Abstract: An improved fusion welding system having a perforating device and a heating combination is adapted for welding in tandem a set of adjacent overlapping workpieces. The system preferably includes a first laser that perforates the workpieces to produce an opening spaced from the edges; and the combination preferably includes a second laser and electrode for cooperatively melting fusible material into the opening.

Abstract: Methods for measuring laser light transmissivity of a specific position in a work piece prior to the work piece undergoing laser welding at the specific position with a laser beam having a specific welding wavelength. To obtain a baseline measurement reading, a laser light source projects a laser beam at the welding wavelength directly into a detector. Thereafter, the work piece becomes suspended between the laser light source and detector whereby an output of the detector now corresponds to a work piece measurement reading. Differences between the two readings reveal whether the work piece will yield a satisfactory weld at the specific position when later welded by a laser beam at the welding wavelength. Preferred work pieces include inkjet printhead lids and bodies.

Abstract: Laser welding apparatus, in which a laser beam is impinged upon a component to be welded at a laser beam impingement point, wherein a plasma suppressor is arranged to impinge a jet of gas on the component at an angle to its surface, flowing towards the laser beam impingement point.

Abstract: To precisely measure bead cutting shapes of electric resistance welded pipes without being affected by difference in luminance level between cut and uncut portions in optical cutting images, an image is obtained by overlaying an optical cutting image with the optical cutting image subjected to thinning processing. A profile of the welded pipe is approximated with a quadratic function and a region containing the bead apex coordinates is identified as the bead. Shape data of the pipe surface at the portion corresponding to the bead portion is obtained from the preset left and right boundaries of the bead portion and the apex position of the separately-calculated bead portion, and bead width, height, slope angle, and unevenness at the left and right boundaries between the bead portion and base pipe portion, are each calculated, based on the left and right bead shape approximation functions and base pipe shape approximation function.

Abstract: A honeycomb body, which is composed in such a manner that a strip of corrugated foil made of heat-resistant stainless steel containing aluminum and a strip of flat foil made of stainless steel are alternately wound or laminated on each other, is incorporated into an outer cylinder made of metal and integrated into one body by means of diffusion bonding, so that a diffusion bonded metallic catalyst carrier can be formed. Surface roughness of the strip of foil after the completion of diffusion bonding is 0.001 to 2.0 ?m when it is expressed by center line average height Ra, and no sintered bridges are formed at both end portions of the diffusion bonded section in the longitudinal direction. The catalyst carrier is manufactured in a condition so that ?b, which is defined by ?b=6.

Abstract: In a method and system to provide high intensity photic stimulation to disable target subjects, a high intensity light source is activated by trigger signals to produce light flashes in commanded patterns of duration and frequency. A user views a field illuminated through a shutter viewer such as shutter goggles. The goggles are gated to a light blocking state in response to trigger pulses. The light blocking state has a wider time width than the light flashes from the light source produced in response to the trigger pulses to avoid the need for close synchronization. The target subjects are exposed to the high intensity light flashes while the light flashes are blocked from the view of users. Due to a low duty cycle, the users' view through the shutter goggles is unaffected by the intermittent opacity of the shutter goggles.

Abstract: In a first embodiment a spark plug satisfying the relations: t?0.3 mm and St/Sw?7 in which t is the axial-direction shortest distance between a leading end surface 41a of a precious metal tip 41 and a joint portion 43, St is the surface area of the precious metal tip 41 and a joint portion 43 between the precious metal tip 41 and the ground electrode body 4a, and Sw is the area of the joint portion 43 between the ground electrode body 4a and the precious metal tip 41. In a second embodiment, the spark plug satisfies the relations t?0.3 mm and La>Lb; and in a third embodiment the spark plug satisfies the relations t>T and La>Lb, where T, La and Lb are as defined in the specification. The relation t?0.3 mm is specific to the first and second embodiments, and the relation St/Sw?7 is specific to the first embodiment only.

Abstract: An apparatus for formation of a three dimensional object comprising a sealed container; an electron beam subsystem capable of directing energy within said container; a positioning subsystem contained within said container; a wire feed subsystem contained within said container; an instrumentation subsystem electronically connected to said electron beam subsystem, positioning subsystem, and wire feed subsystem; and a power distribution subsystem electrically connected to said electron beam subsystem, positioning subsystem, wire feed subsystem, and said instrumentation subsystem.

Abstract: Provided are a solder ball bonding method and a solder ball bonding device for performing bonding of a plurality of electrode portions formed on objects to be bonded by melting solder balls. The solder balls are suctioned by using a plurality of suction nozzles that follow the electrode portions of the objects to be bonded, and conveyed onto the electrode portions. A laser irradiation portion that is positioned above the suction nozzles is then moved in a direction along which the suction nozzles are arranged, while the solder balls are irradiated with laser light passing through suction openings of the suction nozzles by using the laser irradiation portion. Accordingly, it is possible to melt the plurality of solder balls on the electrode portions by using only a single laser irradiation portion.

Abstract: Apparatus and methods for thermally processing a substrate with scanned laser radiation are disclosed. The apparatus includes a continuous radiation source and an optical system that forms an image on a substrate. The image is scanned relative to the substrate surface so that each point in the process region receives a pulse of radiation sufficient to thermally process the region.

Abstract: A method of improving weld quality between aluminum members by slowing the rate of solidification of a molten weld trough into solidified material. Upper and lower aluminum members are positioned together in contact between facing surfaces thereof to expose a first outer surface of the upper aluminum member to laser irradiation. A welding laser beam is moved in a path over the first outer surface, wherein the welding laser beam has an energy and width to progressively melt a trough of molten metal to a depth through the upper aluminum member and into the lower aluminum member. The molten metal in the trough has a void filled with gas, and the molten metal re-solidifies into re-solidified metal after the passage of the welding laser beam. An area in and around the trough is heated to slow the rate of solidification of the molten metal into the re-solidified metal, thereby preventing entrainment of the gas within the re-solidified metal.

Abstract: A material for welding 5 having a region 11 in which welding such as laser welding or arc welding is performed, the region including indentations 5a-1 which are produced by carrying out a first working step comprising embossing, V-bending, U-bending, L-bending, drawing, stepped drawing, or a combination of these to form a curved portion 5a in the material being worked, and a second working step which is press working which crushes the curved portion 5a which is formed by the first working step. The indentations 5a-1 have a protruded portion 11a which projects from a flat surface which forms the surface of the material being worked 5, and a recessed portion 11b which is formed on the inside of the protruded portion 11. Indentations 5a-1 are provided in the form of at least two separated dots so as to be generally parallel to the predicted welding position and are arranged on the expected welding position.

Abstract: An aluminum alloy filler material for use in welding of metal members including at least one aluminum die-cast member containing Mg includes an aluminum or an aluminum alloy as base material and Al—K—F series flux. The Al—K—F series flux is contained by 2 to 4 mass % with respect to the entire filler material.

Abstract: A method for making a high-power fused collimator, and a fused collimator made thereby, are provided. A fused collimator is provided that includes an end of a stripped end portion of an optical fiber fused to a proximal face of a silica lens. In an embodiment, a toroidal element is positioned in surrounding relation to the fiber's stripped end portion, and a joint formed by the fiber end and the toroidal element proximal face is substantially surrounded with a solder glass in a melted form. A cross-sectional area of the solder glass decreases proximally from a distal edge adjacent the lens to a proximal edge located along the fiber's stripped end portion. Then the solder glass is permitted to harden, forming a fused collimator.

Abstract: The present invention provides a joining method using a method of laser welding wherein two resin molded bodies can be joined with high welding strength. Specifically, this is a method that joins two thermoplastic resin molded bodies using a method of laser welding; the first resin molded body is a laser light transmissive molded body comprising a thermoplastic resin and cellulose fibers with an ?-cellulose content of 80% or more; the second resin molded body is a laser light absorbent molded body containing a thermoplastic resin and a colorant; and the first resin molded body and the second resin molded body are welded by irradiating laser light from the first resin molded body side.

Abstract: A laser weld monitoring system capable of assessing a weld quality of welding using a pulsed laser is provided. The system includes at least one sensor capable of capturing a weld characteristic of welding using said pulsed laser. The weld characteristic has multiple attributes. The system also includes data acquisition and processing equipment adapted for storing and analyzing the weld characteristic. A user first performs multiple welds to capture at least one weld characteristic for each weld. The user then determines the weld quality of each weld, and runs at least one of a library of algorithms associated with the attributes on said at least one weld characteristic for each weld to generate a single value output for the associated attribute. The user selects an attribute indicative of the weld quality by correlating the single value outputs of said at least one algorithm with the weld qualities of the welds.

