US2020212A
Expired / Lapsed
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Method of making dynamic speakers
Assignee: Individual
•
Filing: 1935-09-06
•
Granted: 1935-11-05
•
Expires: 1955-09-06
Abstract
No abstract record available.
Inventors
- 👤 James P Quam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:00
CPC Classifications
H; H04; H04R; H04R25/00; H04R25/65; H04R25/652; H04R25/656; H04R31/00; H04R2209/00; H04R2209/024; H04R31/006; H04R9/00; H04R9/02; H04R9/025; Y; Y10; Y10S; Y10S29/00; Y10S29/026; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49005; Y10T29/4902; Y10T29/4957
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1938-11-04 | 1939-05-06 | 1939-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-11-04 | 1943-05-06 | 1943-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-11-04 | 1947-05-06 | 1947-11-05 | $7700.00 | Window Closed / Lapsed |