| 摘要 |
PURPOSE:To accurately prepare a synthetic resin pipe having a spiral reinforcing ridge. CONSTITUTION:In an apparatus for preparing a synthetic resin pipe by spirally winding a strip like material 3 having a ridge 3b formed to the central part thereof round a plurality of the molding shafts 1... arranged on an imaginary column, sizings 6, 6 each having a cross-sectional shape fitted to the inner surface shape of the strip like material are arranged between the first and second molding shafts 1a, 1b and the second and third molding shafts 1b, 1c at the winding start part of the strip like material 3 and the strip like material 3 is spirally wound round the molding shafts along said sizings 6, 6. |
