Patent US2437898A successfully refreshed from Google Patents.
US2437898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Autofocus photographic enlarger of the folded-light-path type
Assignee: Bell and Howell Co
•
Filing: 1945-08-04
•
Granted: 1948-03-16
•
Expires: 1965-08-04
Abstract
No abstract record available.
Inventors
- 👤 Keith N Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:56
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/34; G03B27/36
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
FR818632A
Cited
US2133978A
Cited
US2137028A
Cited
US2163776A
Cited
US2141176A
Cited
US2303518A
Cited
US2319882A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-03-16 | 1951-09-15 | 1952-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-03-16 | 1955-09-15 | 1956-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-03-16 | 1959-09-15 | 1960-03-16 | $7700.00 | Window Closed / Lapsed |