US3285045A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two stage forming with expanding skirt step
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1964-04-13
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Granted: 1966-11-15
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Expires: 1984-04-13
Abstract
No abstract record available.
Inventors
- 👤 John W Berg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:55
CPC Classifications
B; B21; B21D; B21D26/00; B21D26/02; B21D26/021; B21D26/025
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
A METHOD OF FORMING DEEP-DRAWN SHEET MATERIAL PARTS FROM GENERALLY FLAT SHEET MATERIALS BLANKS COMPRISING THE STEPS OF: CLAMPING A PERIPHERAL AREA OF SAID BLANK TO PREVENT MOVEMENT OF SAID PERIPHERAL AREA; PRODUCING A DRAWING FLUID PRESSURE ON ONE SURFACE OF SAID BLANK TO PARTIALLY EXTEND THE MATERIAL AND PRODUCE A CENTRAL BOWED PORTION IN SAID BLANK; CLAMPING A REDUCED PERIPHERAL AREA OF SAID BLANK TO PREVENT MOVEMENT OF SAID REDUCED PERIPHERAL AREA AND TO EXPOSE AN AREA OF UNWORKED MATERIAL; AND PRODUCING A FURTHER DRAWING FLUID PRESSURE ON SAID ONE SURFACE TO EXTEND THE NEWLY EXPOSED AREA WHILE SAID BULGED PORTION IS FREE TO MOVE UNDER SAID FURTHER DRAWING FLUID PRESSURE.
Claim 2
Independent Claim
112 words
A METHOD OF FORMING DEEP-DRAWN SHEET MATERIAL PARTS FROM GENERALLY FLAT SHEET MATERIALS BLANKS COMPRISING THE STEPS OF: CLAMPING A PERIPHERAL AREA OF SAID BLANK TO PREVENT MOVEMENT OF SAID PERIPHERAL AREA; PRODUCING A DRAWING FLUID PRESSURE ON ONE SURFACE OF SAID BLANK TO PARTIALLY EXTEND THE MATERIAL AND PRODUCE A CENTRAL BOWED PORTION IN SAID BLANK; CLAMPING A REDUCED PERIPHERAL AREA OF SAID BLANK TO PREVENT MOVEMENT OF SAID REDUCED PERIPHERAL AREA AND TO EXPOSE AN AREA OF UNWORKED MATERIAL; AND PRODUCING A FURTHER DRAWING FLUID PRESSURE ON SAID ONE SURFACE TO EXTEND THE NEWLY EXPOSED AREA WHILE SAID BULGED PORTION IS FREE TO MOVE UNDER SAID FURTHER DRAWING FLUID PRESSURE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-11-14 | 1970-05-16 | 1970-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-11-14 | 1974-05-16 | 1974-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-11-14 | 1978-05-16 | 1978-11-15 | $7700.00 | Window Closed / Lapsed |