UMBRELLA-TYPE FISH-PROTECTING HEADBAND Russian patent published in 1994 - IPC

FIELD: hydraulic engineering. SUBSTANCE: water from water conduit passes through annular sucking-in unit and enters internal space of cup. Water stream acts on vibrator made in form of a ball and mounted with its central hole onto vertical axis which is fastened by flexible couplings to lower cap. Due to pulsation of suck-in speeds water flow makes vibrator to change its vertical position. Lower cap is connected rigidly to the bottom of the cup which reciprocates monotonously, as a result, young fishes are scarred away. EFFECT: improved efficiency. 2 cl, 3 dwg