an annular groove 16 in the periphery of each of the end sections 11' of the pipe 1 1 so that the stop ring 15 can be snap fitted therein. Further, each stop ring 15 is preferably respectively located substantially in the centre of the distance (L2) (Figure 3) of the space 14 when the joint pipe 11 is in its normal position as shown in Figures 1 and 2.

The front end section 17 of each of the annular members 1 2a, 1 2b is formed with an annular projection 18 serving as a stopper and also as a guide for the relative axial movement between the joint pipe 1 1 and the associated annular member.

The projection extends radially inwardly and has an internal wall 18' (Figures 2 and 5) arranged so as to be engageable with the stop ring 15. For convenience of assembly and disassembly, this projection 18 is preferably formed as a separate piece of metal and then embedded in the front section 17, as best shown in Figure 2.

Alternatively, the projection may be mounted on the front end of each annular member by screwing as indicated at 24 in Figure 5. It is also possible to form the projection 18 integral with each body of the annular members 1 2a, 1 2b. The configuration of the projection may be modified in various ways. The length (L) (Figure 3) of the joint pipe 11 should be predetermined in the manner as will be hereinafter described.

The rear end section of each of the annular members 1 2a, 1 2b is formed with an annular extension 19 which extends radially inwardly and has an internal wall 19' (Figure 2). The extension 19 is formed with a pair of annular grooves 20, 21 in which a pair of known sealing members 22, 23 such as sealing rings or packings are fixedly positioned, so that a desired fluid sealing effect can be obtained between the joint pipe 11 and the annular members. One of the pair of sealing members 22, 23 may be eliminated as shown at 22' in Figure 5, or otherwise, three or more sealing members (not shown) may be employed, if desired. Anyway, it is important that the sealing member or members should be arranged so as to permit axially sliding motion of the joint pipe 11 relative to the annular members 1 2a, 1 2b.

A further sealing member 25 such as a sealing ring or packing known per se is interposed between the first housing 1 a and the annular member 1 2a, and also between the second housing 1 b and the annular member 1 2b for the known fluid sealing effect.

As shown in Figures 2 and 4, the joint pipe 11 is preferably provided with a pair of indication zones 26 on the periphery thereof in order than an operator or plumber can easily recognize how far the joint pipe 1 1 is axially pulled out of the housings. If the joint pipe has been pulled out to the maximum degree, the operator can know the fact by the indication zones 26 and do something to prevent an accident or damage to the coupling which might be caused for instance by an excessive fluid pressure axially applied to the coupling. The indication means may be a painted zone, a coloured tape, scale marks or any other suitable indications known per se.

In the embodiment of Figure 2, the indication zones 26 are respectively located under the annular projection 18, and the width (W) of the indication zone is substantially equal to one half of the distance (D1) between the projection 18 and the stop ring 15. Thus, when the joint pipe 11 is positioned at its fully inserted position as shown in Figures 1 and 3, the indication zones 26 are not visible from outside. However, as the pipe 26 is pulled out of the housings 1 a, 1 b, the indication zones appear gradually. When the pipe 1 1 is pulled out of the housings to the maximum degree, in other words, the pipe coupling takes its maximum extended position as shown in Figure 4, the indication zones appear substantially entirely so as to give visible warning that the pipe 1 1 should not be pulled out any further.

Figures 6 to 8 illustrate another embodiment of the invention, wherein one of the ball members is in the form of a spherical bulge 1 2C formed integral with or connected to one end of the joint pipe 11. The bulge 1 2C has a spherical outer surface 13' whose spherical radius is equal to that of the internal spherical surface 2 of the housing 1 a for achieving a relative sliding contact relationship therebetween. Thus, the joint pipe 11 is angularly movable with respect to the housing 1 a. As will be noted from Figures 6 to 8, the fundamental structure of the modification other than the ball member 1 2C is substantially the same as the structure of the preceding embodiment already described with reference to Figures 1 to 4.

The pipe coupling according to the invention is normally installed in such a manner that the centreline C, of the first pipe line 4a and the centreline C2 of the second pipe line 4b lie on the same plane or level, as shown in Figures 1, 3 and 6. When the level where the second pipe line 4b lies is lowered in the direction of an arrow P (Figures 3 and 7), for instance, by ground subsidence, resulting in the centreline C2 of the second line 4,6 being forcibly lowered by the distance (H) with respect to the centreline C2 of the first line 4a, while maintaining the parallel relationship therebetween, the joint pipe 1 1 can be inclined in the direction of an arrow Q (Figures 3 and 7) by a certain angle 0 defined by said distance (H,) since both of the ball members are independently rockable with respect to the socket housings. If the joint pipe is inclined to the maximum degree, the stopper surfaces 1 0' of the housings come into contact with the periphery of the pipe 1 1 to restrict its further inclination as shown in Figures 3, 4, 7 and 8.However, if the level of the second pipe line 4b is lowered by more than the distance (H,) and if the housing 1 b and the line 4b are permitted to go down further in the direction of an arrow R (Figures 4 and 8) by their own weight, while maintaining the parallel relationship between the centrelines C, and C2, the ball member 1 2b slides axially down on the joint pipe 1 1 until the internal wall 18' of the annular projection 18 is engaged with the stop ring 15.In this case, as will be easily understood, the value of the angle 0 does not vary but the distance (H2) between the centrelines C, and C2 is increased as compared with the aforementioned distance (H,). It also be easily understood that the value of (H2) in Figure 4 is greater than that in Figure 8, because in the embodiment of Figures 1 to 4, the pipe 11 is axially slidable within substantially the range of the distance (L2) (Figures 2 and 3), relative to the ball member 1 2a in the direction of the arrow R, while, in the embodiment of Figures 6 to 8, the pipe 1 1 is not axially slidable relative to the left-hand ball member 12c.

