US4139734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pivoted loudspeaker enclosure with visual indicator of optimum listening position
Assignee: KEF Audio UK Ltd
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Filing: 1978-02-28
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Granted: 1979-02-13
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Expires: 1998-02-28
Abstract
Abstract The present invention provides a loudspeaker comprising a plurality of enclosures each provided with a loudspeaker drive unit connected to an input, at least one of the enclosures being pivotally mounted with respect to another of the enclosures, said at least one enclosure being provided with means defining an aperture and a light emitting device, the means defining aperture being shaped and the light emitting device being positioned with respect to said aperture defining means whereby the device will be visible only when a listener is in the correct position.
Inventors
- 👤 Lawrence R. Fincham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:27
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/26; H04R1/02; H04R3/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
86 words
A loudspeaker comprising a plurality of enclosures each provided with a loudspeaker drive unit connected to an input, at least one of the enclosures being pivotally mounted with respect to another of the enclosures, said at least one enclosure being provided with means defining an aperture and a light emitting device, the means defining aperture being shaped and the light emitting device being positioned with respect to said aperture defining means whereby the device will be visible only when a listener is in the correct position.
Claim 2
Dependent Claim
86 words
A loudspeaker comprising a plurality of enclosures each provided with a loudspeaker drive unit connected to an input, at least one of the enclosures being pivotally mounted with respect to another of the enclosures, said at least one enclosure being provided with means defining an aperture and a light emitting device, the means defining aperture being shaped and the light emitting device being positioned with respect to said aperture defining means whereby the device will be visible only when a listener is in the correct position.
Claim 3
Dependent Claim
23 words
A loudspeaker according to claim 1, wherein the light emitting device is connected in a circuit connected to said input of the loudspeaker.
Claim 4
Dependent Claim
27 words
A loudspeaker according to claim 1, wherein said at least one enclosure is pivotally mounted so as to be pivotable about a horizontal and a vertical axis.
Claim 5
Dependent Claim
31 words
A loudspeaker according to claim 1, wherein said at least one enclosure comprises two portions, one provided with a mid-range drive unit and the other with a high frequency drive unit.
Claim 6
Dependent Claim
28 words
A loudspeaker according to claim 4, wherein the mid-range and high frequency drive units are staggered with respect to the drive unit in said another of the enclosures.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |