| 摘要 |
<p>PURPOSE:To supply different back tension on a tape at the time of feeding the tape at fast and regular speed, by providing a selection means which brings into contact with a braking means by pressing selectively on braking planes with different friction coefficients of members to be controlled corresponding to the rotating speed of a tape reel board. CONSTITUTION:When a supplying reel board 8 is rotated, a moving member 38 is also rotated, and a centrifugal force functions in a direction of (c). Since the centrifugal force is increased as the increase of the rotating speed, the pressing force of a spring 39 is larger than the centrifugal force at the time of regular recording and reproduction, and the moving member 38 is positioned as shown in figure. Therefore, a brake band 14 is brought into contact with the braking plane 33 of the member 32 to be controlled by pressing, and brake is applied on the supply reel board 8, and appropriate back tension is applied on the magnetic tape 3. Next, at the time of feeding the tape at high speed, the supply reel board 8 is rotated at high speed, and the centrifugal force acting on the moving member 38 overcomes the pressing force of the spring 39, thereby, the moving member 38 overcomes the pressing force of the spring 39, thereby, the moving member 38 is moved in the direction of (c), and consequently, the member 32 to be controlled being pressed by a flat spring 35 is lowered in a direction of (d), and the brake band 4 is brought into contact with the braking plane 34 of the member 32 to be controlled by pressing.</p> |
