US3817538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brush for phonograph pick-up apparatus
Assignee: Shure Inc
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Filing: 1973-03-09
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Granted: 1974-06-18
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Expires: 1993-03-09
Abstract
Abstract A brush assembly mounted on the pick-up apparatus or tone arm of a phonograph is provided for cleaning a phonograph disc. The brush bristles are connected to a brush-mounting bracket and in the preferred embodiment are grouped together in any suitable configuration, such as a substantially rectangular crosssectional shape. The bristles are substantially parallel with respect to one another. In operative position, the bristles are oriented toward and angled toward the center of the disc, to offset the skating force caused by the brush contacting the record grooves. The longitudinal axis of the cross section of the group of brush bristles is oriented at an acute angle away from the direction of movement of the disc grooves at the point of contact between the brush and the groove to continuously sweep dust particulate on the phonograph disc toward the center of the record without contacting the stylus.
Inventors
- 👤 P Jenrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:17
CPC Classifications
G; G11; G11B; G11B3/00; G11B3/58; G11B3/5809; G11B3/5818; G11B3/5827; G11B3/5836
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
217 words
A phonograph disc cleaning brush for a phonograph of the type adapted to receive a phonograph disc having a plurality of sound encoded grooves defined on said disc and spiraling inwardly toward the center of said disc, said phonograph including a stylus mounted in a stylus-retaining member comprising, in combination a brush-mounting bracket; and a brush having a plurality of substantially parallel bristles connected to said mounting bracket about a longitudinal axis and extending from said bracket, said bracket and said brush being arranged so that when said stylus tracks in the grooves of said disc and when said brush and brush-mounting bracket are in operative position, the longitudinal axis of the brush is oriented at an acute angle phi in relation to the tangent of the grooves of the disc in contact with said brush, said bristles also being oriented toward the disc and toward the center of said disc at an acute angle theta in relation to the normal of the disc, said angle theta being directly related to the friction between the disc and the bristles of said brush such that said forces at the stylus may be counterbalanced to prevent skating and such that dust particulate on the phonograph disc may be moved toward the center of the record without contacting said stylus.
Claim 2
Dependent Claim
217 words
A phonograph disc cleaning brush for a phonograph of the type adapted to receive a phonograph disc having a plurality of sound encoded grooves defined on said disc and spiraling inwardly toward the center of said disc, said phonograph including a stylus mounted in a stylus-retaining member comprising, in combination a brush-mounting bracket; and a brush having a plurality of substantially parallel bristles connected to said mounting bracket about a longitudinal axis and extending from said bracket, said bracket and said brush being arranged so that when said stylus tracks in the grooves of said disc and when said brush and brush-mounting bracket are in operative position, the longitudinal axis of the brush is oriented at an acute angle phi in relation to the tangent of the grooves of the disc in contact with said brush, said bristles also being oriented toward the disc and toward the center of said disc at an acute angle theta in relation to the normal of the disc, said angle theta being directly related to the friction between the disc and the bristles of said brush such that said forces at the stylus may be counterbalanced to prevent skating and such that dust particulate on the phonograph disc may be moved toward the center of the record without contacting said stylus.
Claim 3
Dependent Claim
17 words
The combination as set forth in claim 1 wherein said brush has a substantially rectangular cross section.
Claim 4
Dependent Claim
27 words
The combination as set forth in claim 1 wherein said bristles are connected to a bristle-holder member, and said holder member is connected to said mounting bracket.
Claim 5
Dependent Claim
25 words
The combination as set forth in claim 1 including a stylus grip assembly and including means for pivotally mounting said bracket on said grip assembly.
Claim 6
Dependent Claim
43 words
The combination as set forth in claim 4 wherein said pivotal mounting means includes first and second pivot pins connected to said grip assembly and first and second mounting apertures on said bracket adapted to receive the first and second pivot pins, respectively.
Claim 7
Dependent Claim
47 words
The apparatus as set forth in claim 4 including first and second stop members connected to said grip assembly, adapted to contact said brush-mounting bracket so as to upwardly bias the mounting bracket and position the bracket when the stylus is lifted away from the phonograph disc.
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) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |