Abstract: Process and apparatus for thermal cutting of workpieces, such as plate, made of materials which can be melted or decomposed thermally by means of a stream of liquid heated to a temperature above the melting or decomposition temperature of the workpiece to be cut. The stream of liquid serves to transport the heat used to melt or thermally decompose the workpiece to be cut and to induce momentum for the removal of the melted or thermally decomposed material from the workpiece. Apparatus to implement the process can comprise a crucible made of heat resistant material with an insertion opening to accept a metal wire or metal rod inserted into this opening in such a way as to be sealed. The wire is moved by feed rollers. A heating unit at the crucible melts the end of the wire or rod in the crucible. A discharge nozzle for the stream of molten metal produced.

Abstract: The present invention is a process and apparatus for determining the position and diameter of the focal point of a laser beam, specifically for use in material processing with a heavy-duty laser beam. In a process for determining the position and diameter of the focal point of a laser beam, specifically a heavy-duty laser beam, a rotationally symmetric reflector which reproduces a laser beam on a focal line is introduced in the path of rays of a focused laser beam. Reflected on the reflector, the laser beam is captured by way of at least one sensor which is fixedly coordinated with the reflector in the focal line, while the focal plane, the lateral position of the focal point and the diameter of the focal point are then determined by way of measured values captured in the sensor, with the sensor being shifted relative to the focusing optics of the laser beam or relative to the reflector.

Abstract: In the cutting of workpieces by means of a laser beam, gas is blown onto workpiece at high speed together with the beam. It is proposed to design gas outflow nozzles (60) in such a way that they are formed as grooves in the conical end face (49) of a nozzle insert (47) and, on the other hand, are formed by a nozzle cap (48) which has a portion of such a matching conical shape that the grooves are covered. It is also proposed to provide a unifying chamber (formed by an attached cap), in which the gas jets are unified, so that they then flow out, together with the laser beam, as a single gas jet.

Abstract: The machining results of high-power lasers with machining optical systems 5) for beam shaping are dependent on the fact that decisive machining parameters, namely the beam power, the beam diameter, the position of the beam relative to the optical axis (54) and the intensity of the radiation reflected back, are supervised. To this end, the invention proposes a process by which the essential beam parameters can be measured during machining directly at a machining optical system (25) designed in an appropriate manner according to the invention. To this end, the appropriate measurement value receivers are associated, according to the invention, with the deflecting mirror (26) and/or the focusing mirror (27) of the machining optical system (25).