SCREW FASTENER PROVIDED WITH POSITION INDICATOR

PURPOSE:To surely fasten a screw with no jig even if the kind ofmembers to be fastened varies, by irradiating light from at least two directions to a screw fastening position, and by visually adjusting the screw fastening position of the members to be fastened to the above-mentioned light. CONSTITUTION:Light from a bidirectional light source 4 is adjusted by a bracket 6 so that the light is converged to a screw fastening center (b) through a lens 5. The screw fastening position of members to be fastened by a screw is visually adjusted to the screw fastening center (b), and then the fastening is carried out by operating a screw fastening machine 7. With this arrangement, the screw- fastening may be carried out with no use of a specific jig, and even if the number of screw-fastening positions is plural, the screw-fastening may be carried out only by moving the members to be fastened, thereby it is suitable for a multi-produce production system for products produced in small quantities, and products may be obtained at a low cost.