| 摘要 |
<p>A different duct adapter of self-assembly according to the present invention comprises an inner pipe which is inserted into a manhole preliminary hole, has an inner reinforcement rib in one end thereof, has a thread on the inner surface, and a first thread which bonds the inner reinforcement rib to an inside wall when connecting an outside pipe, an outer pipe which is inserted into the preliminary hole, has a second thread and a third thread on the outer surface of the end of the outside reinforcement rib which bond the outside reinforcement rib to a manhole outside wall when screw-combining the inside pipe, a connection tube which has a forth thread which is combined with the third thread of the outer pipe, and a first straight tube, a different tube which has a waveform part and a second straight tube inserted into the straight tube of the connection part, and a wire tube combined with the waveform part.</p> |
