Document Type and Number:
Japanese Patent JPS5474701
Kind Code:
U
Application Number:
JP14868677U
Publication Date:
May 28, 1979
Filing Date:
November 05, 1977
Export Citation:
International Classes:
E21B10/44; E21B17/22; (IPC1-7): E21C13/04; E02D17/144
Domestic Patent References:
| JPS5034724U | 1975-04-14 |