Title:
DRILLING TOOL
Document Type and Number:
Japanese Patent JP2964739
Kind Code:
B2
Abstract:
PURPOSE: To make the diametral contraction of a block achievable without entailing any problem.
CONSTITUTION: Three blocks 11a are installed on the bottom of a device 2 free of rotation, and the blocks 11a are rotated by drilling resistance at the time of drilling a relative position of a block shaft 3a in relation to the blocks 11a, and thereby one side end 12a of the blocks 11a and a crossed part of a circular part are projected out as far as a portion of the specified drilled value from an outer circumferential surface of the device 2. At that time, both side ends 12a, 12b of the these blocks 11a come into contact with both side ends of these adjacent blocks 11a. In a drilling tool set up like this, in the device 2, is provided, a nozzle hole 18 being opened in a bottom central part of the device 2 and spraying a fluid is provided.
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Inventors:
SABURI AKIHIRO
HAYASHI TAKESHI
TSUJIMOTO KATSUAKI
HAYASHI TAKESHI
TSUJIMOTO KATSUAKI
Application Number:
JP28897991A
Publication Date:
October 18, 1999
Filing Date:
November 05, 1991
Export Citation:
Assignee:
MITSUBISHI MATERIARU KK
International Classes:
E21B10/32; E21B10/36; E21B10/60; (IPC1-7): E21B10/32; E21B10/36
Domestic Patent References:
| JP441891A | ||||
| JP6311789A | ||||
| JP5976391A | ||||
| JP6285592U |
Attorney, Agent or Firm:
Masatake Shiga (2 outside)