Induction heating system for 360.degree. curing of can body coatings
AssigneeNordson Corporation
InventorsBarbara Sprenger, Mark Gacka, Robert A. Sprenger, deceased
Life of this patent
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Abstract
A method and apparatus for 360.degree. induction heating of a can body to cure or partially cure a protective coating applied thereto. The can bodies are inductively heated by placing them in a medium frequency, oscillating magnetic field generated by a multiple turn induction coil helically wound around the transport path of the can body. By using a medium-frequency field and by centering the can bodies with respect to the induction coil, the can bodies may be evenly and uniformly heated around 360.degree. of their circumference.
Claims46
A method of at least partially curing a coating onto an electrically conductive cylindrical workpiece by induction heating comprising the steps of:
- (a) generating a magnetic field oscillating at a frequency of approximately 500 Hz to 50 kHz along a heating path;
- (b) transporting the workpiece through the magnetic field generated in said step (a) along the heating path;
- (c) at least partially curing the coating onto the workpiece around a 360.degree.circumference of the workpiece during said step (b) of transporting the workpiece through the magnetic field.
An apparatus for at least partially curing a coating onto an electrically conductive cylindrical workpiece by induction heating comprising:
- a path of travel within the apparatus;
- an induction coil circumjacent about said path of travel for heating the workpiece around a 360.degree. circumference of the workpiece;
- a current source for generating a current within said induction coil oscillating at a frequency of approximately 500 Hz to 50 kHz so as to generate an oscillating magnetic field within said path of travel;
- a conveyor for transporting the workpiece along said path of travel;
- and
- a controller for controlling said current source.
An apparatus for at least partially curing a coating onto an electrically conductive cylindrical workpiece around a 360.degree. circumference of the workpiece by induction heating comprising:
- a path of travel within the apparatus;
- a non-liquid cooled induction coil circumjacent about said path of travel;
- a current source for generating a current within said non-liquid cooled induction coil so as to generate an oscillating magnetic field along said path of travel;
- a conveyor for transporting the work piece along said path of travel;
- and
- a controller for controlling said current source.
An apparatus for heating a coating on an electrically conductive cylindrical workpiece around a 360.degree. circumference of the workpiece by induction heating comprising:
- a housing;
- an electrically non-conductive tube supported within said housing and having a first end and a second end;
- an induction coil within said housing provided around said tube;
- a conveyor for conveying the workpiece through said tube;
- and
- a controller operatively connected to said induction coil for controlling operation of said apparatus.
An apparatus for heating a coating on an electrically conductive cylindrical workpiece around a 360.degree. circumference of the workpiece by induction heating comprising:
- a housing;
- a tube supported within said housing and having a first end and a second end;
- an induction coil within said housing wound around said tube;
- a conveyor for conveying the workpiece through said tube;
- a sensor for monitoring the workpiece as it is conveyed through said tube;
- and
- a controller for controlling a supply of current to said induction coil in response to preset parameters and in response to feedback signals from said sensor.
Dependencies are inferred from the claim text.