Abstract: An ultrasonic toothbrush for use in personal dental hygiene care includes an exchangeable ultrasonic implement which may be rigidly and removably mounted to ultrasonic power means and readily removed therefrom with a relatively small separating force. Provision is made for coupling the toothbrush to the power means and is arranged to transfer the ultrasonic energy from the power means to the ultrasonic implement with the power means remaining substantially free from absorbing ultrasonic energy as the vibratory energy is transmitted therethrough.

Abstract: A device for adjusting a nominal value of the dimension of an actuator, the longitudinal dimension of which can be changed by applying an external electromagnetic or electrostatic field, the magnitude of the external electromagnetic or electrostatic field being associated with the longitudinal dimension of the actuator, or soft-magnetic and highly magnetoelastic layer being connected to the actuator in such a manner that a change in length of the actuator produces a change in the mechanical stress in the layer. The change in mechanical stress in the layer produces a change in the value of an inductance, the mechanical stress in the layer being inferred from the magnitude of the inductance in sensor electronics and the longitudinal dimension of the actuator being inferred from the mechanical stress in the layer.

Abstract: An ultrasonic toothbrush for daily removal of soft plaque including a handle constructed of a rigid material, a battery pack, an electronics driving module, a piezoelectric member, and a removable brush-head. The low voltage DC energy supplied by the battery pack is converted to an ultrasonic frequency DC current by the electronics driving module. The piezoelectric crystal resonates, expands and contracts volumetrically, in the tune with the frequency supplied by the electronics driving module and thereby converts the electronic energy into sound-wave energy. The sound-waves driving the dentifrices in the mouth of the user against the teeth causing mild cavitation within the dentifrices at the junction with the teeth, resulting in a loosening effect on the soft plaque on the surface of the teeth and in the periodontal pockets formed in the gums around the neck of the teeth. The loosened soft plaque is then dislodged by the bristle clusters of the toothbrush by the normal brushing movements of the user.

Abstract: A harmonic traction motor for converting linear motion to rotational motion. A driven shaft is surrounded by the annulus of a shaft driving member having a circumference slightly larger than the circumference of the shaft. At least two actuating devices are connected between the support and the driving member at 90.degree. with respect to each other and sequentially energized to cause the annulus to exert a force around the shaft in a hypocycloidic motion. This motor has high torque, high stiffness, zero backlash and small volume and can be operated in a stepping mode and can be used as a brake or clutch, if desired.

Abstract: Axially elongated drive modules are interconnected at their opposite ends angularly spaced supports in a polygonal arrangement on an inner ring to establish tensile stress therein, while intermediate module centers are spaced from an inner shaft by solenoid locks. Each module includes at least two magnetostrictive rod elements held in axial alignment at their adjacent ends by a coupling, through which the module is radially spaced from the common axis. Drive coils electrically energized to generate magnetic fields cause simultaneous elongation and contraction of the rod elements to apply unidirectional torque to a rotor formed by either the outer ring or the inner shaft.

Abstract: The magnetostrictive rod of a linear motor is made of twinned single crys Terfenol-D having its crystalline axis aligned with the rod axis to produce non-uniform transverse magnetostriction during axial magnetostrictive elongation of the rod in response to a triggering magnetic field. Slide bearing forces applied through spring biased support plates are limited to flat surfaces formed on the rod perpendicular to a transverse axis along which the rod is magnetostrictively contracted.

Abstract: An automotive motor-driven device controlling and driving system for controlling and driving the respective ultrasonic linear motors of a plurality of automotive motor-driven devices, such as power seats, power windows and power antenna. The automotive motor-driven device controlling and driving system comprises a power circuit connected to the battery of an automobile, a single ultrasonic oscillator, a plurality of power amplifiers having input terminals connected to the power circuit and the ultrasonic oscillator, and output terminals connected through motor control switches to the ultrasonic linear motors, respectively, and a control unit for controlling the power circuit, the ultrasonic oscillator and the power amplifiers.

Abstract: Apparatus and method for precisely controlling the movement of a magnetostrictive transducer including an elongated magnetostrictive rod, means for inducing a magnetic field in the rod and supplying drive current for moving the rod in response to the drive current. A temperature compensated strain sensor configuration on the rod detects the amount of rod movement in response to the drive current and provides an output signal proportionate thereto. Feedback control means coupled between the strain sensor and the current driver respond to the strain sensor output signal and vary the drive current until the strain sensor output signal matches the voltage reference set point developing the drive current.

