| 摘要 |
<p>One (40) of two mold halves to be clamped is composed of an insert holder (18), an insert (1) mounted detachably on the insert holder, and a rotary core (6) supported rotatably by the insert and having a threaded portion (7) formed on an outer peripheral surface thereof. When clamping is effected, the rotary core (6) is caused to project into a cavity (29) formed in the other mold half (28), and moldings are injection molded inside the cavity (29) around the rotary core (6). The inset holder (18) is provided with a driving source such as a motor-driven gear (25), while the insert (1) is provided with a rotation transmitting mechanism composed of such as gears (15, 16, 17) for rotating the rotary core (6). If the insert (1) is mounted in the insert holder (18), the driving source provided in the insert holder is coupled with the rotation driving mechanism provided in the insert, rotating the rotary core (6) and making it possible to remove the moldings having a thread formed on an inner surface thereof from the rotary core (6) by rotating the rotary core (6). When the type of moldings is to be changed, it suffices if the rotary core (6) and the insert (1) are replaced, allowing the mold replacing time to be reduced appreciably and the costs of producing the mold can be lowered substantially.</p> |
