首页>
外国专利>
Improvements made to machines for manufacturing the tubes by transformation, by welding together of their edges with the aid of electricity, tubes are brought together in a continuous section tubes, and, consequently, to said tubes themselves - same
Improvements made to machines for manufacturing the tubes by transformation, by welding together of their edges with the aid of electricity, tubes are brought together in a continuous section tubes, and, consequently, to said tubes themselves - same