Fecha de publicación: 30/06/1932 Fuente: WIPO "honey" 375,853. Diaphragms. HONEY, A., 7, Buckley Road, Brondesbury, London. March 31, 1931, No. 9707. [Class 40 (iv).] A diaphragm for telephone instruments, loud-speakers, gramophones, &c. is shaped so as to have a central portion in the form of a sharply angled cone, as shown in the Figure, or a short central solid or tubular part, which may be cylindrical, connected by a gradually curved portion to a flat base, the outer edge of which is mounted on a frame or casing. The flat outer portion of the diaphragm is intended to be particularly responsive to low frequencies, and the central portion to high frequencies. The diaphragm is made of any material of suitable rigidity and elasticity such as metal, paper, fabric, glass, ebonite, or celluloid, and is formed by moulding, spinning or drawing a flat sheet to the required shape. Specifications 193,727, 257,317 and 312,130, [all in Class 40 (iv), Telephones &c.], are referred to. The Provisional Specification also describes diaphragms of varying thickness, one form of which has a flat surface at one side and a curved surface on the other, so that the centre part is relatively thick ; in another construction both sides may have curved conical or annular surfaces," with the thickest part at the centre.