Abstract: A generator and lighting assembly is provided for use on a mechanism, e.g. a power driven tool, having a shaft that is rotated during use. The assembly includes a rotor assembly 122 including a rotor shaft 102 affixed to the mechanism shaft, and a permanent magnet 132 supported on the rotor shaft for rotation therewith. A stator assembly 124 is also provided, and includes a body presenting pair of electrically conductive arms 138 extending on opposite sides of the rotor and an electrically conductive shank 140 connecting the arms together, and a winding 136 of electrically conductive wire supported on the body and presenting a pair of opposed ends. The assembly includes a lamp assembly 128 for providing illumination to an area to be lighted, and includes a light emitting diode (LED) embedded in a solid transparent bulb formed of a synthetic resin composition.

Abstract: A miniature electric generator and lighting apparatus is provided for use in a power-driven tool. The apparatus includes a rotor assembly 22 having a permanent magnet, and a stator assembly 24 within which the shaft and magnet are received. The stator assembly 24 includes a pair of electrically conductive arms 38 extending on opposite sides of the rotor, an electrically conductive shank 40 connecting the arms together, and a winding 36 of electrically conductive wire presenting a pair of opposed ends. A lamp 54 is connected to the ends of the winding by a circuit 52 so that it is powered upon rotation of the shaft. A housing assembly 30 supports the stator assembly 24 on the output shaft of the tool, and is secured to the tool. The housing assembly 30 and cooperating structure 42 position the stator assembly 24 relative to the magnet 32 to prevent contact between the stator element 34 and the magnet during rotation of the output shaft 14.

Abstract: The present invention discloses a positioning apparatus that, together with rotating an object (driven object), positions and guides said object to an arbitrary position within its rotating plane. This positioning apparatus can easily be made compact in size and its rotary motion is not restricted by a power supply cord and so forth. The above-mentioned effects are obtained by arranging a driving force generation device, more specifically a motor, which generates driving force to be applied to a linear motion table of a linear motion table mechanism, within the base portion of a rotary table mechanism.

Abstract: An electric machine which can be operated optionally as a motor or generator and in particular can be installed in the drive train of a motor vehicle with a hybrid drive. The machine includes a stator and a rotor of substantially cylindrical shape, The rotor is positioned about the stator to form a circumferential air gap between the stator and the rotor. An integrated switchable clutch is provided for the transmission of torque. The rotor is arranged on the outside (external-rotor machine) of the stator and the clutch is arranged within the stator.

Abstract: To make the turning "on" and "off" of a clutch in an electro-magnetic clutch smoother, the electro-magnetic clutch has a first rotating member rotatable in response to the driving force applied to the input axis, and a second rotating member arranged opposite to the first rotating member and freely rotatable about the rotation axis of the first rotating member and coupled to the output axis. A movable member is coupled to one end of a return spring and is disposed between the first rotating member and the second rotating member for movement along the rotation axis of the first rotating member. An electric coil generates a force to drive the movable member along the rotation axis of the first rotating member. Cylindrical auxiliary slide members are arranged approximately at equal intervals on the movable member and are disposed between the movable member and the second rotating member.

Abstract: In order to be able to completely eliminate the axial play of an armature spindle of an electric motor, especially for a windshield wiping system of a motor vehicle, even though conditions change over time, a prestressing member acted upon by a spring leg continuously presses against the end of the armature spindle. The prestressing member does not necessarily have to abut directly on the end of the armature spindle, but rather a cap is inserted onto the end of the armature spindle and non-rotatably fixed to the motor housing or a gear housing. An eccentric formed as the housing of the prestressing member abuts on the outside of the bottom of the cap. In an alternative embodiment, a mushroom shaped prestressing member having a mushroom head presses against the end of the armature spindle.

