Patent US4173701A successfully refreshed from Google Patents.
US4173701A
Expired / Lapsed
US
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Speaker diaphragm molded from poly-biphenol phthalate type resin film
Assignee: Panasonic Holdings Corp
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Filing: 1977-09-26
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Granted: 1979-11-06
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Expires: 1997-09-26
Abstract
Abstract A speaker diaphragm molded from a poly-bisphenol phthalate type plastic film having ester linkages prepared from an aromatic dicarboxylic acid such as isophthalic acid or terephthalic acid or a mixture thereof and a bifunctional phenol such as bisphenol A. This speaker diaphragm has an excellent low-pitched sound reproducing performance and is further featured by the flat acoustic pressure-frequency characteristic and improved transduce efficiency.
Inventors
- 👤 Kosaku Murata
- 👤 Satoshi Takayama
- 👤 Hirotoshi Niguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:40
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
73 words
A speaker diaphragm having a lowest resonant frequency of about 300 to 400 Hz, molded from a poly-bisphenol phthalate type resin film having ester linkages prepared from an aromatic dicarboxylic acid selected from isophthalic acid, terephthalic acid and a mixture thereof and a bifunctional phenol, wherein said film has a specific gravity of about 1.2, an elastic modulus of 9,000 to 13,000 kg/cm 2 , and an inner loss of 0.009 to 0.02.
Claim 2
Dependent Claim
73 words
A speaker diaphragm having a lowest resonant frequency of about 300 to 400 Hz, molded from a poly-bisphenol phthalate type resin film having ester linkages prepared from an aromatic dicarboxylic acid selected from isophthalic acid, terephthalic acid and a mixture thereof and a bifunctional phenol, wherein said film has a specific gravity of about 1.2, an elastic modulus of 9,000 to 13,000 kg/cm 2 , and an inner loss of 0.009 to 0.02.
Claim 3
Dependent Claim
36 words
A speaker diaphragm according to claim 1, wherein the aromatic dicarboxylic acid is a mixture of isophthalic acid and terephthalic acid mixed in the ratio of 1:9 to 9:1, and the bifunctional phenol is bisphenol A.
Claim 4
Dependent Claim
34 words
A speaker diaphragm according to claim 2, wherein the aromatic dicarboxylic acid is a mixture of isophthalic acid and terephthalic acid mixed in the ratio of 3:7, and the bifunctional phenol is bisphenol A.
References Cited (Backward Citations)
JPS4995650A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |