Magnetic tape cassette with tape locking means

Claim 1

A magnetic tape cassette of the type having a pair of hubs (4) on which a magnetic tape (T) is wound; said cassette further including: normally activated braking means (6) for preventing rotation of at least one of said hubs when activated said braking means including a braking member extending in a substantially longitudinal direction of said cassette, and said braking member including a pair of protrusions (7) thereon for contacting respective ones of said pair of hubs when said braking means is activated; and means for automatically deactivating said braking means upon insertion of said cassette into a cassette machine, wherein said cassette further includes a cassette casing having an opening through which said magnetic tape can be accessed, and a movable guard member (8) for covering at least a portion of said opening, said means for deactivating comprises coupling means for coupling said guard member to said braking member, whereby said protrusions are moved out of engagement with said hubs when said guard member is opened, and wherein said guard member includes means (17b) for contacting said braking member to maintain said protrusions in engagement with said hubs when said guard member is closed.