Multiple arm map point plotter - has rectangular swivelling frame on case plate, with two transparent strips having movable reference lines

摘要

There are two plane, narrow, transparent strips crossing each other at a right angle. Each strip has a straight reference line. A rectangular case plate (1) has a clamp (13, (14) for a map edge at two opposite edges (11, 12). Fixtures (5) hold the ends (21, 22) of a rectangular pressing frame (20) swivelling about an axis (15) parallel to another edge. Both strips (31, 32) are self-fastening to the pressing frame (20). The case plate (1) consists of transparent material on the edges of the case plate (1), on which the fixtures (5) are set, a wide case plate (2) is hinged (pivoted). When the rectangular case plates are closed together, the pressing frame (20) lies between them.