A disk-jacket assembly including a flexible disk rotatably disposed in a square jacket having radially extending registering slots in its two thicknesses for receiving a pair of opposite transducers or alternately a single transducer in one slot and a pressure member in the other slot. Panels of porous...http://www.google.fr/patents/US4263634?utm_source=gb-gplus-shareBrevet US4263634 - Magnetic disk-jacket assembly
