| 摘要 |
PURPOSE:To mass-produce members used for electronic component parts of variable condensers, printers, etc., in a highly accurate manner, by machining two plane surfaces of a cylindrical basic material simultaneously by means of cutting edges rotating on these plane surfaces. CONSTITUTION:To manufacture an oval-shaped shaft 2 with a cylindrical basic material 1 ground, first the cylindrical basic material being cut into the specified length is secured tight in the space between chucks 11 and 11 being installed on a material stand 10. Then, a tool rest 9 is shifted while a rotary shaft 12 is set in motion and cutting edges 13 contact two plane surfaces of the basic material 1 whereby the material stand 10 is as well shifted in an arrow direction along a guide groove 8a, so that machining is over. That is to say, these cutting edges 13 and 13 in rotation are pressed against the two plane surfaces of the basic material 1 while they are shifted, thus both plane surfaces are machined at the same time. |
