Inwardly directed wave mode ultrasonic transducer, gas analyzer, and method of use and manufacture
First Claim
1. An ultrasonic transducer device for producing an inwardly directed ultrasonic wave comprising a cylindrically shaped means having a plurality of ripples therein for emitting an ultrasonic wave of a desired frequency and for sensing a returned ultrasonic wave, the emitted ultrasonic wave being directed radially inward from the cylindrically shaped means for emitting, and the returned ultrasonic wave being reflected by a pressure center formed by the inwardly directed ultrasonic wave.
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Accused Products
Abstract
An ultrasonic transducer is disclosed for emitting an ultrasonic wave radially inward. The transducer is constructed with a strip of piezoelectric material laminated with a pair of electrically conductive metal layers that are conductively isolated from one another. In a preferred embodiment, the strip of piezoelectric material is formed in a cylindrical shape and with continuous sinusoidal ripples along the circumference. The sinusoidal ripples are designed to emit a specific wave length of a desired frequency. The radius of the sinusoidal wave is based on material characteristics and the desired resonance frequency. The invention discloses various methods and apparatus for constructing and maintaining the transducer sinusoidal shape. One method includes attachment of a pair of rigid end caps on the laminated piezoelectric material, and another discloses weaving the laminated piezoelectric material through a nonconductive mesh cage, and yet another includes adhesively attaching the transducer to a housing. The invention also includes an application of the above described transducers in a gas analyzer having an internal chamber in which the transducer is arranged. The method of analyzing gas includes passing the gas through the internal chamber and across the surface of the transducer, energizing the transducer to emit an ultrasonic wave into the passing gas toward the center of the transducer. The ultrasonic wave is reflected from a pressure center and sensed by the same transducer that emitted the wave. The invention also includes a method of manufacturing the transducer with sinusoidal ripples to accomplish an emission of desired frequency.
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Citations
36 Claims
- 1. An ultrasonic transducer device for producing an inwardly directed ultrasonic wave comprising a cylindrically shaped means having a plurality of ripples therein for emitting an ultrasonic wave of a desired frequency and for sensing a returned ultrasonic wave, the emitted ultrasonic wave being directed radially inward from the cylindrically shaped means for emitting, and the returned ultrasonic wave being reflected by a pressure center formed by the inwardly directed ultrasonic wave.
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4. An inwardly directed wave mode ultrasonic transducer comprising:
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a strip of piezoelectric material having inside and outside surfaces and two edge surfaces; a pair of electrically conductive metal layers, each metal layer placed on the inside surface and on the outside surface and spaced apart to form a gap on each surface between the pair of electrically conductive metal layers, the gaps running parallel with one another along a perimeter of the strip of piezoelectric material; a pair of end caps attached at each edge surface; and wherein the transducer is constructed substantially cylindrically and having a plurality of ripples therein to create and maintain a hollow center and is capable of radiating an ultrasonic wave radially inward from the transducer. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An ultrasonic transducer comprising:
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a strip of piezoelectric material having a pair of electrically conductive metal layers on an inside surface and an outside surface such that each is electrically isolated from one another; a nonconductive mesh cage having a plurality of vertical members, a plurality of horizontal members, and a plurality of vertical openings between the plurality of vertical members wherein the strip of piezoelectric material is weaved therebetween; and wherein the transducer is constructed substantially cylindrically and having a plurality of ripples therein to create and maintain a hollow center and is capable of radiating an ultrasonic wave radially inward. - View Dependent Claims (15, 16, 17, 18)
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19. A method of producing an ultrasonic transducer comprising the steps of:
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determining a modulus of elasticity and density of a piezoelectric material; determining a desired operating frequency of the ultrasonic transducer; calculating an optimal radius of a sinusoidal ripple based on the modulus of elasticity and the density of the piezoelectric material and the desired operating frequency; and shaping the piezoelectric material to form a continuous full wave sinusoid, wherein each half-wave of the sinusoid has a radius substantially equal to the calculated optimal radius. - View Dependent Claims (20, 21, 22, 23, 24, 25)
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26. A method of analyzing gas comprising the steps of:
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passing a gas to be analyzed through an inside surface of a substantially cylindrical shaped ultrasonic transducer having periodic ripples therein; energizing the substantially cylindrically shaped ultrasonic transducer; radiating an ultrasonic cylindrical wave into the passing gas and toward a center of the substantially cylindrically shaped ultrasonic transducer wherein the ultrasonic cylindrical wave detects characteristics of the gas; and sensing a reflected ultrasonic cylindrical wave containing acoustical characteristics indicative of the detected characteristics of the gas with the substantially cylindrically shaped ultrasonic transducer. - View Dependent Claims (27, 28)
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29. A gas analyzer comprising a housing having a gas inlet, a gas outlet, and an internal chamber in gaseous communication with the gas inlet and gas outlet;
- and a cylindrical ultrasonic transducer having a series of ripples therein, a hollow center, and arranged in the internal chamber of the housing to allow a flow of gas therethrough, and wherein an ultrasonic emission from the ultrasonic transducer converges radially inward toward a center of the internal chamber.
- View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
Specification