公开(公告)号：US11077504B2

公开(公告)日：2021-08-03

申请号：US16313967

申请日：2017-07-12

Applicant: Mapal Fabrik für Präzisionswerkzeuge Dr. Kress KG

Inventor： Ulrich Krenzer ,  Serkan Topal

IPC: B23B51/00 ,  B23B47/34 ,  B23B51/02

Abstract: A step drill includes a distal end, an opposite proximal end, a drill tip and at least one drill step. The drill tip has a tip at the distal end of the step drill and comprises a first number of geometrically defined cutters, each of which is paired with a first flute and lies on an imaginary first circular line about a longitudinal axis of the step drill. The imaginary first circular line has a first radius. The at least one drill step is arranged at a distance from the distal end and has an end face with a second number of geometrically defined cutters each of which is paired with a second flute and lies on an imaginary second circular line that runs about the longitudinal axis of the step drill and has a second radius. The first radius is smaller than the second radius. The first flutes of the drill tip and the second flutes of the drill step merge in a region, which is arranged at a greater distance from the distal end than the end face of the drill step, and form a single flute.

公开(公告)号：US09862036B2

公开(公告)日：2018-01-09

申请号：US14915314

申请日：2014-08-25

Applicant: Mapal Fabrik für Präzisionswerkzeuge Dr. Kress KG

Inventor： Ulrich Krenzer ,  Serkan Topal

IPC: B23B51/02

CPC classification number: B23B51/02 ,  B23B2250/12 ,  B23B2251/04 ,  B23B2251/14 ,  B23B2251/18 ,  Y10T408/909 ,  Y10T408/9097

Abstract: A drill has a central axis, a front side, a circumferential surface, at least two main edges on the front side, which reach up to the circumferential surface and merge there with secondary edges, at least two central edges extending from the end of the main edge facing away from the circumferential surface, cutting surfaces associated with the main edges and central edges, chip flutes associated with the main edges and central edges and introduced into the circumferential surface, at least one cross edge adjoined by the ends of the central edges facing away from the main edges which passes through the central axis, a point thinning and chip run-up shoulders associated with at least the cutting surfaces of the central edges. An angle γ of the chip run-up shoulder decreases in the region of the point thinning towards the central axis as the distance from the front side increases.