Patent ID: 7547389

Claim:
A bottom seal at the lower end of a step screen provided with a grating and adapted to convey solid particles and objects positioned in flowing water, the grating comprising alternately fixed and movable lamellar rods with intermediate gaps to allow the water to pass through the grating and with steps at their longitudinal edges upstream, the movable lamellar rods being movable in a closed motion path in their plane with an upwards component which is greater than the height of the steps, for step by step conveyance of the solid particles and the objects from the water and along the fixed lamellar rods to an outlet, the bottom seal extending substantially across the entire width of the grating to seal the ducts that arise between the fixed lamellar rods at their lowermost step as the movable lamellar rods move upwards between the fixed lamellar rods, the bottom seal comprising: at least one elongate bottom cover, connected at a longitudinal edge upstream to the step screen and guided at a longitudinal edge downstream on guides on the lowermost steps of the movable lamellar rods to follow the entire motion cycle of the moveable rods and, in the motion, being pivotable up and down close to and past the edges upstream on the lowermost steps of the fixed lamellar rods.