Adjustable orifice air knife

An adjustable orifice fluid knife comprising;

• a supporting structure adapted to be connected to a source of fluid, a passage network on the supporting structure terminating in an opening for transmittal of fluid from the fluid source and out of the opening, a nozzle assembly on the supporting structure in alignment with the opening for directing the flow of fluid therefrom in a controlled high velocity stream capable of acting as a knife, the nozzle assembly including a fixed plate on one side of the opening at the predetermined angle with respect to the opening and a bar assembly on the opposite side of the opening and including an adjustable blade of very thin highly flexible spring-like material on the blade assembly responsive to adjustment means at closely spaced points to be angularly substantially flexed with respect to the opening and the fixed plate to a variety of different positions at the same time at different closely spaced points to provide an adjustable variable gap along its length with each point being adjustable independent of other points along the length thereby providing simultaneously for a non-uniform range of orifice sizes between open and closed position along the length of the blade and within a short portion thereof in alignment with the opening for passage of fluid therethrough.