US3793410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection moulding process
Assignee: Imperial Chemical Industries Ltd
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Filing: 1972-09-07
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Granted: 1974-02-19
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Expires: 1992-09-07
Abstract
Abstract Injection molding process wherein a skin material and then a core material are sequentially injected into a mould cavity and then a tap operated to prevent further injection to give an article having a skin of one material enclosing a core of a dissimilar material. In order to avoid hesitation marks on the molding, injection of the core material is commenced before injection of skin material is completed. preferable, a pressure operated shuttle valve controlled by the relative pressures in the two polymer streams is used to select which composition is injected.
Inventors
- 👤 P Garner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:40
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/16; B29C45/1603; B29C45/1604; B29C45/1642; Y; Y10; Y10S; Y10S264/00; Y10S264/83
Claims Analysis
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |