Patent US2293729A successfully refreshed from Google Patents.
Patent US3843846A successfully refreshed from Google Patents.
US3843846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Demountable capacitive protective coupling for pickup transducers
Assignee: RCA Corp
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Filing: 1973-02-08
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Granted: 1974-10-22
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Expires: 1993-02-08
Abstract
Abstract To protect a playback stylus against excessive charge flow, a capacitor is provided in series circuit relationship with the electrode of the stylus assembly. The capacitor is formed of cooperating respective elements on the stylus assembly and a supporting tracking arm which are demountably intercoupled.
Inventors
- 👤 M Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:39
CPC Classifications
G; G11; G11B; G11B9/00; G11B9/06; G11B9/07; G11B9/075
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
230 words
In a system for effecting playback of a disc record having geometrical variations in spiral groove form on a major surface thereof, the combination comprising: an arm pivotally mounted at one end thereof, a stylus assembly including a conductive stylus electrode adapted for entry in said record groove; a first conductive member secured to an end of said arm remote from said one end; signal processing means electricallY coupled between said first conductive member and a point of reference potential; a second conductive member secured to a segment of said stylus assembly remote from said stylus electrode and electrically coupled to said stylus electrode; said stylus assembly segment and said remote end of said arm subject to mechanical engagement in an operating relationship providing support for said stylus assembly by said arm during record playback, and subject to manual release from said engagement for facile disassembly of said arm and said stylus assembly; the mechanical engagement of said stylus assembly segment and said remote arm end in said operating relationship effecting a juxtaposition of said conductive members in a substantially parallel relationship of substantially fixed spacing; an electrical coupling of a direct current blocking character being provided between said stylus electrode and said signal processing means during record playback by a capacitance of substantially fixed value established between said conductive members, said coupling being provided without hindrance to said disassembly.
Claim 2
Dependent Claim
230 words
In a system for effecting playback of a disc record having geometrical variations in spiral groove form on a major surface thereof, the combination comprising: an arm pivotally mounted at one end thereof, a stylus assembly including a conductive stylus electrode adapted for entry in said record groove; a first conductive member secured to an end of said arm remote from said one end; signal processing means electricallY coupled between said first conductive member and a point of reference potential; a second conductive member secured to a segment of said stylus assembly remote from said stylus electrode and electrically coupled to said stylus electrode; said stylus assembly segment and said remote end of said arm subject to mechanical engagement in an operating relationship providing support for said stylus assembly by said arm during record playback, and subject to manual release from said engagement for facile disassembly of said arm and said stylus assembly; the mechanical engagement of said stylus assembly segment and said remote arm end in said operating relationship effecting a juxtaposition of said conductive members in a substantially parallel relationship of substantially fixed spacing; an electrical coupling of a direct current blocking character being provided between said stylus electrode and said signal processing means during record playback by a capacitance of substantially fixed value established between said conductive members, said coupling being provided without hindrance to said disassembly.
Claim 3
Dependent Claim
228 words
In a playback system for use with a disc record having geometrical variations in a spiral groove on a major surface thereof, said record including a deposit of conductive material covered with a coating of dielectric material, the combination comprising: a stylus assembly including a conductive electrode which engages said record groove and further cooperates with the conductive material and dielectric coating of said disc record to form a varying capacitance as said disc record is rotated; a tracking arm having a first end pivotally mounted and a second end having a recess therein; a first generally flat conductive member secured to said arm in the vicinity of said second end; signal processing means electrically coupled between said first conductive member and a point of reference potential; a second generally flat conductive member secured to said stylus assembly and electrically coupled to said stylus electrode; said stylus assembly further including a protruding portion adapted to be received in the recess of said second end of said arm under operating conditions to provide demountable support of said stylus assembly from said second end of said arm, with said first and second conductive members in proximate spaced relation to form a capacitive element of substantially fixed value, said capacitive element providing an electrical signal path, independent of said variable capacitance, for coupling said stylus electrode to said signal processing means.
Claim 4
Dependent Claim
228 words
In a playback system for use with a disc record having geometrical variations in a spiral groove on a major surface thereof, said record including a deposit of conductive material covered with a coating of dielectric material, the combination comprising: a stylus assembly including a conductive electrode which engages said record groove and further cooperates with the conductive material and dielectric coating of said disc record to form a varying capacitance as said disc record is rotated; a tracking arm having a first end pivotally mounted and a second end having a recess therein; a first generally flat conductive member secured to said arm in the vicinity of said second end; signal processing means electrically coupled between said first conductive member and a point of reference potential; a second generally flat conductive member secured to said stylus assembly and electrically coupled to said stylus electrode; said stylus assembly further including a protruding portion adapted to be received in the recess of said second end of said arm under operating conditions to provide demountable support of said stylus assembly from said second end of said arm, with said first and second conductive members in proximate spaced relation to form a capacitive element of substantially fixed value, said capacitive element providing an electrical signal path, independent of said variable capacitance, for coupling said stylus electrode to said signal processing means.
Claim 5
Dependent Claim
62 words
The invention according to claim 2 wherein said stylus assembly includes a rod member, means securing said conductive electrode to a first end of said rod, a resilient member providing flexible coupling between a further end of said rod and said protruding portion, and said first and second conductive members supported in cantilevered manner from said arm and said protruding portion respectively.
Claim 6
Dependent Claim
46 words
The invention according to claim 2 wherein each of said first and second conductive members comprise a metal plate having a major surface area, said major surface areas being relatively spaced under said operating conditions to provide a capacitance value in the order of 2 picofarads.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |