Document Type and Number:
Japanese Patent JPS5134881
Kind Code:
Y2
Application Number:
JP6602771U
Publication Date:
August 28, 1976
Filing Date:
July 24, 1971
Export Citation:
International Classes:
E21B17/01; B63B35/44; E21B7/12; E21B17/10; (IPC1-7): E21B17/10; B63B35/44