Acoustical Tone Arm Patents (Class 369/158)
  • Patent number: 4261580
    Abstract: An arm pipe for a record player tonearm comprises a composite material essentially consisting of a thermoplastic resin and graphite powder. The composite material is prepared by kneading the components, rolled to impart a degree of orientation to the graphite powder particles, which are in the form of flaky graphite and then molded into a pipe, along the surface of which the graphite particles are oriented. Arm pipes wherein the composite material is oxidized at the surface of the pipe and arm pipes wherein the composite material is carbonized or graphitized are also included. A light weight, rigid arm pipe having a high specific modulus of elasticity is obtained through a simple procedure at low cost.
    Type: Grant
    Filed: August 3, 1979
    Date of Patent: April 14, 1981
    Assignee: Pioneer Electronic Corporation
    Inventors: Tsunehiro Tsukagoshi, Shinichi Yokozeki, Toshikazu Yoshino, Yasuyuki Arai