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:
Oct. 21, 1997
Filed:
Mar. 28, 1996
Friedhelm Schlawne, Duisburg, DE;
Heinz Schneider, Dusseldorf, DE;
Mannesmann Aktiengesellschaft, Dusseldorf, DE;
Abstract
A process for detecting flaws on stretched workpieces, especially tubes and bars, in which the test specimen is passed in the axial direction and without rotation by fixed electrodynamic transducers arranged separately in the peripheral direction. Wave pulses travelling in both peripheral directions are generated in the test specimen at different locations in alternating fashion in the test cycle, and the location of reception for the reflection signals is different from that for the transmission signals. The wave pulses travelling in both directions are generated at at least four locations separated symmetrically from one another in the peripheral direction in alternating fashion in the test cycle. Each particular sequence of reception signals is evaluated separately, and for each cycle the reception signal and a burst signal are fed to a peak detector and the output signal of the peak detector is transmitted in digital form to a computer. The device for carrying out the process includes electrodynamic transducers, which have separate transmitting and receiving coils, and lie on a peripheral plane, and are staggered around the perimeter of the test specimens. The transducers are arranged in a fixed manner, and are connected to an analysis unit. The device calls for 2.multidot.n transducers, where n>2, arranged symmetrically around the perimeter, whereby every two transducers are placed together on one transducer carrier and the spacing of the transducer carriers is 360.degree./n. Furthermore, each transducer has its own local electronics system and its own analysis channel.