Document Type and Number:
Japanese Patent JPS57137693
Kind Code:
U
Application Number:
JP2147781U
Publication Date:
August 27, 1982
Filing Date:
February 19, 1981
Export Citation:
International Classes:
B25D9/26; E21B1/00; E21B1/26; G05D13/62; (IPC1-7): E21C3/20; G05D13/62