Title:
LOCK RELEASE CONFIRMATION DEVICE FOR ROTARY TABLE AND LOCKING KELLY-BAR IN EARTH DRILL
Document Type and Number:
Japanese Patent JP3502922
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a rotary table with a lock release confirmation device for easily recognizing from the outside whether lock is released or not when releasing lock between a kelly-bar 3 and the rotary table 6 for driving the kelly-bar 3, in unlocking to shorten the kelly-bar 3 and hoisting by a base machine since the kelly-bar 3 is locked in the extended state in order to excavate underground and to discharge excavated earth taken in with a bucket or an auger, onto the ground in the case of excavating using the locking kelly- bar 3 in an earth drill.
SOLUTION: In the locking kelly-bar and the rotary table for driving locking kelly-bar in the earth drill, a cover is fitted to the lower part of the rotary table, and the bottom face of the cover is provided with a display body allowing the discrimination of a lock/unlock state by visual observation.
Inventors:
Junichi Hasezawa
Application Number:
JP2000154946A
Publication Date:
March 02, 2004
Filing Date:
May 25, 2000
Export Citation:
Assignee:
Sumitomo Heavy Industries Construction Crane Co., Ltd.
International Classes:
E21B3/04; (IPC1-7): E21B3/04
Domestic Patent References:
| JP57174590U | ||||
| JP547819Y2 |
Attorney, Agent or Firm:
Isamu Ohashi (1 outside)