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US1659083A Expired / Lapsed US ⏱️ 0.0 years remaining

Telephone-exchange system

Assignee: AT&T Inc
•
Filing: 1925-06-27
•
Granted: 1928-02-14
•
Expires: 1945-06-27
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Abstract

No abstract record available.

Inventors

  • 👤 Edgar H Clark

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-22 19:26
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1931-02-13 1931-08-15 1932-02-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1935-02-13 1935-08-15 1936-02-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1939-02-13 1939-08-15 1940-02-14 $7700.00 Window Closed / Lapsed

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