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US2798716A Expired / Lapsed US ⏱️ 0.0 years remaining

Hearth structures for high temperature furnaces

Assignee: AT&T Inc
•
Filing: 1954-01-08
•
Granted: 1957-07-09
•
Expires: 1974-01-08
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Abstract

No abstract record available.

Inventors

  • 👤 Pugh Emerson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 11:45
CPC Classifications
C; C21; C21D; C21D9/00

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US1234789A Cited
US1569444A Cited
US1977399A Cited
US2006685A Cited
US2137869A Cited
US2178527A Cited
US2215322A Cited
US2245647A Cited
US2545877A Cited
US2556962A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1960-07-08 1961-01-07 1961-07-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1964-07-08 1965-01-07 1965-07-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1968-07-08 1969-01-07 1969-07-09 $7700.00 Window Closed / Lapsed

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