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US2535104A Expired / Lapsed US ⏱️ 0.0 years remaining

Selective signaling equipment only operative by two-voice frequencies

Assignee: International Standard Electric Corp
•
Filing: 1947-02-04
•
Granted: 1950-12-26
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Expires: 1967-02-04
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Abstract

No abstract record available.

Inventors

  • 👤 Stanislas Van Mierlo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 18:00
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/45

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US2141944A Cited
US2145053A Cited
US2255190A Cited
US2293869A Cited
US2418116A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1953-12-25 1954-06-26 1954-12-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1957-12-25 1958-06-26 1958-12-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1961-12-25 1962-06-26 1962-12-26 $7700.00 Window Closed / Lapsed

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