Document Type and Number:
Japanese Patent JPS56105556
Kind Code:
U
Application Number:
JP274680U
Publication Date:
August 17, 1981
Filing Date:
January 14, 1980
Export Citation:
International Classes:
E21B1/38; E02F3/02; (IPC1-7): E02F3/02
Domestic Patent References:
| JP41002681A |