Abstract: To reduce the number of parts and simplify the structure by permitting the forward-rotation components and the reverse-rotation components to share a mechanism of transmitting the driving force to a pair of reel blocks 42F,42R. A pair of capstans 41F,41R respectively serving for forward rotation and reverse rotation and a pair of reel blocks 42F,42R respectively serving for forward rotation and reverse rotation are provided. One of the capstans, i. e. the capstan 41F, is provided with a low-speed gear 48, while the other capstan 41R is provided with a high-speed gear 49. The reel blocks 42F,42R are respectively provided with reel gears 50F,50R.

Abstract: Preselected teeth of a gear tooth are truncated by removing their radially outermost ends. Thus, whenever teeth that should mesh become misaligned, the truncation allows the teeth to quickly return to their proper meshing. This reduces the sound generated by nonmeshing teeth. In a tape player using gears having preselected truncated teeth, an idler arm carries an idler gear at its free end and is pivotal into first, neutral, and second positions. At low speed operation, when a cassette is in the player, a pair of driving gears are not intermeshed, and the first position of the idler gear causes recording or playing back and the second position causes rewinding. At high speed operation, when no cassette is in the tape player, the driving gears are intermeshed, and the first and second positions of the idler arm cause fast forwarding and rewinding, respectively.