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:
Mar. 22, 1988
Filed:
Dec. 11, 1985
Wolfgang Boettger, Duesseldorf, DE;
Friedhelm Schlawne, Kerpen, DE;
Willi Weingarten, Krefeld, DE;
Heinz Schneider, Duesseldorf, DE;
Mannesmann AG, Duesseldorf, DE;
Abstract
An electrodynamic transducing device includes two staggerdly coils with a distance of staggering equal to a quarter of a wavelength of ultrasonic waves; unidirectional transmission characteristics of the transducer is obtained by feeding the two coils separately with HF current at a time difference of feeding of the respective two signals to be equal to a quarter of the wavelength such that a reinforcing ultrasonic signal is produced in the direction of the coil receiving said signal earlier in time and complete cancelation of acoustic waves obtains in the opposite direction, whereby in case of equal pitch of said coils the HF signals are of equal contour but of opposite polarity while in case of opposite winding pitch the signals not only have equal signal contour but also the same polarity.