| 摘要 |
PROBLEM TO BE SOLVED: To prevent backlash by an inexpensive structure, to obtain a stable pressing force, to reduce costs, and to reduce the number of assembling steps. SOLUTION: A head lift body 42 used for the head feeding mechanism 40 for moving a head assembly 30 up and down in an axial direction of a vertically extended shaft is provided with a through hole on a center axis part to pass through a lead screw 41, a hollow opening for housing a backlash prevention mechanism 43 of a simple structure to always press the head lift body 42 along the rotational center axis of the lead screw 41, and with a guide part 47 fitted to a guide bar fixed to a housing by the rotation of the lead screw 41 to prevent the rotation of a main body, and to guide its own body for vertical movement, which are integrally formed by a resin mold. The backlash prevention mechanism 43 is simply constituted of a pressurization bush 431 and a pressurization spring 432. |
