.~ By changing phasing of plural pistons in single chamber
DEFINITION
Classification: 417/215
(under subclass 212) Apparatus in which the pump comprises an expansible chamber-type pump having a plurality of relatively movable pumping elements working in a single pump chamber and relatively movable driving elements are connected to the pumping elements so that they may be driven into the pumping chamber together, e.g., in phase, or at different times, e.g., out of phase, to vary the volume of fluid pumped; the control means acting to change the relationship, e.g., phasing, between the driving elements to vary the output of the pump.
