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US1487267A
Expired / Lapsed
US
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Testing system
Assignee: AT&T Inc
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Filing: 1921-05-04
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Granted: 1924-03-18
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Expires: 1941-05-04
Abstract
No abstract record available.
Inventors
- 👤 John B Retallack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:02
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22
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) | 1927-03-18 | 1927-09-17 | 1928-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1931-03-18 | 1931-09-17 | 1932-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1935-03-18 | 1935-09-17 | 1936-03-18 | $7700.00 | Window Closed / Lapsed |