Device i.e. circular graphic ruler, for allowing balancing staircases by division of collars, has graduated listel equipping two faces in opposite data zones, where listel allows to find division of collars of balanced staircase

摘要

The device has a circular disk (1) on which graphic data is printed on two faces (A) of the device. A graduated listel (2) articulated at center of the device equips two faces in opposite data zones, and allows to find division of collars of a balanced staircase. The graphic data printed on each face allows division of collars into five distinct zones (10-14) on one of the faces, and allows division of collars into other five zones on the other faces, respectively, by direct reading on the listel.