Electro-mechanical transducer with negative feedback for the recording and reproduction of sound waves

Claim 1

AN ELECTRO-MECHANICAL TRANSDUCER OPERATING IN ACCORDANCE WITH THE ELECTRO-DYNAMIC PRINCIPLE FOR RECORDING AND REPRODUCTION OF SOUND WAVES IN A LATERAL RECORDING TECHNIQUE COMPRISING AN OSCILLATING BODY HAVING A CONE-SHAPED SHELL, INCLUDING A ROTARY-SYMMETRICAL HOLLOW CONE TAPERED IN DOWNWARD DIRECTION, A STYLUS SECURED TO THE APEX OF SAID OSCILLATING BODY, A PERMANENT MAGNET SURROUNDING SAID OSCILLATING BODY AND FORMING POLE-SHOES TO CREATE A MAGNETIC FIELD, A DRIVING COIL DISPOSED AT THE PERIPHERY OF SAID OSCILLATING BODY, AT LEAST ONE FEED-BACK COIL ADJACENT TO THE APEX OF SAID OSCILLATING BODY, THE IMPROVEMENT RESIDING IN SAID DRIVING COIL BEING DISPOSED ON SAID CONE-SHAPED SHELL OF SAID OSCILLATING BODY, SAID CONE-SHAPED SHELL BEING INCLINED SUCH THAT ITS SURFACE AND THEREBY THE MAGNETIC FORCES EMERGING FROM SAID DRIVING COIL AND FROM SAID PERMANENT MAGNETIC FIELD BEING DIRECTED TOWARDS THE APEX OF SAID STYLUS, SAID FEEDBACK COIL BEING DISPOSED RECTANGULARLY TO THE PLANE OF SAID DRIVING COIL, A SOFT-IRON CORE IMMOVABLY DISPOSED WITHIN A PORTION OF SAID OSCILLATING BODY, AND A MEMBRANE MOUNTED ON SAID SOFT-IRON CORE AND DISPOSED INSIDE OF AND SUPPORTING SAID OSCILLATING BODY.