Abstract: A ball-splined shaft assembly suitable for use in a robot arm or the like is provided. The assembly includes a shaft formed with a plurality of circumferential grooves spaced apart from one another at a predetermined pitch and a pair of longitudinal grooves which are located opposite sides and extend in parallel with the center line of the shaft. An outer sleeve unit fitted onto the shaft includes a pair of endless circulating paths each provided with a plurality of balls. Each of the endless circulating paths includes a load path section where the balls are partly exposed and thus received in the corresponding one of the longitudinal grooves. The outer sleeve unit is mounted on a housing through a pair of ball bearings. Thus, the shaft may rotate together with the outer sleeve unit relative to the housing and the shaft may move in its longitudinal direction relative to the outer sleeve unit and thus the housing. A stepping motor is mounted on the housing and operatively coupled to the outer sleeve unit.

Abstract: An electromagnetic clutch of the type which includes a rotor secured around a rotation shaft, a drive member rotatably mounted around the rotation shaft, an armature mounted through a resilient member to the drive member with a gap to the rotor, a bearing mounted around the rotation shaft, a yoke mounted around the bearing for rotation about the rotation shaft, and the yoke locking mechanism for locking the yoke to a frame so as to prevent the yoke from accompanying the rotation shaft when the rotation shaft is rotated, the yoke having a coil wound therearound, and in which the rotor, the armature and the yoke are arranged to form a magnetic path so that the armature is electromagnetically attracted to the rotor for transmitting torque from the drive member to the rotation shaft when the coil is energized.

Abstract: An electrical drive device comprising a stator arrangement of the claw pole type surrounding a stator chamber or compartment and producing therein at least one magnetic field containing at least one rotary field component. There is provided a permanent magnet-rotor arranged in such rotor chamber in such a manner that it rotates in synchronism with such magnetic field and a hysteresis magnetic coupling, the driving part of which is form-lockingly connected with such rotor and the driven part of which is force-lockingly secured to a shaft constituting the power take-off shaft of the drive device. The stator arrangement, the rotor, the driving part of the hysteresis magnetic coupling and the driven part of such coupling are all housed in a common housing.

Abstract: A trapped energy type of piezoelectric filter includes a polarized ceramic wafer 9, input and output electrodes 11, 13 secured to one major surface of the wafer and spaced from each other by a constant width gap, and a ground electrode 15 secured to the opposite major surface underlying the input and output electrodes. The configuration of the ground electrode is made symmetrically concave or convex about its longitudinal axis in varying degrees to thereby control the band pass width, the symmetry of the filter characteristic about a center frequency, and eliminate peak ripples.

Abstract: An elastic surface wave device comprises a substrate of dielectric material, a thin layer of piezoelectric material, a plurality of electrodes and a thin layer of dielectric material. The piezoelectric layer is spaced from the electrodes with the thin dielectric layer formed therebetween and is so arranged as to facilitate the employment of a known photo-etching method to form the electrodes.

Abstract: Surface acoustic wave devices having broadband characteristics with a desired transfer efficiency of less than unity at a desired center frequency are described, the devices incorporate a multistrip coupler array of a predetermined number N of conductive strips disposed on a piezoelectric substrate which is capable of supporting two tracks of approximately equal widths of propagating surface acoustic wave energy, the array having a tapping portion in one of the tracks and an approximately equal length launching portion in the other of the tracks for launching only a portion of the energy incident on the tapping portion, the strip periods p.sub.1 and p.sub.2 of the two portions being different and the ratio of p.sub.1 /p.sub.2, in conjunction with N, provides the desired characteristic.

Abstract: This invention provides a multi-layered substrate for a surface-acoustic-wave device which substrate comprises a piezoelectric layer on a base, the temperature coefficient of a phase velocity of the surface-acoustic-wave in the piezoelectric layer being different from that of the base, the piezoelectric layer having a thickness less than a wavelength of the SAW. This multi-layered substrate can have a large electromechanical coupling and controlled temperature coefficient of the phase velocity.

