Global Patent Index - EP 3978719 A1

EP 3978719 A1 20220406 - LOW STRESS CAVITY EXIT FOR CONICALLY CONNECTING DRILL BIT

Title (en)

LOW STRESS CAVITY EXIT FOR CONICALLY CONNECTING DRILL BIT

Title (de)

SPANNUNGSARMER HOHLRAUMAUSGANG FÜR KONISCH VERBUNDENEN BOHRMEISSEL

Title (fr)

SORTIE DE CAVITÉ À FAIBLE CONTRAINTE POUR CONNECTER CONIQUEMENT UN TRÉPAN

Publication

EP 3978719 A1 20220406 (EN)

Application

EP 20199284 A 20200930

Priority

EP 20199284 A 20200930

Abstract (en)

A percussive drill bit comprising a sleeve section and bit section having a longitudinal axis; wherein the sleeve section has an axial end at the opposing end of the drill bit compared to the bit section from which a generally conically shaped internal cavity extends from for receiving a conically shaped drill rod to form a conical frictional connection; characterised in that: the internal cavity has a transition section extending between the axial end of the drill bit and the a straight tapered region; wherein the transition section has at a first curved region having a first radius,TRi, wherein its tangent, TT, is positioned at a first distance, TD<sub>1</sub> from the axial end.

IPC 8 full level

E21B 1/00 (2006.01); E21B 17/04 (2006.01)

CPC (source: EP)

E21B 1/00 (2013.01); E21B 17/04 (2013.01)

Citation (applicant)

Citation (search report)

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 3978719 A1 20220406; EP 4222337 A1 20230809; JP 2023543851 A 20231018; WO 2022069652 A1 20220407

DOCDB simple family (application)

EP 20199284 A 20200930; EP 2021076974 W 20210930; EP 21786207 A 20210930; JP 2023519717 A 20210930