| 摘要 |
PURPOSE:To easily mold by engaging a pair of spiral molds in which spiral parts are spirally formed along sides of screws of screw molded forms to be molded and forming gaps for molding the forms between ends of the spiral parts of the one and the other of the molds. CONSTITUTION:Spiral parts 18 are spiral parts of spiral molds 14, and formed along the other side of the screw parts of screw molded forms to be molded. A pair of spiral molds 12, 14 are so formed as to be continuously narrowed toward ends, and spiral parts 16, 18 are so engaged with the molds 12, 14 that rear end side end faces of the parts 16, 18 are slidably brought into contact. A gap 30 is formed between the end side end faces of the parts 16, 18 in a mold 10 formed to be engaged as above. The gap 30 is a gap for molding a screw molded form. Thus, the screw molded form of a smooth surface can be easily molded by injection molding, etc. |
