Reel shaft device of a magnetic recording tape running apparatus

摘要

A reel shaft device comprises a reel hub engaging member; a rotating member capable of rotating relatively to the reel hub engaging member; a driving member having a circumferential surface facing a circumferential surface of the rotating member and capable of rotating eccentrically with the reel hub engaging member, the driving member to be rotated by a rotary power supply means; a plurality of rolling members disposed between the circumferential surfaces so as to be able to rotate; a cam member disposed on the surface of said rotating member, the cam member holding the rolling members in cooperation with the surface of the driving member to rotate the rotating member together with the driving member in one direction when the driving member rotates in the one direction, and releasing the hold of the rolling members to allow the rotating member to rotate independently of the driving member when the driving member rotates in the other direction; and a variable rotation transmitting means formed of felt and capable of variable transmitting rotation between the reel hub engaging member and the rotating member.