Method of molding fluidic oscillator devices

1. A method of making a fluidic oscillator device having at least a power nozzle for projecting a jet of liquid into an interaction region with an upstream end, opposing side walls, opposing top and bottom walls, and a pair of control ports at the upstream end, one control port juxtaposed to the respective sides of said interaction region, an inertance loop passage and an inertance loop connecting said pair of control ports, said opposing side walls diverging from said power nozzle, comprising:

providing a mold cavity in which said power nozzle, interaction region and control ports can be molded as a core without any seam lines,

filling said mold cavity with a solidifieable plastic,

removing said core from said mold cavity, and

providing top and bottom inertance plates with channels which form an inertance loop with said inertance loop passage and connecting said pair of control ports for controlling the frequency of oscillation, the said body of the fluidic oscillator device being capable of assembly with top and bottom inertance plates with different lengths of inertance loops, thereby providing oscillations with different operating frequencies.

2. A fluidic oscillator made according to the method defined in claim 1 .

3. A method defined in claim 1 wherein said interaction region is of the crossover type having a downstream end and in which the upstream end diverge and the downstream end converge to a common throat area and coupled to an outlet aperture, the further improvement comprising providing a further mold cavity in which said converging portion of said crossover type interaction region is formed as a second core having a joinder line to the first said core which is transverse to the direction of liquid flow in said fluidic,

filling said further mold cavity with a solidifieable plastic, and

removing said second core from said further mold cavity and joining said cores along said joinder line.

4. A fluidic oscillator made according to the method of claim 3 .

5. A method of molding a fluidic oscillator having at least a power nozzle for projecting a jet of liquid into an interaction region with upstream and downstream ends, opposing side walls, opposing top and bottom walls, and a pair of control ports at the upstream end of said interaction region, one control port juxtaposed to the respective sides of said interaction region, said side walls diverging from said power nozzle comprising:

providing a first mold cavity in which said power nozzle, the upstream end of said interaction region and control ports are molded as a core without any seam lines,

providing a second mold cavity in which the downstream end of said interaction region includes an exit throat, can be molded as a core without any seam lines,

filling said mold cavities with a solidifieable plastic, and

removing said cores from said mold cavities, and

joining said cores together along a line which is transverse to the direction of liquid flow through the oscillator.

6. The method defined in claim 5 , said fluidic oscillator has an inertance loop passage, including:

providing top and bottom inertance plates with channels which form an inertance loop with said inertance loop passage connecting said pair of control ports for controlling the frequency of oscillation, the said body of the fluidic oscillator device being capable of assembly with top and bottom inertance plates with different lengths of inertance loops, thereby providing oscillations with different operating frequencies.

7. A fluidic oscillator made according to the method defined in claim 6 .