| 摘要 |
A measuring tool for checking frameworks, comprising a fixed part intended to be suspended between two opposing sides of the framework, and a movable part displaceable in or on the fixed portion. Both parts have longitudinal scales readable against indexes, variations in the distance between the sides of the framework being reflected on the scale of the fixed part which has graduations twice as large as those on the scale of the movable part. Graduations of the scales are so arranged that when the movable part is adjusted with its scale showing against its index the same value as that read on the scale of the fixed portion against its index, the movable portion will always assume the same position in relation to the centerline between the sides of the framework.
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