| United States Patent | 6,417,487 |
| Nagura , et al. | July 9, 2002 |
A laser beam machining head includes a dividing optical system for dividing laser light into two separate laser beams, and providing spacing therebetween; a condensing optical system for condensing the separate laser beams into condensed laser light, and projecting it onto a cutting site of an object to be cut; and an inner assist gas nozzle placed between the separate laser beams, a width of an opening of a tip portion of the inner assist gas nozzle being nearly equal to a cutting width. Or the tip opening of the inner assist gas nozzle is slender; or its tip side is inclined, and the angle of inclination is variable; or the relative positions of the inner assist gas nozzle and a workpiece, or the relative positions of the focal position of the condensing optical system and the workpiece are variable independently; or an outer assist gas nozzle surrounding the separate laser beams is provided.
| Inventors: | Nagura; Yasumi (Takasago, JP); Nayama; Michisuke (Takasago, JP); Ishide; Takashi (Takasago, JP); Hashimoto; Yoshio (Takasago, JP); Michishita; Yukio (Takasago, JP); Okimura; Koji (Kobe, JP) |
| Assignee: | Mitsubishi Heavy Industries, Ltd. (Tokyo, JP) |
| Appl. No.: | 920823 |
| Filed: | August 3, 2001 |
| Jun 08, 1998[JP] | 10-159022 | |
| Jan 14, 1999[JP] | 11-007999 |
| Current U.S. Class: | 219/121.84; 219/121.77 |
| Intern'l Class: | B23K 026/14; B23K 026/067 |
| Field of Search: | 219/121.84,121.76,121.77,121.67,121.68,121.7 |
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| 4315130 | Feb., 1982 | Inagaki et al. | 219/121. |
| 5651904 | Jul., 1997 | Franke et al. | 219/121. |
| 6034343 | Mar., 2000 | Hashimoto et al. | 219/121. |
| 6172323 | Jan., 2001 | Ishide et al. | 219/121. |
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