| 摘要 |
<p>The process for fabricating hollow metal balls for games, forms two demi-spheres (1b) which are welded together, but forms surface patterns during a preliminary phase, and prepares the edges of the demi-spheres in the formative phase. The process includes pressing or rolling a surface pattern onto a metal sheet. Circular plates are press cut and formed into demi-spheres. Their edges are rectified and calibrated then welded together. Finally the ball is coated with plastics or other material. The pre-welding plases are carried out on a multipost machine, and the edge calibration and finishing may be carried out by punches on the sphere-forming punch. Complex surface patterns may be obtained by multi-stage initial pressing or rolling.</p> |
