GB418620A - Improvements in or relating to mouthpieces for telephones, microphones and the like - Google Patents

Abstract

418,620. Mouthpieces; sanitary and hygienic devices. COLASSI, W. L., Mark Lane Station Buildings, London. April 29, 1933, No. 28372. Divided out of 402,444. [Class 40 (iv).] A telephone mouthpiece comprises a sound passage, a perforated platform disposed at or adjacent the end of the sound passage nearest to the microphone unit and a chamber, primarily for disinfectant, in the wall of the sound passage, said chamber being disposed wholly or partly in front of the perforated platform and communicating by relatively long and narrow passages with the sound passage behind the perforated platform. The construction described with reference to Figs. 1-6 (not shown), is identical with that described with reference to Figs. 7-12 of Specification 402,444 whilst a modification of such a construction formed in one piece is also described, Fig. 7 (not shown). Fig. 9 shows a construction of two - part mouthpiece for a pedestal type telephone in which one part 20 is threaded at 22 to screw into the microphone cover and at 23 to engage an internal thread 24 on the second part 21. The part 20 is formed with perforations 26, a circular groove 27 and slant passages 28 countersunk at 29 whilst the part 21 has an imperforate flare portion 30, the back end of which is adapted to enter the groove 27, and a chamber 31 adapted to be packed with solid disinfectant, the vapour from which passes through the passages 28 and perforations 26 into the sound passage m. If desired, straight passages may be substituted for the slant passages 28. According to a modified construction, Fig. 12 (not shown), the perforated platform is formed across the inner end of the flare 30 instead of on the part 20, this latter part having a large diameter central hole formed with a ledge adapted to receive and be engaged by the platform. A modification of this construction is described, Fig. 14 (not shown), in which the slant passages 28 are dispensed with and the central hole in the part 20 is made slightly larger so as to leave a narrow annular passage surrounding the end of the flare 30. Figs. 15 and 16 show constructions in which the flare 30 is formed partly on the part 20. In the form shown in Fig. 15, slant passages 28 are employed and the outer periphery of the flare portion on the part 20 is cylindrical so as to receive a ring-shaped mass of solid disinfectant before the parts are screwed together. In the form shown in Fig. 16 which employs straight passages 32, a larger capacity chamber is obtained, but the solid disinfectant has to be formed in two or more pieces to enable it to be placed in position. Breather holes may be provided leading from the chamber 31 to the atmosphere.