EP 3209442 A1 20170830 - TWIST DRILL AND PRODUCTION METHOD
Title (en)
TWIST DRILL AND PRODUCTION METHOD
Title (de)
WENDELBOHRER UND HERSTELLUNGSVERFAHREN
Title (fr)
FORET HÉLICOÏDAL ET PROCÉDÉ DE FABRICATION
Publication
Application
Priority
- EP 14190033 A 20141023
- EP 2015074206 W 20151020
Abstract (en)
[origin: CA2964814A1] A method for producing a twist drill 1 has the following steps. A blank 27 is shaped to form a semi-finished product 34. The semi-finished product 34 is formed from a core 38, coaxial with the drill axis 2, having a radius 51 and a number of webs 39, arranged on the core 38, having a height 40. The semi-finished product 34 has a constant cross section along the drill axis 2. The webs 39 have a first portion 42 which adjoins the core 38 and in which a width 44 of the web 39 remains constant or decreases in the circumferential direction 11 with increasing radial distance from the drill axis 2. The webs 39 have a second portion 43 which adjoins the first portion 42 and in which the width 44 of the web increases in the circumferential direction 11 with increasing radial distance from the drill axis 2. The webs 39 of the semi-finished product are shaped into helical segments using a plurality of rolling tools that annularly enclose the semi-finished product 34 and roll on the webs 39 along the drill axis 2. The rolling tools 31 have teeth 48 that are inclined with respect to the drill axis 2. A height 20 of the helical segments is less than the height 40 of the webs 39. Helical segments formed from adjacent webs 39 are in contact with one another in a closing fold 26. The invention also relates to a twist drill.
IPC 8 full level
B21H 3/10 (2006.01); B23B 51/02 (2006.01)
CPC (source: CN EP US)
B21H 3/10 (2013.01 - CN EP US); B23B 51/02 (2013.01 - CN EP US); B28D 1/146 (2013.01 - US); B23B 2226/75 (2013.01 - EP US); B23B 2251/204 (2013.01 - US); B23B 2251/241 (2013.01 - CN EP US); B23B 2251/406 (2013.01 - EP); B23B 2251/408 (2013.01 - US)
Citation (search report)
See references of WO 2016062683A1
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
EP 3012039 A1 20160427; CA 2964814 A1 20160428; CA 2964814 C 20190219; CN 107073598 A 20170818; EP 3209442 A1 20170830; US 10252321 B2 20190409; US 2017348760 A1 20171207; WO 2016062683 A1 20160428
DOCDB simple family (application)
EP 14190033 A 20141023; CA 2964814 A 20151020; CN 201580057231 A 20151020; EP 15781928 A 20151020; EP 2015074206 W 20151020; US 201515519970 A 20151020