GB318564A - Improvements relating to sound reproducing means - Google Patents

Abstract

318,564. Green, H., and Celebritone, Ltd. June 1, 1928. No Patent granted (Sealing fee not paid). Phonographic reproducers; magnetic instruments. - Acoustic vibrations, direct or after amplification, or vibrations produced from a sound record are transmited by a pneumatic transmission system and are reproduced directly or after amplification. The pneumatic system may be maintained at atmospheric pressure, or above or below this pressure and serves to amplify the vibrations. As shown in Fig. 1, vibrations imparted by a record 7 through a stylus 6 to the movable member 5 of a bellows 2 are transmitted through a flexible inexpansible conduit 1 to a bellows 8, the movable member 10 of which carries a coil 13 on a former 14 which is thereby vibrated in the field of a pot magnet 11 and reproduces the sound through an amplifier 15 in a loud speaker 16. The pressure in the conduit may be maintained above or below atmospheric by a valved pipe connection 17 to a suitable pressure supply means, and in this case the vibrations may be produced in the conduit by a reed 19, Fig. 2, vibrated opposite to the end of the conduit by the stylus 6 or by a magnet influenced by currents set up by a microphone, which currents may be amplified before reaching the magnet coil. Alternatively, the transmitting bellows may be influenced directly by sound waves, and, as shown in Fig. 2, the receiving bellows 20 may operate directly a loud-speaker unit 22. Reference has been directed by the Comptroller to Specification 6042/86; 20925/12, [Class 40 (ii), Phonographs &c.]; 16549/13; 6079/14, [Class 40 (ii), Phonographs &c.]; 198,799; and 270,238, [Class 40 (ii), Phonographs &c.].