A nutating pump is disclosed which has a modified piston and housing or
casing that provides two distinct pump chambers or areas. Output from the
first pump chamber is delivered during a first half of the dispense cycle
or the piston movement cycle. A substantial portion of this output is
held for delivery by the second chamber during a second part or half of
the dispense cycle. Thus, the output generated by the pump is not altered
or reduced, it is delivered over the entire piston movement cycle as
opposed to prior art pumps which deliver all of the fluid during a first
half or first portion of the piston movement cycle. In this way, superior
pulse modification is achieved as fluid is delivered across the entire
piston movement cycle as opposed to a first half or first portion of the
piston movement cycle. In additional embodiments disclosed, two distinct
chambers are also provided but each chamber generates its own output as
the piston includes two machined or flat sections for active pumping.
Thus, each chamber generates its own positive output flow but the flow
from each chamber is delivered during a different half of the piston
movement cycle. Thus, the flow is still distributed throughout the entire
piston movement cycle. In the first embodiment with a first and second
chamber, the second chamber essentially acts as a holding station for
fluid to be delivered during a second half of the piston movement cycle.