Abstract: A ferroelectric wave transducer device comprising an unpoled ferroelectric substrate having a substantially sinusoidal poled region at a surface thereof. A metal plate electrode is disposed on the opposing surface of the substrate. In operation an A.C. voltage applied across the two electrodes gives rise to a surface elastic wave in the substrate. Also disclosed is a method of producing a surface wave transducer of the type described. A pair of interdigitated metal electrodes are applied to a surface of an unpoled ferroelectric substrate. A poling potential is applied between the electrodes, preferably while the substrate is heated. The interdigitated electrodes are then removed and a metal plate electrode is applied over the region where the interdigitated electrodes had been. Finally, another metal electrode is applied to the opposite surface of the substrate. Further disclosed is a surface wave variable delay device which includes a metal plate slidably disposed over a sinusoidally poled region.

Abstract: An acoustic surface wave filter device for use in video IF stages in television receivers and the like, which comprises a substrate of a piezoelectric material and a spaced pair of transducers each of which is composed of a pair of interleaved comb type electrodes. One of the transducers is designed so as to have a frequency response curve in which attenuation poles at the both sides of the main lobe thereof, respectively, occur at frequencies corresponding to the upper adjacent-channel picture carrier frequency and the lower adjacent-channel sound carrier frequency. The other of the transducers is designed so as to have a frequency response curve in which the bandwidth thereof corresponds to the width from the sound carrier frequency of the associated channel to the lower adjacent-channel sound frequency. The substrate may be provided with a piezoelectric resonator. The substrate may be further provided with at least one ancillary transducing element.

Abstract: An electromechanical filter, e.g. two duals, in which undesired resonances are damped out. A special choice of the damping material leads to a substantial improvement.

Abstract: The disclosure relates to a novel device for performing signal convolution functions such as auto and cross correlation through the use of combined acoustic surface wave and semiconductor devices. A detector or pickup unit comprising a plurality of interdigital fingers coupled to associate semiconductor diodes is disposed on the surface of an acoustic substrate in the path of surface waves propagated along the surface of the substrate. The diodes are operatively connected to a summing bus from which an output signal indicative of some characteristics of the surface waves may be obtained.

Abstract: A transducer for a surface acoustic wave device. In accordance with an embodiment of the invention, there is provided an acoustic wave propagating substrate and first and second spaced elongated conductive fingers disposed on the substrate. A layer of dielectric material is formed over the first and second fingers. A first electrode is formed on the dielectric layer above the first finger, the first electrode being proportioned to oppose a predetermined portion of the first finger. A second electrode is formed on the dielectric layer above the first finger, the second electrode being spaced from the first electrode and proportioned to oppose another predetermined portion of the first finger. A third electrode is formed on the dielectric layer above the second finger, the third electrode being proportioned to oppose a predetermined portion of the second finger.

Abstract: An acoustic surface wave filter for use as an intermediate frequency filter in a P.A.L. color television receiver comprising input and output transducers each having fingers of conductive material supported on a piezoelectric substrate the fingers of each transducer being electrically connected to a pair of terminal pads so that the fingers connected to one pad interleave with the fingers connected to the other pad, the transducers being mutually offset in a direction orthogonal to the direction of acoustic surface wave propagation and coupled by means of a multistrip coupler.

Abstract: A surface acoustic wave filter having a piezo-electric substrate with a major surface and input and output transducers, each haing a plurality of finger electrodes formed on the major surface to define a propagation path for surface acoustic waves. Finger electrodes of one of the transducers have a step-like configuration to divide the surface wave propagation path into a plurality of surface wave propagation channels. The phase differences of the channels and the length of the steps of the finger electrodes are selected to minimize the multiple reflection echo between the input and output transducers to reduce ripples in the pass band.

