Patent US2218635A successfully refreshed from Google Patents.
US2218635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffuser
Assignee: Electro Refractories & Alloys
•
Filing: 1939-12-04
•
Granted: 1940-10-22
•
Expires: 1959-12-04
Abstract
No abstract record available.
Inventors
- 👤 Borge Johan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:09
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/20; B; B01; B01F; B01F23/00; B01F23/20; B01F23/23; B01F23/231; B01F23/23105; B01F23/2312; B01F23/23123; B01F23/23126; B01F23/231263; Y; Y02; Y02W; Y02W10/00; Y02W10/10
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1943-10-22 | 1944-04-22 | 1944-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-10-22 | 1948-04-22 | 1948-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-10-22 | 1952-04-22 | 1952-10-22 | $7700.00 | Window Closed / Lapsed |