US3539728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single record telephone answering and recording device
Assignee: Learning Appliances Ltd
•
Filing: 1967-11-02
•
Granted: 1970-11-10
•
Expires: 1987-11-02
Abstract
No abstract record available.
Inventors
- 👤 Leonard Rubenstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:03
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/64; H04M1/65; H04M1/6515
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US952778A
Cited
US2783303A
Cited
US2928898A
Cited
US3110775A
Cited
US3188407A
Cited
US3208682A
Cited
US3248956A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |