Patent US3493686A successfully refreshed from Google Patents.
US3493686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone switching system serving long customer loops and short customer loops
Assignee: AT&T Inc
•
Filing: 1966-09-15
•
Granted: 1970-02-03
•
Expires: 1986-09-15
Abstract
No abstract record available.
Inventors
- 👤 Alfred L Spittler
- 👤 Charles W Zehe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:32
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)
US3339027A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-02-02 | 1973-08-04 | 1974-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-02 | 1977-08-04 | 1978-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-02 | 1981-08-04 | 1982-02-03 | $7700.00 | Window Closed / Lapsed |