Abstract: A method of ultrasonic welding aluminum parts together includes placing the aluminum parts in an ultrasonic welding apparatus and contacting at least one of the aluminum parts with a horn tip of a weld horn of the ultrasonic welding apparatus. A weld amplitude is profiled during a weld cycle of the ultrasonic welding apparatus by producing a high weld amplitude above 55 ?m at the horn tip of the weld horn during an initial period of a weld cycle and producing a low weld amplitude below 55 ?m at the horn tip after the initial period.

Abstract: A laser imaging apparatus having a laser source outputting a laser beam and an electronic display device. The electronic display device is positioned downstream from the laser source. The electronic display device is operable to selectively polarize a discrete portion of the laser beam to define a modified portion and an unmodified portion. A polarizing filter is then positioned downstream from the display device so as to prevent passage of either the modified portion or the unmodified portion of the laser beam therethrough so as to define an imaging beam having a specific pattern.

Abstract: A laser imaging apparatus having a laser source outputting a laser beam and an electronic display device. The electronic display device is positioned downstream from the laser source. The electronic display device is operable to selectively polarize a discrete portion of the laser beam to define a modified portion and an unmodified portion. A polarizing filter is then positioned downstream from the display device so as to prevent passage of either the modified portion or the unmodified portion of the laser beam therethrough so as to define an imaging beam having a specific pattern.

Abstract: The present invention is directed to a method and apparatus using a light guide for directing a laser beam to a weld zone. The light guide includes an entrance end, an exit end and a flexible body therebetween. The entrance end of the light guide is operatively coupled to a laser source such as a diode and is adapted to receive and communicate the laser radiation through the light guide. The light guide is formed of a flexible material to permit the exit end of the light guide to be spaced from and aligned with complex two-dimensional and three-dimensional weld zone configurations. The internal reflection of the light guide contains the laser radiation therein as it passes from the entrance end and through the exit end of the light guide. The light guide and corresponding methods of welding parts permit laser welding of complex geometric configurations.

Abstract: The present invention is directed to a method and apparatus using a light guide for directing a laser beam to a weld zone. The light guide includes an entrance end, an exit end and a flexible body therebetween. The entrance end of the light guide is operatively coupled to a laser source such as a diode and is adapted to receive and communicate the laser radiation through the light guide. The light guide is formed of a flexible material to permit the exit end of the light guide to be spaced from and aligned with complex two-dimensional and three-dimensional weld zone configurations. The internal reflection of the light guide contains the laser radiation therein as it passes from the entrance end and through the exit end of the light guide. The light guide and corresponding methods of welding parts permit laser welding of complex geometric configurations.

Abstract: A laser diode array comprises a plurality of substantially parallel spaced metal plates, each plate having a laser diode mounted upon one side of the plate. The plates are supported electrically insulated from one another on mounting means. The diodes, connected electrically in series, when energized illuminate an oblong workpiece area disposed a certain distance opposite the array. In a preferred embodiment, the mounting means comprises flexible rod means passing through respective apertures of the plates, thus enabling the array to assume a curved configuration, thereby enabling the array to illuminate a straight as well as a curved oblong workpiece area.

Abstract: A filter for absorbing electromagnetic radiation which is used in heating a welding zone wherein a first part is joined to a second part. The filter includes a solid material for absorbing undesired wavelengths of radiation from a heating source before the radiation reaches the welding zone. The filter also has a housing which contains a chamber within which a fluid is placed. The fluid cools the solid material and also may absorb undesired wavelengths of radiation from the heating source before the radiation reaches the welding zone. A heat exchanger is connected to the filter in order to cool the fluid during the filtering process.

Abstract: A filter for absorbing electromagnetic radiation which is used in heating a welding zone wherein a first part is joined to a second part. The filter includes a solid material for absorbing undesired wavelengths of radiation from a heating source before the radiation reaches the welding zone. The filter also has a housing which contains a chamber within which a fluid is placed. The fluid cools the solid material and also may absorb undesired wavelengths of radiation from the heating source before the radiation reaches the welding zone. A heat exchanger is connected to the filter in order to cool the fluid during the filtering process.

Abstract: An ultrasonic processing method is disclosed wherein during the processing time interval the motional amplitude and engaging force of the resonating horn and thereby the power and engaging pressure to the workpiece is varied to improve weld strength and decrease weld cycle time. The variation in motional amplitude and engaging force may be in response to a process condition such as a change in dimensions of the workpiece, a sharp rise in the transducer power curve, or in response to the lapse of a predetermined time interval.

Abstract: A method of welding two thermoplastic workpieces (W) together along a predetermined weld line during a weld cycle utilizing a high frequency vibration sonic or ultrasonic welding apparatus. This welding apparatus includes an electroacoustic transducer (18) which transmits such vibrations to a horn (19) which is dimensioned to be resonant with the horn being brought into forced engagement with at least one of the workpieces to be welded. The method comprising the steps of bringing the workpieces into bearing relation against one another along the weld line. Then the electroacoustic transducer is energized so as to resonate the horn with a desired motional amplitude. Forceful contact is established between the horn and one of the workpieces. Then, the forceful contact between the horn and the one workpiece is maintained throughout the weld cycle. The motional amplitude of the horn is varied in accordance with a desired motional amplitude profile.

Abstract: For accurately determining, in real time, the collapse of a thermoplastic workpiece processed in a press, such as an ultrasonic welding apparatus or a vibration welding apparatus, a two-phase method is used. In the calibration phase signals are generated which are responsive to the yielding or displacement of the movable press portion relative to the substantially stationary portion arising from forced engagement of the workpiece within the press. The force responsive displacement value is stored.In the subsequent workpiece processing phase, when the workpiece collapses due to the softening and flowing of thermoplastic material as the workpiece is coupled to vibrations, the previously stored force responsive displacement value is recalled as a correction signal and subtracted from the newly obtained displacement signal related to the same force. The result of the subtraction is a true on-line signal indicative of the collapse of the workpiece as it occurs.

Abstract: An expert system for a welding machine has an installed knowledge base concerning weld problems and preferred solutions. Trial welds are made from which input data concerning weld quality is obtained. The expert system applies predetermined rules and historic confidence levels to determine changes in weld parameters to attempt to correct any weld defects.

Abstract: A method of welding two thermoplastic workpieces (W) together along a predetermined weld line during a weld cycle utilizing a high frequency vibration sonic or ultrasonic welding apparatus. This welding apparatus includes an electroacoustic transducer (18) which transmits such vibrations to a horn (19) which is dimensioned to be resonant with the horn being brought into forced engagement with at least one of the workpieces to be welded. The method comprising the steps of bringing the workpieces into bearing relation against one another along the weld line. Then the electroacoustic transducer is energized so as to resonate the horn with a desired motional amplitude. Forceful contact is established between the horn and one of the workpieces. Then, the forceful contact between the horn and the one workpiece is maintained throughout the weld cycle. The motional amplitude of the horn is varied in accordance with a desired motional amplitude profile.

Abstract: A process for obtaining long, continuous, thermoplastic welds on large structures. A series of tabs are used in pairs and especially in alternating, overlapping pairs to obtain resistance heating of a strip material placed in the bond line. The resistance of the tabs is less than that of the strip material. Conducting braid-tubes afford continuous welding when the bond line is curved. Alternatively, an electromagnetic field is used to take advantage of the induction heating. A wide susceptor is used to weld a current conducting substrate while avoiding bulk heating of the substrate. The unexpected property of current-conducting braid-tube susceptors, in which induction heating takes place at the center rather than at the edges of a flattened braid-tube susceptor, is used to obtain long continuous curved welds.