JOACHIM BERKMANNS
Pilots at Whitmore Bay Dr, Hamburg, MI

6087619, Jul 11, 2000

May 13, 1997

8/855375

Joachim Berkmanns - Whitmore Lake MI
Frank W. Kuepper - Ann Arbor MI
Chen-Jen Rey Hsu - Ann Arbor MI

Fraunhofer USA Resource Center - Ann Arbor MI

B23K 2626

21912163

A welding arrangement for welding first and second sheets of material to one another, the sheets having different figures from one another, employs a source of energy, illustratively a laser, for producing a primary beam of energy and propagating the beam toward a focusing element and a splitter. The splitter is formed of stepped mirrors that facilitate adjustment of the distance between the beams. The distance can be adjusted in response to the width of a gap between the sheets to be welded. The welding beams impinge upon respective ones of the sheets to be welded with an intensity characteristic that is responsive to the thickness of the sheets. Thus, the thicker sheet will be subjected to a higher intensity beam to insure penetration sufficient to effect a good continuous weld. One or more heat sources are provided to preheat the sheets of material so that thermal expansion will close the gap between them. Additionally, a monitoring arrangement controls the focus of the energy beams on the materials to be welded and the distances between the beams, in response to the width of a gap between the materials to be welded.