Patent US2657138A successfully refreshed from Google Patents.
US2657138A
Expired / Lapsed
US
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Photographic film developing composition containing beta, beta'-di-chloroethyl ether
Assignee: Individual
•
Filing: 1950-01-03
•
Granted: 1953-10-27
•
Expires: 1970-01-03
Abstract
No abstract record available.
Inventors
- 👤 Leonard A Robbins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:28
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/305
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
18 words
A PHOTOGRAPHIC DEVELOPING COMPOSITION, CONTAINING AN ORGANIC SILVER HALIDE DEVELOPER; SODIUM CARBONATE; TRIETHANOLAMINE; AMMONIUM BROMIDE; AND BETA-BETA''-DICHLOROETHYL ETHER.
Claim 2
Dependent Claim
18 words
A PHOTOGRAPHIC DEVELOPING COMPOSITION, CONTAINING AN ORGANIC SILVER HALIDE DEVELOPER; SODIUM CARBONATE; TRIETHANOLAMINE; AMMONIUM BROMIDE; AND BETA-BETA''-DICHLOROETHYL ETHER.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-10-26 | 1957-04-27 | 1957-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-26 | 1961-04-27 | 1961-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-26 | 1965-04-27 | 1965-10-27 | $7700.00 | Window Closed / Lapsed |