GB333884A - Improvements in or relating to sound reproducing devices for telephony or the like applications - Google Patents

Abstract

333,884. Price, S. L. Feb. 20, 1929. Magnetic instruments.-The armature of a loud-speaker or pick-up is suspended from a semirigid member by a resilient member or members, so as to give the armature comparatively unrestricted freedom to vibrate. Fig. 1 shows a construction in which an armature 10 is carried by a substantially rigid, non-magnetic, intermediate member 7 which is' hinged at one end at 5 to the semi-rigid supporting member or. reed 1 and is suspended at its other end from the member 1 by a U-shaped spring 6. A rod 11 passing through an aperture 4 in the member 1 connects the armature to a diaphragm. The strip 1 is secured at its ends to a casing containing the magnets (Fig. 3, not shown). Fig. 2 shows a similar construction in which the intermediate member 7 is dispensed with, the armature comprising a portion 10 of greater area with two portions 14, 15 of smaller area for connecting to the hinge 5 and spring 6 respectively. Various forms of the hinge or pivot 5 are described, that shown comprising one or more lengths of wire passing through holes in or otherwise engaging the members 1 and 7. In the modified constructions shown in Figs. 4 - - 7, the intermediate member 7 is formed with integral or attached resilient extensions 25, 27, 29 or 31 adapted to be attached to the member 1, e.g. by soldering to struts rigidly carried by the member 1. The longer limb of a spring 6 is attached at the points 8, the other end of the spring being secured to the member 1 as in Fig. 1. In the case of Fig. 7 in which the extensions 31 are to one side of the centre of the member 7, the armature 10 is displaced as shown in order that the centre of gravity of the whole lies in the lines of the extensions. According to a further modification. the armature may be suspended from the member 1 by leaf or U- shaped springs (Fig. 8, not shown). All the various suspension means may be applied either for suspending the armature directly from the member 1 or for mounting the intermediate member 7 carrying an armature. The member 1 may be formed of magnetic material.