CPC F16K 11/07 (2013.01) [F15B 15/223 (2013.01); F15B 21/14 (2013.01); F16K 3/24 (2013.01); F15B 2211/7052 (2013.01); F15B 2211/755 (2013.01)] | 8 Claims |
1. A spool valve for controlling the flow of a fluid into a reciprocating piston cylinder, comprising:
an outer casing;
a spool slideably inserted into the casing, the spool valve having a first and a second non-waisted end portions and having a waisted middle portion;
an intake port for fluids entering the casing;
an output port for fluids exiting the casing;
wherein a first non-waisted end portion covers the intake port during a first valve-closed event as the spool slides in one direction within the casing to a first position;
wherein the waisted middle portion is sufficiently wide to uncover both the intake port and the output port during a valve-open event as the spool slides in the one direction within the casing to a second position;
wherein a second non-waisted end portion covers the output port during a second valve-closed event as the spool slides in the one direction within the casing to a third position; and
wherein the spool is operable to prevent the flow of the fluid into or out of the casing during the first valve-closed event and the second valve closed event.
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