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US2884074A Expired / Lapsed US ⏱️ 0.0 years remaining

Deep well casing orifice and check valve

Assignee: Phillips Petroleum Co
•
Filing: 1953-06-17
•
Granted: 1959-04-28
•
Expires: 1973-06-17
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Abstract

No abstract record available.

Inventors

  • 👤 Roy A Bobo
  • 👤 George S Ormsby

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 13:41
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/10

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US1893934A Cited
US2037896A Cited
US2272388A Cited
US2642140A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1962-04-27 1962-10-27 1963-04-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1966-04-27 1966-10-27 1967-04-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1970-04-27 1970-10-27 1971-04-28 $7700.00 Window Closed / Lapsed

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