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US2992147A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of heat treatment using dual atmospheres

Assignee: Individual
•
Filing: 1957-04-29
•
Granted: 1961-07-11
•
Expires: 1977-04-29
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Abstract

No abstract record available.

Inventors

  • 👤 Carl I Hayes

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 09:02
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/74

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US890314A Cited
US1643775A Cited
US1905809A Cited
US2061910A Cited
US2701712A Cited
US2892744A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1964-07-10 1965-01-09 1965-07-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1968-07-10 1969-01-09 1969-07-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1972-07-10 1973-01-09 1973-07-11 $7700.00 Window Closed / Lapsed

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