US3531597A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone reporting set
Assignee: AT&T Inc
•
Filing: 1967-02-06
•
Granted: 1970-09-29
•
Expires: 1987-02-06
Abstract
No abstract record available.
Inventors
- 👤 Raymond J Andrews
- 👤 Gary C Fields
- 👤 Harold K Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:29
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/04; H04M11/045
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2717986A
Cited
US3049592A
Cited
US3098123A
Cited
US3207849A
Cited
US3287500A
Cited
US3383467A
Cited
US3427402A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-09-28 | 1974-03-30 | 1974-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-09-28 | 1978-03-30 | 1978-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-09-28 | 1982-03-30 | 1982-09-29 | $7700.00 | Window Closed / Lapsed |