Patent ID: 7018476

Claim:
An apparatus for applying a coating medium, the apparatus comprising: a substrate; at least one spray valve having a nozzle opening, said nozzle opening having an outlet area, the spray valve having a supply section arranged in front of said nozzle opening; a closing means cooperative with said nozzle opening for adjusting a size of said outlet area; a positioning means for positioning said closing means, said substrate being movable with respect to the spray valve; a supplying means connected by a supply line to the spray valve for supplying the spray valve with the coating medium under pressure, said closing means being continuously adjustable by said positioning means within a desired adjustment field; a regulator means assigned to said positioning means, said regulator means having at least one target value input for setting an instantaneously required outflow rate of the coating medium from the spray valve, said regulator means for setting at least one input value for a mass flow rate of the coating medium through said supply section, said regulator means for creating an adjustment signal which moves said positioning means relative to a deviation between the target value input and the input value for the mass flow rate, the spray valve having a spraying head, said nozzle opening formed on a conical nozzle, said conical nozzle emerging from a storage chamber connected to said supply line, said closing means being a needle valve cooperative with said nozzle opening, said positioning means for axially moving said needle valve in said nozzle opening, said regulator means for controlling said positioning means, said positioning means being a linear motor with a current supply, said regulator means for regulating said current supply to said linear motor, the target value input being adjustable by said regulator means relative to a desired coating thickness profile over a length of said substrate movable with respect to the spray valve; and a path measurement means for detecting a position of said substrate relative to the spray nozzle, said path measurement means having an output corresponding to said target value input, said regulator means for forming a target value for the outflow rate from an instantaneous value of the position of said substrate and the desired profile coating thickness at the position of said substrate.