Title:
【発明の名称】穿孔ストリング要素
Document Type and Number:
Japanese Patent JP2952092
Kind Code:
B2
Abstract:
Drill string component for top hammer drilling comprising a rod (13) surrounded by a tube packet (4,5). The rod is provided with a thickened section (14) for cooperation with a diameter reduction (15) in the tube packet which at upwards drilling is situated below the section (14). Through this flushing liquid is prevented from flowing out of the drill string when the drill string is extended.
Inventors:
RENNARUTO DONSE
Application Number:
JP29565091A
Publication Date:
September 20, 1999
Filing Date:
November 12, 1991
Export Citation:
Assignee:
ATORASU KOPUKO KONSUTORAKUSHON ANDO MAININGU TEKUNIIKU AB
International Classes:
E21B7/20; E21B17/00; E21B21/00; E21C47/08; E21B21/10; E21B34/12; (IPC1-7): E21C7/08; E21B17/00; E21B34/12
Attorney, Agent or Firm:
Shigeru Yagita (2 outside)