Patent US3574807A successfully refreshed from Google Patents.
US3574807A
Expired / Lapsed
US
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Method of molding with an angulated cavity form
Assignee: Gulf Development Inc
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Filing: 1967-12-20
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Granted: 1971-04-13
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Expires: 1987-12-20
Abstract
Abstract SHEET MATERIAL TO BE FORMED OVER THE ANGULATED CAVITY FORM C (FIGS. 1 AND 2) IS CLAMPED ON A FRAME F. THE FRAME F AND PREHEATED SHEET M ARE LOWERED BY HYDRAULIC MOTORS H. ABUTMENTS A ENLARGE THE LOWERING FRAME F AND CAUSE IT TO FOLD ABOUT THE ANGULATED FORM (FIGS. 4A AND 4B) PROGRESSIVELY TO EFFECT SEALS ALONG SIDE FLANGES S OF THE FORM (FIG. 2) AND ULTIMATELY TO FORM SEALS ALONG THE END FLANGES E BY AN OVERDRAW. VACUUM IS THEN APPLIED. THE DEPTH OF DRAW IS MINIMIZED; THE WALL THICKNESS IS SUBSTANTIALLY MAINTAINED TO ACHIEVE SUBSTANTIAL STRENGTH IN THE FINISHED PART; VERY LITTLE PLASTIC MATERIAL IS WASTED AS THE MOLDED PART IS TRIMMED.
Inventors
- 👤 Edward A Heavener
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:01
CPC Classifications
B; B29; B29C; B29C51/00; B29C51/26; B29C51/261; B29C51/262; B29C53/00; B29C53/02; B29C53/04
Claims Analysis
Total Claims: 0
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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) | 1974-04-12 | 1974-10-12 | 1975-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-12 | 1978-10-12 | 1979-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-12 | 1982-10-12 | 1983-04-13 | $7700.00 | Window Closed / Lapsed |