Abstract: A vapor degreaser continually vaporizes and condenses a solvent bath and comprises two closed water loops associated with a refrigeration system. The water loops provide thermal storage for the degreaser and conduct heat to the solvent bath for heating the solvent and from the solvent vapors for condensing the vapors. The degreaser includes auxiliary heating and cooling coils which may be rendered totally inoperative when their operation is not energy efficient.

Abstract: An ultrasonic test apparatus for testing tubes or rods by rotating transducers to provide a helical scan, the test transducer, or each of a plurality of transducers, is mounted for adjustable motion along an axis which is inclined by an angle .omega. with respect to a perpendicular axis intersecting the workpiece surface. The angle .omega. is selected to provide a desired incident angle .alpha. of the ultrasonic energy upon the workpiece surface, whereby to cause a refracted angle .beta. of the ultrasonic energy. Within the range of measuring accuracy for small angles it can be assumed that angle .omega. approximates angle .alpha..

Abstract: The acoustic energy responsive deformation of a workpiece surface is sensed in a contact-free manner by optical means using a laser which illuminates the surface at which deformation is expected. The reflection light energy is transmitted to an optical interferometer as previously shown in the art. The present improvement comprises the use of a multi-wavelength laser beam light and separating the light after passing through the interferometer into the distinct wavelengths. Each light signal corresponding to a specific wavelength is converted individually to an electrical signal, each electrical signal is rectified, and the plurality of rectified signals are then averaged in an electrical summing means.

Abstract: A corner is formed in corrugated thermoplastic material or board using ultrasonic vibrations by disposing the corrugated material between an anvil and a half wavelength resonator having a portion of its frontal surface shaped for producing a crease. Contact is provided between the shaped portion of the resonator frontal surface and the material so as to crush the material. The resonator is rendered resonant for causing the material in contact with the resonator frontal surface to soften and flow. After a sufficient period of time, usually a fraction of a second, the frontal surface is withdrawn from contact with the material. When the softened and flowing material solidifies a crease is manifest in the material which then is folded to form a corner.

Abstract: In an ultrasonic pulse-echo test measuring or gaging system wherein a workpiece is coupled to the ultrasonic transducer by a liquid coupling medium, the temperature of the liquid affects precise measurement of the workpiece as the acoustic velocity of a liquid changes with temperature. To compensate for the change of acoustic velocity during measurement periodically a search pulse is transmitted along its normal path over a calibrated fixed distance. The resulting transit time value is converted to a distance value and compared witht the calibrated distance value. Any difference in the values updates a compensation factor which subsequently is used in the test system. Periodic updating may be set to occur, for example, every one-half second.

Abstract: A horn for operation in the sonic or ultrasonic frequency range and made preferably from aluminum or titanium is provided at its lateral surface with a soft metallic coating which acts as a cushion and/or lubricant when the horn accidentally contacts a juxtaposed horn or mechanical fixture. The soft metallic coating in the described embodiment comprises an alloy of tin and lead which is applied over the nickel plated horn surface.

Abstract: A method of producing a corner in thermoplastic flexible channel material having a base portion and at least one leg comprises flattening the leg portion outwardly while folding the material with a "U" bend upon itself to provide an overlapped base and leg portion. Ultrasonic energy is applied to the overlapped flattened leg portion for simultaneously sealing and cutting the overlapped leg portion at an oblique angle to the longitudinal axis of the channel material. Upon releasing the channel material, the material is restored to its original shape, but exhibiting a formed corner.

Abstract: An acoustic lens having nonuniform cross sectional thickness is disposed in the path of an ultrasonic energy search beam traveling from a transducer probe to an object to be examined. In an alternative embodiment the lens has at least one contoured surface. As the lens undergoes motion in a plane substantially normal to the direction of the search beam, the search beam exhibits a varying focal zone depth and beam path for providing real time ultrasonic scanning of the examined object.

Abstract: A method and apparatus are provided for converting into digital form the analog ultrasonic echo signals received as a result of cyclically transmitted ultrasonic search signals intercepting an acoustic discontinuity in a workpiece. The ultrasonic echo signals are divided into a discrete number of raster-like scan lines which are scanned electronically by a microprocessor. Digital signals are generated for each line of the raster-like scan and such signals assume either a first or second state along the scan line in accordance with the signal amplitude along that line. As successive scans are made at progressively higher amplitudes of the echo signal, the amplitude required for varying the digital signal between the states for a particular scan line is incrementally increased with each scan line. A comparator receives at a first input the echo signals and at a second input a signal from a digital-to-analog converter whose output is incrementally increased on successive scan lines by the microprocessor.

