Amerigear.., the first, the finest... flexible coupling with Fully-Crowned Gear Teeth. In contrast with ordinary gear tooth forms, the Amerigear Fully-Crowned Tooth represents the ultimate achievement in the art of gear tooth design, wherein all three working portions of the tooth are crowned. As a result, the teeth act much like a rocking chair, capable of sliding freely in the axial direction without digging or gouging the internal mating teeth. Because of this design advantage, Amerigear Flexible Couplings with Fully-Crowned Gear Teeth offer operational benefits of maximum load-carrying capacity with minimum size, maximum reliability and long life.