US4126204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speaker system
Assignee: Trio KK
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Filing: 1977-01-31
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Granted: 1978-11-21
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Expires: 1997-01-31
Abstract
Abstract In a bass-reflex type speaker system, in which sound signal waves radiating from the back of a speaker within a cabinet are emitted out through a hollow duct while the phase of the sound signal wave is reversed, the improvement comprising at least one dividing plate secured within the hollow duct and disposed parallel to the longitudinal direction of the duct or a hollow pipe with a diameter smaller than that of the duct, the hollow pipe being coaxially disposed within the hollow duct where the pipe may be made of sound absorbing material.
Inventors
- 👤 Kenji Ogi
- 👤 Masakatsu Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:20
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2815; H04R1/2823; H04R1/2826
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
110 words
A base-reflex loudspeaker system comprising a cabinet, a loudspeaker opening in said cabinet, a loudspeaker mounted over said loudspeaker opening in said cabinet, a further opening in said cabinet, a first hollow duct mounted in said further opening and substantially extending into said cabinet, and a standing wave prevention member comprising a further hollow duct with a diameter smaller than that of said first hollow duct, said further hollow duct being substantially as long as said first hollow duct and being coaxially disposed and mounted therein, so that standing waves can be prevented from forming in said first hollow duct without introducing a high impedance to sound waves radiating therethrough.
Claim 2
Dependent Claim
110 words
A base-reflex loudspeaker system comprising a cabinet, a loudspeaker opening in said cabinet, a loudspeaker mounted over said loudspeaker opening in said cabinet, a further opening in said cabinet, a first hollow duct mounted in said further opening and substantially extending into said cabinet, and a standing wave prevention member comprising a further hollow duct with a diameter smaller than that of said first hollow duct, said further hollow duct being substantially as long as said first hollow duct and being coaxially disposed and mounted therein, so that standing waves can be prevented from forming in said first hollow duct without introducing a high impedance to sound waves radiating therethrough.
Claim 3
Dependent Claim
19 words
A system as in claim 1 where said standing wave prevention member is made of a sound absorbent material.
Claim 4
Dependent Claim
15 words
A system as in claim 1 where said first and further hollow ducts are tubular.
References Cited (Backward Citations)
DK61871C
Cited
GB696671A
Cited
FR1065126A
Cited
US2810448A
Cited
US3327808A
Cited
US3443660A
Cited
US3684051A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-20 | 1982-05-22 | 1982-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-20 | 1986-05-22 | 1986-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-20 | 1990-05-22 | 1990-11-21 | $7700.00 | Window Closed / Lapsed |