US2163436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical feeding apparatus and automatic control therefor
Assignee: Individual
•
Filing: 1937-05-20
•
Granted: 1939-06-20
•
Expires: 1957-05-20
Abstract
No abstract record available.
Inventors
- 👤 Raymond Gwynne
- 👤 Walden W Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:01
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/34; Y; Y10; Y10T; Y10T137/00; Y10T137/2931; Y10T137/3003; Y10T137/3102; Y10T137/3115; Y10T137/3127; Y10T137/7722; Y10T137/7771; Y10T137/7772; Y10T137/7777; Y10T137/8593; Y10T137/877; Y10T137/87829; Y10T137/87837; Y10T137/87845
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) | 1942-06-19 | 1942-12-19 | 1943-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-06-19 | 1946-12-19 | 1947-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-06-19 | 1950-12-19 | 1951-06-20 | $7700.00 | Window Closed / Lapsed |