| 摘要 |
A vacuum chuck having a work face including a plurality of linearly extending parallel passages or grooves intersecting each other at right angles to form a rectangular grid pattern. The grooves are dimensioned to receive an elongated rubber sealing member having a closed cell construction. The sealing member is discontinuous so that it may be placed in various different grooves to define a continuous seal in the work face of the chuck with the area enclosed by the sealing member being dependent on the size of the workpiece to be held by the chuck. Passages are provided in the chuck to communicate with the grooves inwardly of the sealing member for transmitting a vacuum in the area enclosed by the seal under the work piece. When handling very thin workpieces, a conversion plate is placed on the work face of the chuck in engagement with the sealing member. The thin workpiece is then placed on the conversion plate and held thereon by vacuum transmitted to the bottom of the work piece by apertures in the conversion plate which register with grooves in the chuck inwardly of the seal. When the work piece is very small in overall length and width, it is positioned by placing it in an aperture of similar shape formed in a "block-in" plate which rests on a conversion plate. The bottom surface of the work piece rests on the conversion plate, and vacuum is applied to the bottom of the work piece through apertures in the conversion plate. The chuck may also be adapted for profiling work pieces by placing an apertured conversion plate on the chuck inwardly of the sealing member. The work piece extends beyond the edges of the conversion plate and in spaced relation to the work face of the chuck to provide sufficient space for profiling.
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