Abstract: Method for producing an electrical connector connecting between a first and a second mating contact partner, wherein at least one contact partner is surrounded by a plug housing. The first and the second contact partners are lead with latching means together to form a plug-in electrical connection in the plug housing. Laser-welding is applied to the first and the second contact partners to make the connection an integral, non-detachable connection, by directing a laser beam through a single opening in the plug housing.

Abstract: A head suspension for a disk drive has a base plate (19) to be attached to a carriage of the disk drive and a load beam (21) consisting of a rigid part (27) and a resilient part (29), to apply load onto a slider. The rigid part and resilient part are separately formed. The rigid part is joined to a first side (29a) of the resilient part. The suspension also has a reinforcing plate (37) to hold and fix a second side (29b) of the resilient part between the reinforcing plate and the base plate. The base plate stably and resiliently supports the load beam. This suspension satisfies required characteristics.

Abstract: A hand-held laser-welding wand includes a gas lens assembly that develops an inert gas atmosphere around a weld pool. The lens assembly additionally reflects laser light and thermal radiation that is reflected off a work piece surface away from the hand of a user of the hand-held laser welding wand.

Abstract: The invention is directed to a beam-shaping unit for generating a beam bundle which is focused in a punctiform manner, propagates in a ring shape, and has a radiationless central area, comprising a focusing lens, a first axicon and a second axicon, and to an arrangement with a beam-shaping unit of this kind for introducing radiation energy into a workpiece comprising weakly absorbent material which is arranged between a first resonator mirror and a second resonator mirror. The first resonator mirror which is arranged in front of the workpiece in the radiating direction is located in the radiationless central area. The radiation energy can be absorbed to the maximum extent by repeatedly passing through the same interaction volume in the workpiece.

Abstract: A method and apparatus for manufacturing a spark plug which avoids depth insufficiency of the weld metal portion or thickness insufficiency of the spark portion and which thus enhances the weld strength and service life of the spark portion. According to the method, a noble metal chip is attached to a chip joint face formed on a distal end of a center electrode of a spark plug workpiece, along the direction of the longitudinal axis of the workpiece, so as to form a chip-attached assembly. The chip-attached assembly is irradiated with a laser beam LB so as to form a laser-beam weld metal portion intruding into the noble metal chip and into the chip joint face, thereby forming a noble-metal spark portion having a discharge face.

Abstract: An apparatus for processing workpieces by relative displacement of a plurality of simultaneously operating functional elements in relation to the workpieces being worked on is provided. The present apparatus includes a device for the mounting of the functional elements, characterized in that the device has apparatus for keeping the functional elements constantly in their operative position in relation to their workpiece section presently to be processed on the processing path by altering their position during a relative displacement with any desired change of direction. A method for tracing a processing path is also provided. The method includes tracing a processing path by a plurality of functional units arranged in succession one behind another in the path direction and moved along the path. The functional units are aligned on the path independently of each other by positioning means individually assigned to them.

Abstract: A sensor pre-load and welding apparatus and method are disclosed. A weld fixture apparatus includes a fixture base upon which a sensor package having a sensor base and a sensor cover is located, and a load bar associated with a spring, wherein the load bar provides a specific weight to the fixture base in order to assist in maintaining the sensor cover and the sensor base parallel to one another upon the fixture base. An adjustable load foot is generally located above the fixture base, such that the adjustable load foot applies a pre-determined load with a specific weight to the sensor base in order to maintain the sensor cover and the sensor base securely in place as the sensor base and the sensor cover are welded to one another in order to configure the sensor package.

Abstract: A method of affixing head suspension components to one another using an edge weld formed at the edge of one head suspension assembly component positioned in an overlapping fashion relative to another head suspension assembly component, and an apparatus assembled by the method.

Abstract: A method and a device for the longitudinal welding of profiles (2,5, 13) is provided in which a profile (13) that is to be provided with a weld seam (22, 23) is guided through a welding device (1), and in the welding device (1) a welding head (14, 15) produces a weld point (20, 21) on the profile (13), in order to manufacture a weld seam (22, 23). The profile movement is braked at selectable intervals from an essentially constant production speed down to the point at which the profile (13) is at a standstill, and is subsequently accelerated back to the production speed, while the application of welding energy to the profile (13) is switched off below a threshold transport speed.

