Patent US3521164A successfully refreshed from Google Patents.
US3521164A
Expired / Lapsed
US
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Rms voltage measuring apparatus
Assignee: Weston Instruments Inc
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Filing: 1968-01-03
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Granted: 1970-07-21
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Expires: 1988-01-03
Abstract
No abstract record available.
Inventors
- 👤 Peter L Richman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:09
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/22; G01R19/225; G01R19/02; G01R19/03
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) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |