DRILLING METHOD OF ANCHOR HOLE

Title:

DRILLING METHOD OF ANCHOR HOLE

Document Type and Number:

Japanese Patent JPS54137401

Kind Code:

A

Inventors:

ICHIHARA KENICHI
HIROHATA YUKINORI
NAGAYAMA YOSHIHISA

Application Number:

JP4617778A

Publication Date:

October 25, 1979

Filing Date:

April 18, 1978

Export Citation:

Assignee:

TONE BORING CO

International Classes:

E21D20/00; E21B7/00; E21B7/20; E21B7/28; E21B10/32; E21D21/00; (IPC1-7): E21B7/00; E21C19/00

Domestic Patent References:

JPS518704A

1976-01-23

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