(under subclass 437) Apparatus including two or more
distributors through which the pumped fluid must pass serially in the course of flowing to the pump chamber or from the pump chamber to the point of use, each distributor having a cyclically moved flow controlling element which is capable of or constrained to move relative to the flow controlling element of another.
SEE OR SEARCH THIS CLASS, SUBCLASS:
502, for multiple cyclic outlet paths from a single pump chamber including a cyclically controlled bypass valve downstream of the discharge distributor from the chamber.
