Magnetic recording tape erasure apparatus

Claim 1

AN ERASER FOR MAGNETIC TAPE ON A REEL WHICH COMPRISES: (A) A FIRST HOLLOW CORE SOLENOID OF RECTANGULAR CONFIGURATION TO RECEIVE SAID REEL THEREIN WITH THE AXIS OF SAID REEL PERPENDICULAR TO THE AXIS OF SAID SOLENOID, (B) A SECOND HOLLOW CORE SOLENOID OF CONFIGURATION TO RECEIVE SAID FIRST SOLENOID AND SAID REEL THEREIN WITH THE AXES OF SAID REEL AND OF SAID FIRST SOLENOID MUTUALLY PERPENDICULAR TO THE AXIS OF SAID SECOND SOLENOID, (C) A UNIDIRECTIONAL VOLTAGE SOURCE, (D) NORMALLY OPEN SWITCH MEANS FOR CONNECTING SAID SOURCE TO SAID SOLENOIDS, (E) CONTROL MEANS FOR PERIODICALLY CLOSING AND OPENING SAID SWITCH MEANS TO INITIATE AND TO TERMINATE FLOW OF CURRENT THROUGH SAID SOLENOIDS FOR STORAGE OF ENERGY THEREIN, AND (F) CAPACITOR MEANS CONNECTED TO SAID SOLENOIDS FOR PRODUCING SUSTAINED OSCILLATORY CURRENTS IN SAID SOLENOIDS OF AMPLITUDE DECREASING WITH TIME IN DEPENDENCE UPON THE LOSSES IN SAID SOLENOIDS, SAID REEL AND SAID CAPACITOR MEANS DURING THE INTERVAL FOLLOWING EACH CLOSURE AND OPENING OF SAID SWITCH MEANS.