Patent US3223540A successfully refreshed from Google Patents.
US3223540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractory composition
Assignee: Republic Steel Corp
•
Filing: 1962-10-11
•
Granted: 1965-12-14
•
Expires: 1982-10-11
Abstract
No abstract record available.
Inventors
- 👤 Robert W Limes
- 👤 Michael P Fedock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:31
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
A COMPOSITION SUITABLE FOR IMPROVED REFRACTORIES CONSISTING ESSENTIALLY OF 60-75 PERCENT BY WEIGHT OF COARSE SILICA HAVING A PARTICLE SIZE THAT WILL PASS THROUGH A 3MESH SCREEN BUT WILL NOT PASS THROUGH A 20 MESH SCREEN, AND 25-40 PERCENT BY WEIGHT OF FINELY DIVIDED ALUMINA OF A PARTICLE SIZE THAT WILL PASS THROUGH A 100-MESH SCREEN.
Claim 2
Dependent Claim
56 words
A COMPOSITION SUITABLE FOR IMPROVED REFRACTORIES CONSISTING ESSENTIALLY OF 60-75 PERCENT BY WEIGHT OF COARSE SILICA HAVING A PARTICLE SIZE THAT WILL PASS THROUGH A 3MESH SCREEN BUT WILL NOT PASS THROUGH A 20 MESH SCREEN, AND 25-40 PERCENT BY WEIGHT OF FINELY DIVIDED ALUMINA OF A PARTICLE SIZE THAT WILL PASS THROUGH A 100-MESH SCREEN.
References Cited (Backward Citations)
US2047457A
Cited
US2748007A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-13 | 1969-06-14 | 1969-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-13 | 1973-06-14 | 1973-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-13 | 1977-06-14 | 1977-12-14 | $7700.00 | Window Closed / Lapsed |