Abstract: On an apparatus (10) for laser processing workpieces (18), and whereby a laser beam (11) is directed on to a portion (13) of a substantially perpendicular work surface (14), a jet (21) of shielding gas is fed over the work surface portion (13) crosswise in relation to the laser beam (11) and at such high speed as to substantially prevent any alteration of the physical and/or chemical properties of the gas. The jet (21) is supplied along a solid-walled conduit (26) comprising two transverse openings (29, 31) for the passage of the beam (11) on to the work surface portion (13); and a nozzle (32) for producing a gas jet (21) of appropriate speed.

Abstract: A method for cutting a piece (2) of ferrous material by a laser beam (3), wherein an oxygen jet is conveyed on to cutting area (6) through a solid walled duct (13), guiding the jet substantially until it comes into contact with a surface (7) of workpiece (2); the laser beam (3) exercising on workpiece (2) a power density greater than 10.sup.6 kW/cm.sup.2, oxygen being conveyed on to the workpiece (2) with such impact pressure, as to trigger, at such power density, iron oxidation exothermic reactions of the combustion type, and being conveyed in such quantities, as to slightly exceed the relevant stoichiometric ratio, so that such reactions may be complete, as well as maintained under dynamic balance conditions.

Abstract: In order to remove the plasma cushion and loose metal material created by the action of the laser on a metal workpiece, a shielding gas jet is directed from a nozzle across the workpiece surface through the zone of action of the laser beam.The shielding gas rather than being allowed to go to waste is collected, purified of the metal material contained therein and fed back to the nozzle. This recirculation of the shielding gas is effected in ducting which incorporates in succession between the gas-collecting input end and the nozzle, a diffuser to slow the gas, a cooling chamber, a separator for removing metal particles condensed out of the stream, a pump, a filter and further cooling means.