| 摘要 |
<p>PURPOSE:To prevent the operation vectors of a control ball from varying when the control ball is started only in one coordinate axis direction by varying the axial diameter of rotary rolling bodies which contact the control ball. CONSTITUTION:At least one of the rolling bodies 4 and 5 which rotate is varied in diameter axially so that the rolling bodies 4 and 5 contact the control ball 3 at two contacts. Namely, the control ball 3 is given momentum as shown by an arrow 17 and then when the control ball is left as it is, the control ball 3 is accurately guided not by the friction at contacts 5a and 5b of the rolling body 5, but principally by the friction at contacts 4a and 4b of the rolling body 4. The control ball 3 is guided at the contacts 4a and 4b (where the statical friction at those contacts exceeds the slide friction at the points 5a and 5b), namely, only the rolling body 4 rotates to maintain rotary momentum in the initial direction. This makes it secure that a cursor moves completely linearly as shown by 2'.</p> |
