Patent US3543544A successfully refreshed from Google Patents.
US3543544A
Expired / Lapsed
US
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Locking device for use with an electric plug
Assignee: EVAN N EFSTON
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Filing: 1968-08-19
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Granted: 1970-12-01
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Expires: 1988-08-19
Abstract
No abstract record available.
Inventors
- 👤 Evan N Efston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:33
CPC Classifications
H; H01; H01R; H01R13/00; H01R13/62; H01R13/639; H01R13/6397; H01R13/60; Y; Y10; Y10T; Y10T70/00; Y10T70/40; Y10T70/413; Y10T70/417; Y10T70/422; Y10T70/424; Y10T70/426; Y10T70/70; Y10T70/7153; Y10T70/7181; Y10T70/7198; Y10T70/7237; Y10T70/726; Y10T70/7305
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) | 1973-11-30 | 1974-06-01 | 1974-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-30 | 1978-06-01 | 1978-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-30 | 1982-06-01 | 1982-12-01 | $7700.00 | Window Closed / Lapsed |