GB378938A - Improvements in or relating to loud speakers and like sound reproducing apparatus - Google Patents

Abstract

378,938. Diaphragms. COLASSI, W. L., Mark Lane Station Buildings, London. May 14, 1931, No. 14249. [Class 40 (iv).] A diaphragm for a loud-speaker or the like, formed as a cone with a peripheral extension lying in a plane at rightangles to the axis of the cone, is mounted by means of a ring or rings of sponge rubber or the like attached by an adhesive to one or both sides of the s a i d peripheral extension, and not projecting beyond it. In the construction shown, the peri, pheral portion 3 a is connected tc the cone 1 by an intermediate reversely bent portion 1a. Rings 4, 4a of sponge rubber are attached by rubber solution or other adhesive to the flange 3a, in which radial cuts at intervals are first made, and a wooden ring 5 is glued to the ring 4. The ring 5 serves for attachment to a chassis 6. The assembly comprising the chassis, the diaphragm, and the actuating unit (not shown) may then be arranged so that the rubber ring 4a bears lightly against a baffle board 8, to which it may be secured by an adhesive, the weight of the unit being taken by supports (not shown) When the diaphragm is to be used without a chassis frame, the ring 5 is dispensed with, and there may be only one rubber ring, which is secured to the baffle board. More than one non-resilient ring such as 5 may be employed, and may be screwed or bolted to the baffle board or cabinet. The internal diameter of the rings and of the aperture in the baffle board (where this is provided), is less than the external diameter of the peripheral extension of the diaphragm.