Since the 1694 invention of the involute curve by the French scientist, Philippe de la Hire, and the application
thereof to gearing by the prolific Swiss mathematician Leonard Euler, the world has embraced and developed
this type of gear tooth form to a very high degree of engineering and manufacturing excellence.
Improvements in recent years have been relatively modest, since this form has been so rigorously studied
and applied. The long-term adoption of the involute is rooted in large part to the simplicity of its tools and field
operation. Straight sided tools and conjugacy, even with limited changes in center distance, were consistent
with the industrial revolution of the 18th, 19th, and 20th centuries, and the mechanically based machine tools
and tolerance capabilities of these ages. The recent ubiquitous nature of computers and CNC machinery
enhances the cost-efective freedom to optimize many parameters affecting our everyday life including gear
tooth forms.