On the evolution of graphical representation of gears

In this paper, a historical evolution of graphical representation of gear designs is reported as a short survey by using significant drawings bath in the history of gear systems and design standards. A graphical representation of gear systems has evolved from a pictorial illustration towards a synthetic drawing of functionality and characteristics of gears that is today summarised in international stan-dards. Those standards as from ISO and Italian UNI codes are still based on graphical schematic repre-sentation of gear characteristics with pictorial representation for an intuitive understanding of an intui-tive understanding of main features of gear designs. A historical study is focused on the last century practical application of this gear representative