Patent attributes
A laser welding head is configured to fasten under a focusing lens for focusing the laser and including at least one annular nozzle for injecting a protective gas, and a protective chamber for protecting the focusing lens with a transverse flow of air. The annular nozzle is arranged around an unobstructed optical axis passing through the laser welding head. The chamber for protecting the focusing lens with a transverse flow of air includes air admission and air exhaust in register with the air admission in a plane substantially perpendicular to said optical axis. The laser welding head is configured to be fastened against the focusing lens without any lateral opening between the focusing lens and the protective chamber. The head presents a distance of at least 100 mm between an outlet of the annular nozzle and the protective chamber.