US3517218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency control circuit
Assignee: Guardian Electric Manufacturing Co
•
Filing: 1966-09-29
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Granted: 1970-06-23
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Expires: 1986-09-29
Abstract
No abstract record available.
Inventors
- 👤 Albert Metzler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:39
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/286; H03K3/2893; H03K17/00; H03K17/51; H03K17/56; H03K17/72; H03K3/35; H03K3/351
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3036225A
Cited
US2985828A
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US3184606A
Cited
US3235750A
Cited
US3299288A
Cited
US3315246A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-06-22 | 1973-12-22 | 1974-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-22 | 1977-12-22 | 1978-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-22 | 1981-12-22 | 1982-06-23 | $7700.00 | Window Closed / Lapsed |