Method and apparatus of inductively heating elongated workpieces

Abstract

A device for heating an elongated workpiece having a central axis which device comprises first and second axially spaced and axially aligned multiturn induction heating coils, each of which has a workpiece receiving passage extending therethrough. Means are provided for indexing a workpiece axially first into the passage of the first coil and then, after a time delay, axially into the passage of the second coil. There is also provided a quenching device used with the heating device for the previously heated workpieces which involves moving the workpiece to a first location above the liquid level of a quenching liquid in a tank with the axis of the workpiece extending in a given direction, shifting the heated workpiece transversely to a second position still above the liquid level, shifting the workpiece vertically downwardly into the quenching liquid of the tank at the second location, rotating the workpiece under the liquid level at a second location, shifting the workpiece transversely to a third location while still under the liquid level, lifting the workpiece vertically upwardly from the quenching liquid to a position above the liquid level, shifting the workpiece transversely to a fourth position still above the liquid level and then moving the workpiece from the tank.