US3922501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moving voice coil electro-acoustic converter with laminated magnetically anisotropic poles
Assignee: Pioneer Corp
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Filing: 1972-12-18
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Granted: 1975-11-25
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Expires: 1992-12-18
Abstract
Abstract An improvement is an electro-acoustic converter having a magnetic circuit with an air gap therein, the improvement including a magnetically anisotropic material in the magnetic circuit. The axes of the anisotropic material are aligned to eliminate flux caused by a voice coil.
Inventors
- 👤 Isao Yamamuro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:13
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/02; H04R9/025; H04R2209/00; H04R2209/021
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
83 words
In an electro-acoustic converter comprising: a. a center pole; b. voice coil means surrounding said center pole; c. magnetic means surrounding said center pole and said voice coil means; and d. plate means fixed to said magnetic means, said plate means and said center pole defining an air gap accepting said voice coil; the improvement comprising e. wherein all of said plate means and that portion of said center pole defining said air gap consist of magnetically anisotropic sheets laminating magnetically anisotropic sheets.
Claim 2
Dependent Claim
83 words
In an electro-acoustic converter comprising: a. a center pole; b. voice coil means surrounding said center pole; c. magnetic means surrounding said center pole and said voice coil means; and d. plate means fixed to said magnetic means, said plate means and said center pole defining an air gap accepting said voice coil; the improvement comprising e. wherein all of said plate means and that portion of said center pole defining said air gap consist of magnetically anisotropic sheets laminating magnetically anisotropic sheets.
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) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |