.~.~ Inlet or discharge controlled by cooperating port in reciprocating cylinder and fixed member
DEFINITION
Classification: 417/466
(under subclass 460) Apparatus in which the cylinder has an absolute to-and-fro motion along a fixed axis and is provided with an external portion forming a chamber communicating port, said port forming portion being in sliding engagement with and movable relative to a stationary element having at least one port, movement of said cylinder relative to said stationary element serving to change the relative alignment of said ports for controlling the flow of pumped fluid to or from the pump chamber.
