Abstract: An anvil for an ultrasonic textile slitting apparatus comprises an elongated, flat, substantially rectangular, housing in which a piston is disposed for motion relative to the housing. A mass dimensioned to act as a half wavelength resonator is coupled to the piston and is provided with a slitting implement for establishing responsive to fluid pressure acting upon the piston contact with an ultrasonic horn. The mass is dimensioned to be resonant at a frequency not lower than the resonant frequency of the ultrasonic horn and preferably is dimensioned to be resonant at a frequency somewhat higher than that of the horn. In a typical example, the horn has a resonant frequency of 20 kHz while the mass has a resonant frequency of 25 kHz.

Abstract: Thin plastic film is welded by ultrasonic energy by placing two layers of film upon one another on a supporting surface having a cavity. A source of ultrasonic energy, such as a resonator, is brought with its output surface in close proximity to, but non-contacting relation with, the exposed surface of the films for coupling ultrasonic energy via a thin air or gas column to the films at the area of the cavity. The dissipation of ultrasonic energy causes a weld and when the films are moved relative to the resonator output surface and supporting surfce, a seam weld is achieved.

Abstract: The invention concerns resonators of rectangular or blade like configuration providing substantially uniform motional output along the output surface. The improvement is achieved by disposing the change in cross-sectional area for producing increased motional amplitude at the output surface in relation to the nodal region of the resonator in such a manner as to cause the lateral portions of the resonator to exhibit a greater motional amplitude gain than that of the central portion.

Abstract: A conveyor system comprises a runway rail in the form of an extruded hollow body of oblong cross-section. The runway rail has a top portion which includes a pair of parallel surfaces including between them an angle. A similar pair of parallel surfaces is disposed at the bottom portion of the runway rail, which surfaces are parallel to respective surfaces of the top portion and include the same angle. A crab having load and guide wheels is disposed on the runway rail, the load wheels engaging the pair of surfaces at the top portion and at least one guide wheel engaging one of the surfaces at the bottom portion. A driving motor mounted to the lateral flange of the crab is adapted to drive the crab along the runway rail by engaging a stationary drive element mounted to a side rail of the runway rail. A hoist mounted to the crab serves to raise and lower work pieces.

Abstract: This invention discloses a method and apparatus for determining the hardness of a solid workpiece. An elongated rod is excited to be mechanically resonant along its longitudinal axis and is provided at its front end with a defined contact surface of hard material (Vickers diamond). When the rod is rendered resonant at its natural frequency of vibration .omega.o, the contact surface of the rod is pressed into the surface of the workpiece, whose hardness is to be determined, under a predetermined engagement force while the rod is forcibly maintained oscillating at the frequency .omega.o. A sensor coupled to the rod provides a signal indicative of the amplitude of vibrations of the rod when in forced contact with the workpiece and such signal is fed to a computing device for providing a value indicative of the hardness of the workpiece.

Abstract: This invention relates to a method and circuits for the generation and rapid adjustment of direct current voltages, such method and circuits being used particularly for the adjustment of amplifiers, and amplitude and time gates in ultrasonic test instruments. The voltage to be generated is selected by a selector switch and its value is increased or decreased by means of a set switch. For this purpose, the appropriate contents of storage locations of a read-write memory (RAM) are successively read out of the memory for setting the count of a binary counter. The count may be incremented, decremented or left unchanged according to the position of the set switch and of the selector switch. The binary counter contents are then written back into the appropriate storage location of the memory and converted by a digital-to-analog converter (DAC) to an analog value and stored temporarily by means of a capacitor.

Abstract: A fixture for use in conjunction with welding workpieces by vibration welding including a pin adapted to assume two states, namely a first state in which the pin is movable to seek an aperture in the workpiece and is free to enter such aperture, and a second state in which the pin is rigidly fixed. The pin is attached to a plate which responsive to fluid pressure is either free to float in a generally lateral direction, or is clamped rigidly between two superposed plates.

Abstract: An anvil for our ultrasonic textile slitting apparatus comprises an elongated, flat, substantially rectangular, housing in which two pistons are disposed for motion relative to one another along the longitudinal axis of the housing. A first piston, responsive to fluid pressure, is urged against the force exerted by springs into motion toward the second piston for causing the second piston, which is provided with a slitting implement, to be urged toward contact with the output surface of an ultrasonic horn. Further, springs are interposed between the first and the second piston for urging the pistons apart, but becoming compressed responsive to such fluid pressure. The combination of fluid pressure and springs causes the slitting implement to be kept in continuous contact with the horn despite the very high acceleration forces manifest at the horn output surface. In addition, the springs provide vibratory isolation from the vibratory energy of the horn.

Abstract: The method of joining two thermoplastic workpieces by ultrasonic energy along respective confronting surfaces includes providing one workpiece surface with an energy director while the opposing other workpiece surface contacted by the energy director exhibits a rough textured surface, rather than a conventional smooth surface, and an article manufactured according to such method.

Abstract: An ultrasonic cut and seal apparatus comprises a resonator having a removable tip which includes an inclined bore through which a filament is fed to the output surface of the resonator and upon the sheet material to be cut and sealed. The bore accurately guides the filament to the cut and seal region for causing the filament to be fused with the sheet material in the region adjoining the cut. The cutting and sealing is effected by the combination of an anvil exhibiting a cutting surface and at least one tapered sealing surface disposed opposite the output surface of the resonator when the sheet material is fed through the nip between the anvil and the resonant resonator.