Abstract: An arrangement to controllably vibrate a resiliently supported body including electromagnetic drive means energizable to vibrate the body, means to control the device means, means to detect the actual vibration of the body, the control means including digital signal processing means to produce a control pulse train representing a required phased difference from the detected vibration to control the energization of the drive means with an independently set phase difference from the detected frequency to sustain the vibration of the body.

Abstract: A demagnetization compensated magnetostrictive actuator includes a magnetostrictive displacement element and an excitation element responsive to an external signal for providing an applied magnetic field; it further includes a magnetic yoke configuration that encloses both the displacement and excitation elements, for providing a low magnetic reluctance path for the magnetic flux provided by the applied magnetic field.

Abstract: An AC power system for a resonant load. A pair of switching networks and blocking networks are provided to drive the load for half a cycle in a resonant manner to a high energy state, and then maintained in that high energy state for a predetermined period. Then the load is driven for half a cycle in a resonant manner to the opposite polarity high energy state, and maintained in that high energy state for the predetermined period. A controller adjustably controls the frequency of switching between the two high energy states and the length of the predetermined period, so that a desired frequency is obtained.

Abstract: An acoustic transducer for providing large displacements particularly at low acoustic frequencies is formed from a minimum of three curved shells which are attached to each other at their ends. The shells are driven by a ring or corresponding number of attached piezoelectric or magnetostrictive type rod or bar drivers which take the form of a regular polygon. The curved shells are attached to the ends of the driver and vibrate with magnified motion as the rods execute extensional motion. As the polygon expands the curved shells deform and produce additional motional in the same radial direction resulting in a large total displacement and corresponding large acoustic output.

Abstract: An ultrasonic generator system comprising a power oscillator which provides an A.C. signal for driving one or more ultrasonic transducers (TDM). The power oscillator includes a transistor (Tr.sub.1) in series wtih the parallel combination (for A.C. purposes) of a capacitor (C.sub.1) and an inductance (L.sub.1). The transducer load TDM is connected across the inductance L.sub.1 without the use of an intermediate transformer.

Abstract: A linear magnetostrictive actuator with feedback compensation including a force train that has at least one magnetostrictive element, an excitation component disposed on or within the actuator, a feedback apparatus whose output signal is proportional to the magnetic induction within the magnetostrictive element, and actuator control circuitry for providing the difference signal resultant between the feedback output signal and the external signal, such that positional displacement error is compensated by closed loop operation of the actuator.

Abstract: A circuit for driving a plurality of ultrasonic transducers uses an oscillator drive means, first means responsive to the current supplied to the transducers is fed back to vary the oscillator frequency to maintain the transducer current at a maximum level, and second means, independent of the first means, are provided to cyclically sweep between upper and lower limits the oscillator frequency determined by the first means. This assures that each transducer experience resonance at least once each sweep.

Abstract: A power supply is provided for an electromechanical device of the type employing ultrasonic frequency vibratory energy for bonding materials. An automatic frequency control varies the output frequency of the power supply until the ratio of the maximum to minimum amplitudes of a standing wave produced in the mechanical vibratory member falls below a pre-set maximum. The frequency of the power supply is set by a voltage controlled variable frequency oscillator. A sweep generator produces a periodic voltage signal having a frequency substantially less than the frequency range of the voltage controlled oscillator.Means are provided for coupling the voltage signal from the sweep generator to the control input of the voltage controlled oscillator whenever the standing wave ratio exceeds a pre-set value, and for holding the last voltage signal received by the control input of the voltage controlled oscillator whenever the standing wave ratio is equal to or less than the pre-set value.

Abstract: An ultrasonic toothbrush for use in personal dental hygiene care includes an elongated handle member in the form of a hollow housing having disposed therein a low voltage coil and cooperating ferrite core which is driven at ultrasonic frequencies. Affixed to the core is a brush member adapted to be received within the human mouth and moved across tooth and gingival surfaces. The brush member has been adhesively affixed to an impedance transfer device which in turn has been adhesively affixed to the core material. The impedance transfer device insures the maximum transfer of ultrasonic energy from the core material to the brush. The ultrasonic energy driving means for the core requires a relatively low voltage and permits the coil to be sealed in the handle impervious to contamination by water.

Abstract: A device using longitudinal ultrasonic vibrations for rotating a shaft at relatively low rotational speeds is particularly useful for rotating a brush-type tooth polisher on an insert for an ultrasonic dental prophylaxis unit. The device has a sleeve which supports the rotatable shaft and a vibrator. A disc is normal to the axis of rotation of the shaft and connected to the shaft for rotation. A transducer at one end of the vibrator responds to excitation for producing longitudinal ultrasonic vibrations in the vibrator, and the other end of the vibrator which is urged against the disc with a constant force converts the longitudinal vibrations into elliptical motion to engage one face of the disc during an arc of the elliptical motion. This imparts substantially only pulses of tangential driving force and normal vibrational forces to rotate the disc and shaft unidirectionally. In one preferred embodiment, the vibrator has a single driving pad urged against the disc.

Abstract: A high power ultrasonic generator for driving a transducer/horn assembly includes a transistor bridge inverter power output circuit connected to a DC source for producing an alternating output current. A pulse generating circuit produces a bipolar train of pulses for controlling the switching of the transistors in the bridge inverter circuit. The pulse widths are adjusted to provide a dead time therebetween at least equal to the storage time of the inverter transistors to prevent any overlap in the conduction of the opposite legs thereof. Overload control means reduces the widths of the pulses when the output current exceeds predetermined levels, thereby to reduce the output current. A starting circuit in the pulse generator gradually increases the pulse widths during start-up of the generator, and other circuitry protects against unduly high current loads in the power supply during AC turn-on of the system.

Abstract: The vibration motor comprises a concentrator of torsional vibrations, whose end face is in close contact with a rotor, and a piezoelectric cell unit adjoining the concentrator of torsional vibrations. Besides, the vibration motor is provided with a magnetic field source arranged under the rotor at the side of the concentrator of torsional vibrations and having a power sufficient to hold the rotor firmly against the concentrator end face, and with magnetic circuit. One part of the latter is movable, being fashioned as a disk with circumferentially spaced slots and rigidly connected to the rotor. The other part of the magnetic circuit separated from the first one by an air gap is stationary. It surrounds the magnetic field source and has peripheral slots identical to those of the movable disk and arranged opposite to them.

Abstract: An ultrasonic power generator for operation at a one and a half kilowatt power output from a 220 volt, 50 hertz AC line comprising a transducer coil impedance associated with a resonant capacitor, said generator being generally designed for a one kilowatt power output from a 110 volt, 60 hertz AC line. The generator circuit includes at least one thyristor for switching the resonant capacitor terminals and an oscillating circuit having a time basis including said capacitor designed for circulating a high frequency current at the desired ultrasonic operating frequency sufficient to generate one and a half ohmic kilowatts. A small high Q inductance is added to the inductive reactance of said transducer coil for adjustment to the capacitance values of the oscillating circuit.

Abstract: A sonic transducer, having a drive electromechanical transducing element and a pickup electromechanical transducing element or a single transducing element electronically operating as both, is excited through suitable power amplifiers by a voltage controlled oscillator. A phase comparator connected to these transducing elements detects the phase difference between stress and strain in the transducer. Its output is connected to an integrator circuit means which integrates the phase difference signal and applies the integrated signal to control the voltage controlled oscillator. The maximum and minimum values of the voltage which is applied to control the oscillator are independently limited by a pair of diodes connected to sources of two different voltages. An adjustably fixable phase shift circuit is interposed between the pickup transducing element and the phase comparator to permit calibration of the system for optimal operation.

Abstract: The invention discloses various embodiments of an ultrasonic motor and converter adapted to be used in home or industrial ultrasonic devices. The ultrasonic motor is generally of a piezoelectric material having a removable tip or of a design in which the complete motor is contained in a housing, which housing has electrical contact means adapted to be plugged into an adapter which, in turn, is connected to a converter. The motor is designed such that frequency sensing means is provided therein and the feedback signal is utilized by the converter to adjust itself thereto. The converter includes tuned circuit means tuned to a band including a desired frequency for sustaining the vibration of said motor at the desired frequency.

Abstract: A fixed electrical network, in conjunction with an amplifier having varia output impedance, is used to provide each of the transducer elements of an array with a reactance which acts as a large shunt reactance when the amplifier acts as a constant current source, but which acts as a smaller series reactance when the amplifier acts as a constant voltage source. Consequently, the usable bandwidth of the array is greatly increased, without degrading its performance.

Abstract: A sonic converter is mounted in a housing assembly into which a depleted nium rod can be conveniently press fitted and subsequently easily released, for ultrasonic vibrational treatment to reduce residual stress in the rods. The sonic converter is constructed to operate in high temperature environments due to its internal thermal insulation, and an externally connected cooling device. The sonic converter is comprised of a transducer which converts electrical energy into mechanical, vibrational energy, and a horn which amplifies the vibrational energy to the DU rod.