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Patent US4395592A successfully refreshed from Google Patents.
US4395592A
Expired / Lapsed
US
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Ribbon loudspeaker
Assignee: Mark Levinson Audio Systems Ltd
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Filing: 1981-03-06
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Granted: 1983-07-26
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Expires: 2001-03-06
Abstract
Abstract A ribbon loudspeaker is suitable for incorporation into a sound reproduction system without additionally requiring a transformer or series resistor. In one form in which the loudspeaker is bi-directional, a sound reproduction ribbon is received in a pair of magnetic gaps formed from a magnetic system employing a single magnet.
Inventors
- 👤 Thomas P. Colangelo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:34
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/02; H04R9/04; H04R9/046; H04R9/047; H04R9/048
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
83 words
A ribbon loudspeaker comprising: an elongated permanent magnet of substantially rectilinear structure having two pairs of opposite faces; a pair of pole pieces, each contacting against opposite faces and extending outwardly from said faces to form a pair of magnetic gaps, said gaps being parallel to and spaced apart from said second pair of faces and extending the length of said faces; and a ribbon for sound reproduction continuously wound around said magnet and received in and extending the length of said gaps.
Claim 2
Dependent Claim
83 words
A ribbon loudspeaker comprising: an elongated permanent magnet of substantially rectilinear structure having two pairs of opposite faces; a pair of pole pieces, each contacting against opposite faces and extending outwardly from said faces to form a pair of magnetic gaps, said gaps being parallel to and spaced apart from said second pair of faces and extending the length of said faces; and a ribbon for sound reproduction continuously wound around said magnet and received in and extending the length of said gaps.
Claim 3
Dependent Claim
16 words
The loudspeaker of claim 1 wherein said ribbon is wound to form a plurality of layers.
Claim 4
Dependent Claim
19 words
The loudspeaker of claim 1 wherein each of said pole pieces comprises a structure having a truncated v-shaped cross-section.
Claim 5
Dependent Claim
31 words
The loudspeaker of claim 3 wherein said pole pieces are substantially identical and parallel and are positioned to open toward each other, the outer ends of said pieces defining said gaps.
Claim 6
Dependent Claim
14 words
The loudspeaker of claim 4 wherein said magnet is positioned between said pole pieces.
Claim 7
Dependent Claim
16 words
The loudspeaker of claim 4 further comprising means to minimize distortion positioned between said pole pieces.
Claim 8
Dependent Claim
10 words
The loudspeaker of claim 1 wherein the ribbon is corrugated.
Claim 9
Dependent Claim
15 words
The loudspeaker of claim 1 further comprising means for adjusting the tightness of said ribbon.
Claim 10
Dependent Claim
24 words
The loudspeaker of claim 1 wherein said ribbon comprises a layer which is an electrical conductor and a layer which is an electrical insulator.
Claim 11
Dependent Claim
16 words
The loudspeaker of claim 9 wherein said conductor is aluminum foil and said insulator is mylar.
Claim 12
Dependent Claim
38 words
The loudspeaker of claim 1 wherein said gaps are of uniform width and thickness, said ribbon is of a uniform width slightly less than the width of said gaps, and said ribbon is centrally positioned in said gaps.
Claim 13
Dependent Claim
27 words
The loudspeaker of claim 1 wherein the portions of ribbon positioned in said gaps comprise a plurality of corrugations perpendicular to the longitudinal dimension of said ribbon.
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) | 1986-07-25 | 1987-01-24 | 1987-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-25 | 1991-01-24 | 1991-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-25 | 1995-01-24 | 1995-07-26 | $7700.00 | Window Closed / Lapsed |