US2853804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Time teaching device
Assignee: Individual
•
Filing: 1954-07-29
•
Granted: 1958-09-30
•
Expires: 1974-07-29
Abstract
No abstract record available.
Inventors
- 👤 Alfred H Bengeyfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:29
CPC Classifications
G; G09; G09B; G09B1/00; G09B1/02; G09B1/04; G09B1/06; G09B19/00; G09B19/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US146757A
Cited
US802807A
Cited
US1245475A
Cited
GB191517281A
Cited
US1276344A
Cited
US1356929A
Cited
GB599038A
Cited
US2514636A
Cited
US2611193A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-29 | 1962-03-31 | 1962-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-29 | 1966-03-31 | 1966-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-29 | 1970-03-31 | 1970-09-30 | $7700.00 | Window Closed / Lapsed |