Method of molding a peripheral frame with a panel insert

• US 6,033,613 A
• Filed: 11/01/1994
• Issued: 03/07/2000
• Est. Priority Date: 09/24/1991
• Status: Expired due to Term

• Current Assignee: Silgan Containers Corporation (Silgan Holdings Incorporated)
• Original Assignee: Polystar Packaging, Inc.
• Inventors: Fraser, Robert W., Roth, Donald J., Heyn, William M.
• Primary Examiner(s): Bushey, C. Scott
• Application Number:
  US08/333,292
• Time in Patent Office: 1,953 Days
• Field of Search: 264/138, 264/153, 264/163, 264/252, 264/259, 264/328.1, 425/111, 425/116, 425/117, 425/122, 425/125, 425/126.1, 425/127, 425/129.1, 425/292, 425/298, 425/553, 425/554
• US Class Current: 264/259
• CPC Class Codes: B26F 1/3846 cutting out discs or the like B26F1/384, B26F1/40 and B26F1/44 take precedence
• CPC Class Codes: B29C 45/14024 and punching or cutting a portion from the endless articles during mould closing
• CPC Class Codes: B29C 45/14336 Coating a portion of the article, e.g. the edge of the article B29C45/14573 and B29C45/14598 take precedence
• CPC Class Codes: Y10T 83/0524 Plural cutting steps

Abstract

Tooling for forming an article which includes an injection molded peripheral frame defining an opening closed by a panel insert. The panel insert is struck from sheet material and together with an associated punch or carrier cooperates with a split mold to completely define the cavity for injection molding of the article. Inasmuch as the panel insert is heat bondable to the injection molded frame and forms a portion of the walls of the cavity, it is automatically bonded to the injection molded frame. The panel insert may be peelable from the frame and include a pull tab for effecting the same. The pull tab may be formed by the same punch which cuts out the panel insert, or the pull tab may be separately formed from sheet material adjacent an intended position of a panel insert and folded into overlying relation to the intended position of the panel insert and staked to the sheet material, after which the panel insert is cut from the sheet material by a punch. The pull tab is initially connected to the sheet material along an elongated fold line, after which not all of the pull tab connected to the sheet material is removed by the punch so as to define a centrally located pull tab which is aligned with the projecting part of the punch to effect a completely sealed mold cavity utilizing the panel insert with a previously formed and folded over pull tab staked thereto.

Claims

1. A method of injection molding an article having a peripheral frame forming an opening and carrying an insert panel for closing said opening, said method comprising the steps of providing a split mold including an inner open quadrant, associating a strip of material with said mold in facing relation to said open quadrant, providing a punch opposing said strip material remote from said mold and in alignment with maid mold, moving said punch towards said mold to first shear from said strip material a panel insert, then by continuing to move said punch towards said mold, clamping the panel insert against said mold with that panel insert and said punch forming parts of said mold and closing said open quadrant of said mold, and injecting a flowable material into said mold, and including the step of forming radially inwardly directed screw threads on said peripheral frame by providing radially outwardly directed screw threads on said punch.

2. A method of injection molding an article having a peripheral frame forming an opening and carrying an insert panel for closing said opening, said method comprising the steps of providing a split mold including an inner open quadrant, associating a strip of material with said mold in facing relation to said open quadrant, providing a punch opposing said strip material remote from said mold and in alignment with said mold, moving said punch towards said mold to first shear from said strip material a panel insert, then by continuing to move said punch towards said mold, clamping the panel insert against said mold with the panel insert and said punch forming parts of said mold and closing said open quadrant of said mold, and injecting a flowable material into said mold, and including the step of forming radially inwardly directed screw threads on said peripheral frame by providing radially outwardly directed screw threads on said punch wherein the panel insert has a plastic material forming a surface of said mold and the flowable material is a material heat bondable to the plastic material.

3. A method of injection molding an article having a peripheral frame forming an opening and carrying an insert panel for closing said opening, said method comprising the steps of providing a split mold including an inner open quadrant, associating a strip of material with said mold in facing relation to said open quadrant, providing a punch opposing said strip material remote from said mold and in alignment with said mold, moving said punch towards said mold to first shear from said strip material a panel insert, then by continuing to move said punch towards said mold, clamping the panel insert against said mold with the panel insert and said punch forming parts of said mold and closing said open quadrant of said mold, and injecting a flowable material into said mold.