Voice operated safety control unit

Claim 1

A VOICE OPERATED CONTROL UNIT FOR INACTIVATING ELECTRICALLY ENERGIZED EQUIPMENT INCORPORATING A MASTER CONTROL SWITCH, SAID UNIT BEING FORMED AS A SELF-CONTAINED DEVICE ADAPTED TO BE INTERPOSED BETWEEN A POWER OUTLET AND THE CONTROLLED EQUIPMENT, SAID UNIT COMPRISING CIRCUIT MEANS ADAPTED TO FORM A PORTION OF THE LOAD CIRCUIT OF SAID EQUIPMENT, SAID CIRCUIT MEANS HAVING A NORMALLY INACTIVE BRANCH INCLUDING AN IMPEDANCE ELEMENT, MEANS FOR DETECTING THE OCCURRENCE OF VOICED SOUND AND FOR DISTINGUISHING SAME FROM UNVOICED SOUND, THE LAST NAMED MEANS SERVING TO GENERATE AN ELECTRICAL SIGNAL IN RESPONSE THERETO, MEANS RESPONSIVE TO SAID SIGNAL SERVING TO COUPLE SAID IMPEDANCE ELEMENT IN SERIES WITH THE ELECTRICAL LOAD OF SAID EQUIPMENT, THE IMPEDANCE OF SAID ELEMENT BEING SUFFICIENTLY LARGE TO REDUCE THE POTENTIAL ACROSS THE LOAD TO A LEVEL INSUFFICIENT TO ACTIVATE THE EQUIPMENT, AND MEANS OPERATIVELY RESPONSIVE TO OPENING OF SAID MASTER CONTROL SWITCH TO DE-COUPLE AND IMPEDANCE ELEMENT FROM THE LOAD CIRCUIT OF THE EQUIPMENT AND SIMULTANEOUSLY THEREWITH TO RESTORE AND MAINTAIN SAID BRANCH IN ITS SAID NORMALLY INACTIVE CONDITION UNTIL ACTIVATED BY ANOTHER OF SAID SIGNAL DERIVED FROM VOICED SOUND, WHEREBY RECLOSING THE SWITCH SERVES TO REACTIVATE THE EQUIPMENT.