Lid assembly for a tape cassette which protects front and rear surfaces of a magnetic tape

摘要

A tape cassette comprises a case body having a mouth formed in the front portion thereof, a front lid pivotally supported thereon so as to cover the open front side of the case body, and a back lid pivotally joined to the front lid so as to cover a space extending behind the substantially lower half of an exposed portion of a magnetic tape in the mouth. The front lid includes a front wall covering the front opening of the mouth, side walls extending backward from the opposite side edges of the front wall, an upper wall covering the upper opening of the mouth, and a back wall extending downward from the upper wall. The side wall is provided with two guide grooves with two round projections projecting from the inner surface of the side wall being respectively received therein. Each of the two guide grooves has the shape of an arc of a circle having its center at the center of an imaginary circle at one end of the other guide groove. When the front lid is turned toward its opening position, one of the round projections moves first along the corresponding guide groove at the initial stage of turning of the front lid, and then the other round projection moves along the corresponding guide groove at the final stage of turning of the front lid.