Link mechanism

A link mechanism capable of setting any desirable speed of opening/closing a lid during a series of the opening/closing operation and capable of exerting a strong driving force is provided. A lid is attached to a lid bracket. The lid bracket is pivotally connected to a driving lever and a coupled-driving lever with which the lid is opened or closed. The driving lever is provided with a cam having an elongated hole, into which a driving pin provided to a sector gear is fitted. The sector gear is driven by a motor through a pinion. According to rotation of the sector gear, the driving pin moves in the elongated hole and drives the driving lever. Since the distance between the center of the sector gear and the driving pin is larger than the radius of the pinion, such mechanism exerts a strong driving force.