One of the earliest of the articulators with features to create the so-called “seesaw” denture grinding motions was patented by T. G. Lewis of Buffalo, NY, in 1900 (US Patent No . 659,871, October 16, 1900). By using right and left thumb plates, oscillating as well as protrusive movements on the horizontal plane could be achieved. A posterior “return” or tension spring was provided in a casing attached perpendicular to the yoke. Elements of Lewis' articulator were combined with that of R. H. Antes (US Patent No. 547,195, October 1, 1895) to create the Antes-Lewis Articulator.
Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.