Electroacoustic transducers

Claim 1

AN ELECTRO-ACOUSTIC TRANSDUCER COMPRISING AN OSCILLATABLE MEMBRANE OF NON-MAGNETIC MATERIAL, A PERMANENT MAGNET SYSTEM HAVING A SERIES OF ELEMENTAL MAGNET PORTIONS, EACH PORTION HAVING FIRST AND SECOND POLES ON A LINE EXTENDING PERPENDICULAR TO SAID MEMBRANE, SAID MAGNET PORTIONS BEING OF A MATERIAL HAVING CRYSTALLITE GRAINS ORIENTED ALONG SAID LINE AND HAVING A COERCIVE FORCE OF AT LEAST 750 OERSTEDS, SAID FIRST POLES BEING ARRANGED IN A PLURALITY OF ELONGATED UNIPOLAR ZONES EXTENDING PARALLEL TO ONE ANOTHER AND PARALLEL TO SAID MEMBRANE, SAID FIRST POLES ALTERNATING IN POLARITY FROM ONE OF SAID ZONES TO THE NEXT, SAID UNIPOLAR ZONES BEING SEPARATED BY ELONGATED TRANSITION ZONES ACROSS WHICH THERE EXISTS A MAGNETIC FIELD BRIDGING SAID FIRST POLES, AND CONTINUOUS FLEXIBLE CONDUCTIVE STRIP MEANS DISPOSED FLAT ON AND CARRIED BY SAID MEMBRANE AND COVERING A MAJOR FRACTION OF THE SURFACE AREA OF SAID MEMBRANE, SAID STRIP MEANS BEING COEXTENSIVE WITH A MEANDERING PATH INTERCONNECTING ALL OF SAID TRANSITION ZONES WITH SUCH DIRECTIONAL CHANGES THAT, UPON SAID STRIP MEANS BEING TRAVERSED BY AN ELECTRIC CURRENT, THE VECTOR PRODUCT OF SAID CURRENT AND OF SAID MAGNETIC FIELD IS OF THE SAME SIGN THROUGHOUT THE LENGTH OF SAID STRIP.