Patent ID: 6563671
Filing Date: 2003-05-13
Classification: G11B

Abstract:
A magnetic tape cartridge comprising a cartridge casing, a single reel around which a magnetic tape is wound and which is contained in the cartridge casing for rotation, the reel having a reel hub in the form of a cylindrical member which has a bottom wall and is provided with an opening and a stopper gear formed on the bottom wall, and a brake means which is provided with a brake gear and is movable up and down between an operative position where the brake gear is brought into engagement with the stopper gear to prevent rotation of the reel and a retracted position where the brake gear is disengaged from the stopper gear to permit rotation of the reel, the brake means being normally urged toward the operative position and moved to the retracted position by a pusher member of a tape drive system which acts on the brake means through the opening in the reel hub when the magnetic tape cartridge is loaded in the tape drive system,wherein the improvement comprises that a continuous wall portion is erected around the opening in the reel hub, and the brake means comprises a horizontal portion which is disposed above the opening in the reel hub and receives force from the pusher member when the brake means is moved to the retracted position and a continuous skirt portion which extends downward from the horizontal portion and is in contact with the continuous wall portion of the reel hub, thereby closing the opening together with the horizontal portion, the brake means being moved between the operative position and the retracted position with the skirt portion kept in contact with the continuous wall portion of the reel hub.