Improvements in or relating to the high frequency induction heating of metals

摘要

591,150. Induction heating. STANDARD TELEPHONES & CABLES, Ltd., and MADDOCK, A. J. Dec. 5, 1944, No. 24286. Drawings to Specification. [Class 39 (iii)] Heating metals by high-frequency electric fields so as to control the heating effects at different depths within the metal by means of a plurality of frequencies, has for its object a less steep temperature gradient than that obtainable with a single high-frequency field. In one method described, separate H.F. generation and inductor coils operating at different frequencies are employed. In another method, one inductor coil is fed from a single generator supplying two or more frequencies. Various methods of generating the desired frequencies are described.