Molding apparatus with positive collapse core

Claim 2

Apparatus for molding an article comprising a core having molding surface sections that are movable with respect to one another and in a direCtion radially of the core from an extended molding position to a contracted article-release position, means fixing one end of each section against relative movement while the opposite ends are movable between their extended and contracted positions, said sections in the extended positions abutting at said opposite ends to form substantially a peripherally continuous molding surface, means within said sections for supporting the sections in their extended positions, means providing relative axial movement between the core and said section-supporting means for causing retraction of said supporting means from said opposite ends of the sections and radial clearance between said sections and said supporting means, and means responsive to said relative movement for positively urging said sections radially inwardly to their contracted positions substantially without supporting interference from said supporting means; said positively urging means comprising radially outwardly projecting follower elements on said sections and means telescoped over said sections and having radially inwardly extending cam means for engagement with said follower elements.

Claim 3

Apparatus according to claim 1 in which said telescoped means is movable with said core upon an initial relative axial movement of the core and supporting means and is held against movement with the core upon an additional amount of axial movement of the core, said cam means biasing said follower means radially inwardly during said additional amount of movement.

Claim 4

Apparatus for molding an article comprising a core having molding surface sections that are movable with respect to one another from an article-forming position in which the adjacent sections are abutting and form a continuous radial deformation from one section to the next section to a contracted position in which the adjacent sections are radially inwardly shifted, the sections having radially interfering sides such that the radial inward shifting of one group of sections provides clearance for the radial inward shifting of the remaining sections, a pin within said sections for supporting the sections in their extended positions, means including an ejector plate for fixing one end of each section against relative movement while the opposite ends are movable between their extended and contracted positions, said ejector plate and core being movable in unison and relative to said pin to bring said pin into and out of said supporting engagement with said sections, a stripper plate spaced from said ejector plate for removing a molded article from the core, means for moving said ejector plate with said stripper plate, a support plate through which said core projects, a sleeve mounted in said support plate and telescoped with said core, said sleeve having a cam portion, and follower means on said sections and biased by said cam portion for positively urging said sections radially inwardly to their contracted positions substantially without supporting interference from said pin upon movement of said ejector plate in the direction to bring said pin out of said supporting engagement with said sections.

Claim 5

Apparatus for molding an article comprising a core having molding surface sections that are movable with respect to one another from an article-forming position in which the adjacent sections are abutting and form a continuous radial deformation from one section to the next section to a contracted position in which the adjacent sections are radially inwardly shifted, the sections having radially interfering sides such that the radial inward shifting of one group of sections provides clearance for the radial inward shifting of the remaining sections, a pin within said sections for supporting the sections in their extended positions, means including an ejector plate for fixing one end of each section against relative movement while the opposite ends are movable between their extended and contracted positions, said ejector plate and core being movable in unison and relative to said pin to bring said pin into and out of said supporting engagement with said sections, a stripper plate spaced from said ejector plate for removing a molded article from the core, means for moving said ejector plate with said stripper plate, a support plate through which said core projects, a sleeve mounted in said support plate and telescoped with said core, said sleeve having a cam portion, and follower means on said sections and biased by said cam portion for positively urging said sections radially inwardly to their contracted positions substantially without supporting interference from said pin upon movement of said ejector plate in the direction to bring said pin out of said supporting engagement with said sections.

Claim 6

Apparatus according to claim 3 in which said sleeve is fixed in said support plate.

Claim 7

Apparatus according to claim 3 in which said sleeve is axially slidable in said support plate and movable with said core over one portion of the movement of said core in the direction to withdraw said pin from said supporting engagement, and said sleeve and support plate having cooperating means retaining the sleeve against axial movement for another portion of said core movement for effecting said positive urging during said other portion of the core movement.

Claim 8

Apparatus according to claim 1 having means mounting said telescoped means in a predetermined position with respect to said section-supporting means, and said means for providing relative axial movement between the core and the supporting means moves the core to bring said follower elements into following engagEment with said cam means.

Claim 9

Apparatus according to claim 1 wherein the outwardly projecting follower elements on said molding surface sections are substantially farther from said one end of each section than they are from the opposite end of each that together form the continuous molding surface.