APPARATUS FOR EMITTING GAS STREAMS AT LASER CUTTING Russian patent published in 1998 - IPC

FIELD: apparatus for emitting stream at laser cutting of materials by means of high-power irradiation, possibly in combination with mirror lens, for example with mirror off-axis paraboloid. SUBSTANCE: apparatus includes nozzle chamber with two openings in opposite walls for providing two directed mutually opposite streams coaxial with laser beam. When distance between walls of nozzle chamber is sufficiently small it is possible to achieve supersonic stream emission. Such structure eliminates shielding of laser beam by narrow mouth of nozzle as in structures with Laval's nozzle. In order to decrease consumption of cutting gas, double-section chamber is used; expensive cutting gas is pumped to one section nearest to sample and low-cost air is pumped to second protective section by the same pressure as cutting gas. Protective section may be made as supersonic free-swirl nozzle in which direction of flow is normal relative to laser beam axis. In such case static pressure in outer cutoff of nozzle is equal to atmospheric one, and static pressure on inner wall of protective chamber is equal to pressure in first chamber. EFFECT: high quality of cutting process. 11 cl, 9 dwg