ABSTRACT
In 1912 the Austrian inventor Kais Konigl patented a process for manufacture of gear wheels with the asymmetric buttress teeth. Prof. Gustav Niemann and Dr. Heinz Glaubitz have compared the standard 20° pressure angle gears, nonstandard 30° pressure angle gears, internal tooth gears, and asymmetric tooth gears using the photoelastic tooth models and also pulsator tooth testing. The end of the twentieth century and beginning of the twenty-first could be definitely characterized as a period of an explosion of interest in asymmetric gearing. While gears with asymmetric teeth or asymmetric gears have been known for many years, their history is not sufficiently recorded in modern gear literature. Similar to the ratchet wheels, the first asymmetric gears had a buttress tooth shape with low pressure angle at the drive tooth flanks, and with supporting coast flanks with high pressure angle.
