| 摘要 |
PROBLEM TO BE SOLVED: To ensure a free separation at a required position to improve conveniency in inventry management by inserting again a suceeding protrusion of preliminarily formed segment into a mold, then forming a front end unit of next segment into a circumferential part of the projection, and forming a continuous strip for receiving a pin. SOLUTION: In a mold 30 for injection molding plastic material, bisected cavity 32 forms a single segment at one cycle. After the separation of cavity 32, a motor-driven gear 44 indexes the position of formed segment, and a foregoing segment unit 33 is fitted into a left end cavity 34. An adjacent cavity 35 stores a rear end unit 26 of formerly formed segment, and fusion plastic is filled at a next formation cycle, then a front end unit of suceeding segment is superposedly formed so as to surround the rear end unit 26. By inserting a pin in a through hole 16 of connection part formed superposedly, forward and rearward single segments are connected firmly. |
