EP 0276724 B1 19940921 - Core drilling tool with a direct drive.
Title (en)
Core drilling tool with a direct drive.
Title (de)
Direktangetriebenes Kernbohrwerkzeug.
Title (fr)
Outil carottier à entraînement direct.
Publication
Application
Priority
DE 3701914 A 19870123
Abstract (en)
[origin: US4875531A] A core drilling tool with direct drive consisting of an outer pipe that can be connected to a drilling shaft, a core drilling appliance reciprocally mountable in the outer pipe which in turn includes a core barrel that carries a drill bit and an inner pipe mounted in rotatable relation therewith and for reciprocal movement therewith, and a drilling mud driven motor that is integrally coupled to the core drilling appliance and is secured against rotation in the outer pipe and having reaction faces that are put under pressure to produce a downward axial feed force acting on both the core drilling appliance and the motor, plus a capture device for pulling up the motor together with the core drilling appliance. In order to produce a sufficiently great axial feed force of an adjustable size that is essentially independent of the exposure of the core drilling appliance, the motor is connected to the core drilling appliance to form a common movable unit and devices are provided for adjusting the axial feed force.
IPC 1-7
IPC 8 full level
E21B 4/02 (2006.01); E21B 25/04 (2006.01); E21B 44/00 (2006.01)
CPC (source: EP US)
E21B 4/02 (2013.01 - EP US); E21B 25/04 (2013.01 - EP US); E21B 44/005 (2013.01 - EP US)
Designated contracting state (EPC)
BE FR GB NL
DOCDB simple family (publication)
DE 3701914 C1 19880519; CA 1296319 C 19920225; EP 0276724 A2 19880803; EP 0276724 A3 19900822; EP 0276724 B1 19940921; US 4875531 A 19891024
DOCDB simple family (application)
DE 3701914 A 19870123; CA 557188 A 19880122; EP 88100667 A 19880119; US 14867688 A 19880125