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US2996269A Expired / Lapsed US ⏱️ 0.0 years remaining

Helicopter with counter-rotating propeller

Assignee: JUSTIN G SHOLES
•
Filing: 1956-04-12
•
Granted: 1961-08-15
•
Expires: 1976-04-12
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Abstract

No abstract record available.

Inventors

  • 👤 Robert D Parry

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 21:58
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12; B64C27/20

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US1326701A Cited
CA449741A Cited
US1401992A Cited
US1406277A Cited
US1723479A Cited
US2395809A Cited
US2415148A Cited
US2377835A Cited
US2461435A Cited
US2500860A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1964-08-14 1965-02-13 1965-08-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1968-08-14 1969-02-13 1969-08-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1972-08-14 1973-02-13 1973-08-15 $7700.00 Window Closed / Lapsed

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