LASER BEAM DIRECTING DEVICE FOR LASER-WELDING ARTICLE SUCH AS PIPE WITH CIRCULAR SECTION AND LASER WELDING DEVICE WITH SAID LASER BEAM DIRECTING DEVICE

摘要

Laser welding apparatus includes a first mirror whose angle may be adjusted but which is fixed in position and on which a laser beam is incident. The first mirror reflects the laser beam onto a second mirror which may be rotated through at least 180 DEG about the axis of the articles to be welded and which reflects the laser beam onto a third mirror whose angle may be adjusted and which may be rotated through at least 360 DEG about the axis of the articles to be welded. The laser beam then passes to a focussing mirror which focusses the beam through a welding nozzle onto the surfaces to be welded. In use, the third mirror is continuously rotated about the entire periphery of the articles to be welded and the positions and/or angles of all the mirrors are adjusted to ensure that the laser beam is transmitted along the desired pathway.