1372931 Tape cassettes SONY CORP 29 Feb 1972 [8 March 1971] 9412/72 Heading G5R In a cassette 1, a flexible sheet member 25 is mounted with one end 26 fixed and one end 27 free, across an aperture 14, and normally maintains a tape 6 taut across the aperture, e.g. as at the full line in Fig. 3. Positive engagement of the tape with a pin 22 of a tape loop forming mechanism (generally not shown) is therefore ensured when the pin 22 is retracted in the direction 24, 24<SP>1</SP> from the cassette. In practice, the member 25 is deflected to a position 25<SP>1</SP>, but then springs back when pin 22 passes by. The sheet member 25 may support a cleaning film 31, Fig. 5, or a low friction coating (29, Fig. 4, not shown), and the cassette aperture 14 may be closed by a spring loaded lid 7, as described with reference to Figs. 1, 2 (not shown).