GB145100A - Improvements in and relating to sound regulating devices for sound re-producing apparatus - Google Patents

Abstract

145,100. Harris, H. W. July 11, 1919. Sound magnifying and directing appliances.-In a soundregulating device for sound - reproducing apparatus, the back wall 34 of the soundbox a is provided with an integral or detachable socket b in which is placed a casing 1 containing an iris diaphragm 3 and a screw-ring or plate 2 adapted to be rotated to adjust the opening in the diaphragm. In a modified arrangement the diaphragm and plate a.re mounted directly inside the socket b. As shown in Fig. 8. the screw-ring 2 is operated by rotating a ring c connected thereto through a slot in the socket b, the face 31. of the screw-ring being arranged as near as possible to the wall of the sound-box. Fig. 12 shows a form of detachable socket p for containing the diaphragm &c., insulation 6, 7 being inserted to prevent contact with the sound-box. The casing 1 or the screw-ring and diaphragm are sooured within their socket by means of a plate d, Fig. 8, or plate s, Fig. 12, or by means of a plate screwing into the socket Insulating material with roughened surfaces may be inserted between the different parts and the tonearm connexion g may be similarly insulated by disks 4. 5. The diaphragm may be controlled from a distance by a " Bowden " or other transmission. Specifications 133,234 and 114,258, [Class 40 (ii), Phonographs &c. ], are referred to.