US1642040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Public-address system
Assignee: AT&T Inc
•
Filing: 1925-12-12
•
Granted: 1927-09-13
•
Expires: 1945-12-12
Abstract
No abstract record available.
Inventors
- 👤 Brunson S Mccutchen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:31
CPC Classifications
H; H04; H04R; H04R27/00; Y; Y10; Y10S; Y10S84/00; Y10S84/26
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) | 1930-09-12 | 1931-03-14 | 1931-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1934-09-12 | 1935-03-14 | 1935-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1938-09-12 | 1939-03-14 | 1939-09-13 | $7700.00 | Window Closed / Lapsed |