Patent ID: 7404528
Filing Date: 2008-07-29
Classification: G11B

Abstract:
1. A recording tape cartridge, comprising: a case for accommodating a reel on which a recording tape is wound; a brake member provided non-rotatably with respect to the case, the brake member being capable of being moved to selectively assume a rotation locking position where the brake member is disposed in engagement with the reel thereby preventing the reel from being rotated and a rotation permitting position where the brake member is disposed out of engagement with the reel thereby permitting the reel to be rotated; an engagement projection provided on the brake member, the engagement projection having a first tapered surface formed on an end portion thereof; a lock member provided in a mounting portion formed on an inner surface of a top plate of the case, the lock member being slidable in a radial direction of the reel, the lock member being arranged, when the brake member assumes the rotation locking position, to be interposed between an upper surface of the reel and the top plate of the case thereby preventing the reel from being moved axially, lock member being also arranged, when the brake member is moved to assume the rotation permitting position, to be removed from between the upper surface of the reel and the top plate of the case in interlocking relationship with the movement for the brake member to assume the rotation permitting position thereby permitting the reel to be moved axially; a cam portion provided on the lock member, the cam portion being engageable with the engagement projection and having a second tapered surface formed on an end thereof; a stabilizing portion provided on the lock member more inward than the cam portion in a radial direction of the reel, a falling-out preventing member for preventing the lock member from falling out from the mounting portion; wherein a clearance between the first tapered surface and the second tapered surface at the rotation locking position in a direction of the movement of the brake member is made shorter than a length of movement stroke of the brake member from the rotation locking position to the rotation permitting position; wherein a reactive force against a torque imparted to the lock member when the first tapered surface contacts the second tapered surface is produced by the stabilizing portion and the falling-out preventing member.