A cover-locking device for a video tape cassette comprising a cover-locking pin having a lock-releasing protrusion and an engaging protrusion and being pivotably supported in a half-down of the cassette. The cover-locking device also comprises a push member integrally formed on the inner surface of a half-up of the cassette, and an operating member formed on the upper portion of the cover-locking pin. The operating member is always in contact with the push member.

A cassette cover opening mechanism has a cassette cover opening member for opening the cassette cover of a tape cassette when the cassette is loaded in a video tape recorder. The opening member has a first abutment portion and a second abutment portion. The first portion abuts against the lower edge of a front plate of the cassette cover to pivot the cover during a first half of the movement of a cassette holder from its first position to its second position. The second portion abuts against the lower edge of one of side plates of the cassette cover to further pivot the cover during a latter half of the movement of the cassette holder.

A miniature type tape cassette comprises a spring for urging a lid having a first hook in a lid closed direction and a lid locking member like an elastic plate having a projecting part, a second hook and a rear part. The projecting part projects from a side wall of a cassette case through a through window formed in the side wall. The second hook engages with the first hook when the lid is in a closed state. The rear part is fitted into a supporting part of the side wall in the tape cassette, so that the lid locking member is fixed to the side wall of the cassette case. The release of lock of the lid is carried out by pressing the projecting part of the lid locking member.

In a tape cassette housing including a lid which protects the tape at the front of the housing, and a lid locking member turnably pivoted in the housing and having two leg levers, one to lock the lid when the latter closes the front opening of the housing and the other to release the lid when the same is turned open, the distance between the rotational center of the pivot of the lid locking member and the crown of its head is longer than the distance between the center of pivot bearing in the housing and the rear wall of a space in which the lid locking member is mounted.

In a magnetic tape cassette comprising a cassette housing, a lid pivotally connected to the front of the housing to open and close its front opening, and a lock member fitted in one front side portion of the housing and engageable with and disengageable from the inner surface of the lid, a lock-member-biasing spring is accommodated within the thickness of the lock member, with a free end engaged with the housing. The lock member has means with which to press the both end portions of the spring in place. It has also a bulge formed on its side opposite to the recessed side and which is larger in diameter than a pivot by which the lock member is supported by the housing. The bulge is accommodated within a wall opening of the cassette housing.