US3746125A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective speaker back-can
Assignee: Lowell Manufacturing Co
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Filing: 1971-09-10
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Granted: 1973-07-17
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Expires: 1991-09-10
Abstract
Abstract An integral organic plastic back-can for protection of loud speakers against damage and which is mildew and corrosion proof. The back-can encloses and protects a loud speaker and may simply be connected to a loud speaker baffle by a peripheral flange. In order to prevent vibration and minimize resonance and sound distortion the back-can is provided with a dish-shaped body having relatively steep frustoconical side walls joined by a gentle radius of curvature to a flat bottom. The flat bottom is provided with protruding diammetrical ribs which strengthen the bottom and prevent vibration and serve to diffuse the sound waves and minimize resonance.
Inventors
- 👤 J Hammes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:25
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/02; H04R1/021; H04R1/025
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
132 words
In a back can for connection with a loud speaker: a molded plastic, unitary body having steeply sloping continuous side walls spanned by a bottom wall, the body being open at the top, the side walls converging from the open end toward the bottom wall, the side walls and bottom wall being connected by a curving connecting portion integral with both bottom and side walls, the bottom wall having integral reinforcing ribs projecting outwardly therefrom, the sloping side walls merging by the curved connecting portion into a rigidified bottom wall affording a back can with reduced vibration characteristics of the kind that interfere with the delivery of acoustical vibrations from a speaker connected with the back can, and means for attaching a loud speaker to the open end of the back can.
Claim 2
Dependent Claim
132 words
In a back can for connection with a loud speaker: a molded plastic, unitary body having steeply sloping continuous side walls spanned by a bottom wall, the body being open at the top, the side walls converging from the open end toward the bottom wall, the side walls and bottom wall being connected by a curving connecting portion integral with both bottom and side walls, the bottom wall having integral reinforcing ribs projecting outwardly therefrom, the sloping side walls merging by the curved connecting portion into a rigidified bottom wall affording a back can with reduced vibration characteristics of the kind that interfere with the delivery of acoustical vibrations from a speaker connected with the back can, and means for attaching a loud speaker to the open end of the back can.
Claim 3
Dependent Claim
16 words
The back-can of claim 1 in which said ribs protrude on the interior of said body.
Claim 4
Dependent Claim
22 words
The back-can of claim 1 in which ribs extend radially from the center of said flat bottom and intersect with one another.
Claim 5
Dependent Claim
25 words
The back-can of claim 1 in which the body has steep frustoconical side walls joined to the flat bottom with a gentle radius of curvature.
Claim 6
Dependent Claim
30 words
In the back can of claim 1, the means for attaching a loud speaker including an integral flange around the sloping side walls of the body at their open end.
Claim 7
Dependent Claim
28 words
The back-can of claim 5 in which a speaker baffle is connected to the peripheral flange of the back-can and extends acrosS the open end of the body.
Claim 8
Dependent Claim
31 words
The back-can of claim 6 in which said ribs protrude on the interior of said body and extend radially from the center of said flat bottom and intersect with one another.
Claim 9
Dependent Claim
25 words
The back-can of claim 6 in which the body has steep frustoconical side walls joined to the flat bottom with a gentle radius of curvature.
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) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |