The principle objective of the “Rotary Occlusal Grinder” was to provide a grinding or milling mechanism that may be applied to articulators to eliminate “locked” relations that commonly exists between articulated denture teeth. This grinding or milling device with a moveable cast holder and incisal pin was designed to be mounted in lieu of the upper member of the articulator. The milling device was controlled by three eccentric gears which created an elliptical movement. The grinding procedure was intended to result in a horizontal freedom of movement of the dentures in various positions of occlusion. It also produced to a lesser extent, freedom in protrusion and retrusion. The “Rotary Occlusal Grinder” is powered by a suitable belt drive (usually a laboratory lathe) designed to be applied to the central pulley. In this instance (as is also illustrated in the US patent letter) the “Occlusal Rotary Grinder” is mounted on a Gysi “Simplex” articulator. Models were also designed for the Hanau , Snow, Wadsworth , McCollum, and Monson Articulators.
House MM: Observations and studies of occlusion. J Am Dent Lab Assoc 1926; 1: 17-21.
Dr. Edgar N. Starcke's articles in the Journal of Prosthodontics have more information on the history of articulators.