Movable barrier for e.g. maintaining objective low water level of stream, has upper panel with surface that is situated above objective low water level, where pressure exerted by current acts on surface in opening direction of valve

摘要

The barrier has a valve composed of three parts i.e. closing panel (D3), opening panel (D4) and an upper panel (D5), that are movable around a rotation axis (C). The valve is actuated i.e. opened and closed, following the axis by the flow of water. The upper panel has a surface situated above an objective low water level, where pressure exerted by a current acts on the surface in an opening direction of the valve to permit maximal natural flow of water. The panel (D3) is situated at the left of the rotation axis, and the panels (D4, D5) are situated at the right of the rotation axis.