Document Type and Number:
Japanese Patent JPH0344871
Kind Code:
Y2
Application Number:
JP10001084U
Publication Date:
September 20, 1991
Filing Date:
July 04, 1984
Export Citation:
International Classes:
E02F5/18; E21B7/00; E21B7/02; E21B7/04; E21B10/44; (IPC1-7): E21B7/00