Patent ID: 6493311
Filing Date: 2002-12-10
Classification: F16F,G11B,Y10T

Abstract:
An automatic balance device for a CD-ROM driver comprising:a hollow annular turntable having inner and outer annular walls, said inner and outer annular walls defining an annular chamber; an annular magnetic member being received within said annular chamber, an inner surface of said annular magnetic member abutting against said inner annular wall; a first set of beads being received within said annular chamber and being magnetically attracted to said annular magnetic member, each of said beads having a first radius; and, a second set of beads being received within said annular chamber and being magnetically attracted to said annular magnetic member, each of said beads having a second radius, said second radius being greater than said first radius, a distance between said second set of beads and said outer annular wall being less than a first diameter of said first set of beads, said first set of beads being greater or equal in number to said second set of beads, whereby at least a portion of said first set of beads collides with a portion of said second set of beads for transferring kinetic energy therebetween thereby counterbalancing unwanted vibration in said hollow annular turntable.