Patent ID: 7766215

Claim:
Process for the friction-stir production of a welded joint of two plates ( 20 , 21 ), respectively upper plate ( 21 ) and lower plate ( 20 ), whereby said welded joint is produced between a first beginning end and a second separate final end of the first end, using a welding device ( 25 ) having a retractable pin ( 29 ), said process comprising the following steps: positioning and keeping the two plates ( 20 , 21 ) in contact along a cover zone ( 24 ) in the desired relative position after welding, bringing the welding device into contact with one or more plates in a zone close to a front edge of the cover zone for forming the beginning of the welded joint, longitudinally welding the two plates by moving the welding device to a rear edge of the cover zone for forming the final end of the welded joint, whereby the welded joint extends from a rear edge up to a front edge of the cover zone, continuing the movement of the welding device ( 25 ) along a path that extends beyond the final end of the welded joint, and retracting the retractable pin ( 29 ) in a portion of the path of the welding device ( 25 ) that extends beyond the final end of the welded joint, so as to have a constant welded joint quality over the entire length of the welded joint and to prevent the appearance of a weld hole.