Patent ID: 6914754
Filing Date: 2005-07-05
Classification: G11B,Y10T

Abstract:
1. A head feeding mechanism for moving a head assembly in a vertical direction perpendicular to a housing base, said head feeding mechanism comprising: a lead screw having an external thread formed on an outer surface thereof, said lead screw being mounted on said housing base to be rotatable around a screw center axis extending in said vertical direction; a head lift body integrally formed as a head lift assembly by resin molding and mounted on said lead screw above said housing base so as to be nonrotatable but movable in the vertical direction, said head lift assembly comprising a portion for fixedly supporting the head assembly thereon, a hollow portion, a vertical through-hole which includes said hollow portion and which receives said lead screw passing therethrough, and a guide portion slidably fitted to a guide bar extending in the vertical direction; a nut embedded in a bottom of said hollow portion to be integral with said head lift body, said nut having an internal thread formed thereon for engaging with said external thread of said lead screw; and a backlash preventing mechanism placed in said hollow portion of said head lift body and having an internal thread formed thereon for engaging with the external thread of said lead screw; wherein said backlash preventing mechanism continuously presses said head lift body in a first direction along the screw center axis of said lead screw and continuously presses itself in a second direction opposite to the first direction.