| 摘要 |
<p>1. A method for producing a metallic jewelry chain starting with a continuous metallic wire (1), in which the continuous metallic wire (1) is wound on a mandril in order to cause it to conform to a helix (1a) with non-joined turns (2), successively and one by one the individual turns (3) formed are cut up, the individual cut turns (3) are fashioned into links (4) with a predetermined form, and in order to completely close each of the links (4) the individual links (4) are separately welded while fitted into each other by directing, into the gap (5) formed in each link (4) a laser pulse (20 and 30) with a duration (T) and a peak power (P1 , 22 and 32) predetermined in accordance with the diameter of the metallic wire (1) utilized and of the nature of the metal constituting the said metallic wire, characterized in that the separate welding of each cut turn is performed immediately after causing it to conform to a predetermined link (4) form, in that the laser pulse (20 and 30) has a steep ascending flank (21 and 31) corresponding to a rise time (tm) comprised between approximately 40 and 70 microseconds and making it possible to rapidly attain the said maximum predetermined peak power (P1 , 22 and 32) a summit (23 and 33) of a predetermined duration (ts) and descending slightly as from the said maximum predetermined peak power (P1 , 22 and 32) adjacent to the ascending flank (21 and 31), then a descending flank (24 and 34), which is practically vertical, corresponding to a descent time (td) less than the rise time (tm) and in that, during the said predetermined duration (ts) corresponding to the slightly descending summit (23 and 33) of the laser pulse (20 and 30), the drop in power (P1 -P2 ) is of the order of 20% of the peak power (P1 , 22 and 32), P2 representing the power of the laser pulse corresponding to the point of intersection of the summit (22 and 33) with the descending flank (24 and 34).</p> |
