公开(公告)号：US20230302550A1

公开(公告)日：2023-09-28

申请号：US18328181

申请日：2023-06-02

Applicant: MILWAUKEE ELECTRIC TOOL CORPORATION

Inventor： Brett A. Parendo ,  Richard Hohnl, JR. ,  David Hlavac ,  Alexander R. Greenhill ,  Ingolfur Ludviksson ,  Max R. Sawa ,  James E. Pangerc

IPC: B23B51/00

CPC classification number: B23B51/009 ,  B23B2251/043

Abstract: A step drill bit includes a shank and a body that defines a plurality of axially stacked, progressively sized steps including a first step, a terminal step, and a plurality of intermediate steps having incrementally increasing diameters disposed between the first and terminal steps. The step drill bit includes a flute in the body extending from the distal end to the proximal end and a plurality of cutting edges formed in the body. Each cutting edge is disposed along one of the plurality of steps. Each cutting edge defines a helix angle and a radial rake angle. The helix angle of the cutting edge at a first intermediate step of the plurality of intermediate steps is greater than the helix angle at the first step. The radial rake angle of the cutting edge at the first intermediate step is greater than the radial rake angle at the first step.

公开(公告)号：US11407039B2

公开(公告)日：2022-08-09

申请号：US16260226

申请日：2019-01-29

Applicant: MILWAUKEE ELECTRIC TOOL CORPORATION

Inventor： Brett A. Parendo ,  Alexander R. Greenhill ,  David Hlavac ,  Carter A. Gibson

IPC: B23B51/02

Abstract: A drill bit includes a body having a first end, a second end opposite the first end, and an axis of rotation extending centrally through the body. The drill bit includes a cutting head with a cutting tip on the axis of rotation and a cutting portion. The cutting portion includes first tip surfaces on opposite sides of the axis of rotation and second tip surfaces on opposite sides of the axis of rotation. Each first tip surface extends radially outward from the cutting tip to a corresponding second tip surface. Each second tip surface extends from a corresponding first tip surface to an outer periphery of the body. The first tip surfaces define a first tip angle measured through the axis of rotation that is oblique. The second tip surfaces define a second tip angle measured through the axis of rotation that is smaller than the first tip angle.

公开(公告)号：US11273501B2

公开(公告)日：2022-03-15

申请号：US16387621

申请日：2019-04-18

Applicant: MILWAUKEE ELECTRIC TOOL CORPORATION

Inventor： Brett A. Parendo ,  Richard Hohnl, Jr. ,  David Hlavac ,  Alexander R. Greenhill ,  Ingolfur Ludviksson ,  Max R. Sawa ,  James E. Pangerc

IPC: B23B51/02 ,  B23B51/00

Abstract: A drill bit includes a shank extending along a bit axis and a body with a proximal end adjacent the shank and a distal end opposite the proximal end. The body defines a plurality of axially stacked, progressively sized steps including a first step at the distal end and a terminal step at the proximal end. The drill bit also includes a flute in the body. The flute defines an elongated groove that extends from the distal end to the proximal end. The drill bit further includes a plurality of cutting edges formed in the body. Each cutting edge is disposed along one of the plurality of steps and defines a helix angle and a rake angle. The helix angle of the cutting edge at the terminal step is greater than the helix angle of the cutting edge at the first step. A ratio of the helix angle to the rake angle of the cutting edge at the first step is in a range from 0.5 to 2.4, and a ratio of the helix angle to the rake angle of the cutting edge at the terminal step is in a range of 0.9 to 1.7.