Patent ID: 7605342

Claim:
A laser processing head comprising: a first housing region associated with a beam guidance of a laser processing machine; a second housing region associated with the laser processing head; and an aperture in a wall separating the first and second housing regions, wherein the head is configured such that a laser beam may pass sequentially through the beam guidance, the first housing region, the aperture, and the second housing, wherein the second housing region comprises an annular gap nozzle positioned to accommodate the laser beam, the annular gap nozzle being used for pressuring a cutting gas, and at least one opening in the second housing for discharging a reverse flow of the cutting gas, the opening being disposed between the annular gap nozzle and the aperture, and wherein the first housing region includes a first gas atmosphere associated with the beam guidance and maintained at a higher pressure than a second gas atmosphere in the second housing region.