| 摘要 |
PURPOSE:To make withdrawal of a core easy, by using a core jig composed of a short cylindrical body and an angle-sectional molding ring member having a bias cut which is freely removable thereon, in preparing a bellows having an angle-section on their outer wall. CONSTITUTION:A laminated sheet 7 consisting of a raw rubber sheet and a fabric is wound on a core jig 6 composed of a short cylindrical body 8 whose outer circumferential face is similar to that of a circular cylinder and an angle- sectional molding ring 10 having a bias cut 9 which is thereon sheathed, and vulcanized under heating. Thereafter, the short cylindrical body 8 is drawn out and then, the angle-sectional molding ring 10 is drawn out. As the bias cut 9 is provided to the angle-sectional molding ring 10, withdrawal of the core is easy.
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