Separation preventive pipe joint and pipeline constituent member

Abstract

A separation preventive pipe joint having an adjustable angle of deflection. A lock ring storage groove accommodates a metallic lock ring that can be engaged with a spigot protrusion and a cushioning material that comes into contact with a bottom of the lock ring storage groove and a side wall on a socket opening side. The cushioning material is made of a material softer than the lock ring.

Claims

1. A separation preventive pipe joint comprising: a socket formed on an end of a first pipeline constituent member; and a spigot formed on an end of a second pipeline constituent member, the spigot being inserted into the socket, wherein the socket has a lock ring storage groove on an inner periphery of the socket, the lock ring storage groove accommodating (i) a metallic lock ring engageable with a protrusion formed on an outer surface of the spigot, and (ii) a cushioning material that comes into contact with a radially-inward directed lock ring-facing bottom of the lock ring storage groove and a side wall of a socket opening, the cushioning material being made of a material softer than the lock ring, wherein an empty space is formed between a radially-outward directed socket-facing surface of the lock ring and the bottom of the lock ring storage groove, wherein the cushioning material is configured such that when the first pipeline constituent member and the second pipeline constituent member are connected in a deflected state, a contact area of the cushioning material with the lock ring is deformed to expand in a circumferential direction according to an increase in force in a direction that separates the spigot from the socket.

2. The separation preventive pipe joint according to claim 1, wherein the cushioning material is made of resin.

3. The separation preventive pipe joint according to claim 1, wherein the lock ring has a socket opening side where a surface inclines outward, and the cushioning material has a socket rear side where a surface inclines inward so as to come into contact with the inclined surface of the lock ring.

4. The separation preventive pipe joint according to claim 1, wherein the cushioning material is polyethylene.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cross-sectional view showing the principal part of a separation preventive pipe joint according to an embodiment of the present invention;

(2) FIG. 2 is a cross-sectional view showing the principal part of the separation preventive pipe joint in a deflected state according to the embodiment of the present invention;

(3) FIG. 3 is a cross-sectional view showing the principal part of a conventional separation preventive pipe joint;

(4) FIG. 4 is a cross-sectional view showing the principal part of the conventional separation preventive pipe joint in a deflected state;

(5) FIG. 5 is a cross-sectional view showing the principal part of another conventional separation preventive pipe joint;

(6) FIG. 6 is a cross-sectional view showing the principal part of this conventional separation preventive pipe joint in a deflected state;

(7) FIG. 7 is a cross-sectional view showing the principal part of still another conventional separation preventive pipe joint;

(8) FIG. 8 is a cross-sectional view showing the principal part of this conventional separation preventive pipe joint in a deflected state;

(9) FIG. 9 is a cross-sectional view showing the principal part of yet another conventional separation preventive pipe joint; and

(10) FIG. 10 is a cross-sectional view showing the principal part of this conventional separation preventive pipe joint in a deflected state.

DETAILED DESCRIPTION OF THE INVENTION

(11) A separation preventive pipe joint according to an embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing the principal part of the separation preventive pipe joint according to the embodiment of the present invention.

(12) In FIG. 1, reference numeral 1 denotes a socket formed on the end of one pipe (pipeline constituent member) and reference numeral 2 denotes a spigot formed on the end of another pipe (pipeline constituent member). When these pipes (pipeline components) are connected to each other, as shown in FIG. 1, the spigot 2 is inserted into the socket 1.

(13) On the inner periphery of the socket 1, a lock ring storage groove 3 and a seal member storage groove 4 are formed in this order from the opening of the socket. An annular spigot protrusion 5 is fixed around the spigot 2 by welding or the like. The seal member storage groove 4 formed on the inner periphery of the socket 1 has an annular elastic seal member 6 made of rubber or the like. The lock ring storage groove 3 formed between the opening and the seal member storage groove 4 of the socket 1 has a lock ring 7 having one slit in its circumference and a cushioning material 8 having one slit in its circumference.

(14) Small pieces (not shown) are attached to opposing ends of the one slit of the lock ring 7 in its circumference. Moreover, a cut-out portion is provided at a point on the circumference of the opening end face of the socket 1. The intervals of the small pieces are adjusted from the outside of the socket 1 through the cut-out portion by using, for example, a bolt or a nut (not shown). This can expand or shrink the lock ring 7 disposed in the lock ring storage groove 3 in the socket, in diameter.

(15) Consequently, when the socket 1 and the spigot 2 are joined to each other, the spigot protrusion 5 can pass through the interior of the lock ring 7, which is elastically expanded in diameter by an operation from the outside of the socket, to the rear of the socket 1. After the passage, the lock ring 7 is fit onto the outer periphery of the spigot 2 by an operation from the outside of the socket so as to be engaged from the rear of the socket 1. The annular seal member 6 is compressed between the socket 1 and the spigot 2 so as to seal a clearance between the socket and the spigot. The end rim of the spigot 2 has an inclined surface 2a that tapers toward the end of the spigot 2.

