Title:
EARTH DRILL
Document Type and Number:
Japanese Patent JP3519041
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an earth drill enabling execution of excavation without lifting of a boom even when the thrust-in force of a thrustor cylinder is the maximum.
SOLUTION: A boom 2 is erected on a base machine 1 by holding it in stretch from the rear by a derricking rope 2a so that it can be dipped and elevated, and a kelly bar 3 equipped with an excavating bucket 8 at the fore end is suspended from the upper end of the boom 2, while a front frame 6 whereon a kelly bar driving device 5 is mounted with the thrustor cylinder 7 interposed is provided in the lower part of the boom 2 so that it can be turned up and down. In the earth drill thus constituted, a rotation fixing device 10a engaging the boom 2 to prevent it from rotating to the rear side when the thrustor cylinder 7 operates to thrust in is interposed between the boom 2 and the base machine 1.
Inventors:
Murate, Tokuo
Application Number:
JP2000138574A
Publication Date:
April 12, 2004
Filing Date:
May 11, 2000
Export Citation:
Assignee:
NIPPON SHARYO SEIZO KAISHA LTD
International Classes:
E21B11/00; E21B3/02; E21B3/03; E21B15/00; (IPC1-7): E21B3/02; E21B15/00
Attorney, Agent or Firm:
足立 勉 （外１名）