Abstract: The invention concerns an ultrasonic test probe for use in connection with testing workpieces wherein the angle of propagation of the ultrasonic search beam is adjustable. The probe comprises a linear array of ultrasonic transducer elements and a plastic wedge. An acoustic lens disposed between the array and the wedge causes the individual ultrasonic beams to come to a focus at an acoustic energy exit aperture of the probe. The angle adjustment of the ultrasonic beams is accomplished by energizing in-phase a respective group of transducer elements forming the array.

Abstract: A programmable ultrasonic thickness and acoustic velocity measuring instrument is provided which includes automatic zeroing (calibrating) means, automatic temperature compensation and high temperature warning means, automatic probe identification means, means for automatically correcting the measurement readings for probe characteristics, means for storing and displaying of the minimum wall thickness during a predetermined time interval, and means for providing a display indicative of the difference between a measured thickness and a preprogrammed value.

Abstract: An ultrasonic test instrument includes a pulse generator, a receiver, a cathode ray tube screen display and a time gate means providing a gated time interval for viewing only echo signals which arise from a predetermined workpiece region under test. The time gated interval is shown as a horizontal gate bar display on the screen and the length of the bar being indicative of the gated time interval. Circuitry provided generates a reference signal to cause the gate bar to appear at a height commensurate with the echo signal received in the gated intervals having the highest peak amplitude. Unless reset, the amplitude of the gate bar remains at this peak value although subsequent echo signals may have a lower amplitude.

Abstract: A method for sealing the neck of a thermoplastic container to a thermoplastic cap superposed upon the neck and the cap having a lateral edge extending beyond the periphery of the neck using an ultrasonic welding apparatus includes an ultrasonic resonator having a domical internal cavity in its output end for reshaping the lateral edge of the cap in order to form a peripheral bead along the interface between the cap and the neck of the container.

Abstract: An ultrasonic test probe comprises a transducer and an electrical circuit, particularly means for generating the high voltage transmit pulse to the transducer, all disposed within the probe housing. The high voltage transmit pulse is produced by current flow through an electrical inductor. Other circuit components are also arranged within the probe housing.

Abstract: In an apparatus for receiving ultrasonic waves by optical means a laser beam illuminates a workpiece surface at which ultrasonic waves are manifest in the form of cyclically occurring surface deformations. The reflected light is transmitted to an optical interferometer as a measuring light beam and the beam exiting from the interferometer is converted to an electrical signal and amplified to provide a measuring beam responsive electrical signal. A portion of the laser beam immediately before being incident on the workpiece surface is also passed through the interferometer as a comparison beam. The exiting comparison beam light is converted to an electrical signal, amplified and time delayed to provide a comparison beam responsive electrical signal. By means of a subtracting circuit the comparison beam responsive electrical signal is subtracted from the measuring beam responsive electrical signal to provide a difference signal which is evaluated.

Abstract: A flexible cover, blind or shade is fabricated from thermoplastic rod or tubular members which are spaced from another on a support. The free-standing side is engaged by an ultrasonic resonator to bond the members to one another. The pressure exerted during bonding is of such magnitude as to compress and flatten the members to cause a thin web joining juxtaposed members, the web forming a flexible joint.

Abstract: An apparatus for sensing the acoustic energy responsive deformation of a workpiece surface by optical means, that is without physical contact with the workpiece surface, comprises the use of a laser light beam illuminating the workpiece surface portion along which the acoustic energy responsive deformation is manifest. The laser light incident upon the workpiece surface is reflected at the workpiece surface and, modulated responsive to the surface deflection, is transmitted to an optical phase interferometer and to a photoelectric means associated therewith. The output from the photoelectric means is transmitted to an evaluation unit. The improvement shown in this invention concerns means for maintaining the reflected light intensity at a predetermined level by comparing the reflected light intensity with a preset level and feeding a control signal to a light control means controlling the laser light intensity incident upon the workpiece surface.

Abstract: Laser light for producing acoustic waves in a specimen to be examined is carried to the specimen from a single laser by a plurality of fiber optic cables. The fiber optic cables have different path lengths to cause a specific time delay between adjacent fiber optic cables to focus and steer the sonic waves in a desired direction.

Abstract: An apparatus for maintaining the adjustment of coincidence and relative phase relationship of light beams in an optical interferometer comprises the passing of a measuring light beam and of a control beam through substantially the same paths of the interferometer. Any change in optical alignment of interferometer components from a set condition is manifest as a change of the electrical signal produced by photoelectric sensing means which receive the control beam. The change of the electrical signal is processed by an electrical circuit and fed to one or more positioning means supporting an optical component of the interferometer for causing a repositioning of such component to thereby restore the set condition. In a typical embodiment, the component is a reflective surface mounted on a set of piezoelectric positioning means.

