Patent ID: 7560659

Claim:
A method for laser welding for use with a structure consisting of metal sheet elements comprising: providing a multi-axis handling robot including a plurality of electric motors controlling the movement of elements of the robot around said axes, together with a programmable electronic control unit for controlling said electric motors in order to shift a terminal element of the robot in any position, with any orientation and on any trajectory inside a given three-dimensional spatial volume; mounting onto said terminal element of the handling robot an accessory device for focusing a laser beam coming from a laser source, said accessory device being designed to orient the focused laser beam by oscillating it around one single oscillation axis; controlling said handling robot so as to shift the aforesaid accessory device at a selected first speed which is higher than a selected second speed at which at least two welding beads are to be created along a rectilinear trajectory parallel to a direction along which the at least two welding beads are to be positioned orthogonal to said single oscillation axis; wherein while the aforesaid accessory device is shifted by said handling robot along said rectilinear trajectory at the first speed, oscillating the direction of the focused laser beam around said single oscillating axis by means of said accessory device, in order to shift the area of the structure to be welded that is locally illuminated by the focused laser beam along a trajectory at the second speed; and on completion of one of the at least two weld beads at a first weld bead end, abruptly oscillating the focused laser beam about the oscillating axis from the first bead end to a start end of a second weld bead at a third speed greater than the second speed while the accessory device continues moving at the first speed.