摘要 |
<p>With a desired intermediate portion as a boundary, in a hose, a corrugated wall is formed on one side of the boundary while a scalene-triangularly corrugated wall is formed on the other side of the boundary, the whole of a hose is formed of a soft synthetic resin material and a hard synthetic resin material in the form of a double-layered wall. The soft synthetic resin material is made thicker than the hard synthetic resin material in a portion on a connection cylindrical portion side while the hard synthetic resin material is made thicker than the soft synthetic resin material in a portion on a drainage cylindrical portion side.</p> |