Abstract: A method of friction welding thermoplastic materials, such as a reinforcing plate to the inner surfaces of oppositely disposed legs of a generally U-shaped workpiece, wherein a flexible force applying means applies a force in a direction normal to the direction of relative motion between the parts but in the plane of the mating surfaces for urging the legs of the U-channel into intimate contact with the edges of the reinforcing plate. During a weld time interval the parts undergo relative linear reciprocating motion while being urged in intimate contact by the flexible force applying means which causes the mating surfaces to soften under the influence of friction. After the weld interval, the parts are returned to their original position and are held in forced contact for a time sufficient for the mating surfaces to solidify. Upon solidification the force ceases and the welded parts are removed from the apparatus.

Abstract: The results of the non-destructive testing of objects with a beam of ultrasonic energy is enhanced by generating display control signals commensurate with a precisely defined region in the test object. These region related signals may be displayed as a "gate" bar on the screen of a cathode ray tube simultaneously with the display of echo related signals. Echo related signals having a magnitude greater than a threshold level, as also defined by the "gate" bar, are detected and may be employed to energize an alarm.

Abstract: An ultrasonic transducer probe for testing workpieces exhibiting compound surfaces includes a molded plastic body which precisely fits to the shape of such workpiece surfaces. Moreover, the body includes, as an integral part thereof, an indexing portion for accurately locating the transducer probe in relation to a predetermined workpiece test area to cause the transducer element embedded in the molded body to transmit ultrasonic energy in the predetermined test area. The transducer probe is secured to a manipulator for remote operation.

Abstract: This invention relates to resonators as used in sonic or ultrasonic apparatus. Particularly with bar type resonators there is manifest a reduction of vibrational amplitude at the output surface from the central area toward the lateral edges. In the present arrangement the input surface is provided with pads to increase the mass ratio between the input and output sections for effecting substantially uniform motional amplitude along the entire output surface.

Abstract: A method and apparatus for determining by the pulse-echo method the acoustic velocity of a workpiece of known thickness utilize measurement of the transit time of the first rear wall echo signal and that of the second rear wall echo signal. The two transit times are then processed in a microprocessor which also controls the entire measuring cycle. For accurate measurement the transit time is defined as the time interval from the leading edge of the trigger pulse, which triggers the transmit pulse generator, to the time at which the respective echo signal exceeds a preset threshold amplitude.

Abstract: A friction welding apparatus for joining thermoplastic materials, such as a reinforcing plate to the inner surfaces of oppositely disposed legs of a generally U-shaped workpiece, includes flexible force applying means for applying a force in a direction normal to the direction of relative motion between the parts but in the plane of the mating surfaces for urging the legs of the U-channel into intimate contact with the edges of the reinforcing plate. During a weld time interval the parts undergo relative linear reciprocating motion while being urged in intimate contact by the flexible force applying means which causes the mating surfaces to soften under the influence of friction. After the weld interval, the parts are returned to their original position and are held in forced contact for a time sufficient for the mating surfaces to solidify. Upon solidification the force ceases and the welded parts are removed from the apparatus.

Abstract: A method for closing an open end of a thermoplastic tube by applying ultrasonic energy to the end in a direction normal to the longitudinal axis of the tube. A horn adapted to undergo ultrasonic vibrations is provided and includes an open cavity disposed substantially at an antinodal region of longitudinal motion of the horn and oriented normal to the direction of longitudinal motion of the horn. The horn is rendered resonant along its longitudinal axis while the open end concomitantly is urged into the cavity in a direction normal to the direction of longitudinal motion of the horn thereby forming the end to the shape of the cavity.

Abstract: A power measuring arrangement is incorporated in a vibration welder at the area of welding workpieces. The arrangement comprises force and velocity sensing means, each providing respective electrical output signals which are multiplied to provide an output signal of the actual power available at the weld plane.

Abstract: When sensing the presence of ultrasonic energy in a workpiece portion by illuminating such portion with light from a single-mode frequency stabilized laser, the reflected light, frequency modulated by the Doppler effect due to the ultrasonic energy induced deflection of the workpiece portion, is passed through a gas filled light filter. The frequency modulated light is amplitude modulated by the filter by selecting the frequency of the laser to cause a point of operation which is located along a steep slope portion of the absorption curve characteristic of the filter. To increase the steepness of the slope portion of the filter, the present invention discloses the use of laser light to saturate the filter in a part region.