EP 0374788 A3 19910313 - TELESCOPIC DRILL STRING
Title (en)
TELESCOPIC DRILL STRING
Publication
Application
Priority
DE 8815738 U 19881219
Abstract (en)
[origin: EP0374788A2] In a telescopic drill string which contains an inner rod (4) and at least one further string part (3) coaxial to the inner rod (4), the string parts being provided with means for transmitting torque and for transmitting a pressure force in the direction of a connecting piece (9) for a tool, a coupling device (11) is provided for the inner rod (4) and the string part (3) adjacent to it. The coupling device (11) has a removable coupling part (16) overlapping a shock absorber (10) of the inner rod (4) in the mounted state and leaving the inner rod (4) with limited axial mobility relative to the adjacent string part (3). <IMAGE>
IPC 1-7
IPC 8 full level
E21B 17/07 (2006.01)
CPC (source: EP)
E21B 17/07 (2013.01)
Citation (search report)
- [A] US 3763666 A 19731009 - TIBUSSEK F
- [A] US 3517760 A 19700630 - KEHRBERGER ACHIM
- [A] FR 1554490 A 19690117
- [XP] DE 8815738 U1 19890202
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI NL
DOCDB simple family (publication)
EP 0374788 A2 19900627; EP 0374788 A3 19910313; EP 0374788 B1 19950405; AT E120829 T1 19950415; DE 58909164 D1 19950511; DE 8815738 U1 19890202
DOCDB simple family (application)
EP 89123365 A 19891218; AT 89123365 T 19891218; DE 58909164 T 19891218; DE 8815738 U 19881219