Patent drawing - Original Hydril Annular BOP Patent Public domain image
Резюме
Patent Drawing of the Original Annular-type Blowout Preventer, by Hydril Corporation,
U.S. Patent 2,609,836 (1952).
Тэги
Дата
16/08/1946
Источник
USPTO
Ссылка
Информация о правах
public domain