Patent US3447937A successfully refreshed from Google Patents.
US3447937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steam cured cement and process
Assignee: Alpha Portland Cement Co
•
Filing: 1965-08-06
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Granted: 1969-06-03
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Expires: 1985-08-06
Abstract
No abstract record available.
Inventors
- 👤 Arthur T Hersey
- 👤 Lorrin T Brownmiller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:07
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2837436A
Cited
US3021291A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-02 | 1972-12-02 | 1973-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-02 | 1976-12-02 | 1977-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-02 | 1980-12-02 | 1981-06-03 | $7700.00 | Window Closed / Lapsed |