US3431431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching apparatus
Assignee: International Business Machines Corp
•
Filing: 1965-12-23
•
Granted: 1969-03-04
•
Expires: 1985-12-23
Abstract
No abstract record available.
Inventors
- 👤 Robert W Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:42
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/01; H03K3/013
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2425570A
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US2441789A
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US3122659A
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US3184619A
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US3209228A
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US3192468A
Cited
US3230394A
Cited
US3376428A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-03-03 | 1972-09-02 | 1973-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-03-03 | 1976-09-02 | 1977-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-03-03 | 1980-09-02 | 1981-03-04 | $7700.00 | Window Closed / Lapsed |