Manufacturing process, tool stand, and drill bit

Patent metadata

Field	Value
Publication number	US-10940527-B2
Application number	US-201616062537-A
Country	US
Kind code	B2
Filing date	Dec 6, 2016
Priority date	Dec 15, 2015
Publication date	Mar 9, 2021
Grant date	Mar 9, 2021

Abstract

A method for producing a drill includes cold forming of a rod-shaped blank to form a semifinished product having three or more rectilinear longitudinal ribs extending along a longitudinal axis of the semifinished product, introducing the longitudinal ribs into a first die and a second die in a working direction, where the first die bears against the longitudinal ribs in a direction of rotation about the longitudinal axis and the second die bears against the longitudinal ribs counter to the direction of rotation, pivoting the first die in the direction of rotation in relation to the second die in order to twist the longitudinal ribs between the first and second dies, pulling the longitudinal ribs 31 through the pivoted first die and the second die counter to the working direction in order to twist the longitudinal ribs and apply a drill head to the rear end in the working direction.

First claim

The invention claimed is:

1. A method for producing a drill bit with a helix, comprising the steps of:
cold reshaping of a rod-shaped blank to form a semifinished product with three or more longitudinal ribs extending rectilinearly along a longitudinal axis of the semifinished product;
introducing the longitudinal ribs of the semifinished product in a first die and a second die in a working direction, wherein the first die bears against the longitudinal ribs in a direction of rotation around the longitudinal axis and the second die bears against the longitudinal ribs counter to the direction of rotation;
pivoting the first die in the direction of rotation in relation to the second die in order to twist the longitudinal ribs between the first die and the second die;
pulling the longitudinal ribs of the semifinished product through the pivoted first die and the second die counter to the working direction in order to twist the longitudinal ribs; and
attaching a drill head to a back end in the working direction;
wherein the first die has interior surfaces that face towards the direction of rotation and are helix-shaped;
wherein the semifinished product is turned in the direction of rotation while pulled out of the first die and the second die.

2. The method according to claim 1 , wherein the first die is pivoted around a pivoting angle in relation to the second die wherein the pivoting angle continuously increases during a first section of the helix during a shifting process of the first and second dies and continuously tapers down to zero during a final section of the helix.

Assignees

• Hilti Ag

Inventors

• Domani Guenter
• Peters Carsten
• Schroeder Florian

Classifications

• B28D1/146 Primary

  Tools therefor (drill bits for earth or rock drilling E21B10/00) · CPC title

• B21K5/04 Primary

  twisting-tools, e.g. drills, reamers · CPC title

• B21H7/187

  Rolling helical or rectilinear grooves · CPC title

• B23P15/32

  twist-drills · CPC title

• B23B51/02

  Twist drills · CPC title