Closed forging press

In a hydraulic forging press having at least one press ram actuated reciprocatively through working oil by reciprocating motion of a pump ram given by mechanical driving means, a closed forging press being provided with at least one punch ram disposed in a position to communize said working oil with said press ram and perform double action with said press ram, and actuated through said working oil by reciprocating motion of said pump ram,

• said press ram and said punch ram being actuated in common by said working oil in the relation that said press ram and said punch ram communize said working oil in the state that said working oil is kept sealed in a cavity provided between said pump ram and said press ram and said punch ram during actuating of said working oil on the pressure areas of said punch ram and said press ram so that said working oil of said state continues to actuate said punch ram after finishing of the working of said press ram,
• said hydraulic forging press including a cylinder, said pump ram being reciprocatively mounted in one end of said cylinder and said press ram and said punch ram being reciprocatively mounted in the other end of said cylinder, with space between said pump ram and said press and punch rams filled with working oil and forming said cavity, and said punch ram being reciprocatively mounted in said press ram with one end open to said cavity whereby the working oil in said cavity is in working communication with said punch ram.