Title:
液体駆動式ダウンホール鑽孔機
Document Type and Number:
Japanese Patent JP4009252
Kind Code:
B2
Abstract:
In a liquid downhole drilling machine, the guiding bushing ( 31 ) for the drill bit is rotatably journaled in the housing ( 11, 12 ) and, via a one-way coupling ( 29 ), coupled to a turning sleeve ( 22 ) that has axial ridges ( 24 ) that bound a number of chambers ( 25, 26, 27 ) and form turning pistons for turning the turnable sleeve to and fro. A number of these chambers are coupled to be pressurized and depressurized simultaneously with said pressure chamber ( 47 ) with the piston area ( 46 ) for urging the piston hammer ( 30 ) forwards. As a result, the drill bit ( 13 ) will be indexed a defined angle between each impact so that the button inserts of the drill bit will change contact points with the rock between every impact and fragment the rock efficiently. The drill tube is not rotated.
Inventors:
Fredrik Egerstrom
Application Number:
JP2003564384A
Publication Date:
November 14, 2007
Filing Date:
November 20, 2002
Export Citation:
Assignee:
Vasara Actie Borrag
International Classes:
E21B6/08
Foreign References:
| US3978931 | ||||
| US4103746 |
Attorney, Agent or Firm:
Chika Takagi
Junji Yuda
Shoji Miwa
Junji Yuda
Shoji Miwa