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US 5,852,589 AGranted
Low cost composite transducer
AssigneeRaytheon Company
InventorsDavid T. Wilson, Roger H. Tancrell
Life of this patent
Estimating the term…
Abstract
A composite sensor includes at least one layer comprising a piezoelectric material such as a molecularly poled polymer material or a ceramic material having disposed therebetween a material which enhances the piezoelectric properties of the piezoelectric material. One pair of edges of said composite sensor are constrained from expanding in response to a force applied to the sensor.
Claims30
In combination:
- a layer comprising a piezoelectric material having a first predetermined Young's Modulus and a pair of in-plane, mutually orthogonal directions in a plane parallel to major opposing surfaces of said layer with said material having a first resistance characteristic to tensional forces applied along a first direction, and a second, lower resistance characteristic to tensional forces applied along a second, orthogonal direction;
- means for concentrating onto the piezoelectric material strains derived from forces applied to the concentrating means, said means including a pair of layers of an elastomer material having a second, relatively small Young's Modulus with respect to the Young's Modulus of the piezoelectric material with said layers of small Young's Modulus material with said layers of small Young's Modulus material being disposed over the opposing major surfaces of said layer of piezoelectric material, and means for preventing expansion of said piezoelectric layer along said second, orthogonal direction while permitting expansion of said layer along said first direction.
A transducer comprising:
- a rigid housing comprised of rigid polyvinylchloride a force sensor disposed in said housing having first and second pairs of opposing surfaces with said first pair of surfaces disposed in intimate contact with inner surfaces of said rigid housing, said force sensor comprising:
- a pair of sheets of an elastomer material;
- and
- a piezoelectric material disposed between and directly on said pair of sheets of electrically conductive elastic material;
- means disposed over opposite surfaces of said housing for transferring stress applied thereto, to said force sensor;
- and
- means disposed between said second pair of edges and said housing for providing strain relief to said force sensor for permitting expansion of said force sensor in a direction orthogonal to said second pair of edges.
4 more elements
In combination:
- a layer comprising a piezoelectric material having a first predetermined Young's Modulus and a pair of mutually orthogonal directions in a plane parallel with opposing major surfaces of said layer with said material having a first resistance characteristic to tensional forces applied along a first direction, and a second, lower resistance characteristic to tensional forces applied along a second, orthogonal direction;
- means for concentrating onto the piezoelectric material strains derived from forces applied to the concentrating means, said means including a pair of layers of an elastomer material having a second, relatively small Young's Modulus with respect to the Young's Modulus of the piezoelectric material with said layers of small Young's Modulus material being disposed directly on opposing major surfaces of said layer of piezoelectric material, and
- means for preventing expansion of said piezoelectric layer along said second, orthogonal direction while permitting expansion of said piezoelectric layer along said first direction.
A transducer comprising:
- a rigid housing comprised of rigid polyvinylchloride;
- a force sensor disposed in said housing comprising:
- a pair of sheets of an elastomer material;
- and
- a piezoelectric material disposed between said plurality of sheets of elastomer material;
- means disposed over opposite surfaces of said housing for transferring stress applied thereto to said force sensor;
- means for inhibiting expansion of said force sensor in a first direction corresponding to a mechanically weakest direction of said piezoelectric material;
- and
- means disposed between said second pair of edges and said housing for providing strain relief to said force sensor for permitting expansion of said force sensor in a second orthogonal direction.
6 more elements
Dependencies are inferred from the claim text.