Acoustical signal generation by elec- trical coils deflecting a diaphragm

Claim 1

APPARATUS ADAPTED TO GENERATE AN ACOUSTICAL SIGNAL UNDER WATER COMPRISING A RIGID MEMBER ADAPTED TO BE SUBMERGED IN WATER; A FLEXIBLE DIAPHRAGM; MEANS POSITIONING SAID DIAPHRAGM IN PARALLEL SPACED RELATIONSHIP WITH ONE FACE OF SAID MEMBER SO AS TO FORM A FLUID-TIGHT CHAMBER BETWEEN SAID MEMBER AND SAID DIAPHRAGM; A FIRST FLAT SPIRAL COIL POSITIONED WITHIN SAID CHAMBER IN ENGAGEMENT WITH SAID DIAPHRAGM; A SECOND FLAT SPIRAL COIL POSITIONED WITHIN SAID CHAMBER IN ENGAGEMENT WITH SAID ONE FACE OF SAID MEMBER; SAID COILS BEING POSITIONED SO THAT THE PLANES THEREOF ARE PARALLEL TO ONE ANOTHER AND PARALLEL TO SAID DIAPHRAGM; AND MEANS TO TRANSMIT CURRENT THROUGH SAID COILS IN SERIES AND IN DIRECTION SO THAT THE RESULTING MAGNETIC FIELDS SET UP ABOUT SAID COILS MOVE SAID COILS APART IN A DIRECTION PERPENDICULAR TO THE PLANES OF SAID COILS, WHEREBY SAID DIAPHRAGM IS MOVED AWAY FROM SAID MEMBER BY THE RESULTING MOVEMENT OF SAID SECOND COIL AWAY FROM SAID FIRST COIL, AND THEREBY DISPLACES WATER IN ENGAGEMENT WITH SAID DIAPHRAGM TO GENERATE AN ACOUSTICAL SIGNAL, SAID MEANS TO TRANSMIT CURRENT COMPRISING A STEP-UP TRANSFORMER, AN ALTERNATING CURRENT SOURCE APPLIED TO THE PRIMARY WINDING OF SAID TRANSFORMER, A RECITIFIER AND A FIRST CAPACITOR CONNECTED IN SERIS WITH THE SECONDARY WINDING OF SAID TRANSFOMER, A SPARK GAP SWITCH HAVING TWO SPACED ELECTRODES AND A SPARK PROBE, MEANS CONNECTING THE ELETRODES OF SAID SPARK SWITCH IN SERIES WITH THE FIRST AND SECOND COILS ACROSS SAID FIST CAPACITOR, A SECOND CAPACITOR, AN AUTOTRANSFORMER CONNECTED THROUGH SAID SECOND CAPACITOR TO THE PROBE OF SAID SPARK SWITCH, A VOLTAGE SOURCE AND SWITCHING MEANS CONNECTING SAID VOLTAGE SOURCE ACROSS A PORTION OF SAID AUTOTRANSFORMER SO THAT CLOSURE OF THE SWITCHING MEANS APPLIES CURRENT TO SAID PORTION OF SAID AUTOTRANSFORMER TO GENERATE A SPARK AT SAID PROBE, THEREBY ESTABLISHING CONDUCTION THROUGH SAID SPARK SWITCH SO AS TO DISCHARGE SAID CAPACITOR THROUGH SAID FIRST AND SECOND COILS.