Abstract: The invention relates to a laser machining equipment including a laser oscillator (1) for generating a laser beam, a laser head (3) through which the laser beam passes, an optical path (2) for conveying the laser beam between the laser oscillator (1) and the laser head (3), and a gas source (9) fluidly connected to the laser head (3) via a main gas pipe (8). In addition, a second pipe (18) fluidly connects the gas source (9) to the laser oscillator (1). The equipment therefore comprises a common gas source for the laser oscillator (1) and head (3). The gas is preferably nitrogen.

Abstract: Methods for laser beam cutting metal workpieces with a thickness between 4 mm and 25 mm. A double focusing lens is provided to make it possible to focus a laser beam on a first focusing and a second focusing point. These points are separate from each other and both lie on the laser's optical axis. The lens has a focal length between 170 mm and 300 mm.

Abstract: The invention relates to a method for laser-beam cutting a metal workpiece having a thickness of less than 5 mm, in which a double focusing lens is employed making it possible to focus the laser beam at least at a first focusing point (PF1) and a second focusing point (PF2) which are separate from each other and lie on the beam axis, characterized in that the lens has a focal length (FL) of between 80 and 135 mm.

Abstract: Method and plant for cutting or welding by a laser beam with dual-flow and double-focus cutting head. The plant includes a laser generator to generate at least one main laser beam (10), a first optical element (1) enabling the main laser beam (10) to be divided into at least two subsidiary laser beams (11, 12), a first outlet nozzle (4) through which one (11) of the subsidiary laser beams passes, and a second outlet nozzle (3) through which the other (12) of the subsidiary laser beams passes, the first and second outlet nozzles (4, 3) being approximately coaxial one with the other. In this way, it is possible to focus the central beam (11) onto a focusing point (PF) by a first focusing element (1), such as a lens, and the other beam (12) onto an annular focusing zone (ZAF).

Abstract: Method and apparatus for cutting a workpiece made of structural steel or mild steel, i.e. alloy or non-alloy steels, by the use of a transparent or reflecting optical unit for focusing a laser beam, and of an assist gas for the laser beam. The optical unit is of the multifocus type and is chosen from lenses, mirrors and combinations thereof. The assist gas is nitrogen or a nitrogen/oxygen mixture. The method of the invention makes it possible to obtain a low or almost zero oxidation of the cut face and to do so while increasing the cutting performance by about 40% compared with a laser cutting method using nitrogen or a nitrogen/oxygen mixture.

Abstract: Method and plant for cutting or welding by a laser beam with dual-flow and double-focus cutting head. The plant includes a laser generator to generate at least one main laser beam (10), a first optical element (1) enabling the main laser beam (10) to be divided into at least two subsidiary laser beams (11, 12), a first outlet nozzle (4) through which one (11) of the subsidiary laser beams passes, and a second outlet nozzle (3) through which the other (12) of the subsidiary laser beams passes, the first and second outlet nozzles (4, 3) being approximately coaxial one with the other. In this way, it is possible to focus the central beam (11) onto a focusing point (PF) by a first focusing element (1), such as a lens, and the other beam (12) onto an annular focusing zone (ZAF).

Abstract: Method and apparatus for cutting a workpiece made of stainless steel, coated steel, aluminum or aluminum alloy by the use of a transparent or reflecting optical means for focusing a laser beam and of an assist gas for said laser beam. The optical means is of the multifocus type and is chosen from lenses, mirrors and combinations thereof. The assist gas is oxygen or a nitrogen/oxygen mixture containing at least 90% nitrogen. The method of the invention makes it possible to increase the cutting performance by 40% compared with a conventional laser cutting method.

Abstract: A plasma torch provided with an electrode (1) having an approximately cylindrical or frustocylindrical elongate shape, the electrode (1) including at least one recess (9) made in at least part of its external peripheral wall (15). In order to deflect and guide the gas flux entering the plasma torch, the recess (9) in the electrode (1) lies opposite the orifice or orifices (7) for introducing or injecting the gas flux into the torch.