| 摘要 |
A bucket-shaped container having a rim opening smaller than the diameter of the side wall thereof is injected molded from thermoplastic material using a die set including a molding core which collapses to allow axial removal of the molded container from the mold. The molding core comprises a plurality of individual, wedge-shaped outer core sections which collectively form a continuous molding surface and are slideably mounted on a tapered inner core to allow axial sliding movement of the outer core section relative to the inner core. The sliding movement of the outer core sections on the inner core is provided by a plurality of keylocks which are fixedly secured in corresponding axial keyways in the inner core and which slideably engage corresponding axial keyways in the outer core sections. Coacting cam faces on the keylock and on the keyway of the outer core sections ensure that the outer core sections move firmly and positively into engagement with the inner core as the outer core sections arrive at their expanded molding positions. Means are also disclosed to ensure that the keylock is firmly and positively seated in the keyway in the inner core and further camming means are disclosed to ensure that the lower ends of the outer core sections are held firmly against the inner core during the molding operation.
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