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:
Jun. 01, 1982
Filed:
Mar. 13, 1981
Stanley Panton, Peterborough, CA;
Milltronics Ltd., Peterborough, CA;
Abstract
A tuned acoustic directional transducer for transmitting and receiving airborne sound, which provides enhanced efficiency and reduced cost without undue narrowing of bandwidth, makes use of an acoustic transducer element (2) coupled to a plate (10) having a higher order flexural mode resonance at approximately the desired frequency of operation, the plate being coupled to the air through low-hysteresis acoustic propagation material having an acoustic impedance much less than that of the plate and much greater than that of the air. The material is disposed so that in the desired direction of propagation there is no substantial reduction of sound intensity in the far field resulting from cancellation occasioned by interaction of sound radiated from adjacent antinodal zones. Preferably the thickness of the material is such that it acts as an efficient acoustic impedance matching transformer. Preferably, the transducer element is piezoelectric and coupled to the center of a circular plate to which the coupling material is applied in rings (16, 18, 20).