Abstract: A quartz crystal vibrator has a vibrator element which includes a quartz crystal plate having obverse and reverse sides. A first excitation electrode is provided on the obverse side of the quartz crystal plate at the central portion thereof, and a first connecting electrode extends radially from the first excitation on the obverse side. A first supporting electrode is connected to the first connecting electrode and is provided fragmentarily along the entire circumference of the quartz crystal plate on the obverse side thereof. A second excitation electrode is provided on the reverse side of the quartz crystal plate at the central portion thereof at a position underlying the first excitation electrode, and a second connecting electrode extends radially from the second excitation electrode on the reverse side.
Abstract: A permanent magnet, direct current motor is made self-starting by the use of permanent magnets with varying magnetization. The use of permanent magnets with varying magnetization results in a rotor position after motor de-energization such that the rotor is angularly offset from a cogged position. This type of motor is made by first, placing uniformly magnetized magnets in a rotor, placing the rotor in an air gap of a toroid on a fixture with a key that correctly positions the rotor, applying a satisfactory magnetic field for a suitable amount of time so that the desired varying magnetization is produced, and finally, assembling the rotor in operative association with the stator so that the at-rest position of the rotor is angularly offset in the direction of rotor rotation from a cogged position.
Abstract: An ultrasonic transducer arrangement having a matrix of oscillators, each such ultrasonic oscillator being formed of a matrix of columnar transducer elements which are electrically controlled together. The spaces between the individual transducer elements are filled with a filler material having an acoustic impedance which substantially differs from the acoustic impedance of the ultrasonic oscillator material from which the transducer elements are formed. The ultrasonic oscillators are provided with electrode strips which are arranged in parallel rows on one flat side of the matrix. The other side of the matrix is provided with electrode strips in the form of parallel columns, so as to be transverse to the direction of the electrode strips on the first side. This arrangement permits high-packing density of the transducer elements, resulting in high resolution which enables line focusing and a close approximation of point focusing.
Abstract: A separate comb transducer is disclosed in a ZnO/Si SAW device to enable doubling of the possible operating frequency for a given photolithographic capability of the device. Frequency doubling is made possible by a single-phase structure having conductive and non-conductive surfaces equal to one-half of the SAW wavelength. By connection of two such structures in parallel, a balanced separate comb transducer is achieved for reducing signal levels due to direct coupling that otherwise occurs in the single-phase structure. Separate comb grating transducers are also disclosed to enable fabrication of higher frequency MZOS convolvers, with both the separate comb transducer and separate comb grating transducer being shown utilized in both the Rayleigh and Sezawa modes.
Type:
Grant
Filed:
September 30, 1982
Date of Patent:
March 13, 1984
Assignee:
Purdue Research Foundation
Inventors:
Robert L. Gunshor, Robert F. Pierret, Michael R. Melloch
Abstract: An interpole for a direct current dynamoelectric machine is provided at the tip thereof with a flux shift winding, or windings, to effect a shifted magnetic flux strength to counteract induced voltages of the commutated armature coils moving through the commutating zone.
Abstract: A transducer (51) extended by an electroexpansive longitudinal effect, actuates a lever (77) through a bendable plate (56). Preferably, the plate actuates a first arm (53) having an end which provides the fulcrum. Another bendable plate (79) actuates a second arm (76) having an end which exterts the power to the lever. The plates are symmetrically disposed on both sides of the transducer axis. The lever is differentially actuated by the arms. When such lever actuators are combined into an impact printer head, a guide for printing elements carried by the respective levers are preferably used in preventing the levers from excessively excursing.
Abstract: A piezoelectric rotary actuator including: a rotatable member; a spiral member fixed at its inner end to the rotatable member; one or more piezoelectric layers attached on one or both sides of the spiral member; means for rotatably supporting the rotatable member relative to the outer portion of the spiral member; and an electrode for applying a voltage across the piezoelectric layer or layers, to bend the spiral and rotate the rotatable member.
Abstract: A spiral pancake armature winding assembly for a superconducting generator is provided which incorporates inner and outer support tubes along with a middle support tube disposed within the pancake coil assembly itself. A plurality of filler pieces, each of which is shaped to fit within a generally rectangular opening of each pancake coil, are rigidly attached to each other in such a way so as to form a middle support tube which provides mechanical support to the pancake coils and prevents relative circumferential movement between adjacent pancake coils. The inner and outer support tubes are shaped to fit within the bore of the spiral pancake armature winding and around its outer periphery. A plurality of spiral wedges, or ramps, are used in conjunction with the inner and outer support tubes in order to provide an improved fit between the support tubes and the spiral pancake armature winding.
Abstract: Transducer structures for use in volume flow measurements which generate a first uniform beam and a second focused beam within the uniform beam. The transducer may include concentric elements, a linear array, or combinations thereof. In a two element concentric array, a central disc generates a uniform beam and a peripheral annular element having a lens thereon defines a second focused beam within the first beam. In a linear array, a plurality of juxtaposed linear elements define a scan surface, and a segmented element within the linear element array defines a focused reference sample volume within the scanned surface. A concentric array having a plurality of annular elements is driven with amplitude weighting of each element, in accordance with a Fourier-Bessel approximation to the desired beam pattern, thereby electronically achieving ultrasonic beam width control.
