US3476351A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expandable form for hollow-core concrete construction
Assignee: HAROLD D BURDETT
•
Filing: 1967-07-03
•
Granted: 1969-11-04
•
Expires: 1987-07-03
Abstract
No abstract record available.
Inventors
- 👤 Harold D Burdett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:01
CPC Classifications
B; B28; B28B; B28B7/00; B28B7/28; B28B7/30; E; E04; E04G; E04G15/00; E04G15/06; E04G15/063; E04G15/065
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-11-03 | 1973-05-05 | 1973-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-11-03 | 1977-05-05 | 1977-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-11-03 | 1981-05-05 | 1981-11-04 | $7700.00 | Window Closed / Lapsed |