Document Type and Number:
Japanese Patent JPH0230546
Kind Code:
Y2
Application Number:
JP13368882U
Publication Date:
August 16, 1990
Filing Date:
September 02, 1982
Export Citation:
International Classes:
E21B17/10; E02D17/13; E02F5/02; E21B3/02; E21B12/00; (IPC1-7): E21B3/02; E02D17/13; E21B12/00