Low friction linear tracking tone arm

摘要

This invention is provides a means of playing LP records with minimal distortion. Low distortion is achieved by eliminating tracking error normally associated with pickup cartridges mounted to pivoting tone arms. This invention discloses a tone arm that constrains the motion of the stylus to straight radial path, mimicking the cutting path of the record lathe, supported on parallel rails by free rolling spherical bearings. Unlike many previous linear tracking tone arms, this invention does not rely on air pressure or servo motor mechanisms. The use of free rolling bearings or axles between parallel tracks fashioned from rails, rods or tubes, eliminates all sources of lateral friction other than pure static and rolling friction of the balls on the rails, rods or tubes. In the preferred embodiment, the fixed rods or tubes are driven synchronously, thereby eliminating static friction of the supporting rolling balls. Friction is further reduced using magnetic or buoyant support of the tone arm to reduce bearing load to that amount minimally sufficient to maintain full contact between the rolling balls and the upper and lower rods.

主权项

1. An apparatus for playing phonograph records comprising:
a. one or more carriages comprising two or more parallel cylindrical rods or tubes, situated parallel to or collinear with the desired radial path of a stylus from the outermost to the innermost groove of a phonograph record, held in parallel position by one or more bearing blocks containing low friction bearings permitting said rods or tubes to rotate about a long axis, b. one or more fixed tracks consisting of two or more parallel cylindrical rods or tubes, situated parallel to or collinear with the desired radial path of the stylus from the outermost to the innermost groove of the phonograph record, held in parallel position by one or more bearing blocks containing low friction bearings permitting said rods or tubes to rotate about the long axis, c. two or more loose ball bearings for each set of carriage and fixed track which roll between the rails of said carriage and track, d. a tone arm assembly comprising a linear member, a phonograph cartridge transducer with the stylus, and a counterweight or other means of controlling the downward force of the stylus on the phonograph record, which assembly is affixed to the one or more carriage(s) to orient the stylus to trace a straight radial path from the outermost groove to the innermost groove of the phonograph, at all times maintaining a strictly tangent orientation of the phonograph cartridge and stylus to the groove of the phonograph record,said apparatus enabling translation of the tone arm assembly and the one or more carriage laterally with very low friction while maintaining perfect tangency of the stylus to the groove in a straight radial path across the record surface, while also permitting free rotation of the tone arm in the vertical plane by virtue of the rotational freedom of the rods in the one or more carriages, or permitting rotation of the tone arm in the vertical plane by one or more bearing blocks or hinges in the one or more carriages.