Phonograph tone arm system
US4239239A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1979 |
| Grant date | Dec 16, 1980 |
| Priority date | — |
| Expiry date | Jun 28, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B3/38
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved phonograph tone arm device is disclosed in which the pickup, including the stylus, is supported on a low friction air-bearing support which provides for essentially frictionless movement of the tone arm and pickup both in horizontal linear travel and vertical pivoting to assure proper stylus pressure. The tone arm support system includes a support member having an upper surface which is shaped as a right circular trough or cylinder section and a floating member which has a juxtaposed matching convex or concave lower surface. A recess in the lower surface of the floating member forms a plenum to which air is supplied from one or more openings in the support member. The length of the plenum is such that the supply openings are always beneath the plenum confines during the full traverse of the stylus across a record to be played to minimize the amount of air required and maximize uniformity of support for the floating member. Alternate embodiments allow either the upper or lower surface of the record to be played.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.