Michael A Mccarty

US Patent:

20080168917, Jul 17, 2008

Filed:

Jan 12, 2007

Appl. No.:

11/653722

Inventors:

Michael McCarty - Harrisonville MO, US

International Classification:

B41F 1/46

US Classification:

101363

Abstract:

A valve assembly includes a digitally controlled piston residing in a cylinder interior of a cylinder, and provides a linear flow rate versus piston position. Ink is pumped into a housing interior containing the cylinder. The ink flows from the housing interior into the cylinder interior through a tapered orifice in the cylinder, then from the cylinder interior to a printing press. The tapered orifice is aligned with the direction of travel of the piston and the position of the piston in the valve body is controlled by a stepper motor to determine how much of the tapered orifice is uncovered by the piston. The tapered orifice is designed to compensate for a pressure drop in the housing interior as the valve assembly opens to allow more flow, and results in the linear relationship between the piston position and the flow rate through the orifice.