| 摘要 |
<p>A printed circuit board working machine includes a spindle (1) which holds a cutting tool (2) and is movable to bring the tool into contact with and away from a printed-circuit board (6) to be worked. A device for pressing down the printed-circuit board comprises a support mechanism (3, 4, 26; 4, 24, 26) associated with the spindle of the working machine for relative movement thereto, a plurality of holding sections (7A, 7B; 25A, 25C) movably supported by the mechanism and a driving mechanism (8; 11 - 13) for the holding sections. The holding sections are formed with holes (7A', 7B'; 25A', 25C') of different sizes, respectively. When working, after the support mechanism (3, 4, 26; 4, 24, 26) causes the holding sections (7A, 7B; 25A, 25C) to move away to a position (C) free from interference with the tool (2), the driving mechanism (8; 11 - 13) moves the holding sections to align one of the through holes (7A' or 7B'; 25A' or 25C'), corresponding to a size of the tool (2) to be used, with the tool. Subsequently, the support mechanism (3, 4, 26; 4, 24, 26) returns the holding sections to an initial position (B) and, before the tool reaches the printed-circuit board, brings the corresponding holding section (7A or 7B; 25A or 25C) into pressure contact with the printed-circuit board (6). <IMAGE></p> |
