| 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 hard 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 hard synthetic resin plate 4 is wound spirally on the outer surfaces of the crest parts 3 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> |
