Tangential pick-up device for a gramophone turn-table

Claim 2

In a pick-up device for a phonograph record turntable comprising a tangentially moving tone arm including a mounting block, at least one rectilinear guide member extending parallel to the radius of a record on said turntable, a servo-motor in said mounting block, a carriage movable along said guide member, a support beneath said carriage, a pickup head at one end of said support, articulation means connecting the other end of said support to said carriage, a device on said carriage supplying an electric signal indicating the position of said support relative to said carriage and said servo-motor controlling the displacement of the carriage in response to said signal, the improvement wherein, said articulation means comprises a pivot member having a conical point at its lower end, a plate member connected to said carriage and having an enlarged conical seat in which said conical point engages, said pivot member extending through said support, a guide block on said carriage having a slot therein in which the upper end of said pivot member is freely movable, whereby said pivot member may move angularly in a plane perpendicular to the surface of and tangential to the grooves of said record and also rotate around a substantially vertical axis of the support, said slot located further away from the surface of the record than said conical point of said pivot member.

Claim 3

In a pick-up device for a phonograph record turntable comprising a tangentially moving tone arm including a mounting block, at least one rectilinear guide member extending parallel to the radius of a record on said turntable, a servo-motor in said mounting block, a carriage movable along said guide member, a support beneath said carriage, a pickup head at one end of said support, articulation means connecting the other end of said support to said carriage, a device on said carriage supplying an electric signal indicating the position of said support relative to said carriage and said servo-motor controlling the displacement of the carriage in response to said signal, the imporvement wherein, said articulation means comprises a pivot member having a conical point at its lower end, a plate member connected to said carriage and having an enlarged conical seat in which said conical point engages, said pivot member extending through said support, a stud fixed to said carriage and depending therefrom, a yoke mounted on the upper end of said pivot member, a pair of parallel guide members mounted on said yoke, said stud movably engaged between said guide members whereby said pivot member may move angularly in a plane perpendicular to the surface of and tangential to the grooves of said record, and also rotate around a substantially vertical axis of the support, said yoke and guide members located further away from the surface of the record than said conical point of said pivot member.

Claim 4

In a pick-up device for a phonograph record turntable comprising a tangentially moving tone arm including a mounting block, at least one rectilinear guide member extending parallel to the radius of a record on said turntable, a servo-motor in said mounting block, a carriage movable along said guide member, a support beneath said carriage, a pickup head at one end of said support, articulation means connecting the other end of said support to said carriage, a device on said carriage supplying an electric signal indicating the position of said support relative to said carriage and said servo-motor controlling the displacement of the carriage in response to said signal, the imporvement wherein, said articulation means comprises a pivot member having a conical point at its lower end, a plate member connected to said carriage and having an enlarged conical seat in which said conical point engages, said pivot member extending through said support, a stud fixed to said carriage and depending therefrom, a yoke mounted on the upper end of said pivot member, a pair of parallel guide members mounted on said yoke, said stud movably engaged between said guide members whereby said pivot member may move angularly in a plane perpendicular to the surface of and tangential to the grooves of said record, and also rotate around a substantially vertical axis of the support, said yoke and guide members located further away from the surface of the record than said conical point of said pivot member.