| 摘要 |
A mechanism for determining the position of a point relative to a coordinate system defined by coordinate scales aligned along coordinate axes includes a coordinate reference plane and a coordinate read plane and a read mechanism associated with each coordinate scale. Each read mechanism is engaged with the coordinate read plane and the coordinate reference plane to be responsive to relative motion between the coordinate read plane and the coordinate reference plane to indicate a position of the point on the along the corresponding coordinate scale, and is coupled to the coordinate read plane and to the coordinate reference plane to allow relative transverse motion between the coordinate read plane and the corresponding coordinate axis. Each read mechanism includes a guide mechanism for retaining the read mechanism at a predetermined position along an axis transverse to the corresponding coordinate axis with transverse motion between the coordinate read plane and the coordinate reference plane.
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