Patent ID: 7097121

Claim:
A color change valve arrangement for selectively connecting an applicator of a coating plant to a plurality of supply lines for coating material of different selectable colors, the arrangement comprising: a plurality of valve assemblies, each of the plurality of valve assemblies associated with at least one of the selectable colors and each of the plurality of valve assemblies including: an outlet port through a valve housing for the coating material flowing toward the applicator, the outlet port forming a valve seat; a valve needle movably carried in the valve housing, the valve needle having a sealing surface abutting the valve seat when the valve is closed; at least one piston connected to the valve needle, the at least one piston operable by a pressure medium to move the valve needle; means for exerting a force on the valve needle, the exerting means positioned to exert the force oppositely directed to pressure from the pressure medium; and at least one drive device for applying the pressure medium to the at least one piston; and a common passage wherein an outlet port of each of the plurality of valve assemblies open into the common passage wherein at least two of the plurality of valve assemblies having valve needle places parallel to each are disposed next to each other along the common passage; and wherein each of the plurality of valve assemblies further comprises means for at least one of amplifying a force exerted by the drive device on the piston and reducing a force in the opposite direction that the drive device is operable to overcome.