US2520902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quaternary ammonium salts of pyridine compounds
Assignee: Individual
•
Filing: 1947-08-05
•
Granted: 1950-09-05
•
Expires: 1967-08-05
Abstract
No abstract record available.
Inventors
- 👤 Frederick C Bersworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:27
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/60; C07D213/72; C07D213/74
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
6 words
A COMPOUND REPRESENTED BY THE FORMULA:
Claim 2
Dependent Claim
6 words
A COMPOUND REPRESENTED BY THE FORMULA:
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) | 1953-09-04 | 1954-03-06 | 1954-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-04 | 1958-03-06 | 1958-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-04 | 1962-03-06 | 1962-09-05 | $7700.00 | Window Closed / Lapsed |