Patent US2819772A successfully refreshed from Google Patents.
US2819772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide range loudspeaker
Assignee: LAB OF ELECTRONIC ENGINEERING
•
Filing: 1954-12-14
•
Granted: 1958-01-14
•
Expires: 1974-12-14
Abstract
No abstract record available.
Inventors
- 👤 Bryan Samuel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:15
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/30
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1865550A
Cited
GB225340A
Cited
US2160166A
Cited
US2310243A
Cited
US2373692A
Cited
US2604182A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-13 | 1961-07-15 | 1962-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-13 | 1965-07-15 | 1966-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-13 | 1969-07-15 | 1970-01-14 | $7700.00 | Window Closed / Lapsed |