Abstract: A tunable surface wave resonator is disclosed comprising a substrate of piezoelectric material having acoustic surface wave absorbing extremities, a pair of spaced acoustic surface wave gradient reflectors positioned adjacent to the absorbing extremities of the substrate, a pair of spaced multiphase surface wave tuning transducers selectively positioned between the pair of gradient reflectors over antinode positions of desired resonant frequency standing wave, and an acoustic surface wave transducer selectively placed for optimum coupling of energy into the acoustic resonant cavity formed by the pair of gradient reflectors.

Abstract: This invention provides a surface elastic wave device constituted by a unitary body of a piezoelectric plate having a pair of transducers thereon, which unitary body is embedded in a casing, and wherein the wave propagation of a surface elastic wave generated on the surface of the piezoelectric plate during excitation of the device is prevented from being transferred to the casing by a thin film inserted between the casing and the wave propagation surface of the piezoelectric plate or by using as the casing a roll of flexible sheet which has the same function of wave propagation prevention as that of the thin film. This device is advantageous because it has a low spurious signal level without incrementing insertion loss, is easy to manufacture and is inexpensive. This invention also provides an effective method of making the device.

Abstract: A length weighted interdigital transducer has .lambda./2 spaced electrodes within the overlap region. Outside the overlap region, the overlapping .lambda./2 spaced electrodes are connected to the bus bars by pairs of .lambda./4 spaced electrodes and extra "dummy" pairs of .lambda./4 spaced electrodes are also connected to the bus bars. The .lambda./2 spaced electrodes give a good manufacturing yield, and the .lambda./4 spaced pairs of electrodes and pairs of dummy electrodes provide compensation for wavefront distortion combined with low "interactions.

Abstract: A filter circuit includes an acoustic surface-wave filter device having an input transducer comprised of a set of interleaved electrodes disposed on a first portion of a body of piezo-electric material adapted to propagate acoustic surface waves for producing an acoustic surface-wave signal in response to an input signal applied to the input transducer, and an output transducer comprised of a set of similar interleaved electrodes disposed on a second portion of the piezo-electric body spaced a selected distance from the first portion for receiving the acoustic surface-wave signals so as to produce a corresponding output signal having a selected frequency response. The frequency response (e.g., bandwidth) of the acoustic surface-wave filter device is controlled by selectively changing the number of conductor elements constituting the interleaved electrodes of the input and output transducers.

Abstract: The present invention relates to surface elastic wave memory correlators, which make it possible to form the correlation product of two successive signals. It consists in sampling the first of said signals at the surface of a surface elastic wave delay line, in storing the samples in capacitors and in forming the product of said samples with said second signal, by varying the impedance of the circuits through which said second signal passes, as a function of the value of the stored samples. The products obtained are added in order to give the correlation signal.

Abstract: An electro-mechanical transducer comprises a LiNbO.sub.3 -piezoelectric substrate containing as an impurity at least one material selected from the group consisting of Ta, Ta.sub.2 O.sub.5, Pd, SiO.sub.2, TiO.sub.2, V.sub.2 O.sub.5 and V, and at least two electro-mechanical transducing interdigital electrode pairs, provided on said LiNbO.sub.3 -piezoelectric substrate.

Abstract: This disclosure concerns a particularly oriented plate-like monocrystalline piezoelectric body of lithium niobate for use as a substrate in an acoustic surface wave filter device, wherein the orientation of the piezoelectric body of lithium niobate is responsible for a substantial reduction in spurious responses including plate modes. More specifically, the piezoelectric body comprises a plate of lithium niobate having a crystalline lattice orientation as determined by a 46.degree. (ZYW) cut. It has been determined that such a piezoelectric body may be employed as a substrate in an acoustic surface wave filter device to effect an improved filter response in that unwanted spurious responses including those caused by plate modes are removed or substantially reduced from the acoustic signals prior to their conversion into electrical output signals.

