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. 17, 1992
Filed:
May. 20, 1991
Alfred Graff, Essen, DE;
Hans-Jurgen Rohde, Duisburg, DE;
Mannesmann AG, Dusseldorf, DE;
Abstract
An electrodynamic permanent magnet transducer for the non-destructive testing of workpieces by means of ultrasound. A soft magnetic housing is preferably provided in magnetically conducting contact with a pole surface of the permanent magnet to provide a compact magnetic return path for the magnetic field created by the permanent magnet. A hollow cylindrical body of nonmagnetic material is disposed to contactingly surround the permanent magnet to substantially eliminate magnetic short circuits parallel to the pole axis of the permanent magnet. The provision of two spiral transducer coils allows for the transmission and reception of ultrasound in a single permanent magnet transducer.