Abstract: Relatively thin microdisc cassette cases having a generally rectangular parallelpiped shape and adapted to house therewithin a standardized 3.5-inch flexible magnetic disc, include a pair of opposing planar cassette case halves, and detent members for joining these cassette case halves one to another in face-to-face relationship. The detent members include a number of registered male and female detents which are sized and configured so as to be in an interference friction fit with one another. In such a manner, the cassette case halves are securely joined one to another without necessarily employing conventional ultrasonic welding techniques. However, the cassette case halves may nonetheless be separated upon application of a separatory force of sufficient magnitude. Preferably, the cassette case halves, and hence the male and female detent members, are unitarily molded from a polyacetal resin.

Abstract: A flexible magnetic disc cassette includes a cassette case formed of a molded plastics material defining an interior space and a window which opens thereinto. A flexible magnetic disc having a central hub is rotatably accommodated with the interior space of the cassette case such that the magnetic disc is exposed beneath said cassette case window. A shutter formed of a plastics material (which may be the same or different than the plastics material form which said cassette case is formed) straddles an edge of the cassette case adjacent to its defined window. The shutter is reciprocally movable along the edge between a closed position (wherein said shutter covers the window) and an opened position (wherein the shutter exposes the window to allow access to said magnetic disc therebeneath). According to the invention disclosed herein, an elongate spring element is integrally molded (unitary) with either the cassette case or the shutter and so as to occupy a position within a corner pocket of the cassette case.