Abstract: A nonlinear delay line correlator and convolver is described which comprises a tapped, piezoelectric surface acoustic wave delay line and an array of series or parallel connected forward biased semiconductor diodes. An interdigital signal transducer is connected to each end of the delay line and voltages are applied to each transducer to generate contra-flowing acoustic strain waves which are radiated toward an interaction region comprising a plurality of equi-spaced weakly coupled interdigital transducers, each transducer being connected to one diode. Nonlinear signal mixing in the diode array is utilized to perform serial product convolution or correlation of the signal modulation applied at the two signal input transducers. Because of the large nonlinearity of semiconductor diodes, insertion loss is relatively low.

Abstract: A piezoelectric monolithic crystal filter having shunt trimming capacitors incorporated into the design of the filter as electrode strips at the edges of the crystal element. This eliminates the need to use discrete low value shunt trimming capacitors which generally are of a few pico-farad capacitance and are expensive and introduce objectionable lead inductance which is non-linear with frequency. A means is provided for producing filters which are less expensive and improve performance over conventional filters, particularly at higher frequencies.

Abstract: A ghost signal erasing system for television receivers in which a variable delay element utilizing the propagation of an elastic surface wave is used. The variable delay element includes a piezoelectric substrate, a plurality of first interdigitated electrode pairs formed on the substrate and a plurality of second interdigitated electrode pairs also formed on the substrate. An elastic surface wave produced by applying a video i-f signal to the first interdigitated electrode pairs is propagated along the surface of the piezoelectric substrate and taken up at the second interdigitated electrode pairs as a delayed a-c signal. By switching the first and second interdigitated electrode pairs to change the combination thereof, various delay times are obtained.

Abstract: In acoustic surface wave devices the bottom of the substrate is provided with a plurality of discrete recesses to attenuate and/or scatter bulk waves.

Abstract: A device for scanning patterns, e.g. optical patterns, in which on the surface of a piezo-electric material Bleustein-waves are produced, while in the material or in a semi-conductor layer deposited on the surface a drift field is produced. Said drift field pulsates between two levels, a low level at which the gain of the surface wave is independent of the "exposure" pattern and a high level at which the surface wave is locally amplified in accordance with the "exposure" pattern.

Abstract: An elastic surface wave filter is disclosed which is composed of a substrate for the propagation thereon of elastic surface waves and transmitting and receiving transducers, each having at least an electrode deposited on the major surface of the substrate and in which the transmitting and receiving transducers are disposed line connectin the major surface of the substrate a predetermined distance apart from each other; the electrode of one or both of the transmitting and receiving transducers is formed with first and second comb-shaped electrodes; and the first and second electrodes are disposed with each electrode element of the latter extending between adjacent ones of the electrode elements of the former. The electrode elements of the first and/or second comb-shaped electrodes are weighted in terms of length and the extent of the region of overlapping of the first and second comb-shaped electrodes in a first direction, i.e.

Abstract: An improved miniaturized electro-acoustic surface-wave filter device is disclosed having broad, deep, adjacent channel stopbands from uniform aperture transducers. The device includes two spaced, interdigital electrode transducer structures fabricated on one surface of a piezoelectric substrate. Each electrode structure includes a central finger group and a number of flanking finger groups spaced from the central finger group at predetermined temporal locations. The strengths of the flanking groups are adjusted by controlling the number of finger pairs within a group, the overlap length of the fingers, and the strip/gap ratio of the fingers. Aperture uniformity is maintained in reduced overlap flanking groups through the series weighting technique. The subject device is particularly useful for channel selection in the IF portion of a television receiver.

Abstract: A surface acoustic wave delay line uses a closed loop principle with separate input and output transducers side by side. 3dB Multistrip couplers are introduced to achieve substantially 100% transfer for surface acoustic wave energy from the propagation path associated with the input transducer to the propagation path associated with the output transducer. Several such delay lines can be formed on a single cylindrical body of piezoelectric material and these can then be cascaded with intermediate amplification to form a long delay or a tapped delay.

