| 摘要 |
<p>In a vacuum holding device for holding items comprising a vacuum source, at least one vacuum cell plate providing a front surface against which items are held, the cell plate providing a plurality of cell areas in the front surface, and conduits for connecting the cell areas to the vacuum source, the improvement comprising, for each cell area, a valve structure effective to open the cell area to the vacuum source only when the cell area is completely covered by an item such that a vacuum can form therein.</p> |
