| 摘要 |
PURPOSE:To obtain a preferred size of body frame simply and cheaply by a method wherein a ferromagnetic material is punched and then bent to the frame, each end of which is butted to form curves. CONSTITUTION:The ferromagnetic material is selected long enough to form sides 1-2, 1-3 by bending bottom 1-1 and both the sides and then punched so that the first projections 1-4a, 1-4b projecting to both sides of both longitudinal ends and the second projections 1-5a, 1-5b projecting in the same direction as the first projections to both sides of those 1-2, 1-3 apart suitably therefrom will be formed accordingly. Then, sections of the punched material which correspond to both sides 1-2, 1-3 of the bottom 1-1 are bent almost rectangularly from positions in dotted line, and each end of the tops is butted to form curves, thus obtaining a body frame 1. Thus a preferred size of the body frame is obtainable simply and cheaply. |
