Tone arm for record player

Claim 2

In a record player comprising: a chassis; a turntable mounted for rotation relative to said chassis and adapted to carry a record having a spiral groove; a spindle extending upwardly centrally of said turntable; an articulated tone arm comprising a rigid main beam and a head assembly connected thereto at a pivot point for pivoting in a plane parallel to the turntable; an upright center post secured to the chassis at one side of said turntable; means mounting said tone arm on said center post for movement of said tone arm in a plane perpendicular to the turntable about a first axis perpendicular to the center post and in a plane parallel to the turntable about a second axis through said center post; pick-up means including a stylus, said pick-up means being carried by said head assembly with said stylus to track the spiral groove of a record on the turntable; and control means for moving said head assembly along a curved path such that the path in which the stylus vibrates extends along a radius of said turntable, the improvement wherein said control means comprises a bearing plate fixed to said head assembly at a predetermined angle and a rigid linkage means spaced beside said main beam, one end of said linkage means secured at a point spaced from said center post for pivoting in a plane parallel to the turntable, said linkage means being of predetermined length such that its other end slidably contacts said bearing plate to provide proper orientation of the head assembly during record play, and means extending between said linkage means and said main beam, intermediate the ends thereof, to co-ordinate pivotal movement of said linkage means with that of said main beam.

Claim 3

A record player according to claim 1 wherein said linkage means comprises a push rod parallel to and spaced beside main beam.

Claim 4

A record player according to claim 2 wherein the bearing plate is positioned such that the angle the bearing plate makes with the push rod is greater than the limiting angle of static friction coefficient of the end of the push rod sliding on the bearing plate for all positions of the push rod during playing of a record.

Claim 5

A record player according to claim 1 wherein said means co-ordinating pivotal movement of the linkage means and the main beam is fixed to said main beam and slidably engages said linkage means.

Claim 6

A record player according to claim 1 wherein said control means further comprises biasing means extending between the head assembly and the main beam to maintain the bearing plate in contact with the linkage means.

Claim 7

A record player according to claim 5 wherein said biasing means comprises an extension spring, one end of which is attached to the head assembly and the other end of which is attached to the main beam, the line of action of said spring being positioned, and the tension of said spring being such that, the bearing plate is maintained in constant contact with said linkage means.

Claim 8

A record player according to claim 5 wherein a counter-weight is secured to said head assembly, the center of gravity of the head assembly and counter-weight falling on the pivot point, whereby the stylus pressure is maintained constant during playing of a record.

Claim 9

A record player according to claim 1 wherein a counter-weight is secured to said head assembly, the center of gravity of the head assembly and counter-weight falling on the pivot point, whereby the stylus pressure is maintained constant during playing of a record.

Claim 10

In a record player comprising: a chassis, a turntable mounted for rotation relative to said chassis and adapted to carry a record having a spiral groove; a spindle extending vertically centrally of said turntable; a tone arm; an upright center post secured to the chassis at one side of said turntable; means mounting said tone arm on said center post for movement of said tone arm in a plane perpendicular to the turntable about a first axis perpendicular to and intersecting the center post and in a plane parallel to the turntable about a second axis through said center post; pick-up means including a stylus being carried by said tone arm, the improvement wherein said means mounting said tone arm comprises a first gimbal ring associated with the tone arm, said first ring lying in a plane generally parallel to the turntable and secured within a second gimbal ring for pivoting about said first axis, said second ring pivotally mounted at its upper inner surface on the top of said vertical center post for rotation about said second axis.

Claim 11

In a record player comprising: a chassis, a turntable mounted for rotation relative to said chassis and adapted to carry a record having a spiral groove; a spindle extending vertically centrally of said turntable; a tone arm; an upright center post secured to the chassis at one side of said turntable; means mounting said tone arm on said center post for movement of said tone arm in a plane perpendicular to the turntable about a first axis perpendicular to and intersecting the center post and in a plane parallel to the turntable about a second axis through said center post; pick-up means including a stylus being carried by said tone arm, the improvement wherein said means mounting said tone arm comprises a first gimbal ring associated with the tone arm, said first ring lying in a plane generally parallel to the turntable and secured within a second gimbal ring for pivoting about said first axis, said second ring pivotally mounted at its upper inner surface on the top of said vertical center post for rotation about said second axis.