Abstract: A surface acoustic wave bandpass filter having a flat frequency response in the passband and an exponentially decaying out-of-band response is realized by designing its transducer electrodes to have an appropriate number of discretely apodized interdigital fingers. The apodization or overlap coefficients H.sub.o (N) of adjacent fingers are determined from an analytically derived expression that incorporates factors for the filter time length parameter, the filter center frequency, bandwidth, transition bandwidth falloff, and a ripple reduction parameter.

Abstract: An acoustic surface wave filter comprises a piezoelectric substrate defining a propagating surface upon which a transmitting and receiving transducer pair are formed in offset alignment. An interposed multistrip coupler provides surface wave coupling between the offset transducers. An elongated isolating barrier is interposed between the transducers in an orthogonal relationship with the coupler to prevent surface wave propagation between the transducers along other than the primary axis. In one embodiment, an isolating barrier is composed of an acoustic surface wave dampening material, while in another a barrier of acoustic surface wave reflective material is used.

Abstract: A temperature stable surface acoustic wave device utilizing reflective gratings in a material such as Y-cut quartz having two propagation directions in which the temperature coefficients of delay are of opposite sign, the gratings reflecting the Rayleigh waves in the two propagation directions along suitable path lengths to provide a total linear zero temperature coefficient of delay. A temperature stable oscillator is formed by providing an amplifier in a feedback path from the output transducer to the input transducer of the surface acoustic wave device.

Abstract: An acoustic surface wave filter comprises a member stimulable to surface oscillations with means for converting electrical energy into mechanical energy and vice versa associated therewith and a plurality of disturbance locations on a surface of the member in the form of a line grating with variable spacing between adjacent lines in the longitudinal direction of the lines.

Abstract: Disclosed is an acoustic surface wave device having reduced temperature coefficient of propagation delay within a desired range of operating temperatures. In one embodiment the device includes a piezoelectric substrate comprising X-propagating Y-cut quartz having a cut angle at which point of zero temperature coefficient of propagation delay is at a temperature which is higher than the desired range of operating temperatures. There is included on the substrate in the desired path of the propagating surface wave a deposit of conductive material which has the effect of lowering the temperature at which the point of zero temperature coefficient of propagation delay occurs, thereby reducing the magnitude of the temperature coefficient of propagation delay within the desired range of operating temperatures.

Abstract: An acoustic surface wave device is disclosed which comprises a crystal of Tl.sub.3 VS.sub.4, Tl.sub.3 NbS.sub.4, or mixtures thereof having at least one surface at least 1/2 cm long, a surface wave generating transducer mounted on the surface, and a surface wave receiving transducer mounted on the surface positioned to receive a surface wave generated by the surface wave generating transducer.The device transmits surface waves at a low velocity and high coupling efficiency and can be used in a delay line, a filter, an FM discriminator, an oscillator, or other device.

Abstract: An elastic surface wave device comprises a piezoelectric substrate and at least one pair of first and second interdigital electrodes provided on the surface of the piezoelectric substrate, in which when a width of one digit section in the first interdigital electrode is represented by l1 and a width of one digit section in the second interdigital electrode adjacent the one digit section in the first interdigital electrode is by l2 and when a clearance between the adjacent digit sections of the interdigital electrode pair is represented by l3 and the central frequency of the fundamental of a surface wave is by f0, the following relation is established: ##EQU1## L1/VM + L3/VF = 1/4F0 L3/VF + L2/VM = 3/4F0Wherevm: surface wave velocity on the digit section of the interdigital electrode; andvf: surface wave velocity between the adjacent digit sections of the interdigital electrode pair.

Abstract: At least three pairs of opposing electrodes on the two major faces of a poelectric or electrostrictive transducer element having a gap which is adapted to change in response to selected control voltages applied across the three pairs of electrodes. The pairs of electrodes are electrically insulated from one another and one pair of electrodes covers substantially one half of the major faces across from the gap, while the other two pairs of electrodes are disposed on the major faces of the transducer adjacent the gap and respectively covering substantially quarter sector portions of the transducer surface. By the mechanical bonding of electrical switch contacts for example to the opposing end faces at the gap, switch actuation is provided by the application of control voltages across all three pairs of electrodes, causing the gap to diminish and thereafter shorting the pairs of electrodes or applying a reverse control voltage to widen the gap.

