Patent GB-1074301-A (GB)
Title: Improvements in optical setting
IPC: B23Q17/24
Filed: 1964-08-04
Abstract: 1,074,301. Tools for setting out work. CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE. Aug. 4, 1964 [July 30, 1963], No. 31062/64. Heading B4X. [Also in Divisions B3, G2 and H1] A workpiece to be machined is marked out by a laser beam which is passed through an optical system and allowed to impinge on the workpiece at a position predetermined by an optical setting effected by utilizing at least a part of the optical system. The laser head, Fig. 1, comprises an active element 1 surrounded by an electronic flash tube and is housed in a tubular chamber 3 slidable in a chamber 4 there being provided a restoring spring 5. The chamber 4 includes two coaxial tubular portions 6, 7 having their axes perpendicular to the axes of the chamber 4. The workpiece is placed on a stage 8 and is illuminated as by a lamp 9 and lens 10, the image being projected on to a semiground glass screen 17 through lenses 11 in the portion 7, orifices 12, 13 of the sliding chamber 3, lenses 14 in the portion 6 and by mirrors 15, 16. The chamber 3 is moved towards the left to the position shown in dotted lines, by a knob 20 sliding in a slot 21 in the chamber 4. This movement closes the orifices 12, 13 and uncovers a further orifice 22 of the chamber 3 and in this position the laser beam passes through a corrective lens 18 in the chamber 3 is reflected on a mirror 19 and passes through the orifice 22 and lens 11 so as to converge at 8 on the workpiece. In a modification, Fig. 2 (not shown), the external lighting device is replaced by a built-in lighting system housed in an extension of the chamber (4). In another modification, Fig. 4 (not shown), a mirror (40) is provided having a thin layer of neodymium glass which will reflect the laser beam but will allow the visible image of the workpiece to pass therethrough. In another modification, Fig. 5 (not shown), the two tubular parts (6 and 7) are perpendicular to the axis of the chamber (4) but their axes are slightly displaced, the mirrors (19 and 32) being fixed at rather less than 45 degrees on the axis of the chamber (4) and the optical and laser beams thus having separate paths. In another modification, Fig. 6 (not shown), the mirror (19) is arranged so that the laser beam strikes the work normally. In another modification, Fig. 7 (not shown), the frame on which the workpiece (8) is mounted, is fixed to the laser head (51), the laser beam being transmitted on to the workpiece (8) through the intermediary of the lenses (11, 14), the mirror (15) and a mirror (53), which is either retractable or of the neodymium type. In another modification, Fig. 8 (not shown), the tubular part (6) is fixed to a support (61), which may be part of a machine tool, the ground glass screen (60) being perpendicular to the axis of the tubular part (4). In another modification, Fig. 10 (not shown), the tubular portion (70) of the chamber (4) is perpendicular to the laser head (71) and is rotatable in a plane parallel to the axis of the tubular portions (6, 7), the screen (60) being oriented, to carry out the optical adjustment. A workpiece (8) having fixed thereto a sheet (78) of cartoline lined with aluminium bearing a drawing or other marks is placed on the object carrier stage (74) and a tracing effected by the laser beam which passes therethrough and perforates the sheet.