Variable inductance magnetic core

Claim 1

A VARIABLE INDUCTANCE MAGNETIC CORE ASSEMBLY COMPRISING, IN COMBINATION, A HOLLOW ANNULAR CORE OF PARAMAGNETIC MATERIAL HAVING AXIALLY SPACED ENDS AND A CYLINDRICAL INNER WALL DEFINING A CYLINDRICAL PASSAGE EXTENDING AXIALLY THERETHROUGH, THE CYLINDRICAL SURFACE OF SAID PASSAGE HAVING AT LEAST A PAIR OF ANGULARLY SPACED SLOTS EXTENDING LONGITUDINALLY THEREOF AND OPENING INTO SAID PASSAGE, AND THE COMBINED ANGULAR EXTENT OF SAID SLOTS BEING A MINOR FRACTION OF THE PERIPHERAL EXTENT OF SAID PASSAGE; RELATIVELY ELONGATED RACK MEMBERS EACH ENGAGED IN ONE OF SAID SLOTS AND HAVING RADIAL THICKNESS SUBSTANTIALLY EQUAL TO THE RADIAL DEPTHS OF SAID SLOTS, THE RADIALLY INNER FACE OF EACH RACK MEMBER HAVING NONMAGNETIC RACK TEETH THEREON EXTENDING INTO SAID PASSAGE; AND A SUBSTANTIALLY SOLID ONE-PIECE RELATIVELY ELONGATED CYLINDRICAL CORE OF PARAMAGNETIC MATERIAL CONTINUOUSLY EXTERNALLY THREADED TO ENGAGE SAID RACK TEETH FOR DISPLACEMENT OF SAID SOLID CORE AXIALLY OF SAID PASSAGE BY RELATIVE ROTATION OF SAID CORES, THE THREAD CREST DIAMETER OF SAID SOLID CORE BEING SUBSTANTIALLY EQUAL TO THE DIAMETER OF SAID PASSAGE; SAID RACK MEMBERS BEING ELASTIC AND BEING BOWED LONGITUDINALLY, WITH THE CONCAVE SURFACE OF THE BOW FACING RADIALLY OUTWARDLY OF SAID HOLLOW CORE.