Abstract: Disclosed herein is a laser welding system having a travel path to carry a first blank and a second blank. An upstream clamp assembly and a downstream clamp assembly are positioned on the travel path and each of the upstream and downstream clamp assemblies are movable to an open position to allow the first blank to pass through the upstream clamp assembly to a first location within the downstream clamp assembly. A laser welding source is directed at a weld location on the travel path between the upstream and downstream clamp assemblies. At least one locating means is operable to locate the first weld edge adjacent the weld location. A first displacement means displaces the first weld edge against the locating means. The downstream clamp assembly is movable from the open position to a closed clamped position to clamp the first blank with the first weld edge adjacent the weld location. The locating means is operable to be withdrawn from the travel path.

Abstract: A wire bonder 50 in which light rays 66 that leave an object on a carrying stand 60 pass through a light path 80 that passes through a parallel flat plate and reach an imaging camera 70 as light rays 68. The light path 80 that passes through a parallel flat plate includes a half-mirror 82 disposed in the light path, a parallel flat plate 86, and a reflective mirror 88 which is disposed perpendicular to the optical axis of the light rays 96 that have passed through the parallel flat plate 86 and which performs a mirror reflection operation, in a plane perpendicular to the optical axis, on the light rays 96, so that the light rays again return to the parallel flat plate 86 as reflected light 98.

Abstract: A powder delivery system for a laser-based additive manufacturing process includes a hopper adapted to contain a powder and continuously feed the powder through an output of the hopper, a rotatable disk having a top surface that is substantially flat, the top surface adapted to receive the powder continuously fed through the output of the hopper, the top surface being disposed below the output of the hopper by a prescribed gap, and a vacuum powder removal device operable to remove the powder from the top surface via a vacuum.

Abstract: Binary gas mixture for welding using a laser beam of up to 12 kW, consisting of 30% to 60% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

Abstract: The invention provides a welding device (10) using a power laser beam (22), the device (10) being miniaturized, the device (10) being suitable for being moved very close to the surface (52a) of the part (52) to be welded and of reaching welding zones that are difficult to access, but without vapor and particles of molten metal (56) being capable of penetrating into the inside and dirtying the optical components (28, 48, 46). Such a device is remarkable in that it includes a feed (26) of gas under pressure suitable for producing a primary flow of gas (50) leaving via the front opening (20) together with the laser beam (22), and in that it also includes a nozzle (60) connectable to a source of gas under pressure, said nozzle (60) producing a secondary flow of gas (62) sweeping the front opening (20) transversely, thereby deflecting the primary flow of gas (50) laterally.

Abstract: A hand-held laser welding wand includes one or more filler media delivery flow passages. The wand is dimensioned to be grasped with a single hand, thus filler media of various types and forms may be supplied to the weld area on a workpiece using various types of delivery systems and methods, including fully automated, semi-automated, or manually. The filler media may be delivered via the filler media delivery passages or separate from the passages.

Abstract: An apparatus for handling a pair of sheet metal workpieces to be welded is provided that includes a first workpiece holder, a second workpiece holder, at least one backing element, and at least one squeeze roller. The first and second workpiece holders are positioned so that an edge of one of the pair of sheet metal workpieces is in contact with, or separated a gap from, an edge of the other sheetmetal workpiece. The backing element is disposed on a first side of the sheet metal workpieces, and the squeeze roller is disposed on a second side of the sheetmetal workpieces opposite the first side. The squeeze roller is substantially aligned with the backing element. The squeeze roller is formed as a body symmetrical in rotation. Force selectively applied to the squeeze roller will cause plastic deformation of one of the pair of sheet metal workpieces and thereby cause the deformed sheet metal workpiece to extend into the gap.

Abstract: A hand-held laser welding wand includes one or more removable filler media delivery extension tips. The wand is dimensioned to be grasped with a single hand, thus filler media of various types and forms may be supplied to the weld area on a workpiece using various types of delivery systems and methods, including fully automated, semi-automated, or manually. The filler media may be wholly or partially delivered via the filler media delivery passages. One or more of the extension tips may be inserted into the filler media delivery passages to efficiently, precisely, and robustly supply filler media of various types and forms to the workpiece weld area.

Abstract: A combustor liner is provided having first and second annular bands which define an overlapping circumferential joint area, wherein a weld is disposed in the joint area encompassing substantially all of the axial length of the joint area. A method for producing such a combustor liner is also provided.

