BACKGROUND ART Conventional pipe joints should ensure that the joint is firmly fixed to the pipe to seal therebetween when metal pipes or resin pipes are branched or elongated by the joint.

These joints employ a threaded engagement for maintaining a sealing condition between the pipe and the joint, and a number of components comprising a tightening ring, 0-ring, stop ring, which are inserted sequentially into the grooves formed on an inner surface of the joint, and a cap nut having a threshold for stopping the stop ring. The

cap nut is threadedly engaged with the joint to tighten the pipe and the joint.

However, this pipe joint has shortcomings of becoming expensive and heavy, since the pipe joint require a formation of additional screw thread in the inner surface of the joint and a significant magnitude of the groove for a good sealing performance of the tightening ring, O-ring and stop ring. In addition, due to an employment of various components, there are problems of difficult assembling procedure and of increased leakage probability.

DISCLOSURE OF INVENTION The present invention has been made to overcome the above problems, and it is an object of the present invention to provide a pipe joint whose joint main body is provided with a packing made of special rubber conjugated and formed such that a semicircular cross section can be formed above and below a clamp ring having lingual parts by being cut away in a zigzag manner and which is coupled to the interconnection pipe by screwing a cap nut with a downward projecting arc to the main body, whereby the interconnection pipe is firmly clamped by the packing contained on the sloping periphery of the main body.

In accordance with the present invention, there is provided a pipe joint comprising a main body provided with an outward tapered portion

at its open end, an inward annular protrusion in which a pipe is seated, and a male thread on outer surface; a packing inserted into the tapered portion; and a cap nut having an inward annular protrusion to bias downwardly the packing into the tapered portion, and a female thread therein to engage with the male thread. The packing of the pipe joint is provided with a zigzagged ring having a number of tongues, and an elastic rubber integrated with the ring in annular shape. The zigzagged ring and the elastic rubber cooperate to provide a firm fixing and sealing between the pipe and the joint. The tongues of the ring is biased downwardly by the cap nut to fasten the pipe to the joint, thereby preventing the pipe from separating from the joint.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of preferred embodiments of the present invention will be more fully described in the following detailed description, taken accompanying drawings. In the drawings: Fig. 1 is a partial cross-sectional plan view of the packing of the pipe joint of the present invention; Fig. 2 is a cross-sectional view taken along the line I-I of the packing of Fig. 1; Fig. 3 is a cross-sectional view of the pipe joint prior to the insertion of the pipe;

Fig. 4 is a cross-sectional view of the pipe joint on the completion of the insertion of the pipe and fastening of the cap nut.

* Description of major reference numerals * 10 : main body 10a : thread portion 11 : inward annular protrusion 12 : tapered portion 20 and 20a : tongue 21 : zigzagged ring 22 and 22a: elastic rubber 23 : packing 30 : pipe 31 : downward annular protrusion 32 : cap nut BEST MODES FOR CARRYING OUT THE INVENTION Hereinafter, the details of the present invention will be described in connection with the accompanying drawings.

Fig. 1 is a partial cross-sectional plan view of the packing of the pipe joint of the present invention and Fig. 2 is a cross-sectional view taken along the line I-I of the packing of Fig. 1.

As shown in Figs. 1 and 2, the packing 23 is provided with a zigzagged ring 21 having a number of tongues 20 and 20a, and an elastic rubber 22 integrated with the ring 21 in annular shape. The zigzagged ring 21 is made of light metals and have a number of tongues 20 inwardly protruded from the elastic rubber 22 and 22a to contact an outer surface of a pipe at the time of fastening. The elastic rubber 22 and 22a is integrally formed from a pair of members, which has a

half-circle cross-section, with the ring 21 in an annular shape.

Now referring to Fig. 3, the pipe joint in accordance with the present invention comprises a main body 10 provided with an outward tapered portion 12 at its open end, an inward annular protrusion 11 in which a pipe is seated, and a male thread 10a formed on outer surface; a packing 23 inserted into the tapered portion 12; and a cap nut 32 having a downward annular protrusion 31 to bias downwardly the packing 23 into the tapered portion 12, and a female thread therein to engage with the male thread 10a.

Fig. 4 illustrates a cross-sectional view of the pipe joint on the completion of the insertion of the pipe and fastening of the cap nut. As shown in Fig. 4, the pipe 30 is inserted into the joint to be seated onto the inward annular protrusion 11. As the cap nut 32 is engaged with the main body 10 along the thread portion 10a, the number of tongues 20 of the zigzagged ring 21 and the elastic rubber 22 are pressurized against the tapered portion 12. The zigzagged ring 21 and the elastic rubber 22 cooperate to provide a firm fixing and sealing between the pipe and the joint. The tongues of the ring is biased downwardly by the cap nut 32 to fasten the pipe to the joint, thereby preventing the pipe from separating from the joint.

Hereinafter, the operation of the pipe joint will be described in connection with the accompanying drawings.

Firstly, the packing 23 is inserted into the tapered portion 12 of

the main body 10, then the cap nut 32 is engaged with the thread portion 10a of the main body 10. After the pipe is located into the inward annular protrusion 11 of the main body 10, the downward annular protrusion 31 of the cap nut 32 is downwardly moved along the thread portion 10a to bias the packing 23 against the tapered portion 12 of the main body 10 and the outer surface of the pipe 30. As the packing 23 is pressurized against the pipe 30, the number of tongues 20 of the zigzagged ring 21 are wedged onto the outer surface of the pipe 30 and elastic rubber 22 and 22a are distorted between the tapered portion 12 and the pipe 30. Consequently, the zigzagged ring and the elastic rubber cooperate to provide a firm fixing and sealing between the pipe and the joint, thereby preventing the pipe from separating from the joint.

In addition, the cooperation of the tongues and the rubber prevents the separation of the pipe and offers very excellent watertight and sealing effects by the semicircular cross-section uniformly deformed and pressed to the pipe.

Further, the pipe joint in accordance with the present invention has a simplified structure and no threaded groove for inserting the clamp ring, O-ring or stop ring, to provide a relatively small diameter of the joint and to make the pipe having a reduced thickness, thereby enabling a manufacture of cost-effective joint and pipe, making a raw material saved and lowering the working time taken for connecting the

pipe joint and the pipe.

INDUSTRIAL APPLICABILITY The present invention relates to a pipe joint comprising a packing provided with a zigzagged ring having a number of tongues, and an elastic rubber integrated with the ring in annular shape. The zigzagged ring and the elastic rubber cooperate to provide a firm fixing and sealing between the pipe and the joint.

The pipe joint in accordance with the present invention has a simplified structure to provide a relatively small diameter of the joint, and no threaded groove on the pipe to make the pipe having a reduced thickness, thereby enabling a manufacture of cost-effective joint and pipe.