Title:
DIGGING BIT
Document Type and Number:
WIPO Patent Application WO/2014/136727
Kind Code:
A1
Abstract:
A reaming section (13) is provided at the front end of a bit body (11) which is rotated about an axis (O), and the reaming section (13) has a greater diameter than the rear end of the bit body (11). Digging tips (15) are arranged at the front end of the reaming section (13). Earth discharge grooves (17) extending in the direction of the axis (O) are formed in the outer periphery of the reaming section (13). Connection grooves (18) connecting to the earth discharge grooves (17) are formed so as to extend from the outer periphery of the reaming section (13) to the rear end.
Inventors:
NAKAMURA KAZUYOSHI (JP)
OTA HIROSHI (JP)
OTA HIROSHI (JP)
Application Number:
PCT/JP2014/055313
Publication Date:
September 12, 2014
Filing Date:
March 03, 2014
Export Citation:
Assignee:
MITSUBISHI MATERIALS CORP (JP)
International Classes:
E21B10/36
Foreign References:
| JP2008174968A | 2008-07-31 | |||
| JPS38606Y1 | ||||
| JP4709226B2 | 2011-06-22 |
Other References:
See also references of EP 2966254A4
Attorney, Agent or Firm:
SHIGA Masatake et al. (JP)
Masatake Shiga (JP)
Masatake Shiga (JP)
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