Abstract: Disclosed herein is a laser welding system having a travel path to carry a first blank and a second blank. An upstream clamp assembly and a downstream clamp assembly are positioned on the travel path and each of the upstream and downstream clamp assemblies are movable to an open position to allow the first blank to pass through the upstream clamp assembly to a first location within the downstream clamp assembly. A laser welding source is directed at a weld location on the travel path between the upstream and downstream clamp assemblies. At least one locating means is operable to locate the first weld edge adjacent the weld location. A first displacement means displaces the first weld edge against the locating means. The downstream clamp assembly is movable from the open position to a closed clamped position to clamp the first blank with the first weld edge adjacent the weld location. The locating means is operable to be withdrawn from the travel path.

Abstract: A combined YAG laser/arc welding apparatus performs a welding operation with a large depth of fusion and a deep fusion at a high efficiency. The welding apparatus includes an arc electrode which targets a point on a welded member where a laser beam from a YAG laser is focused. While an arc power supply is connected between the arc electrode and the welded member, the welded member is irradiated by the YAG laser to produce plasmoid gasses and metal vapors or a plume which is effective to start an arc from the arc electrode. A combined YAG laser/arc welding operation takes place while keeping the plume within and without a keyhole. Welded surface is covered by a hood, and a shielded gas passed through a commutation metal network surrounds the welded focus to prevent an oxidation and keeps the plume maintained. A filler wire is fed to a molten pool.

Abstract: A first electrode part in a rod shape is placed on an upper side, and a second electrode part in a rod shape having a higher melting point than that of the first electrode part is placed on a lower side, so that ends of the first and second electrode parts are brought into contact. Contact ends or vicinities thereof are irradiated with a laser beam, so that the electrode parts are welded. Here, a region irradiated with the laser beam is in a long narrow shape having a minor axis directed in a vertical direction and a major axis directed in a horizontal direction. This makes it possible to manufacture an electrode with a consistent high quality with a high yield.

Abstract: In a method and apparatus for making welded large pipes, a leading end of a hot strip is connected to a trailing end of a leader strip and then subjected to a two-stage leveling for strip flatness in transverse direction and strip flatness in longitudinal direction. The entire surface of the hot strip including strip edges thereof is inspected by ultrasound and the strip edges are prepared in four stages before being pre-bent. The hot strip is then shaped into a slotted tube and the strip edges are welded along the inner and outer sides by laser to produce the pipe. Online process diagnostic is provided for monitoring the welding step and the finished welded pipe diameter is measured through online measurement. Online determination of a profile of a welded seam configuration and computer tomographic determination and evaluation of flaws inside the pipe, as well as ultrasonic inspection of the welded seam are further provided.

Abstract: A hand-held laser welding wand includes internal flow passages through which filler media, gas, and coolant may flow. The wand is dimensioned to be grasped with a single hand, thus filler media of various types and forms, gas, and coolant may be supplied to the hand-held laser welding wand via external systems and delivery devices without substantially impairing operation of the wand.

Abstract: To regulate a laser welding process, an optical sensor detects the seam flank angle and/or the seam position of the laser welded seam directly following its formation, the resulting actual measured information is compared with stored or externally provided nominal information to give a comparison result, and the position of the welding laser beam source is adjusted based on the comparison result to regulate-out any divergence between the actual measured information and the nominal information. The apparatus includes a laser welding device including a welding laser beam source that moves along the joint to be welded, an optical sensor arranged directly on or following the laser welding device, and a circuit including a comparator that compares the actual measured information with the stored or externally provided nominal information regarding the seam flank angle and/or the seam position.

Abstract: An apparatus and method may be used for welding a first panel to a second panel, the first panel having an inboard side partially contacting the second panel and an opposite outboard side. The apparatus has a welding beam generator. The apparatus reduces a pressure along the inboard side of the panel relative to an adjacent pressure along the outboard side so as to produce inward deflection of the first panel along a first portion of the first panel not contacting the second panel relative to a second portion. The apparatus has locates, based on said deflection, at least one of said first portion or said second portion.

Abstract: A machining apparatus includes a light source (1) for generating light energy, an optical system (2, 3) for guiding the generated light energy to a joint position of a workpiece, a table (5a) on which the workpiece is mounted, and a heating device (5b) provided at the table for heating the workpiece. The machining apparatus, a machining method and production equipment using the machining apparatus allow the workpiece to be locally heated fast, which is applicable to soldering or the like.

