| 摘要 |
PURPOSE: To provide an electrofusion coupling which can obtain the firm fusion joint by properly setting the electric conduction time for an electric heating wire and can confirm the completion of the fusion joint. CONSTITUTION: Both the end parts of an electric heating wire 2 embedded on the joint surface of a coupling body 1 made of synthetic resin are connected with the terminal pins 3a and 3b which are projectingly installed on the outer surface of the coupling body 1. In approach to one terminal pin 3a, an auxiliary terminal pin 31a is installed, and a resistor body A is interposed between the auxiliary terminal pin 31a and a terminal pin 3a. Further, an auxiliary terminal pin 31b is installed in approach to the other terminal pin 3b, and between the auxiliary terminal pin 31b and the terminal pin 3b, a relay terminal B for cutting off the electric conduction in the second time through the electric conduction in one time is interposed. Accordingly, the firm fusion joint is obtained, and the fusion joint can be confirmed. |
