| 摘要 |
<p>A ball screw (22) in a transfer drive (10) is rotated to translate first and second carriages (32 and 48) at first and second rates, respectively. First and second ball nuts (32,40) engage the ball screw (22), the first ball nut (32) being fixed to the first carriage (34) and the second ball nut (40) being rotatably mounted on the second carriage (48). A power transmission unit (52) is connected between the ball screw (22) and the second ball nut (40) to establish a specified relationship between the rotation of the ball screw (22) and the second ball nut (40). The relationship is such that rotation of the ball screw (22) causes the first carriage (34) to be translated at the first rate by the first ball nut (32) and the second carriage (48) to be translated at the second rate by the second ball nut (40).</p> |
