US 4,445,210 AGranted

Tone arm mechanism for a record player

AssigneeVictor Company of Japan, Ltd.

InventorKengo Adachi

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Abstract

In a tone arm elevating mechanism, an elevator, which is arranged to raise and lower the tone arm, is driven by a solenoid, and the mechanism comprises a first rotary lever contactable with a portion of the elevator and a second rotary lever arranged to be driven by the solenoid, where the second rotary lever is operatively linked with the first rotary lever by means of an elastic member which prevents transmission of shock. Thus, the reciprocating movement of the solenoid is converted into rotational force to cause the elevator to rise gently and slowly. A viscous and resistive material may be provided to the elevator so that the elevator slowly lowers when the solenoid is deenergized. A portion of the elevating mechanism functions as an electrical switch to detect the highest position of the tone arm, while another portion may also function as another switch to detect the fact that the stylus has been placed on the record disk. The information from these switches may be fed to a circuit which controls various operations of the tone arm, thereby control of horizontal movement of the tone arm as well as antiskating can be accurately and precisely performed.

Claims24

Dependent claims

A tone arm mechanism for a record player, comprising:

(a) first means for raising and lowering a tone arm of a record player with respect to a stationary member to which said tone arm is movably attached, said first means having a member positioned below said tone arm and movable between first and second positions with respect to said stationary member;
(b) a first rotary lever rotatable at a first location about a shaft attached to said stationary member, and contactable with said first means at a point displaced from said first location by a first distance so that the rotation of said first rotary lever causes said first means to move between said first and second positions;
(c) a second rotary lever rotatable about said shaft, said second rotary lever having a long arm extending from said shaft in a direction substantially the same as that of said first lever when said first lever is in said first position, and a short arm, which is shorter than said long arm, extending from said shaft in a different direction from that of said long arm, said long arm being shorter than said first distance of said first lever;
(d) second means for transmitting the rotational force from said second rotary lever to said first rotary lever with a time delay, said second means having a spring operatively connected between said first lever and said long arm of said second rotary lever so that deformation of said spring transmits said rotational force to said first rotary lever with said time delay when said second rotary lever rotates in a given direction;
and
(e) a solenoid having a plunger operatively linked with said short arm of said second rotary lever for driving said second rotary lever,
whereby displacement of said short arm of said second rotary lever is amplified by said second rotary lever and further amplified by said first rotary lever to provide amplified movement of said first means.

4 more elements

A tone arm mechanism for a record player, comprising:

(a) first means for raising and lowering a tone arm of a record player with respect to a stationary member to which said tone arm is movably attached, said first means having a bracket fixed to said stationary member, a bushing fixed to said bracket, an up-down movement shaft movably received in said bushing, an arm member connected to said up-down movement shaft and positioned below said tone arm and movable between first and second positions with respect to said stationary member, and a biasing means for biasing said up-down movement shaft downwardly, wherein said bracket, biasing means, up-down movement shaft and arm member are each made of a conductive material, said bracket and a portion of said tone arm being respectively and electrically connected to a control circuit means for controlling the operation of said tone arm, so that the combination of said arm member and said portion of said tone arm functions as an electrical switch for detecting that a stylus of a pickup of said tone arm has been placed on a record disk when said arm member is lowering, said control circuit means having:
a microcomputer responsive to said electrical switch, to information indicative of a horizontal angular displacement of said tone arm, and to information from manually operable switches;
a switching circuit means for controlling the horizontal movement of said tone arm in accordance with information from said microcomputer;
said switching circuit means having:
a reference voltage generator generating a reference voltage;
a first analog switch responsive to information from said microcomputer for selectively emitting one of the voltage from said reference voltage generator and zero voltage;
a first operational amplifier responsive to a voltage from a detection coil of a driving motor which drives said tone arm in horizontal directions, said first operational amplifier operable for producing an output voltage;
a second analog switch responsive to said output voltage from said first operational amplifier and to various predetermined voltages for selectively emitting one of said voltages in accordance with information from said microcomputer;
a second operational amplifier responsive to the voltages emitted by said first and second analog switches for producing an output voltage;
and
a first driving circuit responsive to the output voltage of said second operational amplifier for controlling the amount and direction of electric current flowing through a driving coil of the driving motor which drives said tone arm in horizontal directions;
(b) a first rotary lever rotatable about a shaft attached to said stationary member, and contactable with said first means;
(c) a second rotary lever rotatable about a shaft attached to said stationary member;
(d) second means for transmitting the rotational force from said second rotary lever to said first rotary lever, said second means having an elastic member for absorbing shock from said second lever;
(e) a solenoid means having a plunger operatively linked with said second rotary lever for driving said second rotary lever;
and
(f) a second driving circuit means responsive to a signal from said microcomputer for controlling the energization of said solenoid means.

14 more elements

Dependencies are inferred from the claim text.