US1653215A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for heat-treating metals
Assignee: AT&T Inc
•
Filing: 1922-11-15
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Granted: 1927-12-20
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Expires: 1942-11-15
Abstract
No abstract record available.
Inventors
- 👤 Frederic S Kochendorfer
- 👤 Arthur E Schulz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:10
CPC Classifications
C; C21; C21D; C21D9/00; C21D9/52; C21D9/54; C21D9/56
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) | 1930-12-19 | 1931-06-20 | 1931-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1934-12-19 | 1935-06-20 | 1935-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1938-12-19 | 1939-06-20 | 1939-12-20 | $7700.00 | Window Closed / Lapsed |