Patent ID: 6974378

Claim:
A ventilator, comprising: a case formed with a supply opening, the case having walls opposite to each other formed respectively with a plurality of shaft holes arranged with predetermined intervals; an operating louver having two longitudinal margins opposite to each other and two lateral ends opposite to each other, each one of the two lateral ends of the operating louver provided with a shaft pin respectively being inserted into the shaft holes, one end of the two lateral ends of the operating louver provided with an operating pin; a train louver having two longitudinal margins opposite to each other and two lateral ends opposite to each other, each one of the two lateral ends of the train louver provided with a shaft pin respectively being inserted into the shaft holes, one end of the two lateral ends of the train louver provided with another operating pin; and a link formed with a plurality of operation holes receiving the operating pin of the operating louver and the operating pin of the train louver, the link transmitting motion of the operating louver to the train louver so that the operating louver and the train louver jointly shut the supply opening at swing limit of the operating louver in a manner such that one of the margins of the operating louver and one of the margins of the train louver meet each other, and a biasing device biasing the meeting state of the operating louver and the train louver and, wherein gaps (A) between the operation holes on the link are set so as to be larger than a gap (B) between a line connecting the shaft pins of operating louver and the operating pin of the operating louver, the operating pin of the operating louver being located at the one of the margins of the operating louver (A >B).