Patent US420094A successfully refreshed from Google Patents.
Patent US4135600A successfully refreshed from Google Patents.
US4135600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loudspeaker system
Assignee: Trio KK
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Filing: 1977-01-12
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Granted: 1979-01-23
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Expires: 1997-01-12
Abstract
Abstract A loudspeaker system has a cabinet in which a loudspeaker is mounted, the cabinet supporting therein a hollow duct which provides sound communication between the exterior and interior of the cabinet. A standing wave prevention member made of a sound absorbent material is disposed within the duct in spaced relation thereto, the member being smaller in volume than the duct.
Inventors
- 👤 Kenji Ogi
- 👤 Masakatsu Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:36
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2815; H04R1/2823; H04R1/2826; H04R1/2869; H04R1/2876; H04R1/288
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
118 words
A bass-reflex loudspeaker system comprising a cabinet, a loudspeaker opening in said cabinet, a loudspeaker mounted over said opening in said cabinet, a further opening in said cabinet, a hollow duct mounted in said further opening and substantially extending into said cabinet, and a standing wave prevention member made of a sound absorbent material and disposed within and removed from the interior wall of said duct in spaced relation thereto, said standing wave prevention member being smaller in volume than said duct and comprising a solid cylinder with a diameter smaller than that of said hollow duct, the length of said solid cylinder being substantially as long as said hollow duct and being coaxially disposed and mounted therein.
Claim 2
Dependent Claim
118 words
A bass-reflex loudspeaker system comprising a cabinet, a loudspeaker opening in said cabinet, a loudspeaker mounted over said opening in said cabinet, a further opening in said cabinet, a hollow duct mounted in said further opening and substantially extending into said cabinet, and a standing wave prevention member made of a sound absorbent material and disposed within and removed from the interior wall of said duct in spaced relation thereto, said standing wave prevention member being smaller in volume than said duct and comprising a solid cylinder with a diameter smaller than that of said hollow duct, the length of said solid cylinder being substantially as long as said hollow duct and being coaxially disposed and mounted therein.
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) | 1982-01-22 | 1982-07-24 | 1983-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-22 | 1986-07-24 | 1987-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-22 | 1990-07-24 | 1991-01-23 | $7700.00 | Window Closed / Lapsed |