Map reader with interchangeable cassette - has map movable between two parallel rolls and light underneath visible map portion

摘要

The map carrier includes a rectangular case housing a map carried between two parallel rollers, with the relevant part of the map passing beneath a clear window (8) in the box. The two rolls form a cassette which can be exchanged, and they are driven by an electric motor at one end of the case. Control switches are mounted at the same end of the case (9) as the motor where there may also be a battery. The device may alternatively be connected to a car battery. Underneath the portion of the map which appears in the window is a light.