HEAD DRIVING DEVICE FOR FLOPPY DISK DRIVE

PURPOSE:To prevent the trouble of penetration and to lower loss torque fluctuation by rolling a supporting roller, which is fit to a pinion shaft, in a channel to be bored on the sleeve part upper surface, etc., of a head carriage while the height of the head carriage is held to be constant. CONSTITUTION:When a motor 10 is revolved and a pinion shaft 9 is operated, a head carriage 7 is displaced along a guide stick 2 together with a rack board R while a tooth part 9a, which is provided in the edge part of the pinion shaft 9, is engaged to a rack tooth part (t) of the board R. Then, the carriage 7 is moved to a prescribed position. At such a time, a roller 8 is rolled on a sleeve part 7a of the carriage 7. Since preload operation is operated when the rack tooth part (t) of the board R and the tooth part 9a of the pinion shaft 9 are engaged, back crush is not generated while both members are operated. Even when a change is generated in the engaging condition of the tooth parts of the both members, especially, in an interval by abrasion to be caused by friction between the tooth part (t) and tooth part 9a, the bad influence of the interval change is prevented from being generated by the abrasion between the both members since the height of the carriage 7 is regulated by the interval between the roller 8 and sleeve part 7a.