Document Type and Number:
Japanese Patent JPS56116496
Kind Code:
U
Application Number:
JP1495780U
Publication Date:
September 07, 1981
Filing Date:
February 06, 1980
Export Citation:
International Classes:
E02D7/18; E02D7/02; E21B1/02; E21B43/10; (IPC1-7): E21B43/10; E02D7/02
Domestic Patent References:
| JPS4742303A |