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US2991692A Expired / Lapsed US ⏱️ 0.0 years remaining

Filter devices for enlarging apparatus

Assignee: Kamera und Kinowerke Dresden VEB
•
Filing: 1957-11-15
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Granted: 1961-07-11
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Expires: 1977-11-15
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Abstract

No abstract record available.

Inventors

  • 👤 Korf Erich

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 12:46
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US340213A Cited
US1398952A Cited
US1878857A Cited
US727524A Cited
US1024242A Cited
US1127763A Cited
US1721411A Cited
US1766637A Cited
US1887654A Cited
US2291347A Cited
US2460507A 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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