Abstract: According to one embodiment of the invention, a method for controlling the size of the molten pool in a laser based additive manufacturing process includes coaxially aligning an imaging device with a laser nozzle and imaging a molten pool, created by a laser, on a substrate with the imaging device. The method further includes comparing at least one characteristic of the molten pool with a respective characteristic of a target molten pool, and adjusting, in substantially real-time, a laser power of the laser based on the comparison in order to correlate the characteristic of the molten pool with the respective characteristic of the target molten pool.

Abstract: A control console that is used in conjunction with a hand-held laser welding wand is adapted to couple to an electrically controllable filler media supply source, and to an electrically controllable laser source. The control console includes a control switch that is electrically coupled to the filler media supply source and the laser source and is configured to such that an operator can independently and simultaneously control the filler media supply source to either supply or not supply filler media, and the laser source to either emit or not emit laser light therefrom. The control switch is preferably further configured to control the optical power level of the laser source.

Abstract: A method for producing a seal-welded connection between a stamped grid designed to conduct electricity and embedded in a laser-transparent plastic, and a plastic component positioned underneath the stamped grid, using a laser method, including the following method steps, executable in any order: a) carrying out a first welding operation by emitting laser beams, the laser beams falling on the surface of the stamped grid embedded in the plastic, at an angle ?, and the angle ? being inclined in a positive direction with respect to the vertical; and b) carrying out a further welding operation by emitting laser beams, the laser beams falling on the surface of the stamped grid embedded in the plastic, at an angle ?, and the angle ? being inclined in a negative direction with respect to the vertical.

Abstract: In one form of the invention, a laser beam propagates directly through bulk material of a TAB tape or base, to heat and form a bond between electrical leads formed on the base and aligned contact bumps. In another form, a chromium seed-metal layer is formed on a TAB tape or base, and leads are in turn formed on the chromium; the chromium absorbs a laser beam to heat the leads. In both forms, an optical fiber preferably presses copper leads and gold bumps together with over 300 g force, without aid by a gas stream—and then also conducts the beam to the bond site, forming a bond of shear strength over 200 g. Also preferably gold contacts are plated on the leads; and the method makes an inkjet printhead—with the bumps formed on a die or other printhead component, and nozzles formed through the base.

Abstract: Methods for measuring laser light transmissivity of a specific position in a work piece prior to the work piece undergoing laser welding at the specific position with a laser beam having a specific welding wavelength. To obtain a baseline measurement reading, a laser light source projects a laser beam at the welding wavelength directly into a detector. Thereafter, the work piece becomes suspended between the laser light source and detector whereby an output of the detector now corresponds to a work piece measurement reading. Differences between the two readings reveal whether the work piece will yield a satisfactory weld at the specific position when later welded by a laser beam at the welding wavelength. Preferred work pieces include inkjet printhead lids and bodies.

Abstract: A method is provided for repairing degraded and/or eroded areas on gas turbine blades and vanes. The method is directed to turbine blades and vanes made of advanced superalloy materials with high elevated-temperature properties. The method uses multiple laser beams to perform steps of preheating the repair area, welding the repair area, and post-welding heating of the repaired area. The method uses an array of two or more lasers to perform the steps of heating, welding, and post-weld heat treatment in nearly simultaneous operation thereby dramatically reducing or eliminating the hot cracking associated with other welding methods used with superalloy materials. The method is further directed to cladding or material buildup of degraded turbine blades where the weld material is the same as the matrix or better superalloy materials.

Abstract: A laser welding nozzle used as a working tool, a linear movement mechanism of a pressing device, and a servomotor are fixed to a bracket. A roller support frame is fixed on a moving side of the linear movement mechanism. A roller is pivotally mounted at a distal end of the roller support frame. The roller is located in the vicinity of a weld point of the laser welding nozzle. By driving the servomotor in a controlled manner, a portion in the vicinity of the weld point of a plate portion to be welded is pressed by the roller to restrain a floating of the weld portion, by which a gap between the plate portions is regulated, and thus uniform weld can be obtained. The pressing position, speed, and pressing force of roller can be controlled easily, so that the pressing device can be used for various types of workpieces.

Abstract: A process gas for use in laser welding with a laser beam focused onto the work piece to be welded. The inventive process gas comprises helium, nitrogen, and at least one of carbon dioxide in an amount of up to 40% by volume, and oxygen in an amount of up to 30% by volume. The gas may comprise not more than 85% by volume of helium. Also disclosed are methods of laser welding using the inventive process gas. The invention is suitable for laser welding of low-alloy steels and coated, especially zinc-coated steels.