GB1159443A - A Microphone having Protection Against Shock and Wind - Google Patents

Abstract

1,159,443. Microphones; windshields. AKUSTISCHE U. KINO-GERATE G.m.b.H. 15 May, 1967 [17 June, 1966], No. 22479/67. Heading H4J. A microphone protected from shock and wind comprises at least one electro-acoustic transducer having a unidirectional pattern embedded on all sides in open-cell foam filling the interior of a rigid housing permeable to sound. The foam is preferably polyurethane-containing polyester. A microphone (Fig. 1a), comprises treble and base cardioid transducers 1, 2 in recesses 3, 4 of an open cell body 6. The recesses 3, 4 are bisected by a parting plane (5), Figs. 1b 1c (not shown), and are formed by adjacent semicylinders. Additional recesses in the body 6 accommodate circuit elements 7. The body 6 is enclosed in a housing 10 of perforated sheet iron, die cast metal or plastics web. A resilient lead 9 protrudes from the body 8. The sound inlet surface is identified by distinguishing patterning, by a dot or by the size of perforations (Fig. 2, not shown). An articulated joint (22), Fig. 3 (not shown), may connect the housing (10) to a stand 3 or the housing may have a handle. Air cavities (14, 15, 16), Fig. 6 (not shown), may be adjacent the sound openings of the transducers to improve acoustic coupling. Alternatively the foam body 13, Fig. 4, is a single piece, or is in two parts, and has a cylindrical hole 13a closed at both ends by plugs 13b of open-cell plastics after insertion of the transducers 11, 12. A housing (Fig. 5, not shown) may be perforated throughout or at each end. A multi-layer porous body has a layer (18), Fig. 7 (not shown) of all pore open-cell and elastic foam surrounded a thicker layer (19) of large pore foam. An @uter wind-screen consisting of a cap 26 (Fig. 8), of open cell foam may be fitted on the housing.