| 摘要 |
<p>Disclosed is a device for accurately indexing rotary arms in small angular steps which can be the basis for a device which produces repeatable and accurate stepping in a basically radial direction (vis-a-vis a disk media). It can accurately position read/write elements over tracks on disk based information storage media that have high track densities. The device uses two sets of paired gear members or clutch pairs, one set having slightly more teeth than the other, one member of the four being immovable and the movable member of that set being directly linked to one member of the other set. In a first embodiment, a single stepping motor is used to drive two mechanisms. The first of these two mechanisms in the first embodiment is simply a gear reduction to index an arm to approximately the required angle in steps of approximately the size required. The second mechanism used in both the first and second embodiments comprises two high-precision toothed face clutches which, when engaged, accurately position the rotary arm. In the second embodiment the secomd mechanism is also employed but a different "first" mechanism is used. This different "first" mechanism is driven by a second stepper motor which steps at larger increments thus turning the indexed arm further per step than the motor of the first embodiment.</p> |
