Dual flux path voice coil motor

Claim 1

A linear voice coil motor actuator having a dual magnetic flux path for head positioning in a disk file comprising: a magnetically permeable center core having a central longitudinal axis generally parallel to the linear path of the actuator and two parallel faces on opposites sides of and generally parallel to the central longitudinal axis, the center core further comprising two generally like sections; means for supporting the two center core sections in a spaced apart relationship along the center core longitudinal axis; a magnetically permeable outer core generally surrounding the center core and having parallel inner walls, each of said outer core inner walls being generally parallel to and spaced from a corresponding center core face; at least one generally flat permanent magnet attached to each of said center core faces; at least one generally flat permanent magnet attached to each of said outer core inner walls, the magnet on each inner wall having its magnetic polarity opposing the magnetic polarity of the corresponding center core magnet and being spaced therefrom so as to define a gap; an electrically conductive coil surrounding the center core and located within the gap; and means for supporting the coil within the gap and for providing linear movement of the coil through the gap in a direction generally parallel to the longitudinal axis of the center core.