Band drive actuator

Claim 1

An actuator for a disk drive having a rotating recording medium, said actuator comprising the combination of a head/carriage assembly; a rolling suspension means for supporting said head/carriage assembly and for guiding said head/carriage assembly for translational movement radially relative to said recording medium; said suspension means including a capstan, a fixed precision positioning bearing, and a spring biased preload bearing; said preload bearing being biased against a substantially flat surface on one side of said said head/carriage assembly to load a parallel surface on the opposite said of said head/carriage assembly against said capstan and said positioning bearing, whereby said suspension means constrains said head/carriage assembly against movement toward and away from said recording medium; a precision bearing motor coupled to said capstan; a nonextensible, tensioned band wrapped around said capstan, said band being secured at an intermediate point along its length to said capstan and having a pair of ends extending substantially tangentially in opposite directions from said capstan, the ends of said band being secured to spaced apart points on said head/carriage assembly, whereby said head/carriage assembly moves radially of said recording medium under the control of said motor, and wherein said preload bearing is disposed between said capstan and said positioning bearing lengthwise of said head/carriage assembly whereby the load forced applied to said capstan and said positioning bearing are substantially independent of the position of said head/carriage assembly radially relative to said recording medium.