Bearing arrangement for a record player tonearm
AssigneeWilli Studer
InventorsPaul Zwicky, Eduard Marthaler
Life of this patent
Estimating the term…
Abstract
The disclosed arrangement is for a short pickup arm used with a tangential scanning system. The arm is supported on a single jewel thrust bearing and held against sideways tilting by a pair of attracting magnets, one mounted on the arm above the bearing and the other fixed above the first. This permits the arm to move freely in a plane parallel to the record and in a plane perpendicular to the record and tangent to the grooves. The center of gravity of the arm is chosen to be on a line between the bearing point and the stylus point in order to minimize the effects of outside disturbances.
Claims8
A pickup arm device for a record player, the device being of the type which has a short pickup arm and is guided along a guide direction substantially parallel to a radius of the record to be played by the record player, so that the arm remains oriented substantially tangential to the grooves of the record, wherein the improvement comprises:
- thrust bearing means for supporting said arm mechanically from below at only a single point, said thrust bearing means having a movable bearing member with a movable bearing axis and a fixed bearing member with a fixed bearing axis, said movable bearing member being fastened to said pickup arm, and magnetic means including a movable magnetic member fastened to said arm and a fixed magnetic member separated from said movable magnetic member by an air gap and fixed in relation to said fixed bearing member for acting through said air gap to partially support said arm from above and constrain its movement to a rotation about said movable bearing axis and a pivoting of said movable bearing axis in a plane substantially perpendicular to said guide direction.
Dependencies are inferred from the claim text.