Abstract A transducer assembly for converting electrical energy into acoustical energy and vice versa in which a single multi-layer piezoelectric transducer drives (or is driven) a flat diaphragm secured at its edges in a housing. The piezoelectric transducer is a multi-layer wafer which is secured to a flexible sheet which in turn is secured over an aperture in the diaphragm. The piezoelectric multi-layer wafer has its central portion constrained from movement which increases its edgewise movement to twice its unconstrained value. The movement constraint is provided by a post on the housing which is cemented to a central aperture in the wafer. It has been found that there is a maximum ratio of the post diameter to the wafer diameter for optimum performance of the speaker.
Inventors
👤 Jeffery T. Bage
👤 Kenneth R. Cowles
👤 Paul D. Montgomery
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-26 16:12
CPC Classifications
H; H04; H04R; H04R17/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
104 words
A transducer assembly for converting acoustic energy into electrical energy or for converting electrical energy into acoustic energy, which comprises: a housing; a flexible diaphragm mounted in said housing with its non-peripheral portion substantially free for movement, and an aperture in said non-peripheral portion; a flexible sheet overlying said aperture and secured to said diaphragm; a single piezoelectric multi-layer wafer secured to said flexible sheet, said piezoelectric multi-layer wafer having a central portion and a peripheral edge portion; and movement constraining means on said housing for preventing movement of said central portion whereby movement of said multi-layer wafer is restricted to said edge portion.
Claim 2
Dependent Claim
104 words
A transducer assembly for converting acoustic energy into electrical energy or for converting electrical energy into acoustic energy, which comprises: a housing; a flexible diaphragm mounted in said housing with its non-peripheral portion substantially free for movement, and an aperture in said non-peripheral portion; a flexible sheet overlying said aperture and secured to said diaphragm; a single piezoelectric multi-layer wafer secured to said flexible sheet, said piezoelectric multi-layer wafer having a central portion and a peripheral edge portion; and movement constraining means on said housing for preventing movement of said central portion whereby movement of said multi-layer wafer is restricted to said edge portion.
Claim 3
Dependent Claim
22 words
The transducer assembly as claimed in claim 1 wherein said flexible sheet is secured between two adjacent layers of said multi-layer wafer.
Claim 4
Dependent Claim
34 words
The transducer assembly as claimed in claim 1 wherein said movement constraining means comprises: a rigid post mounted at one end on said housing and secured to said central portion at said other end.
Claim 5
Dependent Claim
27 words
The transducer assembly as claimed in claim 3 wherein said rigid post extends into a central aperture in said piezoelectric multi-layer wafer and is secured by adhesive.
Claim 6
Dependent Claim
23 words
The transducer assembly as claimed in claim 4 wherein the ratio of the post contact area to wafer area is less than 10%.