Electrical pick-ups for gramophones

Abstract

Abstract 333,895. Lissen, Ltd., and Richardson, R. P. May 21, 1929. Gramophone pick-ups ; magnetic instruments.- The stylus of a pick-up con. stitutes the armature and is fulcrummed near its point. A semi-circular permanent magnet 1, Figs. 1 and 2, has pole pieces 2 on opposite faces of each pole. The stylus 11 extends between both pairs of pole pieces and pivots about the lower pair, bevelled at 3, its upper end projecting into a rubber cushion 10. The coil former 4 and coil 5 are mounted concentrically with the magnet. Figs. 3 and 4 show a modified construction, in which the stylus 21 is pivoted on a steel washer 19 fixed in the bore of the coil former 4 by a rubber tube 18; the upper end of the stylus is surrounded by a rubber cushion 17. Fig. 6 shows the construction of a U.section tone arm 23, the leads 28 being retained by transverse pins 27. The stylus may be of spear point type, or of Swedish iron with a rounded collar to abut on washer 19 and a hard point of platinum or other hard wearing alloy. Specifications 254,403, 276,466, 307,971, and 324,943 are referred to.

Inventors

No inventors recorded.

Bibliographic Details