GB1124830A - Improvements in or relating to electro-acoustic transducers such as telephone receivers - Google Patents

Abstract

1,124,830. Moving armature transducers. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. 12 May, 1967 [18 May, 1966], No. 22106/66. Heading H4J. In a receiver " inset " or other electroacoustic transducer, an armature 11 (Fig. 3), associated with a permanent magnet 8 and a polepiece 9, is mounted in cantilever fashion and vibrates by flexing, and is coupled to a diaphragm 12 by a lever 13 that has the armature 11 and diaphragm 12 coupled to it on opposite sides of a fulcrum 14 about which it pivots or rocks. Preferably almost the whole of the total stiffness of the moving system is provided by the armature 11, the diaphragm 12 being extremely compliant. A thin, floating diaphragm 12 may be used but, as shown, the diaphragm 12 is secured to a casing 15 by the turned-over part of a centre-perforated guardplate 19. A clamping strap 17 and clamping screws 16 secure the magnet 8 and armature 11 to the casing 15. Alternatives.-The lever 6 (Fig. 2) extands away from the permanent magnet 1. Compliant armature 11A (Fig. 6) has at its unclamped end a right-angled portion in which is a V-shaped groove with which a pointed end of the lever 13A, on a pivot 20, operatively registers.