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US3679843A Expired / Lapsed US ⏱️ 0.0 years remaining

Moving coil type phonograph pickup cartridge

Assignee: MICRO SEIKI CO Ltd
•
Filing: 1971-01-04
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Granted: 1972-07-25
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Expires: 1991-01-04
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Abstract

Abstract A moving coil type phonograph pickup cartridge consisting of a magnet assembly containing a permanent magnet therein and a stylus assembly detachably mounted on the magnet assembly and including an armature with coils wound thereon. The armature is substantially of a V-shape having two leg portions which are at right angles to each other. The coils are wound on the leg portions. By this construction, a vertical tracking angle of a cantilever arm relative to a record disc can be reduced.

Inventors

  • 👤 Masanobu Cho

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 21:23
CPC Classifications
H; H04; H04R; H04R9/00; H04R9/12; H04R9/16

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 294 words
A moving coil type phonograph pickup cartridge comprising: a stylus assembly comprising; a cantilever arm, a stylus provided at the foremost end of said cantilever arm, an armature having two leg portions which extend obliquely and upwardly with a right angle to each other, said armature being provided with the rear end of said cantilever arm which is secured to a crossing point of virtual center lines of said two leg portions, coils Wound around respective of said two leg portions, two yoke member located so as to form an air gap between the opposed end surfaces thereof, a damping member attached of its both surfaces to the rear surface of said armature and to the end surface of one of said yoke members so that the leg portions of said armature are located in said air gap formed between the yoke members, a housing for accommodating said yoke members, said damping member and said armature, said cantilever arm extending through said housing and substantially extending of its virtual axis through said armature, said damping member and a part of said one yoke member, and terminals provided at the housing and electrically connected to said coils; a magnet assembly comprising; a housing, a permanent magnet accommodated in said housing and exposing the magnetic poles thereof at the lower surface, and terminals provided in said housing for being connected with the terminals of said stylus assembly and with terminals of a pickup arm, said permanent magnet being positioned in the housing so that the permanent magnet forms a magnetic circuit in said yoke members passing through said air gap when the stylus assembly is connected to the magnet assembly by connecting of the terminals of the stylus assembly with the terminals of the magnet assembly.
Claim 2
Dependent Claim 294 words
A moving coil type phonograph pickup cartridge comprising: a stylus assembly comprising; a cantilever arm, a stylus provided at the foremost end of said cantilever arm, an armature having two leg portions which extend obliquely and upwardly with a right angle to each other, said armature being provided with the rear end of said cantilever arm which is secured to a crossing point of virtual center lines of said two leg portions, coils Wound around respective of said two leg portions, two yoke member located so as to form an air gap between the opposed end surfaces thereof, a damping member attached of its both surfaces to the rear surface of said armature and to the end surface of one of said yoke members so that the leg portions of said armature are located in said air gap formed between the yoke members, a housing for accommodating said yoke members, said damping member and said armature, said cantilever arm extending through said housing and substantially extending of its virtual axis through said armature, said damping member and a part of said one yoke member, and terminals provided at the housing and electrically connected to said coils; a magnet assembly comprising; a housing, a permanent magnet accommodated in said housing and exposing the magnetic poles thereof at the lower surface, and terminals provided in said housing for being connected with the terminals of said stylus assembly and with terminals of a pickup arm, said permanent magnet being positioned in the housing so that the permanent magnet forms a magnetic circuit in said yoke members passing through said air gap when the stylus assembly is connected to the magnet assembly by connecting of the terminals of the stylus assembly with the terminals of the magnet assembly.
Claim 3
Dependent Claim 59 words
The moving coil type phonograph pickup cartridge as defined in claim 1, in which said armature comprises a circular portion at the center of which said rear end of the cantilever arm is secured and said two leg portions projecting from the upper portion of the circular portion, said circular portion having the circular lower portion with no projection.

References Cited (Backward Citations)

US2114471A Cited
US2432444A Cited
US2631857A Cited
US3184555A Cited
US3299219A Cited
US3040136A Cited
GB1000035A Cited
US3538266A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-07-25 1976-01-24 1976-07-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-07-25 1980-01-24 1980-07-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-07-25 1984-01-24 1984-07-25 $7700.00 Window Closed / Lapsed

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