US3293378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loudspeaker
Assignee: HEPPNER Manufacturing CO
•
Filing: 1963-06-28
•
Granted: 1966-12-20
•
Expires: 1983-06-28
Abstract
No abstract record available.
Inventors
- 👤 Elmore A Heppner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:48
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R9/00; H04R9/02; H04R9/025
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
86 words
IN COMBINATION WITH A LOUDSPEAKER HAVING A PLATE PROVIDED WITH A CIRCULAR OPENING THEREIN, A MAGNET SECURED IN POSITION ON ONE SIDE OF THE PLATE AND HAVING A PORTION EXTENDING INTO THE OPENING TO PRODUCE AN ANNULAR GAP THEREWITH AND A VOICE COIL MOVABLE IN SAID GAP, A DUCT COVER FOR ONE SIDE OF SAID PLATE, SAID DUCT COVER BEING PERFORMED OF POLYSTYRENE FOAM AND BEING SECURED IN DUSTPROOF RELATIONSHIP TO SAID INSIDE OF THE PLATE AND SAID DUCT COVER HAVING A RECESS ENCLOSING THE MAGNET.
References Cited (Backward Citations)
US3222753A
Cited
FR1326414A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-12-19 | 1970-06-20 | 1970-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-19 | 1974-06-20 | 1974-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-19 | 1978-06-20 | 1978-12-20 | $7700.00 | Window Closed / Lapsed |