← Back to Patent Explorer
US2884490A Expired / Lapsed US ⏱️ 0.0 years remaining

Telephone intercommunication system

Assignee: Individual
•
Filing: 1956-09-12
•
Granted: 1959-04-28
•
Expires: 1976-09-12
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

No abstract record available.

Inventors

  • 👤 Trachsel Fritz

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 13:09
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004

Claims Analysis

Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.

References Cited (Backward Citations)

US2057868A Cited
US2068726A Cited
US2037221A Cited
US2244920A Cited
US2258853A Cited
US2402446A Cited
US2542079A Cited
US2787667A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1962-04-27 1962-10-27 1963-04-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1966-04-27 1966-10-27 1967-04-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1970-04-27 1970-10-27 1971-04-28 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag