Pickup arm device dynamically damped
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsKatsuhiko Morita, Hiroshi Yasuda
Life of this patent
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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.
Claims8
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.
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.
Dependencies are inferred from the claim text.