US3428897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric voltage measuring apparatus including a current-regulated zener diode for zero suppression
Assignee: Weston Instruments Inc
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Filing: 1965-01-22
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Granted: 1969-02-18
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Expires: 1985-01-22
Abstract
No abstract record available.
Inventors
- 👤 Ian Arthur Rew
- 👤 Robert Valentine Bell
- 👤 Raymond Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:44
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/005; G01R15/007; G01R19/00; G01R19/0084
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) | 1972-02-18 | 1972-08-19 | 1973-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-18 | 1976-08-19 | 1977-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-18 | 1980-08-19 | 1981-02-18 | $7700.00 | Window Closed / Lapsed |