| 摘要 |
1,229,876. Cutting by fusion. LASER TECHNIQUE SA. 17 Sept., 1968 [25 Sept., 1967], No. 44022/68. Heading B3V. [Also in Division H1] A bore is formed in a workpiece, particularly a watch jewel, by locating the workpiece at the focus of a laser having a focused optical system, and applying a train of laser pulses each directed to a different spaced point about the axis of the bore to be formed. The workpiece may be moved relatively to the laser system, or as shown in Fig. 1 the axis 9a of the emergent laser beam may be offset by a tilted glass disc 11 from the bore axis 9 of a fixed workpiece 21, and be rotated about that axis. The laser beam is focused on to the workpiece by an axially displaceable lens 8, the lens being mounted in an inner tube 5 slidable with respect to an outer tube 1. Successive laser pulses are directed at points spaced about the bore axis by rotating the outer tube, a drive (not shown) engaging a gear-wheel 3 attached to the tube 1. A cam 4, also mounted on the outer tube, controls the emission of laser pulses. Adjustable displacement of the axis 9a from the bore axis 9 is effected by rotating a screwed cap 12 which alters the tilt of the glass disc 11, rotation of the disc within the tube being prevented by a spring- loaded plunger 15 which engages a notch 19 in the disc. In a modification, Fig. 3, the angle of the light incident on the workpiece may be varied by the combined use of a rotatable refracting block 33 and a lens 8 displaceable in a plane normal to the optical axis by one or more adjusting screws 29. The lens is mounted on a frame 25 adjacent to a sapphire window 27 and is urged by a spring 28 against the adjusting screw. A bore may be formed by a plurality of complete rotations of the tube 1 with those pulses applied during the second rotation aimed at points intermediate the points acted upon during the first rotation. An example is given of a 9-step cam controlling the laser through a divide-by-two frequency divider, the laser in its first rotation acting on four points equally spaced about the axis 9, and acting in points intermediate the first points during its second rotation. The focus may be adjusted in the axial direction during boring of bores of substantial depth with automatic control effected by a cam disc. |
