109,708. Drew, V. Dec. 4, 1916. Variable - resistance transmitters; receivers; e a r - pieces.-Apparatus for assisting hearing comprises a battery from which a current passes through a generator or sound-collecting de. vice, Fig. 1, to the ear-piece of a " sounding- box," Fig. 3, and thence through the head to a " receiver," Fig. 4, placed at the back of the opposite ear and connected to the other pole of the battery. The generator comprises a box V perforated at U and into which passes a screw A connected to the battery by a non-insulated wire coiled on a soft iron wire and passing successively through a carbon block B, graphite granules C, metal disk D. a parchment cover, carbon block E, perforated metal disk F, and carbon block G. The end of the screw is fitted with a spring-mounted platinum contact L adjacent to a hollow carbon block J carried by a steel rod M soldered to the screw. A wire I connected to the screw A is wound round the carbon G and the rod M, passes through carbon blocks 0, and is connected to a screw W on the sounding-box. The generator is fitted internally with metal tubes &c. H, N, P arranged as shown. The sounding-box is provided with a metal lining H in two separate parts and fitted with a screw W, carbon blocks X, Y, Z, e, metal ring c containing graphite granules, and metal disks, tubes, &c. arranged as shown. A wire j terminates in a loop within the ear-piece f. The sound terminal, Fig. 4, mounted behind the other ear is supported by a wire r and comprises a crescent-shaped metal bar y with a flange w. The Provisional Specification states also that artificial ear-drums may be connected,to the wire within the ear-piece f of the sounding-box and to the sound terminal respectively.
展开▼
