Patent US3218656A successfully refreshed from Google Patents.
US3218656A
Expired / Lapsed
US
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Method of forming a self-tapping or thread-forming screw
Assignee: National Lock Co
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Filing: 1963-09-03
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Granted: 1965-11-23
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Expires: 1983-09-03
Abstract
No abstract record available.
Inventors
- 👤 Bernard F Reiland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:47
CPC Classifications
F; F16; F16B; F16B25/00; F16B25/0036; F16B25/0078; B; B21; B21H; B21H3/00; B21H3/02; B21H3/027; F16B25/001; F16B25/0021; F16B25/0084
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
126 words
A METHOD OF PRODUCING A THREAD-FORMING SCREW ADAPTED TO SWAVE CHIP-FREE THREADS IN A WORKPIECE, COMPRISING THE STEPS OF DRAWING A CYLINDRICAL WIRE BLANK TO FORM THE SHANK, FORMING AN ENLARGED DRIVING HEAD AT ONE END OF THE SHANK AND FORMING THE OPPOSITE END OF THE SHANK BY METAL DISPLACEMENT INTO A CONICAL SURFACE WITH CIRCUMFERENTIALLY EQUAL SPACED FLATTENED AREAS ON SAID CONICAL SURFACE EXTENDING AXIALLY ALONG SUBSTANTIALLY THE ENTIRE LENGTH OF SAID CONICAL SURFACE AND FORMING A SUBSTANTIALLY SQUARE END ON THE SHANK, AND PROGRESSIVELY PRESSURE ROLLING A THREAD ONTO THE SHANK AND ONTO THE PORTIONS OF THE CONICAL SURFACE TO FORM LEADING SWAGING EDGES, GENERALLY ARCUATE LAND PORTIONS AND ECCENTRIC TRAILING EDGES ON SAID ARCUATE PORTIONS WITH SAID INITIALLY FLATTENED AREAS PROVIDING DISHED AREAS.
Claim 2
Independent Claim
126 words
A METHOD OF PRODUCING A THREAD-FORMING SCREW ADAPTED TO SWAVE CHIP-FREE THREADS IN A WORKPIECE, COMPRISING THE STEPS OF DRAWING A CYLINDRICAL WIRE BLANK TO FORM THE SHANK, FORMING AN ENLARGED DRIVING HEAD AT ONE END OF THE SHANK AND FORMING THE OPPOSITE END OF THE SHANK BY METAL DISPLACEMENT INTO A CONICAL SURFACE WITH CIRCUMFERENTIALLY EQUAL SPACED FLATTENED AREAS ON SAID CONICAL SURFACE EXTENDING AXIALLY ALONG SUBSTANTIALLY THE ENTIRE LENGTH OF SAID CONICAL SURFACE AND FORMING A SUBSTANTIALLY SQUARE END ON THE SHANK, AND PROGRESSIVELY PRESSURE ROLLING A THREAD ONTO THE SHANK AND ONTO THE PORTIONS OF THE CONICAL SURFACE TO FORM LEADING SWAGING EDGES, GENERALLY ARCUATE LAND PORTIONS AND ECCENTRIC TRAILING EDGES ON SAID ARCUATE PORTIONS WITH SAID INITIALLY FLATTENED AREAS PROVIDING DISHED AREAS.
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) | 1968-11-22 | 1969-05-24 | 1969-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-22 | 1973-05-24 | 1973-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-22 | 1977-05-24 | 1977-11-23 | $7700.00 | Window Closed / Lapsed |