Patent US3495286A successfully refreshed from Google Patents.
US3495286A
Expired / Lapsed
US
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Tunnel-like structures
Assignee: Individual
•
Filing: 1968-01-24
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Granted: 1970-02-17
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Expires: 1988-01-24
Abstract
No abstract record available.
Inventors
- 👤 Charles H Harper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:22
CPC Classifications
E; E04; E04H; E04H15/00; E04H15/32; E04H15/34; E04H15/44; E04H15/48; E04H15/50; E01; E01D; E01D1/00; E01D15/00; E01D15/12; E01D15/124; E04C; E04C3/00; E04C3/02; E04C3/04; E04C3/08; E01D2101/00; E01D2101/30; E01D2101/32; E01D2101/34; E04C2003/0486; E04C2003/0495
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US837602A
Cited
US1507977A
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US2097663A
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US2648720A
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US2859683A
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US2841072A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-02-16 | 1973-08-18 | 1974-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-16 | 1977-08-18 | 1978-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-16 | 1981-08-18 | 1982-02-17 | $7700.00 | Window Closed / Lapsed |