US2934611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic speaker
Assignee: Pickering Associates Inc
•
Filing: 1955-11-09
•
Granted: 1960-04-26
•
Expires: 1975-11-09
Abstract
No abstract record available.
Inventors
- 👤 Lindenberg Theodore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:31
CPC Classifications
H; H04; H04R; H04R19/00; H04R19/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1622039A
Cited
US1762981A
Cited
US1764008A
Cited
FR695243A
Cited
US1978200A
Cited
US2520798A
Cited
US2681446A
Cited
US2686847A
Cited
FR1083302A
Cited
US2824178A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-04-26 | 1963-10-26 | 1964-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-26 | 1967-10-26 | 1968-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-26 | 1971-10-26 | 1972-04-26 | $7700.00 | Window Closed / Lapsed |