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Vassil Bontchev
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Measurement Of Mechanical Vibrations Or Ultrasonic Waves
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Abstract
4470. Bontchev, V. June 13, 1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Phonographs and gramophones.-A sound - box has a needle r for use with gramophone records, and a rounded stylus t for use with phonograph records. An arm p which carries the styles is secured to a flat spring l reinforced by a central metal plate i, which has conical cavities resting against corresponding points or knife-edges n, the spring l being fixed by screws m in a tangential groove in the sound-box casing a. The arm p may be bifurcated and attached to both sides of the diaphragm, as shown by the dotted lines, Fig. 2. The diaphragm b is held in the casing between rubber washers by a screwed ring c. The casing a is made of aluminium, ivorine, &c.
GB190804470D1907-06-131908-02-27Improved Reproducing Apparatus for Talking Machines.
ExpiredGB190804470A
(en)