US3310131A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reinforcing cap for moving coil loudspeakers
Assignee: EMI Ltd
•
Filing: 1964-06-11
•
Granted: 1967-03-21
•
Expires: 1984-06-11
Abstract
No abstract record available.
Inventors
- 👤 Ward Dennis Charles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:59
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/02; H04R9/04; H04R9/045; H04R9/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
57 words
IN AN ELECTRO-ACOUSTIC DEVICE OF THE MOVING COIL TYPE, AN ELLIPTICAL CONICAL DIAPHRAGM, AN OPENING IN THE DIAPHRAGM, A MOVING COIL AFFIXED TO THE DIAPHRAGM AROUND SAID OPENING, A CAP AFFIXED TO THE DIAPHRAGM SO AS TO CLOSE SAID OPENING, SAID CAP COMPRISING A LAYER OF STIFF MATERIAL FORMED WITH A PLURALITY OF APERTURES, SAID LAYER HAV-
Claim 2
Dependent Claim
57 words
IN AN ELECTRO-ACOUSTIC DEVICE OF THE MOVING COIL TYPE, AN ELLIPTICAL CONICAL DIAPHRAGM, AN OPENING IN THE DIAPHRAGM, A MOVING COIL AFFIXED TO THE DIAPHRAGM AROUND SAID OPENING, A CAP AFFIXED TO THE DIAPHRAGM SO AS TO CLOSE SAID OPENING, SAID CAP COMPRISING A LAYER OF STIFF MATERIAL FORMED WITH A PLURALITY OF APERTURES, SAID LAYER HAV-
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-03-20 | 1970-09-19 | 1971-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-03-20 | 1974-09-19 | 1975-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-03-20 | 1978-09-19 | 1979-03-21 | $7700.00 | Window Closed / Lapsed |