Abstract: An automatic welding machine for lap welding the edges of plastic webs, comprising a movable supporting frame, a heating device for partially melting the plastic webs, at least two opposing, counter-rotating pressing rollers and/or advancing rollers, at least one of which being driven, and at least one driving device comprising a drive motor and at least one gearbox for driving the pressing and/or advancing rollers, wherein the pressing rollers and/or advancing rollers are driven by the driving device by way of at least one flexible shaft. Furthermore, the gearbox can be implemented as a worm gear mechanism comprising a worm that is seated directly on a motor shaft of the drive motor and two counter-rotating worm gears driven by the worm.

Abstract: An automatic welding machine, comprising a supporting frame and a tensioning device for reversibly joining at least two opposing booms to one another and applying a tension force between these, having an open position in which the opposing booms are separated from one another by a gap and a closed position in which the opposing booms are joined to one another and braced with respect to one another. One boom is mounted in a torsion-proof manner on the tensioning device and is pivotable in relation to the other boom and can be moved out of the open position into the closed position by the pivoting of the tensioning device.

Abstract: A hot-wedge welding device for overlap welding plastic webs, comprising a hot wedge, a pressure device for pressing the plastic webs against the hot wedge which comprises a respective pressure unit associated with one of the hot-wedge flat sides, and further comprising two mutually opposing pressure rollers. The hot wedge is pivotably mounted on a bearing shaft by way of a bearing bushing, which extends between the two hot-wedge flat sides parallel to the hot-wedge front edge at a distance therefrom. The hot wedge is mounted to have defined degrees of freedom with respect to the bearing shaft in the longitudinal direction and in the transverse direction of the bearing bushing, which in addition to the rotational movement of the hot wedge about the transverse axis thereof, also allow a tilting movement of the hot wedge about the longitudinal axis thereof and a vertical displacement of the hot wedge.

Abstract: The invention relates to a process for the adjustment of a laser light spot of high intensity for the laser processing of work pieces as well as a laser device for performing the proposed process. The laser device comprises a laser emitting a laser beam and at least one focusing lens for converging the laser beam as well as an optical operating element for adjusting the beam diameter of the laser beam. The invention proposes to use as operating element a diffractive optical element that separates the laser beam emitted by the laser into partial laser beams, with the partial laser beams generated by the diffractive optical element being assembled to form a resulting laser beam that acts on the work piece. By means of a suitable design of the diffractive optical element it is possible to adjust, in particular enlarge, the diameter of the laser light spot as required.

Abstract: The hand-held hot air device, preferably for the local heating of thermoplastic materials, with a housing that forms a wand-shaped handle part with air inlet openings, and with an air guidance tube that protrudes from the handle part and radially delimits an air canal, with an electric heating element contained in the air guidance tube and an electric motor with a fan wheel contained in the handle part, and with an electronic control system arranged inside the handle part with one semiconductor power switch each arranged upstream of both the heating element and the electric motor, and with a display screen and an operating device for the hand-held hot air device arranged on the outside of the handle part.

Abstract: A device and a process for processing and/or joining work pieces via laser radiation, with an effective power laser and a pilot target laser that emit laser beams of different wavelengths, with the laser beams being directed at the work pieces by laser optics. Regarding the laser beams, by the laser optics that comprise at least one diffractive optical element (DOE) as a masking system, the beam pattern of the pilot target laser is adjusted to match the beam pattern of the effective laser beam. This is accomplished preferably by removing the pilot laser beam from the effective laser beam for part of the path length by dichroic mirrors, and by expanding the diverging pilot laser beam on said part of the path length by deflecting mirrors whose distance from the dichroic mirrors is variable.