Abstract: An acoustic surface wave filter has offset transmitting and receiving transducers formed on a wave propagating surface of a piezoelectric substrate. A multistrip coupler interposed between the transducers on the propagating surface includes a plurality of identical conductor groups forming coupler elements uniformly spaced on the surface and selectively attenuates either of the symmetrical or anti-symmetrical mode components of coupled waves within a predetermined range of acoustic wavelengths. In one embodiment, each conductor group includes electrically connected pairs which attenuates the symmetrical mode component while in another embodiment each conductor group includes a first continuous filamentary conductor and a second filamentary conductor having a discontinuity at its approximate center which attenuates the anti-symmetrical mode component.

Abstract: An elastic surface wave propagation device is disclosed which is composed of a substrate for elastic surface wave propagation and at least one transducer disposed on the major surface of the substrate for converting an electric signal into an elastic surface wave or vice versa. The substrate is formed of quartz crystal and the major surface of the substrate is 43.degree. rotated Y cut plane of the quartz crystal. The angle between the direction of propagation of the elastic surface wave and the X-axis direction of the quartz crystal is selected to be in the range of 8.degree. to 12.degree. so that spurious components are sufficiently suppressed or negligible.

Abstract: An acoustic surface wave filter has offset transmitting and receiving transducers formed on the wave propagating surface of a piezoelectric substrate. A two-segment multistrip coupler is interposed on the propagating surface and provides "track switching" or "sidestepping" action for signals within the coupler passband. The coupler includes a split-connected portion formed by electrically connected filamentary conductor pairs and a split-isolated portion formed by electrically continuous filamentary conductors and interleaved conductors having a discontinuity at their center. The split-connected portion attenuates the symmetrical mode components of acoustic waves within the coupler stop band while the split-isolated portion attenuates the anti-symmetrical mode portion of acoustic waves within the coupler stop band, producing an improved trap response.

Abstract: A surface wave apparatus which comprises an insulation substrate having a smooth surface; a surface wave conversion interdigitated electrode evaporated on the smooth surface of the insulating substrate; a piezoelectric plate, on the smooth surface of which the insulation substrate is mounted at a prescribed space in contact with the electricity-surface wave conversion interdigitated electrode; an insulation liquid layer provided between the smooth surface of the piezoelectric plate and the electricity-surface wave conversion interdigitated electrode as well as between the smooth surface of the piezoelectric plate and the smooth surface of the insulation substrate.

Abstract: Disclosed is an acoustic surface wave device having surface wave transducers coupled to a piezoelectric substrate by harmonic coupling. In one embodiment the device has two transducers, each having a different selected fundamental periodicity and harmonic piezoelectric coupling in a selected range of operating frequencies.

Abstract: A piezoelectric ignition device for spark-igniting a fuel of such burning instruments as cigaret lighters, gas ranges and the like, utilizing a high electric voltage obtained by giving a bending stress in lengthwise direction to an elongated rectangular plate-shaped porcelain piezoelectric element. A plurality of electrodes is formed at least on one of the surfaces of the plate-shaped element along the respective lines parallel to lengthwise both ends and dividing the element lengthwise into "n" divisions, and adjacent divisions are polarized reversely to each other also in the lengthwise direction. A force-to-electricity conversion is made with a piezoelectric constant g.sub.33.

Abstract: An acoustic surface wave filter which includes a strip member of a piezoelectric material having input and output interdigital transducers formed on a major surface thereof, each of the interdigital transducers including two interlaced rows of parallel spaced-apart elongated members, each of the elongated members of at least one of the rows being bifurcated to provide two parallel limbs, the limbs of each of the bifurcated members being connected together by means of at least one connecting link.