F04C18/40 - CPC Classification

Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups , , , , , or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group or and having a hinged member

• F04C18/44 » with vanes hinged to the inner member 13
• F04C18/46 » with vanes hinged to the outer member 13