Reel brake operable from both sides of magnetic tape cassette

A magnetic tape cassette comprising:

• a cassette casing having upper and lower parts, each part having a respective insertion aperture formed therein, the insertion apertures being in mutual axial alignment;
• and
• braking means provided within said cassette casing in such a manner that said braking means can be brought in contact with or come away from peripheral surfaces of a pair of real hubs arranged in said casing and around which a magnetic tape is wrapped and said braking means is spring-biased in a locking direction in which first and second front protruding members integrally formed with and rigidly extending from said braking means are respectively urged against said reel hubs, and said braking means having integrally formed therewith inclined cam surfaces on upper and lower sides relative to said upper and lower parts of the cassette casing and said inclined cam surfaces being aligned with said insertion apertures, so as to be pushed by a pin inserted through any one of said insertion apertures formed through said upper and lower parts of said cassette casing, whereby a hub lock releasing operation by said braking means is performed and wherein said braking means is provided with a pair of integrally formed, oppositely arranged rear protruded portions extending substantially perpendicular from a direction in which said first and second front protruding members extend, so that when the braking means is moved in a skewed fashion in the hub lock releasing operation one of the pair of rear protruded portions is brought in contact with a portion of said lower part of said cassette casing and the braking means is returned to an unskewed position in the hub lock releasing operation.