Proximity responsive device

Claim 1

IN A PROXIMITY SENSING DEVICE FOR DETECTING THE PRESENCE OF ELECTRICALLY CONDUCTING ELEMENTS ADJACENT THERETOR AND FOR PROVIDING AN OUTPUT CONTROL SIGNAL IN RESPONSE THERETO, A CYLINDRICAL PROBE HAVING A SENSING END AND A PLUG END, SAID PROBE COMPRISING A TUBULAR EXTERNAL HOUSING MEMBER OPEN AT OPPOSITE ENDS, A CYLINDRICAL MOUNTING MEMBER SPACED COAXIALLY WITHIN SAID HOUSING MEMBER, SAID MOUNTING MEMBER HAVING A SENSING END FLUSH WITH ONE END OF SAID HOUSING MEMNER AND HAVING A PLUG END EXTENDING BEYOND THE OTHER END OF SAID HOUSING MEMBER, SENSING COILS MOUNTED ADJACENT THE SENSING END OF SAID MOUNTING MEMBER IN SPACED APART RELATION COMPRISING A PRIMARY COIL AND A PAIR OF SECONDARY COILS, A PAIR OF SPACED INSULATING DISCS MOUNTED ON SAID SUPPORTING MEMBER WITHIN SAID HOUSING MEMBER BETWEEN SAID COILS AND SAID OTHER END OF SAID HOUSING MEMBER, MEANS MOUNTED BETWEEN SAID DISCS FOR ENERGIZING SAID PRIMARY COIL WITH AN ALTERNATING VOLTAGE, AN AXIAL BORE EXTENDING THROUGH SAID SUPPORTING MEMBER, MAGNETIC MEANS WITHIN SAID BORE FOR COUPLING SAID SECONDARY COILS TO SAID PIRMARY COIL, SAID COILS BEING ARRANGED TO PROVIDE A DIRECTIVE MAGNETIC FIELD EXTENDING AXIALLY FROM THE SENSING END OF SAID PROBE, SAID SECONDARY COILS BEING BALANCED TO PROVIDE NO NET VOLTAGE WHEN SAID MAGNETIC FIELD IS UNDISTURBED, CONVEYANCE OF AN ELECTRICALLY CONDUCTIVE ELEMENT INTO SAID MAGNETIC FIELD BEING EFFECTIVE TO CAUSE SAID SECONDARY COILS TO PROVIDE AN OUTPUT VOLTAGE, CIRCUIT MEANS MOUNTED BETWEEN SAID DISCS FOR UTILIZING SAID OUTPUT VOLTAGE, POTTING MATERIAL FILLING THE SPACE AROUND SAID SUPPORTING MEMBER WITHIN SAID HOUSING MEMBER, AND AN ELECTRICAL CONNECTOR MOUNTED ON THE EXTENDING END OF SAID MOUNTING MEMBER AND ELECTRICALLY CONNECTED TO SAID CIRCUIT MEANS.