by using a valve in a system with several pumping chambers wherein the flow-path through the chambers can be changed, e.g. between series and parallel flow

Full Title

Multi-cylinder machines or pumps characterised by number or arrangement of cylinders (machines or pumps with pistons coacting within one cylinder F04B3/00) > having cylinders in star- or fan-arrangement > Control > by using a valve in a system with several pumping chambers wherein the flow-path through the chambers can be changed, e.g. between series and parallel flow