The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Aug. 26, 1997

Filed:

Sep. 13, 1995
Applicant:
Inventor:

Shizuo Hayashi, Kawasaki, JP;

Assignee:

Fuji Electric Co., Ltd., Kanagawa, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
373145 ; 373148 ; 373150 ;
Abstract

Temperature sensors are embedded in a refractory material that make up the walls of a body of an induction furnace and detect an increase in the temperature of a molten metal in the body of the furnace due to the bridging of a metal material that is to be melted in the furnace body. The temperature sensors are connected to an antenna for detecting runout. Since various electrical data (voltage, current, power, frequency, etc.) that affect an alternating current to be supplied to a coil of the induction furnace change depending on the temperature of the molten metal, bridging of the metal material is detected by determining the rates of temporal change in these electrical data. Furthermore, the changes in the electrical data with respect to the progress of the operation of the induction furnace are previously stored in data storage, and the electrical data stored are compared with electrical data detected in the induction furnace in operation. An alarm is given when the deviation of the detected electrical data from the stored electrical data is kept larger than a predetermined value for a predetermined time period.


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