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.
Patent No.:
Date of Patent:
Sep. 08, 1992
Filed:
Jul. 03, 1991
Abstract
An eddy current flaw detection apparatus, having: a pair of detecting coils disposed in a separated manner along a transit path of a conductor and coaxial with the conductor, magnetic fields generated by said detecting coils being in anti-phase; an alternating current bridge circuit, two sides of a bridge of which are comprising the detecting coils, and which, when a relative change occurs in inductances of the detecting coils and equilibrium of the bridge is thus disturbed, outputs an abnormality detection signal; a pair of resonance coils, which are disposed between the detecting coils, and coaxial with the detecting coils, and magnetic fields of which are in phase, and which are so set that in a state in which the bridge is in equilibrium, induction currents generated by said resonance coils cancel each other out; and a capacity circuit for the purpose of bringing oscillation frequencies of the detecting coils into resonance, which is connected to the resonance coils.