Patent ID: 6844997

Claim:
A head feeding mechanism for linearly moving a head assembly along guide bar arranged on a housing and extending in a linear movement direction of said magnetic head assembly, said head feeding mechanism comprising: a lead screw having an external thread formed on an outer surface thereof and a screw center axis extending in parallel to said linear direction, said lead screw being rotatable around said screw center axis by a drive machine; a head lift body for supporting said head assembly, which is mounted on the head lift body, and having a bearing portion for receiving said lead screw, which extends in the bearing portion; and a protrusion projecting from an internal wall surface of said bearing portion so as to engage with said external thread of said lead screw, such that said protrusion slides up and down alone said external thread following rotation of said lead screw, so as to move said head lift body linearly alone said screw center axis; wherein said head lift body comprises: a base portion comprising said bearing portion having said protrusion; a ceiling portion extending in parallel with the base portion and comprising a ceiling side bearing portion receiving said lead screw, and a column portion connecting said base portion and said ceiling portion and comprising a hallow portion receiving said lead screw; and wherein said column portion comprises a semi-cylindrical portion partially surrounding said lead screw.