IP Library Granted Patent US 8,168,108
Granted Patent B2
US 8,168,108 · App. 12/916,171 · Granted May 1, 2012

Molding apparatus and method of forming undercuts

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Quick Facts
Patent No.
US 8,168,108
App. No.
12/916,171
Granted
May 1, 2012
Kind
B2
Abstract

A molding apparatus can include a primary mold, a stripper, and a swinging member. The swinging member can comprise a molding surface defining an undercut portion of a molded item. The swinging member can directly contact or attached to the stripper and the primary mold. To facilitate removal of a molded item, the swinging member can withdraw through a hole in the primary mold as a direct result of a motion of the stripper to pull the molded item off the primary mold. The molded item can then be easily removed.

Claims (37)

1. A method for molding undercuts, the method comprising:

providing a molding apparatus including

a primary mold configured to define a portion of a surface of a molded item, said primary mold defining at least one hole,

a stripper alongside the primary mold, wherein the stripper comprises a stripping section and a receiving surface, and

at least one swinging member coupled by at least one pivot to one of the primary mold or the stripper, wherein the swinging member comprises a molding surface and a contact feature;

inserting molding material into the molding apparatus;

allowing the molding material to set while the molding surface of the swinging member protrudes into the material to define an undercut portion of the surface of the molded item; and

displacing the stripper to strip the molded item from the molding apparatus, whereby displacing of the stripper moves the swinging member relative the at least one pivot to move the molding surface of the swinging member out of engagement with the undercut portion of the surface of the molded item.

2. The method of claim 1 , wherein displacing the stripper includes simultaneously withdrawing the molding surface of the swinging member and removing the molded item from the molding apparatus.

3. The method of claim 1 , wherein inserting the molding material includes positioning the molding surface of the swinging member in engagement with the at least one hole.

4. The method of claim 1 , wherein inserting the molding material includes positioning the molding surface of the swinging member out of engagement with the undercut portion of the surface of the molded item.

5. The method of claim 1 , further comprising removing the molded item from the molding apparatus.

6. The method of claim 5 , wherein removing the molded item from the molding apparatus comprises removing a set of products from the molding apparatus that have been formed from a single sheet of plastic, the method further comprising cutting the molded item to separate the products from each other.

7. The method of claim 5 , wherein the method for molding undercuts is repeated a plurality of times.

8. The method of claim 5 , wherein removing the molded item comprises providing a high pressure between the molded item and the molding apparatus.

9. The method of claim 1 , wherein displacing the stripper directly causes movement of the molding surface of the swinging member.

10. The method of claim 1 , further comprising contacting the receiving surface of the stripper with the contact feature of the swinging member to move the swinging member.

11. The method of claim 10 , wherein contacting the receiving surface of the stripper includes rolling the contact feature of the swinging member on the receiving surface of the stripper.

12. The method of claim 10 , wherein contacting the receiving surface of the stripper includes sliding the contact feature of the swinging member on the receiving surface of the stripper.

13. The method of claim 1 , further including moving the stripper to a first position to move the swinging member into engagement with the at least one hole.

14. A method for molding undercuts, the method comprising:

providing a molding apparatus including

a primary mold configured to define a portion of a surface of a molded item, said primary mold defining at least one hole,

a stripper alongside the primary mold, wherein the stripper comprises a stripping section and a receiving surface, and

at least one swinging member coupled by at least one slide to one of the primary mold or the stripper, wherein the swinging member comprises a molding surface and a contact feature;

inserting molding material into the molding apparatus;

allowing the molding material to set while the molding surface of the swinging member protrudes into the material to define an undercut portion of the surface of the molded item; and

displacing the stripper to strip the molded item from the molding apparatus, whereby displacing of the stripper moves the swinging member relative the at least one slide to move the molding surface of the swinging member out of engagement with the undercut portion of the surface of the molded item.

15. The method of claim 14 , wherein displacing the stripper includes simultaneously withdrawing the molding surface of the swinging member and removing the molded item from the molding apparatus.

16. The method of claim 14 , wherein inserting the molding material includes positioning the molding surface of the swinging member in engagement with the at least one hole.

17. The method of claim 14 , wherein inserting the molding material includes positioning the molding surface of the swinging member out of engagement with the undercut portion of the surface of the molded item.

18. The method of claim 14 , further comprising removing the molded item from the molding apparatus.

19. The method of claim 18 , wherein removing the molded item from the molding apparatus comprises removing a set of products from the molding apparatus that have been formed from a single sheet of plastic, the method further comprising cutting the molded item to separate the products from each other.

20. The method of claim 18 , wherein the method for molding undercuts is repeated a plurality of times.

21. The method of claim 18 , wherein removing the molded item comprises providing a high pressure between the molded item and the molding apparatus.

22. The method of claim 14 , wherein displacing the stripper directly causes movement of the molding surface of the swinging member.

23. The method of claim 14 , further including moving the stripper to a first position to move the swinging member into engagement with the at least one hole.

Assignments (4)
SECURITY INTEREST Recorded Apr 2, 2025
From: BLUE RIDGE PAPER PRODUCTS LLC; EVERGREEN PACKAGING LLC; FABRI-KAL LLC; PACTIV LLC; PACTIV PACKAGING INC.
To: WILMINGTON TRUST, NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 070705/0859 →
RELEASE OF SECURITY INTEREST Recorded Apr 1, 2025
From: THE BANK OF NEW YORK MELLON, AS COLLATERAL AGENT
To: PACTIV LLC; EVERGREEN PACKAGING LLC; PACTIV PACKAGING INC.
Reel/Frame 070704/0420 →
PATENT SECURITY AGREEMENT Recorded Nov 9, 2017
From: CLOSURE SYSTEMS INTERNATIONAL INC.; EVERGREEN PACKAGING INC.; GRAHAM PACKAGING COMPANY, L.P.; GRAHAM PACKAGING PET TECHNOLOGIES INC.; PACTIV LLC; PACTIV PACKAGING INC.; REYNOLDS CONSUMER PRODUCTS LLC; REYNOLDS PRESTO PRODUCTS INC.
To: THE BANK OF NEW YORK MELLON
Reel/Frame 044722/0528 →
CHANGE OF NAME Recorded Nov 16, 2012
From: PWP INDUSTRIES, INC.
To: PACTIV PACKAGING INC.
Reel/Frame 029308/0623 →