Type:
Grant
Filed:
February 18, 1982
Date of Patent:
February 14, 1984
Assignee:
The Board of Trustees of the Leland Stanford Junior University
Abstract: An improved construction for piezoelectric crystal assemblies has significant advantages both from the standpoint of operational attributes of the finished product and of adaptability to being mass produced in an expeditous and economical manner. A related, improved method of making piezoelectric crystal assemblies, including those of the aforementioned improved construction, is also provided, which similarly has significant advantages from the standpoints of speed and economy.
Abstract: An electrically actuated control and positioning element formed of a lamella packet as a piezoelectric transducer whose ends are designed to form a power transmission element, and which is capable of transmitting tensile forces. Lamellae spaced from one another engage with parts of the power transmission element, preferably in a dovetailing or interlocking manner. Further active lamellae may be situated in the spaces between the spaced lamellae.
Abstract: Sensor structure integrates multiple piezoelectric bender elements into a single piezoelectric unit. A single base member comprising a plurality of plates of piezoelectric material includes three or more electrodes for forming two or more bender elements. Preferred embodiments include one or more of the following: (i) electrodes for forming inactive regions near structure center and/or ends, (ii) aspects of structural symmetry aiding to establish preferred signal phase and amplitude relationships (iii) base member fashioned according to a three layer laminated structure (iv) circular base member (v) uniform plate polarization (vi) two or four substantially matched bender elements.
Abstract: A brake assembly includes a non-magnetic brake housing fixedly mounted to a motor shaft and a magnetic brake disc axially movable along the shaft in mechanically interlocked relationship with the brake housing between a braking position where it is attracted by an electromagnet against a fixed friction surface and a non-braking position into which it is biased by a pair of compression springs.
Abstract: An external rotor electric synchronous hysteresis motor. A stator provides a rotating electromagnetic field. The hysteresis ring is formed by a deep-drawn rotation symmetrical steel rotor pot having a jacket part for surrounding the stator coaxially and having a bottom part which is provided with a center hole. An end shield is cast into the bottom part of the rotor pot. A shaft is set into the end shield for supporting the rotary motion of the rotor pot.The rotor pot can be deep-drawn from a steel plate into a molded pot blank, the molded pot blank can be machined to a finished rotor pot, the rotor pot can be heated to a temperature from 750.degree. C. to 900.degree. C. in an inert atmosphere and the jacket part of the rotor pot can be quenched by lowering the same into a cold oil bath under continuous rotation.
Abstract: A group-arranged type unidirectional surface acoustic wave transducer, which includes, in combination, groups of interdigital electrodes wherein the center-to-center distance between the electrodes is made equal to an integral number of wavelengths plus a quarter wavelength and further groups of interdigital electrodes wherein the center-to-center distance between the electrodes is made equal to an integral number of wavelengths plus three quarter wavelengths. According to the present invention, there is also provided a unidirectional surface acoustic wave device which can be employed as a filter by changing the frequency-amplitude characteristic of the surface acoustic wave.
Abstract: An ultrasonic transducer assembly having three layers. The front and back layers are made of piezoelectric materials, and are acoustically matched by the intermediate layer. The back layer functions as an ultrasound transmitter, and the front layer functions both as a transmission matching layer and as an ultrasound receiver. During reception, by delaying the signal which is generated by the front layer so that it is in phase with a signal which appears across the back layer and then adding them together, the back layer also functions to enhance the received signal.
Abstract: A pancake armature winding in which the turns of each phase coil are insulated to withstand turn-to-turn voltage potential has phase-to-phase insulation provided by inner and outer insulative skins which act cooperatively with insulative filler pieces which also provide mechanical support for the phase coil. The reduced amount of insulation on each turn of the phase coil permits the overall size of the pancake coil to be reduced. The armature winding is supported mechanically by inner and outer insulative cylinders.
Abstract: A placing stand for use with a microfilm copying device or the like is driven by means of a step motor connected to the stand by wires or the like. A flywheel is coupled to the shaft of the step motor via a one way clutch so as to damp vibrations of the step motor, while allowing the stand to be quickly returned; the flywheel is not a load on the motor in the return direction.
Abstract: A rotor includes an annular hub for accommodating a motor shaft, a tubular permanent magnet around the hub and radially spaced from it, and an annular support between the hub and magnet, the support being bonded to the hub and magnet. The support, a single piece of thin sheet metal, has inner and outer tubular walls, joined at corresponding ends by a disc-shaped bridge.
Abstract: High-silicon steel sheets or ribbons having the crystal texture described by (100)[011] are used for the fabrication of magnetic cores of electrical machinery in such a way that the easy axes of magnetization <001> coincide with the directions of magnetic circuits or lines of magnetic flux. Magnetic cores of, for instance, electric motors or transformers can be remarkably improved in efficiency.
Type:
Grant
Filed:
June 18, 1982
Date of Patent:
January 24, 1984
Assignee:
Matsushita Electric Industrial Co., Ltd.