| 摘要 |
<p>PROBLEM TO BE SOLVED: To make a space for custody small as compared with the case where protective pipes are wound one by one around a reel so as to be convenient for carriage, and to reduce labor in laying work by drawing out three pieces, for example, of protective pipes together prior to laying, and also to reduce the execution cost of works by making the sectional area of an excavated ditch for laying small. SOLUTION: The three pieces of protective pipes 12 can be wound in a lump around the reel and the three pieces of protective pipes wound around the reel can be drawn out together from the reel 12 prior to laying since the three pieces of protective pipes 12 are in contact with each other and are bound together, with each contact point becoming a fused part 14. The sectional area of the excavated groove for laying can be made small since the three pieces of protective pipes 12 are in contact with each other and are bound together.</p> |
