Improvements in or relating to machines adapted for use in assembling electrical components upon workpieces

854,367. Photo-electric indicating arrangements. BRITISH UNITED SHOE MACHINERY CO. Ltd. April 23, 1957 [April 21, 1956], No. 12258/56. Addition to 802,658. Class 40(3). [Also in Group XXII] In a'machine for assembling electrical components upon work-pieces such as printed circuit boards W by a component inserting means 350 which moves relatively to a work support 640 to insert a component lead through a hole in the workpiece, illuminating means 644 are provided for directing a beam of light towards the work support such that it will coincide with the position at which the hole must be placed to receive the component lead whereby the machine operator can use the beam for positioning the werkpiece. The machine is of the kind shown in Figs. 20 to 35 of the parent Specification except that the circuit boards W mounted on pallets P1 are positioned manually on the work support 640. Twin sources of light 644 are directed by optical systems, Fig. 4 (not shown), on to a mirror 646 mounted on the component support 438 and which directs two beams of light, corresponding to the two leads of a component, on to the circuit board W. The light sources are adjustably mounted on the machine. Photo-electric cells may be positioned to detect the passage of the light beams through the holes in the board and to actuate the machine automatically or alternatively to prevent its actuation unless the boards are positioned correctly.