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: 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 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: 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: 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: 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 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: A method for securing a thermoplastic part to another part by applying ultrasonic energy to a projection of the thermoplastic part in a direction substantially normal to the longitudinal axis of the projection. The exposed end of the projection is urged into an open cavity disposed in a side wall of a horn adapted to undergo ultrasonic vibrations. The cavity further is 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 exposed end concomitantly is urged into the cavity.

Abstract: An ultrasonic half-wavelength resonator characterized by an input surface and an output surface both being disposed at antinodal regions of the longitudinal vibratory energy travelling through the resonator and a medially disposed nodal region is provided with a plurality of slots disposed in the resonator extending from a region near the input surface to a region near the output surface and passing through the nodal region. The slots being angled relative to the longitudinal axis of the resonator from the input surface to the output surface to provide substantially uniform motion along the output surface of the resonator.

Abstract: An ultrasonic seaming method and apparatus for continuously bonding thermoplastic material are disclosed. A movable anvil is disposed opposite the output end of a horn for providing a gap through which the thermoplastic material is conveyed. The anvil cyclically is moved away from the face of the horn and immediately thereafter is urged under slight adjustable pressure against the underside of the material and then is clamped in position for a predetermined period of time or an amount of material feed.

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: 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: 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 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: 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 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: The invention refers to a method of joining two non-fusible workpieces using frictional energy. A first workpiece having a higher melting temperature is provided with a recess extending from the mating surface of the workpiece into the interior thereof. The recess is shaped for trapping material. A static force applied in a direction normal to the mating surfaces of the workpieces to be joined urges the first workpiece into intimate contact with a second workpiece having a lower melting temperature. The workpieces are subjected to relative motion in the plane of the mating surface for causing frictional energy and a softening of the second workpiece. The softened material flows into the recess and solidifies upon cessation of the relative motion. The workpieces are thus joined by virtue of the solidified material trapped in the recess.