| 摘要 |
<p>PURPOSE:To obtain a tapered resin tube of an uniform thickness of the titled device by a method in which an inside mold having a small-diameter portion is inserted into a thermoplastic resin tube from both sides by turning the small- diameter portion inwards, and the resin tube with the inside molds is stretched and cut off. CONSTITUTION:In the manufacture of a resin tube having a small-diameter portion (f) and a large-diameter portion (e) for covering the branch lines (b) and (c) of a pole, inside molds 1, consisting of a large-diameter portion 11, a small- diameter portion 12, and a shoulder portion 13 connecting these portions 11 and 12, are inserted into a thermoplastic resin tube 2 having an inside diameter enough to fit in with the large-diameter portion 11 from both sides by turning their small-diameter portions inwards. Fitting tools are attached to the resin tube 2 inserted with the large-diameter portion 11 of the inside molds 1 and clamped, the fitting tools 3 are pulled from both sides to stretch the resin tube 2 to form a small-diameter portion (f) in the resin tube 2. The small-diameter portion (f) of the resin tube 2 is cut off at the center, and splits (g) are formed in the longitudinal direction of the tube 2.</p> |