Abstract: This invention relates to an interferometric laser method and apparatus for sensing the acoustic wave responsive deformation of a workpiece surface. A laser provides a coherent beam of light which after reflection at the workpiece surface is split into a first measuring beam portion and a second reference beam portion, the latter portion being delayed by being transmitted over a long delay path. The optical length of the delay path is dimensioned to be a multiple integer of the optical length of the resonator of the laser.

Abstract: A delicate workpiece, such as a semiconductor wafer is cleaned by supporting the workpiece on a shaft which is rotated. A film of liquid solvent is caused to continuously flow across the exposed workpiece surface while the workpiece is in rotation and ultrasonic energy is applied to the liquid film for causing cavitation in the solvent, thereby effecting cleaning of the workpiece surface. Upon shutting off the solvent and the ultrasonic energy, the workpiece is dried by spinning it at high speed.

Abstract: Focussed acoustic waves are generated free of physical contact in a light absorbing workpiece by the use of laser beam means providing a coherent light beam which in a pulsed manner impinges upon the surface of the workpiece in a Fresnel zone pattern. The zoned pattern is caused in a typical example by a suitable mask interposed between the laser source and workpiece surface. The thermal effect responsive to the laser beam energy produces in the workpiece a plurality of acoustic waves having a common focal point.

Abstract: Metallic workpieces, such as the terminals of a direct current motor armature winding, are welded to a slot, such as a commutator slot, using high frequency vibratory energy. A half wavelength resonator including a tip having a cutting surface is disposed opposite a slot containing the workpieces. As an applied force urges the tip into relative motion with respect to the slot, the cutting surface cleaves a sliver from the slot wall, the sliver being urged by the tip into intimate contact with the workpieces to be welded. When the resonator is rendered resonant for undergoing high frequency vibratory motion in a direction normal to the applied force the sliver and workpieces are welded together and to a surface of the slot.

Abstract: A method and apparatus for producing on the surface of a workpiece free of contact with a source of energy a pulse shaped ultrasonic shock wave comprise the use of laser means. A plurality of strip-shaped equidistantly spaced surface portions of the workpiece are pulsed with coherent light from the laser means in time delayed sequence. The angle of propagation of the ultrasonic wave is determined by the center-to-center distance between the strip-shaped surface portions illuminated with coherent light, the time delay between the light pulses and the velocity of propagation of the ultrasonic wave in the workpiece.

Abstract: In order to stabilize the acoustic wave amplitude in a workpiece, where such acoustic wave is generated by a laser beam pulse transmitted upon the workpiece surface, laser pulses preceding the laser pulse used for acoustic evaluation are utilized to clean the workpiece surface from contamination. Cleaning of the workpiece surface to the bare metal provides a normalized surface condition in respect to absorbed pulsed laser beam energy and, hence, produces acoustic waves of substantially constant amplitude. Either the same laser producing the acoustic wave or a separate laser is used for vaporizing contamination at the workpiece surface where an acoustic wave is subsequently to be produced.

Abstract: A clock circuit comprising a synchronizable voltage controlled oscillator in combination with a programmable address means, which address means is adjusted commensurate with the acoustic velocity of the workpiece, provides clock pulses from the oscillator having a stable and accurate acoustic velocity dependent frequency. An entrant surface responsive electrical signal responsive to an ultrasonic search signal entering the workpiece is also provided to the clock circuit for assuring that the clock pulses are synchronized with the receipt of the electrical signal.

Abstract: A receiver probe for ultrasonic energy is described in which the surface deformation caused by compressive wave energy affects a thin gas-filled gap, its width being in the order of 10.sup.-7 meter. The gap is formed by opposing surfaces of an optical prism and an optical interference means. A beam of light is conducted to the boundary surface between the prism and gas. Changes in reflected and/or transmitted light beam portions resulting from compressive wave energy induced changes in gap width are sensed by opto-electric means.

Abstract: Ultrasonic waves present on the surface of a workpiece are received contact-free by an optical sensing arrangement which includes a frequency stabilized single mode laser which illuminates the vibrating surface portion. Reflected light from the illuminated portion, which light is frequency modulated by the Doppler effect of the ultrasonic wave, is collected by a lens and applied to a narrow band absorption light filter. The frequency of the laser and the filter are selected to cause the center frequency of the light to fall at a point along the steepest slope of the filter absorption curve. The change in light frequency causes a corresponding change in light intensity passing through the light filter and the filtered light, now amplitude modulated, is provided to photoelectric means. A feedback circuit maintains the frequency of the laser constant.

Abstract: A real-time ultrasonic imaging system includes a display which is compensated for the non-ideal characteristics of the search beam profile. Echo responsive electrical signals are provided to a preprogrammed computing means for being processed to compensate for the characteristics of the test probe. The processed signals are displayed as being in focus at all distances from the probe, thereby resulting in an image exhibiting improved resolution.