| 摘要 |
The push actuator has a fixed base which rotatably carries a selectively rotatable rotor. A horizontal band has a lower portion stacked in a helical pattern and has an upper portion engaged by the upper portion of a vertical band, to form a telescopic column. The lower portion of the vertical band is stacked in a spiral, separately from the horizontal band, the horizontal band is supported on the rotor with a helical ball support track along which a number of balls can roll and slide, to allow substantially frictionless rotation of the rotor member while the horizontal band remains rotatably stationary. A ball re-circulation unit allows the balls to circulate between the top of the track and the bottom of the track. Upon rotation of the rotor, the vertical column is formed by the horizontal band being lifted and its turns being spaced through its engagement on the rotating helical ball support track, and by each turn of the vertical band being inserted between two vertically successive turns of the horizontal band. |
