US3946832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm for loud speaker
Assignee: Panasonic Holdings Corp
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Filing: 1974-12-04
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Granted: 1976-03-30
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Expires: 1994-12-04
Abstract
Abstract A diaphragm for a loud speaker is manufactured by impregnating a diaphragm blank made of natural or man-made fibers or formed by molding a synthetic resin, with a water-soluble inorganic flame retarder, and thereafter with an aqueous solution of a fluorine containing water repellent and oil repellent agent, and then by heating and molding into a speaker diaphragm.
Inventors
- 👤 Kazuro Takano
- 👤 Masakuni Hirata
- 👤 Yasuo Kodera
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:15
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
33 words
A diaphragm for a loud speaker made of cellulose impregnated with a solution of a water-soluble inorganic flame retarder and with a solution of a water repellent and oil repellent agent containing fluorine.
Claim 2
Dependent Claim
33 words
A diaphragm for a loud speaker made of cellulose impregnated with a solution of a water-soluble inorganic flame retarder and with a solution of a water repellent and oil repellent agent containing fluorine.
Claim 3
Dependent Claim
30 words
A diaphragm as defined in claim 1 wherein said water soluble inorganic flame retarder is diammonium hydrogen phosphate; and said water repellent and oil repellent agent containing fluorine is polytetrafluoroethylene.
Claim 4
Dependent Claim
29 words
A diaphragm as defined in claim 1 wherein said water soluble inorganic flame retarder is a polyammonium phosphate; and water repellent and oil repellent agent containing fluorine is polytetrafluoroethylene.
Claim 5
Dependent Claim
46 words
A diaphragm as defined in claim 1 wherein said solution of said water soluble inorganic flame retarder is a 20% aqueous solution of diammonium hydrogen phosphate; and said solution of said water repellent and oil repellent agent containing fluorine is a 3% aqueous solution of polytetrafluoroethylene.
Claim 6
Dependent Claim
42 words
A diaphragm as defined in claim 1 wherein said solution of said water soluble inorganic flame retarder is a 20% aqueous solution of polyammonium phosphate; and said water repellent and oil repellent agent containing fluorine is a 3% aqueous solution of polytetrafluoroethylene.
References Cited (Backward Citations)
US3811933A
Cited
US3717218A
Cited
US3770493A
Cited
US3729434A
Cited
US3740264A
Cited
US3790403A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |