Marine position-fixing device using data from satellite radionavigation - includes superimposed slotted scales and discs with mortised recesses in which tenons on edges of scales can slide freely

摘要

The device comprises superimposed reference and readout discs pinned at their centres to upper and lower linear scales with tenons engaging in the mortises of the discs. The horizontal upper scale, used for course-setting, has a double graduation from 1 to 45 cm in each direction. The discs are held together by a central eyelet (24) enabling them to pivot freely as it slides in a slot along the centre line of each scale. A tapped hole near the edge of each disc accepts a locking screw (21).