| 摘要 |
An electrically powered eraser accepts an elongate circularly cylindrical erasing element between three driving rollers symmetrically arrayed about the erasing element with axes angulated to the axes of the other driving cylinders and to the axis of the erasing element so that the driving cylinders contact the erasing element near its exit end. The three driving cylinders are positionally maintained in a housing extending thereabout and are interconnected for similar rotary motion by driving bands, gears or the erasing element itself. At least one of the driving cylinders is powered to rotate all cylinders in the same direction to cause the erasing element to rotate and move axially from the exit end of the rollers by reason of roller rotation.
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