| 摘要 |
<p>A positive displacement positioner (349) employs rigid stops and actuators (312, 313, 314, 332, 333, 334) to position a work piece, such as a microliter plate, in any one of a least three positions. Positioner platforms (326, 345) each of which is capable of moving a work piece between at least two distinct positions, are nested in order to multiply the number of positions available. For example, a two-position rigid stop positioner platform nested in a four-position rigid stop positioner platform, or a four-position rigid stop positioner platform nested in a two-position rigid stop positioner platform would permit the movement of a work piece to any one of eight distinct positions. A four-position platform nested inside a four-position platform yields sixteen positions, and so on. Each positioner platform (326, 345) preferably has a symmetrical polygonal outline and nested platforms provide displacement along each of the polygon's axes of symmetry. Consequently, a positioner will preferably provide displacement to any one of a number of positions.</p> |
