Display unit for symbol out of several symbols - which are placed in squares forming spiral and are displayed in window in ring

摘要

The display unit has a cylinder on whose periphery the symbols to be reproduced are placed in consecutive quadrangles forming a spiral with a specified pitch. The cylinder has a helical thread with the same pitch. A ring (3) is provided on the cylinder (1). It has an inner helical projection fitting into the thread (2), and at least one window (5) the size of which corresponds to that of symbols to be displayed, so that when the ring (3) is rotated about the cylinder, the symbols are consecutively displayed in the window.