Improvements relating to sound boxes for gramophones and similar reproducing machines employing sound boxes

摘要

312,524. Wright, A. F. J. July 2, 1928. Sound-boxes.-In a sound-box for gramophones and the like, a plate arranged at right angles to to the stylus bar is held against pivots on the casing by spring members forming part of a cover-plate protecting the outer face of the diaphragm. As shown, a cupped plate f secured to the casing l is slotted adjacent the stylus-bar a, leaving lugs o which form the holding-down springs for the plate b. The latter bears on two steel balls c are recessed into the casing, and the lugs o are formed with projections p bearing on the other face of the plate; or ball-pivots may be used on both sides of the plate. The cover-plate f may be formed wholly of metal, or of a moulded composition with a metal insert for the lugs o. Specification 290,469 is referred to.