Abstract: The present invention, by manually operating a robot and memorizing a position of the extremity of the robot, teaches a reference point representing a representative position and orientation on a moving path and a relative position of an operating position of a robot extremity in operation from the above-mentioned reference point, and designate a path of a moving position of the robot extremity in operation by an array of the reference points, and teachings of the moving path and a gripping position can be separated each other, and an accurate and easy teaching is enabled.

Abstract: A rack of a thermoplastic resin is produced by heating a rod of a thermoplastic resin so that the temperature of at least the surface of said rod reaches a level within a range expressed by the equation, ##EQU1## (wherein T is a melting point of a resin forming a matrix for said rod), and thereafter forming a rack in one or both surfaces of said rod by a toothed roller and a grooved guide roller which are paired with each other, or a pair of opposed toothed rollers.