Method and apparatus for injection molding of plastic closures
US4155698A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 2, 1977 |
| Grant date | May 22, 1979 |
| Priority date | — |
| Expiry date | May 2, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/058
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for molding a plastic closure cap unit for a container, which cap unit comprises an internally threaded upper closure cap and a downwardly extending skirt forming a sealing ring connected thereto through an intermediate shear zone of reduced thickness, the sealing ring increasing in thickness downwardly from the shear zone and being devoid of abrupt changes in contour such as would preclude axial removal of the cap and sealing ring from a non-expanding mold surrounding the sealing ring, comprises injecting molten plastic into a mold shaped to form the cap unit and including fixed and movable sections forming mold surfaces, disengaging the mold from the outer surface of the upper closure cap by axial movement of the related mold section relative to the remaining sections, then disengaging the mold from the inner surfaces of the closure cap and sealing ring by axial movement of the related mold section relative to the remaining section of the mold still surrounding the outer wall of the sealing ring up to the lower rim of the upper closure cap, and then disengaging the mold from the cap unit by axial movement of the cap unit relative to the remaining section of the mold surr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.