GB239245A - Improvements in or relating to sound reproducing devices - Google Patents

Abstract

239,245. Huguet d' Amour, P. G. Sept. 22, 1923, [Convention date]. Diaphragms.-Relates to sound-reproducing devices, more particularly in connection with telephonic loud-speakers. According to the invention, a sound-box adapted to be used as a hornless loud-speaker comprises two conical members united at their bases, the junction of these members not being directly connected with any extraneous fixture. Fig. 1 shows a loud-speaker embodying such a diaphragm comprising two cones a, b, joined together and mounted so that the margin, formed by the meeting edges of the cones, is free. The apex of the cone a is removed, and the edge of the aperture thus made is clamped between threaded rings J, K. On the ring J are secured two or more strips M, preferably of different materials, the inner ends of the strips being arranged at the centre of the rings, and being attached by nuts O to one end of a threaded rod N. The rod is secured at its other end to the apex of the cone b. The outer nut O is of iron, and serves as the armature of a magnet (not shown) forming part of an ordinary telephone receiver R which, after removal of the usual diaphragm and cap, is adjustably screwed into the ring K. As an alternative, the armature may be integral with the outer strip M. Springs may be fixed on the ring J, to bear against the receiver R. The rod N may be 'built up of several materials. Modifications are described, in which the cone b is wholly inverted within the cone a, or the apex only of the cone b is inverted, and in a further construction, shown in Fig. 6, the outer cone is replaced by a series of conical walls b, b<1> ... rigidly connected together so as to prevent sharp angles at the meeting edges. Such an arrangement of interconnected conical walls may be provided instead of each of the cones a, b. The Specification as open to inspection under Sect. 91 (3) (a) states also that the diaphragm may be built up of members which are spherical or of any other suitable curvature, and in such cases stiffening material, such as strips, or paste, may be provided. This subject-matter does not appear in the Specification as accepted.