| 摘要 |
PURPOSE:To obtain a torus speaker edge having good material yield and manufactured inexpensively, by passing through the material between a pair of speaker edge forming rolls being conical shape for at least one roll. CONSTITUTION:The foamed urethane-made material 1 has rectangular cross section and strip shape, and the entire parts after forming are become the speaker edge and the size is regulated so that no cut-off part exists. A tip 6 of the material 1 is clipped and pressed by bringing a roll 4 close to a roll 5 with a driving device, the rolls 4 and 5 are rotated toward the direction A and B respectively, the material 1 is fed this side of this paper in Figure while being rolled. As to a part where a projection 5a of the rollers and a recessed part 4a of the rolls, the part is formed corrugated in wave shape, and the material 1 being a straight line is formed as a torus member 7 bent with the specified curvature to the side having less elongation. |
