Patent US5903044A successfully refreshed from Google Patents.
Patent US3352724A successfully refreshed from Google Patents.
US3352724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat treatment of structural sections
Assignee: Midland Ross Corp
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Filing: 1965-06-14
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Granted: 1967-11-14
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Expires: 1985-06-14
Abstract
No abstract record available.
Inventors
- 👤 Lewis F Mcnitt
- 👤 Edmund L Melgun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:49
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/0068
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
101 words
THE METHOD OF HEAT TREATING A LOW CARBON STEEL CHANNEL FORM COMPRISING, PREHEATING THE WEB AREA TO A TEMPERATURE OF NOT LOWER THAN ABOUT 400*F. AND THE FLANGE SECTIONS TO ABOUT 900*F. UNAFFECTING A MOLECULAR CHANGE THEREIN, SUBSTANTIALLY IMMEDIATELY THEREAFTER HEATING THE FLANGED PORTIONS AND DESIRED AREA THEREABOUT ONLY TO A TEMPERATURE OF FROM 1600-1700*F. SUBSTANTIALLY IMMEDIATELY APPLYING A QUENCH TO CAUSE HARDENING SUFFICIENT TO FORM A MARTENSITIC STRUCTURE IN THE SAID AREA, THEREAFTER AGAIN APPLYING HEAT AT A TEMPERATURE OF ABOUT 900*F. TO THE SAID DESIRED HIGHER HEATED AREA TO DRAW THE TEMPER OF SAID FLANGES, AND THEREAFTER AGAIN QUENCHING.
Claim 2
Independent Claim
101 words
THE METHOD OF HEAT TREATING A LOW CARBON STEEL CHANNEL FORM COMPRISING, PREHEATING THE WEB AREA TO A TEMPERATURE OF NOT LOWER THAN ABOUT 400*F. AND THE FLANGE SECTIONS TO ABOUT 900*F. UNAFFECTING A MOLECULAR CHANGE THEREIN, SUBSTANTIALLY IMMEDIATELY THEREAFTER HEATING THE FLANGED PORTIONS AND DESIRED AREA THEREABOUT ONLY TO A TEMPERATURE OF FROM 1600-1700*F. SUBSTANTIALLY IMMEDIATELY APPLYING A QUENCH TO CAUSE HARDENING SUFFICIENT TO FORM A MARTENSITIC STRUCTURE IN THE SAID AREA, THEREAFTER AGAIN APPLYING HEAT AT A TEMPERATURE OF ABOUT 900*F. TO THE SAID DESIRED HIGHER HEATED AREA TO DRAW THE TEMPER OF SAID FLANGES, AND THEREAFTER AGAIN QUENCHING.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-11-13 | 1971-05-15 | 1971-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-11-13 | 1975-05-15 | 1975-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-11-13 | 1979-05-15 | 1979-11-14 | $7700.00 | Window Closed / Lapsed |