When a sudden fluid pressure is axially imparted to the coupled pipe lines lying in the same plane, one or both of the socket housings 1 a, 1 b can slide axially within substantially the range of the distance (L2). This results in the fluid pressure being advantageously absorbed to prevent a possible accident. If the joint pipe 11 is fully pulled out of the socket housings, the indication zone 26 appears so as to give a visible warning as described in the foregoing.

The pipe coupling according to the invention is also very useful for connecting a pair of parallel pipe lines which lie in different planes or levels.

For instance, when the pair of pipe lines extend in parallel with each other with a certain distance (H,) therebetween, an inclination angle O and the length (L,) or (L,) of the joint pipe can be adjusted so as to properly meet the distance (H,).

If a distance (D2) (Figure 3) between the pair of housings is so narrow, a joint pipe shorter than a standard length should be employed. On the other hand, in case the distance (D2) is too large to be absorbed by adjustment of the inclination angle 0 of a standard joint pipe 11, a joint pipe longer than the standard length should be employed. In this way, by preparing a longer or shorter joint pipe, it is possible to absorb the distance (D2) whatever value it may be.

Further, by varying a distance (L2) of the hollow space 14 and/or a distance (L3) between a pair of stop rings 1 5, it is possible to adjust the sliding area of the joint pipe. It is also possible to adjust the inclination angle 0 by varying the position of the stopper surface 10'.

Since it is very easy to adjust a length (L,) or (L,') of a joint pipe or a distance (L3) between a pair of stop rings beforehand or even at an actual job site, the pipe coupling of the invention has a large adjustability to absorb any distance (H,) between two centrelines C,, C2 of a pair of pipe lines 4a, 4,6 without losing a parallel relationship therebetween and thus has a wide utility and convenience in actual application.In particular with the embodiments of Figures 1 and 5, if a straight material pipe (not bulged at one end) of a sufficient length and a known slotting and cutting device (or a slotter and a pipe cutter) are available at the actual job site, the required repair to the damaged interconnection between the two pipe lines can easily be performed whatever distance (D2) (Figure 3) between a pair of housings 1 a, 1 b may be. Also with the embodiment of Figure 6, the aforementioned repair can easily be performed provided that either a pipe having a spherical bulge 1 2c formed at its one end and of sufficient length (L,) (Figure 7) in its straight section, or a combination of a ball member 1 2a and a sufficient length (L,) of straight material pipe without a spherical bulge 1 2c, is available at the actual job site. This particular advantage cannot be expected from the known pipe coupling devices heretofore proposed.

Claims

1. A ball and socket type pipe coupling comprising a pair of spaced socket housings each having a spherical concave surface formed internally thereof; a pair of ball members each having a spherical outer surface disposed in spherically sliding contact with the associated concave surface; and a joint means for interconnecting said pair of socket housings characterized in that said joint means is a single piece of joint pipe having at least one end section extended into the associated socket housing; and at least one of said ball members is an annular member mounted on said end section of the joint pipe which is angularly movable in accordance with the spherically sliding movement of said annular member with respect to the associated socket housing; said annular member including a front end section formed with an annular projection extending radially inwardly and having an internal wall, a rear end section formed with an annular extension extending radially inwardly and having an internal wall, and an annular hollow space extending between said walls; said joint pipe being slidable back and forth with respect to the annular member until one of said walls is in contact against a stop member which is fixedly mounted on said end section and positioned within said hollow space, preferably in its centre.

2. A pipe coupling according to Claim 1, wherein both of said pair of socket housings are structurally identical with each other.

3. A pipe coupling according to Claim 1, wherein said joint pipe has its opposite end sections each extending into the respective socket housing and having said stop member fixedly mounted on each of said end sections; both of said pair of ball members being annular members each mounted on the respective end section of said joint pipe.

4. A pipe coupling according to Claim 3, wherein both of said pair of annular members are structurally identical with each other.

5. A pipe coupling according to Claims 1, 2 or 3, wherein said stop member is a split stop ring snap fitted into an annular groove formed in said end section.

6. A pipe coupling according to Claim 1, wherein one of said pair of ball members is a spherical bulge formed with one end of said joint pipe.

7. A pipe coupling according to any of the preceding claims, wherein each of said pair of socket housings has a stopper surface formed at its free end for restricting an excessive angular movement of said joint pipe.

8. A pipe coupling according to any of the preceding claims, wherein each of said socket housings is comprised of a first half section and a second half section coupled together.

9. A pipe coupling according to any of the preceding claims, wherein said projection is formed of a separate piece of metal and embedded in said front end section of the annular member.

10. A pipe coupling according to any of the preceding claims, wherein said projection is formed of separate pieces of metal and mounted upon said front end section of the annular member by screwing.

11. A pipe coupling according to any of the preceding claims, wherein at least one sealing member is interposed between said socket housing and said ball member.

12. A pipe coupling according to any of the preceding claims, wherein at least one sealing member is interposed between said joint pipe ana said annular member.

13. A pipe coupling according to any of the preceding claims, wherein at least one indication means is provided on a periphery of said joint pipe for giving a visible warning against an excessive axial movement of the pipe relative to said annular member.

14. A pipe coupling according to Claim 13, wherein said indication means is a coloured zone.

15. A ball and socket type pipe coupling, substantially as herein described with reference to any of Figures 1 to 8 of the accompanying drawings.