Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
G06G1/02—Devices in which computing is effected by adding, subtracting, or comparing lengths of parallel or concentric graduated scales
G06G1/04—Devices in which computing is effected by adding, subtracting, or comparing lengths of parallel or concentric graduated scales characterised by construction