US Patent 6991533 Flow direction control mechanism

A flow direction control mechanism is provided, which includes at least a rotatable means provided in a passage of an electronic system or apparatus. The rotatable means moves to an open position by means of a force generated from fluids flowing through the passage and returns to a close position in the absence of the force. Further, a restrictor is disposed adjacent to the rotatable means for restricting movement of the rotatable means between the open position and the close position.