Patent US2991335A successfully refreshed from Google Patents.
US2991335A
Expired / Lapsed
US
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Routine testing equipment for use in automatic telephone exchanges
Assignee: Automatic Telephone and Electric Co Ltd
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Filing: 1957-11-18
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Granted: 1961-07-04
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Expires: 1977-11-18
Abstract
No abstract record available.
Inventors
- 👤 Marwing Kenneth George
- 👤 Halton Donald
- 👤 Greenaway John Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:18
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/22; H04M3/26; H04M3/28; H04M3/32; H04M3/326
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-03 | 1965-01-02 | 1965-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-03 | 1969-01-02 | 1969-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-03 | 1973-01-02 | 1973-07-04 | $7700.00 | Window Closed / Lapsed |