Method and apparatus for adjusting the coupling between an inductor and valve seat

Claim 1

In a device for inductively heating several generally circular valve seats of an engine block simultaneously, said device comprising a plurality of inductors, means for positioning said inductors in heating relationship with said valve seats with each of said inductors magnetically coupled with one of said seats, and power means for energizing said inductors whereby said valve seats are inductively heated, the improvement comprising: means for generating a plurality of first electrical signals each proportional to the actual magnetic coupling between one of said inductors and its associated valve seat; means for comparing each of said first electrical signals with a second signal corresponding to a desired magnetic coupling of each inductor; and means responsive to the difference between said first and second signals for automatically and individually adjusting the magnetic coupling of each inductor from said actual sensed coupling toward said desired coupling, each of said first signal generating means includes means for connecting one of said inductors into an electrical circuit having a known current insufficient to cause heating of said seat associated with said one inductor and means for generating a signal representative of the voltage drop across said one inductor which signal is said first signal.

Claim 5

A method of positioning an inductor with respect to a generally circular valve seat of an engine block, said method comprising the steps of: a. positioning said inductor with respect to said valve seat; b. applying a constant current across said inductor; c. measuring the voltage across said inductor to create a signal representative of the actual coupling of said inductor with said seat; d. comparing said signal with a reference signal to determine the difference between said signals; and, e. adjusting the coupling between said inductor and said seat in accordance with said difference.

Claim 6

A method of positioning an inductor with respect to a generally circular valve seat of an engine block, said method comprising the steps of: a. positioning said inductor with respect to said valve seat; b. applying a constant current across said inductor; c. measuring the voltage across said inductor to create a signal representative of the actual coupling of said inductor with said seat; d. comparing said signal with a reference signal to determine the difference between said signals; and, e. adjusting the coupling between said inductor and said seat in accordance with said difference.