초록 ▼

A collapsible core and molding apparatus and method for molding a plastic article having an undercut and a non-undercut portion. The collapsible core includes a center core pin and a core sleeve about the core pin and with the core pin having a small plurality of alternating, uniform, narrow, non-co

A collapsible core and molding apparatus and method for molding a plastic article having an undercut and a non-undercut portion. The collapsible core includes a center core pin and a core sleeve about the core pin and with the core pin having a small plurality of alternating, uniform, narrow, non-collapsing segments secured to the center pin and the same plurality of uniform, alternating, wider, arcuate, collapsing segments secured to the core sleeve, the wide collapsible segments adapted to move between the non-collapsed segments to form the expanded position for a molding operation where the wide segments are separated by the narrower segments, and a collapsed position where the collapsible segments collapse radially inward on the axial withdrawal of the center pin to form a generally cylindrical, cross section, arcuate area and to permit the ejection of a small molded plastic article from the mold.

대표청구항 ▼

An injection mold apparatus which comprises: (a) a mold having a mold cavity therein and a plastic injection inlet into the mold cavity for injection of a plastic to form a plastic article; (b) a core assembly which comprises in combination: (i) an axially-retractable center core pin having a first

An injection mold apparatus which comprises: (a) a mold having a mold cavity therein and a plastic injection inlet into the mold cavity for injection of a plastic to form a plastic article; (b) a core assembly which comprises in combination: (i) an axially-retractable center core pin having a first and second end and having at the first end a pin face, said axially-retractable center core pin having a plurality of elongated, equally radially-spaced apart, raised, non-collapsible segments extending to and forming part of the pin face at the first end; (ii) a core sleeve positioned about the center core pin and having a first and a second end, said core sleeve having a core face at the first end and a base at the second end of the core sleeve and, said core sleeve further having extending from said base a plurality of elongated, equally radially-spaced apart, flexible, collapsible segments extending to the core face, the collapsible segments each having concentric, arcuate interior and exterior surfaces with radial extending side surfaces, the number of collapsible and non-collapsible segments are equal; (iii) the collapsible segments and the non-collapsible segments in the expanded, non-collapsed position are arranged in a close, mating, alternating relationship to form a generally circular pin and core face assembly; and (iv) the collapsible and non-collapsible segments in the collapsed position are arranged wherein the non-collapsible segments are in an axially retracted position and the collapsible segments are in a radially inwardly collapsed relationship with the side surfaces at the core face of the collapsible segments in a close, parallel, non-touching relationship to each other, thereby permitting molding of a plastic article with a deep undercut section and non-undercut section.