| 摘要 |
PURPOSE:To improve productivity ever so high, by rolling a reinforced fiber on a bend barlike lightweight form keeping material continuing to link semicircular rings together with each other, while cutting this material at each semicircular ring and forming each into a ring shaped one. CONSTITUTION:A bend barlike, long lightweight form keeping material continuing mutually to ling semicircular rings facing each other on a reference axis is made up of a plastic or solid foamed material or a thin pipe material as a core material 1. A coupling metal device setting groove part 1d is formed in a continuous part of these semicircular rings. A one-way reinforced fiber 1b is rolled on an outer circumference of this core material 1 in the circumferential direction as crossed at a specified angle. And, this core material 1a is cut off at each semicircular ring, and these bisected semicircular rings of the core material 1a are placed opposite face-to-face whereby they are formed in a single semicircular ring. |
