Oblon, Fisher, Spivak, McClelland, & Maier
Magnetic tape cassette
 A magnetic tape cassette has a pair of tape reels contained in a lower casing in a rotatable manner and a leaf spring fixed to an upper casing to press down at the free end portions central projections of the tape reels, wherein the leaf spring is formed to have a substantially arcuate central portion and linear free end portions under non-loading condition, the free end portions being respectively in contact with the top of the central projection. 
TDK Corporation
G
G11B
inventional
Haruo Masatoshi Makoto
Shiba Okamura Saito