Title:
【発明の名称】掘削工具
Document Type and Number:
Japanese Patent JP2785421
Kind Code:
B2
Inventors:
HAYASHI TAKESHI
SATO SHIGERU
TSUJIMOTO KATSUAKI
SATO SHIGERU
TSUJIMOTO KATSUAKI
Application Number:
JP4823590A
Publication Date:
August 13, 1998
Filing Date:
February 28, 1990
Export Citation:
Assignee:
MITSUBISHI MATERIARU KK
International Classes:
E21B10/32; E21B4/06; E21B6/00; E21B6/02; E21B10/38; (IPC1-7): E21B10/38; E21B4/06; E21B10/32
Domestic Patent References:
| JP5976391A |
Attorney, Agent or Firm:
Masatake Shiga (2 outside)