摘要 |
<p>A mechanical linkage, for use on original equipment or for replacement of existing hydraulic ram based actuators, comprises a rotary to linear transmission. The transmission provides two co-rotatable capstans (2, 3) of different diameters, and two idler wheels (5,8) spaced on a longitudinally slidable linkage (22). The capstans (2, 3) are linked to a first of the idler wheels (5) by means (4) of a pulley line wound from the first capstan (2), around the wheel (5), and then back to the second capstan (3). The first capstan (2) is also linked by means of a pulley line (7) to the second idler wheel (8), and the second capstan (3) likewise to the second idler wheel (8) by a third pulley line (10). The difference in diameters causes a differential winding of the various lengths of pulley line between the idler wheels (5, 8) and the capstans (2, 3), which urges the linkage to slide relative to the capstans (2, 3). Cooperation of the two capstan/idler wheel combinations compensates for possible backlash.</p> |