Document Type and Number:
Japanese Patent JPS4856615
Kind Code:
U
Application Number:
JP9987771U
Publication Date:
July 19, 1973
Filing Date:
October 27, 1971
Export Citation:
International Classes:
F16L21/08; E21B17/08; F16B2/00; F16B7/18; F16B39/00; F16B39/12; (IPC1-7): E21B17/08
Domestic Patent References:
| JPS4430299Y1 | 1969-12-13 | |||
| JP31007958A | ||||
| JPS3610009Y1 |