TAPE TAKE-UP MECHANISM FOR MAGNETIC RECORDING AND REPRODUCING DEVICE

PURPOSE:To keep tape tension almost at a constant value even at the time of reviewing and to obtain a stable head touch capacity at a cylinder part equipped with a rotary magnetic head, by changing the take-up torque of a reel board on a supply side corresponding to the winding diameter of a tape. CONSTITUTION:A force transmitted from a gear 12 to an input side gear 6 is transmitted to the reel board 3 by the magnetic forces of a metallic piece 5 and a magnet 9 provided on planes confronting with each other via an output side gear 8. A spherical member 7 is inserted and arranged between planes confronted oppositely of the input side gear 6 and the output side gear 8 with an oblique plane of an angle (alpha). When the spherical member 7 is displaced in a radius direction corresponding to relative angular velocity between both gears 6 and 8 and an interval between both gears is changed from h1 to h2, the magnetic force between the bears is also changed. Therefore, since the take-up torque of the reel board 3 can be changed corresponding to the take-up diameter of the tape, it is possible to keep the tape tension from the start to the end of tape winding at the time of reviewing constant.