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US2444512A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical filter attachment

Assignee: Individual
•
Filing: 1946-11-20
•
Granted: 1948-07-06
•
Expires: 1966-11-20
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Abstract

No abstract record available.

Inventors

  • 👤 Norman A Kath

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 15:25
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/02; G03B17/12

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US599670A Cited
GB190323658A Cited
GB190511765A Cited
DE515276C Cited
DE581272C Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1951-07-06 1952-01-05 1952-07-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1955-07-06 1956-01-05 1956-07-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1959-07-06 1960-01-05 1960-07-06 $7700.00 Window Closed / Lapsed

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