PURPOSE: To make a tape well windable in a way of giving the tape a constant back tension at all times, by installing an auxiliary spring in series with a main spring impressing braking force to a brake shoe, while varying the braking force according to the back tension.

CONSTITUTION: When the winding diameter of a tape pad decreases whereby the back tension of a tape T grows large, a lever 44 tilts over in a clockwise direction. Motion of the lever 44 is transmitted to a movable plate 42 via wire cables 47 and 48, rotating the movable plate 42 in the clockwise direction as well. With this, a rod 36 is lifted up and an auxiliary spring 37 is compressed whereby it means that the lever 44 is being coupled with a main spring 40 in series via a brake shoe supporting frame 35 so that spring force of the main spring 40 is weakened as much as the spring force produced by compression of the auxiliary spring 37 and the pressure-sticking force of a brake shoe 34 is deadened. Therefore, braking force against a supporting block 30 is decreased, meaning that the back tension to be given to the tape T is also decreased to the extent of that deadened portion.