Patent ID: 8829388

Claim:
An end cap for a laser-based welding apparatus operative to weld together a plurality of stacked sheets of material, comprising: a stationary part extending along an axis, and a movable part mounted to the stationary part and having a passage which extends along the axis between top and bottom surfaces of the movable part, the passage being traversed by co-propagating laser beam and stream of pressurized fluid which builds up a positive pressure acting upon a top surface of the movable part so as to axially displace the latter towards a top sheet of material while the stream, traversing the passage, gradually creates a negative pressure on the bottom surface, the movable part being stopped in a balanced position of the moving part in which the positive and negative pressures substantially uniform, wherein the sheets of material in the balanced position of the movable part are in continuous contact with one another while being welded together by the laser beam.