Abstract: A method and apparatus for degating individual molded thermoplastic parts from runners use the combination of ultrasonic energy at a predetermined frequency and an anvil plate dimensioned to undergo flexural motion of a substantially large motional amplitude at a frequency less than that of the predetermined ultrasonic frequency for degating the parts from runners.

Abstract: An ultrasonic thickness gauge circuit includes a dual transducer probe and a logic circuit for providing square wave signals whose duration is equal to the time interval between the ultrasonic signal entering a workpiece to be measured and the reception of the ultrasonic signal reflected at the rear surface of the workpiece. When measuring thin wall thicknesses a measuring error arises due to the "V"-shaped transit path of the ultrasonic signals being greater than twice the wall thickness of the workpiece. A low-pass filter and a comparator are provided for modifying the square wave signals to effect correction. The modified signal is then used for providing clock pulses, the quantity of which is a measure of the wall thickness of the workpiece.

Abstract: An ultrasonic seal and cut method and apparatus comprises an ultrasonic sealing and cutting station which includes a horn adapted to be resonant at an ultrasonic frequency and an oppositely disposed anvil having a sealing surface and a cutting surface. As sheet material is passed through the station, the sheet material is cut and sealed in a marginal area adjacent to the cut. A substantially thermoplastic thread, either monofilament or multifilament, is fed together with the sheet material through the station in a position to cause the thread to fuse with the material in the marginal area. The provision of the thread permits the ultrasonic seal and cut method to be used for sheet material having a relatively low thermoplastic fiber content or exhibiting an open mesh weave, or being made of natural fibers.

Abstract: An automatic tuning circuit is provided for adjusting the frequency and phase of an oscillatory circuit in a power supply used for providing high frequency electrical energy to an electroacoustic converter. The oscillatory circuit includes an electrically variable inductance means in a feedback loop coupled between the output and an input of the oscillatory circuit and a switching device. The phase relationship of a signal indicative of the voltage across the switching device and a signal indicative of the state of the switching device and hence the current through the switching device is monitored. The inductance of the variable inductance means is adjusted responsive to the phase relationship of the signals indicative of voltage and current through the switching device for maintaining the two signals in phase during operation of the oscillatory circuit.

Abstract: An ultrasonic welding apparatus for providing a closure on plastic film bags wherein the end of the film bags is gathered, twisted or not twisted, and then welded to provide a hermetic seal, includes an anvil having a recess into which the gathered plastic material is placed for welding. The side of the recess is lined with low friction material, such as nylon or Teflon, to accomodate a sliding fit between the resonator and the anvil recess. Absent a close fit between the anvil side surface and the resonator side surface, bag material will escape into such space, thereby preventing a hermetic seal. The low friction material prevents destruction of the opposing surfaces subjected to high intensity vibrational forces.

Abstract: A resonant sensing device for measuring the hardness of a workpiece to be tested includes a diamond tipped rod adapted to be resonant and for determining the hardness of a workpiece to be tested is brought into forced contact with such workpiece. The difference in resonant frequency of the rod between its not-constrained condition and its constrained condition (forced contact) is a measure of the hardness of the workpiece. The present invention describes a circuit wherein during a first time interval an up/down counter accumulates the counts arising from the oscillations of the not-constrained rod. During the ensuing interval of the same duration, the counter counts down the accumulated count responsive to the oscillations of the constrained rod.

Abstract: The invention relates to a method for testing fuel element tubes by ultrasonic energy. For testing, each tube becomes disposed in the space between a transmit transducer and a receive transducer. The echo signals falling within a predetermined time interval are evaluated. Since the distance between the transducers may vary as the transducers move through the space between fuel element tubes, the transmitted signal reaching the receive transducer without passing through the tube may be confused with the revolving echo signal. Therefore, this invention discloses an arrangement for cyclically controlling the setting of the time gate before each such tube is in position between the transducers. To this end, the ultrasonic transit time of signals between the transmit transducer and the receive transducer is measured in the gap between the last tested tube and the next to be tested tube.

Abstract: An improved vapor degreaser apparatus includes means for selectively disposing a desiccator assembly within a conventional water separator for drying and removing excess water from a solvent.

Abstract: A circuit for adjusting the sweep time provided by a sweep generator used in an ultrasonic test instrument is described. The adjustment takes into account three test parameters, i.e. the angle of propagation of the sound in the workpiece, the speed of propagation of sound in the workpiece, and the thickness of the workpiece. To this end, the quartz-stabilized frequency of an oscillator comprising an adjustable frequency divider is divided by the angle function value of the angle of sound propagation to which the test instrument is set. The divided frequency is fed to a frequency multiplier in a phase locked loop circuit, comprising an adjustable frequency divider by means of which the speed of propagation of the sound is adjusted. A succeeding time reference stage contains also an adjustable frequency divider by means of which the workpiece thickness is adjusted.

Abstract: This invention relates to ultrasonic test instruments using wide-band test probes of different nominal frequencies fo and discloses an arrangement wherein each wide-band test probe of different nominal frequency fo is coupled in circuit with a receiving amplifier having a frequency response V(f). The frequency response of the receiving amplifier is so selected that the product H(f) comprising the spectral distribution S(f) of the transmitter and the frequency response V(f) of the receiving amplifier is substantially constant approximately up the the nominal frequency fo of the test probe and has its maximum value in that range. For the transmitters conventionally used in ultrasonic test instruments, in which the transmission pulse is generated by a capacitor discharge, the frequency response V(f) of the receiving amplifier should have a linear rise of 6 dB/octave up to approximately the frequency fo.