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:
Nov. 13, 1984
Filed:
Aug. 26, 1982
Minoru Fujimoto, Hitachi, JP;
Akihiro Tanaka, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A welded steel pipe being turned is subjected to a static magnetic field formed by a sensor. The sensor includes an electromagnet and a transmission and reception coil attached to the end surface of the electromagnet pole facing the steel pipe. The electromagnet is energized by a dc power supply and the transmission coil is supplied a pulse current at certain intervals. As the transmission coil is energized by the pulse current, transverse ultrasonic waves are generated in the steel pipe. The transverse ultrasonic wave propagates through the pipe in the thickness direction thereof and is reflected by the inner surface of the pipe and reaches the outer surface where it is detected by the reception coil. The signal received by the reception coil is amplified by an amplifier and fed to a signal processor which then locates the position of the weld according to the amplitude of the received signals.