Patent US4079943A successfully refreshed from Google Patents.
US4079943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pickup arm device dynamically damped
Assignee: Panasonic Holdings Corp
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Filing: 1976-12-15
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Granted: 1978-03-21
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Expires: 1996-12-15
Abstract
Abstract A phonograph pickup arm device wherein one end of a balance weight is connected to one end of an arm through a spring, and a first magnet is supported at the other end of the weight and is immersed in a viscous oil. A second magnet is disposed for displacement toward or away from the first magnet for adjusting the magnetic force acting therebetween so that the compliance of the device which is related to the arm resonance frequency, may be changed and consequently the arm resonance amplitude may be substantially reduced.
Inventors
- 👤 Katsuhiko Morita
- 👤 Hiroshi Yasuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:28
CPC Classifications
G; G11; G11B; G11B3/00; G11B3/02; G11B3/10; G11B3/12; G11B3/14; G11B3/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
A dynamically damped pickup arm device, comprising: a pickup arm, a balance weight, a resilient member interconnecting one end of said arm and one end of said balance weight, damping means for damping said balance weight, said damping means being coupled to said balance weight and support by said pickup arm, biasing means coupled between said weight and said arm for applying a biasing force to said balance weight, and adjusting means supported on said arm for adjusting the biasing force applied by said biasing means to said balance weight, thereby adjusting the resonance frequency of said balance weight of said resilient member.
Claim 2
Dependent Claim
103 words
A dynamically damped pickup arm device, comprising: a pickup arm, a balance weight, a resilient member interconnecting one end of said arm and one end of said balance weight, damping means for damping said balance weight, said damping means being coupled to said balance weight and support by said pickup arm, biasing means coupled between said weight and said arm for applying a biasing force to said balance weight, and adjusting means supported on said arm for adjusting the biasing force applied by said biasing means to said balance weight, thereby adjusting the resonance frequency of said balance weight of said resilient member.
Claim 3
Dependent Claim
57 words
A dynamically damped pickup arm device as set forth in claim 1 wherein said biasing means comprises: a first magnet supported on said balance weight; a second magnet disposed adjacent said first magnet, so that a magnetic interactive force is generated by said magnets; and said adjusting means includes means for varying the distance between said magnets.
Claim 4
Dependent Claim
60 words
A dynamically damped pickup arm device as set forth in claim 1 wherein one of said biasing means and said balance weight includes a magnetic material and the other of said biasing means and balance weight comprises a magnet adjacent said magnetic material; and said adjusting means includes means for varying the distance between said magnetic material and said magnet.
Claim 5
Dependent Claim
53 words
A dynamically damped pickup arm device as set forth in claim 1 wherein said biasing means and said adjusting means comprise, in combination, an axially movable member disposed adjacent the other end of said balance weight and a second resilient member coupling said other end of said balance weight to said movable member.
Claim 6
Dependent Claim
48 words
A dynamically damped pickup arm device as set forth in claim 1 wherein said biasing means comprises an auxiliary weight supported on said arm for exerting a pulling force on the other end of said balance weight; and said adjusting means includes means for moving said auxiliry weight.
Claim 7
Dependent Claim
59 words
A dynamically damped pickup arm device as set forth in claim 1 wherein said balance weight, said resilient member, said biasing means, said damping means and said adjusting means are assembled as a unit which in turn is axially movably supported at said one end of said arm, whereby the stylus pressure exerted by said arm may be adjusted.
Claim 8
Dependent Claim
20 words
A dynamically damped pickup arm device as set forth in claim 1, wherein said resilient member comprises a coiled spring.
Claim 9
Dependent Claim
96 words
A dynamically damped pickup arm device comprising: a pickup arm; a balance weight having a coaxial stem extending from one end thereof; a resilient member interconnecting one end of said pickup arm and the end of said stem remote from said weight; viscous damping means disposed between said remote end of said coaxial stem of said balance weight and said one end of said pickup arm, whereby vibration of said balance weight may be damped by said viscous damping means; and adjustable means for biasing said resilient member by urging said weight away from said arm.
Claim 10
Dependent Claim
96 words
A dynamically damped pickup arm device comprising: a pickup arm; a balance weight having a coaxial stem extending from one end thereof; a resilient member interconnecting one end of said pickup arm and the end of said stem remote from said weight; viscous damping means disposed between said remote end of said coaxial stem of said balance weight and said one end of said pickup arm, whereby vibration of said balance weight may be damped by said viscous damping means; and adjustable means for biasing said resilient member by urging said weight away from said arm.
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) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |