Patent ID: 8800821

Claim:
A pump for liquid color comprising: a) a one piece PVC plastic fitting of integral construction having an inlet, an outlet and a pumping chamber positioned between the inlet and outlet; b) a piston moveable into the chamber via a third chamber aperture that is in addition to the inlet and the outlet, to displace liquid color from the chamber and out of the fitting via the outlet; c) a cylinder for driving the piston into the chamber; d) a spring for biasing the piston outwardly of the chamber, in opposition to force applied by the cylinder, the spring being positioned at the third chamber aperture; e) a check valve at the conduit inlet, permitting fluid flow into the chamber, but precluding fluid flow out of the chamber responsively to piston displacement into the chamber; and f) a check valve at the conduit outlet permitting fluid flow out of the chamber responsively to fluid pressure increase resulting from piston displacement into the chamber.