Title:
【発明の名称】ケリーバー型掘削機の掘削ロッド押込み装置
Document Type and Number:
Japanese Patent JP2796615
Kind Code:
B2
Inventors:
HIRAKAWA ETSUO
Application Number:
JP5494189A
Publication Date:
September 10, 1998
Filing Date:
March 09, 1989
Export Citation:
Assignee:
SANWA KIZAI KK
International Classes:
E21B19/08; E21B3/02; E21B3/035; E21B19/086; (IPC1-7): E21B3/02; E21B19/08
Domestic Patent References:
| JP5310762B2 | ||||
| JP5624754B2 |
Attorney, Agent or Firm:
Takefumi Tanaka (1 person outside)