US2178520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of tempering glass
Assignee: Hartford Empire Co
•
Filing: 1936-07-01
•
Granted: 1939-10-31
•
Expires: 1956-07-01
Abstract
No abstract record available.
Inventors
- 👤 George E Howard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:40
CPC Classifications
C; C03; C03B; C03B27/00; C03B27/04; C03B27/0404; C03B27/052; Y; Y10; Y10S; Y10S65/00; Y10S65/04
Claims Analysis
Total Claims: 0
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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) | 1942-10-30 | 1943-05-01 | 1943-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-10-30 | 1947-05-01 | 1947-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-10-30 | 1951-05-01 | 1951-10-31 | $7700.00 | Window Closed / Lapsed |