Patent ID: 6369989
Filing Date: 2002-04-09
Classification: G11B

Abstract:
A swing arm for a magnetic disc drive having a plurality of arms on which gimbals is secured, said swing arm for said magnetic disc drive comprising a plurality of arm members,said swing arm for said magnetic disc drive comprising: an upper arm member having an arm portion on which gimbals is secured, a cylindrical potion formed near its proximal end, the cylindrical portion comprising a large diameter upper cylindrical portion having a sleeve which is of length L1, and outside diameter of R1, a small diameter lower cylindrical portion having a sleeve which is of length L2 and outside diameter of R2, a stepped portion, and a fitting hole in which a bearing device is fitted for supporting a spindle, the fitting hole having inside diameter of r1: at least one or more intermediate arm member having an arm portion on which gimbals is secured, and a cylindrical portion formed near its proximal end, the cylindrical portion comprising a large diameter upper cylindrical portion having a sleeve which is of length L1, and outside diameter of R1, a small diameter lower cylindrical portion having a sleeve which is of length L2, and outside diameter of R2, a stepped portion, and a fitting hole in which a bearing device is fitted for supporting a spindle, the fitting hole comprising a large diameter hole, a small diameter hole, the large diameter hole being of depth h1 substantially equal to length of the sleeve of the small diameter cylindrical portion of the upper arm member, the small diameter hole being of inside diameter r2 larger than inside diameter r1 of the cylindrical portion of the upper arm portion, and a receiver portion for receiving the small diameter cylindrical portion of the cylindrical portion of said upper arm member; and a lower arm member having an arm portion on which gimbals is secured, and a cylindrical portion formed near its proximal end, the cylindrical portion comprising a large diameter upper cylindrical portion having a sleeve which of length L3, substantially equal to or less than the length of the sleeve of the cylindrical portion of said intermediate arm member, and outside diameter R1, a small diameter lower cylindrical portion having a sleeve which of length L4 less than the length L2 of the cylindrical portion of the upper arm member or intermediate arm member, and an outside diameter R2, a fitting hole in which a bearing device is fitted for supporting a spindle, the fitting hole having a large diameter hole portion which is of depth h1 substantially equal to the small diameter lower cylindrical portion of said upper arm member or lower arm member, and a small diameter hole portion which is of inside diameter r1, and a receiver portion for receiving the small diameter lower cylindrical portion of said upper arm member or lower arm member, whereby said upper arm member, intermediate arm member, and lower arm member is assembled to be integrally formed such that a swing arm for said magnetic disc drive is formed, and fitting holes of said upper arm member, intermediate arm member, and lower arm member.