US3566566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frictionally secured trench duct cover and partition
Assignee: Butler Manufacturing Co
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Filing: 1969-08-14
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Granted: 1971-03-02
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Expires: 1989-08-14
Abstract
Abstract MEANS ADAPTABLE FOR USE IN HOLDING DOWN TRENCH DUCT COVERS AND FOR PARTITIONING THE TRENCH INTO COMPARTMENTS INCLUDING TWO L-SHAPED PIECES TO EXTEND BETWEEN THE COVER AND THE BOTTOM OF THE TREHC, ONE OF THE PIECES HAVING A YIELDING ARM WHICH ENVELOPES AND GRIPS THE OTHER SO THAT THE TWO PIECES ARE HELD IN FAIRLY TIGHT FRICTIONAL ENGAGEMENT EITHER FOR HOLDING THE COVER OR FORMING A PARTITION.
Inventors
- 👤 Stephen M Janic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:58
CPC Classifications
E; E04; E04F; E04F19/00; E04F19/08; H; H02; H02G; H02G3/00; H02G3/02; H02G3/04; H02G3/0406; H02G3/0418; Y; Y10; Y10T; Y10T292/00; Y10T292/08; Y10T292/0894; Y10T292/0907
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |