Document Type and Number:
Japanese Patent JPS6184791
Kind Code:
U
Application Number:
JP16929684U
Publication Date:
June 04, 1986
Filing Date:
November 09, 1984
Export Citation:
International Classes:
E21B4/10; E21B1/00; E21B1/22; E21B4/12; (IPC1-7): E21C3/16; E21B4/12