PROCESS AND DEVICE FOR HYPERBOLOIDAL SHARPENING OF MULTI.FLUTE TWIST DRILLS WITH CUTTING EDGES IN THE SHAPE OF A CIRCULAR ARC

摘要

The invention relates to a process and a device for hyperboloidal sharpening of twist drills with cutting edges in the shape of a circular arc, employed in machine building. According to the invention, the process consists in composing an oscillating motion () of the drill (), having the axis perpendicular and eccentrically placed with the quantity () in relation with a disjoint oscillation axis () located at a distance () from the rectilinear external generatrix of an abrasive body, having a motion () of axial intermittent advance. The device claimed by the invention consists of an abrasive body () with a cylindrical external active surface, against which the drill () mounted on the prism-shaped surface of a rule () is driven into an oscillating motion about a bearing () having a disjoint axis located at a distance () from the rectilinear generatrix external to the abrasive body () and a slide () allowing the axis of the drill () to be offset in relation with the oscillation axis of the bearing ().