Snap-action ferroelectric transducer
First Claim
1. A piezoelectric actuator comprising:
- a piezoelectric bender element having first and second opposing major faces;
a snap action device for exerting a reaction force in opposition to longitudinal deformation of said piezoelectric bender element and having a predetermined first reaction force magnitude that must be exceeded to cause the snap action,wherein said piezoelectric bender element is mounted on said snap-action devices;
and wherein said piezoelectric bender element comprises piezoelectric means for applying a longitudinal force to said snap-action device in excess of said first reaction force magnitude;
and wherein said piezoelectric means for applying a longitudinal force to said snap-action device comprises a piezoelectric ceramic layer;
and wherein said piezoelectric bender element further comprises means, including a pair of electrodes on opposing major faces of said piezoelectric ceramic layer, for applying an electric field to said piezoelectric ceramic layer to enable said piezoelectric bender element to generate said longitudinal force in excess of said first reaction force magnitude.
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Accused Products
Abstract
A piezoelectric snap-actuator includes a piezoelectric bender element with electrodes disposed on each major face, a spring member for causing the device to snap from a first neutral position to a second neutral position, a prestress layer for applying a compressive force to the piezoelectric bender element, and adhesive layers is provided. The piezoelectric bender element and the spring member are each bonded to the opposite faces of the prestress layer by an adhesive layer. The device assumes one of two neutral positions when not electrically energized. Due to the direction of poling of the piezoelectric bender element, when the piezoelectric bender element is electrically energized it strains in a longitudinal direction. This strain causes the device to deform. When the electrical energy is turned off, the device returns to one of the two neutral positions.
72 Citations
6 Claims
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1. A piezoelectric actuator comprising:
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a piezoelectric bender element having first and second opposing major faces; a snap action device for exerting a reaction force in opposition to longitudinal deformation of said piezoelectric bender element and having a predetermined first reaction force magnitude that must be exceeded to cause the snap action, wherein said piezoelectric bender element is mounted on said snap-action devices; and wherein said piezoelectric bender element comprises piezoelectric means for applying a longitudinal force to said snap-action device in excess of said first reaction force magnitude; and wherein said piezoelectric means for applying a longitudinal force to said snap-action device comprises a piezoelectric ceramic layer; and wherein said piezoelectric bender element further comprises means, including a pair of electrodes on opposing major faces of said piezoelectric ceramic layer, for applying an electric field to said piezoelectric ceramic layer to enable said piezoelectric bender element to generate said longitudinal force in excess of said first reaction force magnitude. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification