Abstract: The present invention comprises an ultrasonic measuring device and method for measuring bone resorption and remodeling using Miniaturized Ultrasonic Transducers. An ultrasonic measuring device for insertion into hard tissue comprises an elongate member with an implant end of the elongate member and an acoustic transducer mounted from the interior of the elongate member at the implant end. The implant end of the ultrasonic measuring device is configured such that the acoustic transducer can measure, when inserted into a hard tissue, variations of the hard tissue using ultrasonic wave propagation. The method of taking measurements of bone resorption and remodeling includes taking measurements of a healthy region and remodeling region of a bone using ultrasonic wave propagation; and calculating the variations in the bone's density and its elasticity along the bone's length a) in the healthy region and b) in the remodeling region.

Abstract: In ultrasonic transducer which can be utilized to detect partial electrical discharges and oil-filled devices is disclosed. The transducer includes a housing, a piezoelectric crystal assembly received within the housing and positioned so that the piezoelectric element contacts the base surface of the housing, and a retaining member which grippingly engages the housing and applies a compressive force to the piezoelectric crystal assembly. The retaining member includes a hub portion and a plurality of angularly spaced-apart arms extending radially outwardly from the hub portion. The arms are positioned with respect to the hub portion so as to grippingly engage the inner surface Of the housing and causing the retaining member to apply a compressive force to the piezoelectric crystal assembly.

Abstract: An ultrasonic piezoelectric transducer for monitoring acoustic events in a medium is disclosed. The transducer includes an elongated body member having a blind bore therein, a piezoelectric crystal which is received in the blind bore within the body member and which contacts the bottom surface thereof, and a rod which is received in the blind bore and which firmly contacts the piezoelectric crystal compressing the crystal against the bottom of the blind bore. The tip of the elongated body member has a convex configuration forming a lens permitting the interception of acoustic events over a wide angle and the direction of same toward the piezoelectric crystal for monitoring and detection purposes.

Abstract: An ultrasonic piezoelectric transducer and a method for measuring and/or monitoring various physical properties of a member, in-situ, are disclosed. The transducer includes a sleeve which is received in a blind bore provided in the member, a piezoelectric element positioned within the blind bore, and an aligning spacer means interposed between the end of the sleeve and the piezoelectric element. By the application of appropriate voltage pulses to the piezoelectric element causing interrogating signals to be applied to the member, and the measurement of the time interval between the application of an interrogating signal and the receipt of a return signal from the member, various physical properties of the member and structural information regarding same can be determined.

Abstract: An ultrasonic piezoelectric transducer and a method for measuring and/or monitoring various physical properties of a member, in-situ, are disclosed. The transducer includes a sleeve which is received in a blind bore provided in the member, a piezoelectric element positioned within the blind bore, and an aligning spacer means interposed between the end of the sleeve and the piezoelectric element. By the application of appropriate voltage pulses to the piezoelectric element causing interrogating signals to be applied to the member, and the measurement of the time interval between the application of an interrogating signal and the receipt of a return signal from the member, various physical properties of the member and structural information regarding same can be determined.

Abstract: An ultrasonic piezoelectric transducer and a method for measuring and/or monitoring various physical properties of a member, in-situ, are disclosed. The transducer includes a sleeve which is received in a blind bore provided in the member, a piezoelectric element positioned within the blind bore, and an aligning spacer means interposed between the end of the sleeve and the piezoelectric element. By the application of appropriate voltage pulses to the piezoelectric element causing interrogating signals to be applied to the member, and the measurement of the time interval between the application of an interrogating signal and the receipt of a return from the member, various physical properties of the member can be determined.

Abstract: An ultrasonic piezoelectric transducer and a method for measuring and/or monitoring various physical properties of a member, in-situ, are disclosed. The transducer includes a sleeve which is received in a blind bore provided in the member, a piezoelectric element positioned within the blind bore, and an aligning spacer means interposed between the end of the sleeve and the piezoelectric element. By the application of appropriate voltage pulses to the piezoelectric element causing interrogating signals to be applied to the member, and the measurement of the time interval between the application of an interrogating signal and the receipt of a return signal from the member, various physical properties of the member can be determined.

Abstract: An ultrasonic piezoelectric transducer and a method for measuring and/or monitoring the thickness of a wear member, in-situ, and the amount of wear that has occurred thereto, is disclosed. The transducer includes a sleeve which is received in a blind bore provided in the wear member, a piezoelectric element positioned within the blind bore, and an aligning spacer means interposed between the end of the sleeve and the piezoelectric element. By the application of appropriate voltage pulses to the piezoelectric element, the wall thickness between the bottom of the blind bore and the inner surface of the wear member can be measured.

Abstract: An induction motor operating system having a pulse width modulation operating system and a time domain signal generating system.The induction motor is operated from the time domain system to provide extremely large motor starting forces compared to the nominal motor force. Opposite ends of each of first, second and third motor windings are connected across a D.C. power supply and individual power supply. Waveforms are supplied to said respective motor windings during a predetermined brief interval. The first waveform, supplied to a first winding, is configured such that current initially flows through the first winding to establish a first magnetic field in the motor. The second and third waveforms are configured so that current is supplied to the second and third windings after establishment of the first magnetic field to establish second and third magnetic fields reacting with the first magnetic field to create a motive force acting on the moving element of the motor.