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US3865529A Expired / Lapsed US ⏱️ 0.0 years remaining

Molding apparatus

Assignee: American National Bank and Trust Company of Chicago
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Filing: 1973-12-05
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Granted: 1975-02-11
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Expires: 1993-12-05
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Abstract

Abstract An injection mold is disclosed for manufacture of a polygonal plastic article having plural side walls, a closed bottom wall and a constricted top opening. A mold core structure corresponds to the interior surface contour of the article in a mold defining position but is collapsible for withdrawal from the constricted top opening. The core includes a generally frusto-pyramidal central segment, and plural side wall and corner segments slidable along the inclined walls of the central segment. Preferred angular relationships of the corner and side wall segments and the slides of the central segment are also disclosed.

Inventors

  • 👤 Francesco Guzzo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 03:24
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/40; B29C45/44; B29C45/4421; B29C45/4435; Y; Y10; Y10S; Y10S425/00; Y10S425/005; Y10S425/058

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 261 words
An injection mold for manufacture of a plastic article having a bottom wall and a plurality of side wall portions forming a generally hollow polygonal enclOsure with an inwardly extending flange portion adjacent an open top of said article thereby to constrict said top opening, said mold comprising: first mold means having a mold defining surface corresponding to the exterior surface dimensions of at least a portion of said article; and second mold means having a mold defining surface corresponding to the interior surface dimensions of said article and comprising a generally frusto-pyramidal central member having a plurality of side wall portions of a predetermined slope and corresponding in number to said plurality of article side walls and having a plurality of corner wall portions located intermediate respective pairs of said central member side wall portions with said corner wall portions having a lesser slope than said side wall portions and further including side wall segments slidably movable along respective ones of each of said side wall portions, and corner wall segments slidably movable along respective ones of said corner wall portions, said side and corner wall segments each being movable from respective mold defining positions in which said segments cooperate with said central member to form said mold defining surface of said second mold means and a collapsed position in which said side and corner wall segments are displaced relative to said central member so that said second mold means is suffficiently reduced in size to permit it to be withdrawn from the constricted top opening of said plastic article.
Claim 2
Dependent Claim 261 words
An injection mold for manufacture of a plastic article having a bottom wall and a plurality of side wall portions forming a generally hollow polygonal enclOsure with an inwardly extending flange portion adjacent an open top of said article thereby to constrict said top opening, said mold comprising: first mold means having a mold defining surface corresponding to the exterior surface dimensions of at least a portion of said article; and second mold means having a mold defining surface corresponding to the interior surface dimensions of said article and comprising a generally frusto-pyramidal central member having a plurality of side wall portions of a predetermined slope and corresponding in number to said plurality of article side walls and having a plurality of corner wall portions located intermediate respective pairs of said central member side wall portions with said corner wall portions having a lesser slope than said side wall portions and further including side wall segments slidably movable along respective ones of each of said side wall portions, and corner wall segments slidably movable along respective ones of said corner wall portions, said side and corner wall segments each being movable from respective mold defining positions in which said segments cooperate with said central member to form said mold defining surface of said second mold means and a collapsed position in which said side and corner wall segments are displaced relative to said central member so that said second mold means is suffficiently reduced in size to permit it to be withdrawn from the constricted top opening of said plastic article.
Claim 3
Dependent Claim 126 words
The mold of claim 1 in which all of said corner wall segments in moving between their mold defining and collapsed positions follow paths having like predetermined lateral and longitudinal components and in which said side wall segments in moving between their mold defining and collapsed positions follow like paths having lateral and longitudinal components different from said predetermined components and further including ejection means comprising an ejection plate movable between first and second positions and separate mechanical linkage elements coupled between said ejection plate and said side wall and corner wall segments, said linkage elements being constructed and arranged for displacing said corner and side wall segments at a like longitudinal rate with movement of said ejection plate means between said first and second positions.
Claim 4
Dependent Claim 75 words
The mold of claim 1 in which said central member includes a top and a bottom wall and in which the planar projection of the line formed by the intersection of each of said corner walls and one of said adjacent side wall portions of said central member is parallel to the planar projection of the line formed by the intersection of the remaining adjacent side wall and the top wall of said central member.
Claim 5
Dependent Claim 27 words
The mold of claim 3 in which the included angle formed between each of said corner wall segments and said adjacent side wall segments is 45* .
Claim 6
Dependent Claim 27 words
The mold of claim 4 in which said second mold means includes four side wall and four corner wall portions, respectively, for defining a generally rectangular surface.
Claim 7
Dependent Claim 31 words
The mold of claim 5 in which the planar projections of the top and the bottom walls, respectively, of each of said corner wall segments defines respective right angle isosceles triangles.

References Cited (Backward Citations)

US2327665A Cited
US2366475A Cited
US2948031A Cited
US3339242A Cited
US3279740A Cited
US3373460A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-02-10 1978-08-12 1979-02-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-02-10 1982-08-12 1983-02-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-02-10 1986-08-12 1987-02-11 $7700.00 Window Closed / Lapsed

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