(16) In this configuration, the lock ring 7 stored in the lock ring storage groove 3 is made of a metal and is fit onto the outer periphery of the spigot 2 as has been discussed. The cushioning material 8 stored in the lock ring storage groove 3 is disposed between the opening of the socket and the lock ring 7 so as to be in contact with a bottom 3a of the lock ring storage groove 3 and a side wall 3b of the socket opening. The cushioning material 8 is made of a material softer than the lock ring 7, for example, a resin material such as polyethylene in the present embodiment.

(17) On the socket opening side of the lock ring 7, an inclined surface 7a is formed so as to incline outward, that is, the inner side of the inclined surface 7a is radially inclined toward the opening of the socket. Accordingly, on the socket rear side of the cushioning material 8, an inclined surface 8a is formed so as to incline inward, that is, the outer side of the inclined surface 8a is radially inclined toward the rear of the socket. As shown in FIG. 1, the inclined surface 7a of the lock ring 7 and the inclined surface 8a of the cushioning material 8, specifically, an inner portion on the inclined surface 7a of the lock ring 7 and an outer portion on the inclined surface 8a of the cushioning material 8 can be brought into contact with each other in an inclined position. As shown in FIG. 1, the lock ring 7 set in the lock ring storage groove 3 does not directly come into contact with the socket 1.

(18) As has been discussed, the lock ring storage groove 3 accommodates the metallic lock ring 7 that can be engaged with the spigot protrusion 5 and the cushioning material 8 that comes into contact with the bottom 3a of the lock ring storage groove 3 and the side wall 3b on the socket opening side. The cushioning material 8 is made of a material such as resin softer than the lock ring 7. With this configuration, in the case of connection in a deflected state, for example, at a point where at least one of a pipe having the socket 1 and a pipe having the spigot 2 is a fitting, e.g., a bend or a tee or at a junction between pipes in a certain distance range continuing to the point, a force is applied in this state in a direction that separates the spigot 2 from the socket 1 in response to an uneven force generated by a water pressure in the pipe so as to move the pipe. Thus, initially, the cushioning material 8 and the lock ring 7 (specifically, the inclined surface 8a of the cushioning material 8 and the inclined surface 7a of the lock ring 7) only partially (an inner portion in the deflected state) come into contact with each other in a circumferential direction, that is, in a so-called edge loading state. However, as a force applied in the separating direction increases, the contact area of the cushioning material 8 with the lock ring 7 is deformed to expand in the circumferential direction, and then as shown in FIG. 2, the cushioning material 8 and the lock ring 7 come into contact with each other on the circumference or a portion near the circumference, that is, over a wide area. Hence, even if a large force, e.g., a drawing force generated by a water pressure in the pipe is applied to the pipe in a removing direction, the cushioning material 8 in contact with the socket 1 and the lock ring 7 in contact with the spigot protrusion are satisfactorily brought into contact with each other without being placed into an edge loading state. This can reliably prevent separation between the socket 1 and the spigot 2, achieving a reliable separation preventing function.

(19) Moreover, the metallic lock ring 7 and the cushioning material 8 made of a material softer than the lock ring 7 are disposed in the lock ring storage groove 3 with a simple structure. Thus, the separation preventive pipe joint can be assembled (worked) with reduced time and work in a working site where pipes are installed and joined, achieving high workability and working efficiency.

(20) In an initial state where a drawing force generated by a water pressure in the pipe is not applied to the pipe, the cushioning material 8 is not considerably deformed and is only partially in contact with the lock ring 7 in the circumferential direction. This facilitates adjustments of the angle of deflection of the pipe joint in a working site, achieving high workability. Moreover, the cushioning material 8 in the initial state is not considerably deformed and is only partially in contact with or is separated from the lock ring 7 in the circumferential direction. Thus, the steps of connecting the pipes are reversed to advantageously disassemble the pipe joint with relative ease.

(21) Furthermore, in this configuration, the socket opening side of the lock ring 7 has the inclined surface 7a that inclines outward while the socket rear side of the cushioning material 8 has the inclined surface 8a that inclines inward so as to come into contact with the inclined surface 7a of the lock ring 7. Thus, the application of a force for removing the spigot 2 from the socket 1 satisfactorily brings the cushioning material 8 and the lock ring 7 into contact with each other. Furthermore, the reaction force of a force applied to the inclined surfaces 7a and 8a brings the cushioning material 8 into contact with the lock ring storage groove 3 with a stronger force and satisfactorily and reliably brings the lock ring 7 into contact with the outer surface of the spigot 2 and the spigot protrusion 5. Consequently, the socket 1 and the spigot 2 can be satisfactorily and reliably engaged with each other via the cushioning material 8 and the lock ring 7. This can prevent the separation with higher reliability, further improving the separation preventing function.

(22) In the present embodiment, the cushioning material 8 is made of resin. The material of the cushioning material 8 is not limited to resin. It is needless to say that the cushioning material 8 may be any material softer than the metallic lock ring 7 and thus may be materials other than resin.