Patent US2721983A successfully refreshed from Google Patents.
US2721983A
Expired / Lapsed
US
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High tension outlet fitting for underfloor duct systems
Assignee: Walker Brothers Co
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Filing: 1955-03-03
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Granted: 1955-10-25
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Expires: 1975-03-03
Abstract
No abstract record available.
Inventors
- 👤 Glenn E Blinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:39
CPC Classifications
H; H02; H02G; H02G3/00; H02G3/02; H02G3/08; H02G3/18; H02G3/185; Y; Y10; Y10S; Y10S439/00; Y10S439/925
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) | 1958-10-24 | 1959-04-25 | 1959-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-24 | 1963-04-25 | 1963-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-24 | 1967-04-25 | 1967-10-25 | $7700.00 | Window Closed / Lapsed |