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. 24, 1991
Filed:
Oct. 05, 1989
Alfred Graff, Essen, DE;
Friedhelm Schlawne, Kerpen, DE;
Michael Wachter, Ratingen, DE;
Wolfgang Bottger, Dusseldorf, DE;
Mannesmann Aktiengesellschaft, Dusseldorf, DE;
Abstract
The invention furnishes an electrodynamic transducer head for a non-destructive testing of workpieces with electrically conductive surfaces by way of ultrasound. A magnet system is employed for generating of a static or a low-frequency magnet field, and at least one transducer coil is disposed at the front face of the magnet system disposed toward the workpiece. The transducer coil is furnished on the side toward the workpiece with a wear-resistant layer, and the transducer coil exhibits between itself and this front face of the magnet system an intermediate part with an insulating layer, which is solidly connected with the front face and with the coil adjoining at the insulating layer. The invention discloses production of a transducer coil, in a way which is simple and economical and results in a transducer head which can be universally employed, and where the eddy current formations, resulting in interfering signals, and the mechanical vibrations, both in the transducer coil as well as in the magnet system, are substantially suppressed or, respectively, damped. The intermediate part (10) comprises at least two layers (11, 12), where one of the layers (12) is electrically conductive and which layer ( 12) is made of a material thickness which is larger than the skin depth for a given high-frequency field.