| 摘要 |
An injection mold for forming the halves of a magnetic tape cassette includes stationary and movable molds defining a cavity, and confronting slidable cores disposed in holes extending through the molds. An opaque primary resin is injected into the cavity to form an outer portion of a cassette half with the core faces abutting each other, whereafter the cores are retracted to define a central window cavity in which a transparent secondary resin is injected. A lip surrounds the inner edge of the hole through which one of the cores extends to laterally support and guide the core, and to avoid any jamming or inaccuracy in the retracted position of the core due to thermal expansion.
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