| 摘要 |
<p>PURPOSE: To provide a corrugated synthetic resin tube which is useful as an underground electric cable tube of which flat compressive strength is increased by sticking a metal covered with a synthetic resin plate along the outer peripheral surfaces of the crest parts of a tube main body of which tube wall is formed in a spiral waveform with a hard synthetic resin. CONSTITUTION: The tube wall 1 of a corrugated synthetic resin tube is formed in spiral recessed and protruded walls with crest parts 2 and bottom parts 3, which provides an excellence in capability of passing cables and flexibility. Also, a molten hard synthetic resin band body is wound spirally so as to fuse its adjacent side edges with each other and form the tube walls 1. Then a metal plate 4 of which overall surfaces are covered 5 with a synthetic resin is wound spirally on the outer surfaces of the crest parts of the tube walls 1, and stuck with the tube walls 1. Thus the wall thickness of the crest parts 3 is increased so as to increase the pressure resistance against external forces.</p> |
