Magnetic tape cassette having friction sheet protruding portions with wavily curved side edges

摘要

A magnetic tape cassette including a pair of hubs which are rotatably supported in an internal opening defined between upper and lower half portions of a body of the cassette and on which a magnetic tape is wound, and friction sheets provided between the tops and bottoms of the hubs and the upper and lower inside surfaces of the cassette. Each of the sheets includes projecting portions having substantially rectangular cross sections and extending substantially in a longitudinal direction of the sheet so that the protruding portions reach both ends of the sheet and at least two hub holes are located between the protruding portions. At least one side edge of the top of each of the protruding portions is wavily curved, and the width of each of the protruding portions is relatively small at both ends of the protruding portion. The hubs and the tape are supported by tops of the protruding portions.