Claim 12

A record player according to claim 9 further comprising a mass which acts with constant predetermined weight on said second gimbal ring to counteract the inward, skate-producing forces acting on the tone arm.

Claim 13

A record player according to claim 10 wherein said mass is connected near the pivot point of said second ring and hangs freely by means of a non-stretching filament which extends from said pivot point connection over a loop or pulley spaced laterally from said connection, to said anti-skate mass.

Claim 14

A record player according to claim 10 wherein said tone arm is an articulated tone arm comprising a rigid main beam and a head assembly connected thereto at a pivot point for pivoting in a plane parallel to the turntable, and said pick-up means being carried by said head assembly with said stylus adapted to track the spiral groove of the record on the turntable and having control means for moving said head assembly along a curved path such that the path in which the stylus vibrates and extends along a radius of said turntable, said control means comprising a bearing plate fixed to said head assembly at a predetermined angle and a rigid linkage means spaced beside said main beam, one end of said linkage means secured at a point spaced from said center post for pivoting in a plane parallel to the turntable, said linkage means being of predetermined length such that its other end slidably contacts said bearing plate to provide proper orientation of the head assembly during record play, and means extending between said linkage means and said main beam, intermediate the ends thereof, to co-ordinate pivotal movement of said linkage means with that of said main beam.

Claim 15

In a record player comprising: a chassis, a turntable mounted for rotation relative to said chassis and adapted to carry a record having a spiral groove; a spindle extending upwardly centrally of said turntable; an articulated tone arm comprising a rigid main beam and a head assembly connected thereto at a pivot point for pivoting in a plane parallel to the turntable; an upright center post secured to the chassis at one side of said turntable; means mounting said tone arm on said center post for movement of said tone arm in a plane perpendicular to the turntable about a first axis perpendicular to and intersecting said center post, said means comprising a first gimbal ring associated with the main beam, said first gimbal ring lying in a plane generally parallel to the turntable and secured within a second gimbal ring for pivoting about said first axis, said second ring pivotally mounted on the top of said vertical center post for rotation about said second axis in a plane parallel to the turntable; pick-up means including a stylus, said pick-up means being carried by said head assembly with its stylus adapted to track the spiral groove of a record on the turntable along a curved path such that the path in which the stylus vibrates extends along the radius of said turntable, said control means comprising a bearing plate fixed to said head assembly at a predetermined angle and a rigid linkage means spaced beside said main beam, one end of said linkage means secured at a point spaced from said center post for pivoting in a plane parallel to the turntable, said linkage means being of predetermined length such that its other end slidably contacts said bearing plate to provide proper orientation of the head assembly during record play, and means extending between said linkage means and said main beam, intermediate the ends thereof to co-ordinate pivotal movement of said linkage means with that of said main beam.

Claim 16

In a record player comprising: a chassis, a turntable mounted for rotation relative to said chassis and adapted to carry a record having a spiral groove; a spindle extending upwardly centrally of said turntable; an articulated tone arm comprising a rigid main beam and a head assembly connected thereto at a pivot point for pivoting in a plane parallel to the turntable; an upright center post secured to the chassis at one side of said turntable; means mounting said tone arm on said center post for movement of said tone arm in a plane perpendicular to the turntable about a first axis perpendicular to and intersecting said center post, said means comprising a first gimbal ring associated with the main beam, said first gimbal ring lying in a plane generally parallel to the turntable and secured within a second gimbal ring for pivoting about said first axis, said second ring pivotally mounted on the top of said vertical center post for rotation about said second axis in a plane parallel to the turntable; pick-up means including a stylus, said pick-up means being carried by said head assembly with its stylus adapted to track the spiral groove of a record on the turntable along a curved path such that the path in which the stylus vibrates extends along the radius of said turntable, said control means comprising a bearing plate fixed to said head assembly at a predetermined angle and a rigid linkage means spaced beside said main beam, one end of said linkage means secured at a point spaced from said center post for pivoting in a plane parallel to the turntable, said linkage means being of predetermined length such that its other end slidably contacts said bearing plate to provide proper orientation of the head assembly during record play, and means extending between said linkage means and said main beam, intermediate the ends thereof to co-ordinate pivotal movement of said linkage means with that of said main beam.