| 摘要 |
Parent patent is for a stamping plate which produce a starting disc in the form of two circular arcs joined by a V-shaped section: in use, the arms of the V are brought together so that the circular arcs combine to form a semi-circle. By this patent, the stamping plate can take form of several circular arcs (not necessarily just two) joined to each other by V-shaped sections. The V is pref. modified slightly to avoid having a sharp angle between its sides. |
