Endless chain apparatus for forming spur and helical gears with means for controlling chain

In apparatus of the type which includes a tool-carrying endless chain assembled from a number of articulated links which each have a gear engaging rack portion depending longitudinally therefrom together with bearing surfaces adjacent to the depending rack portion, the improvement in means for controlling movement of the endless chain as it passes through a work zone in which its tools make contact with a workpiece, characterized by

• a housing defining a path of travel for the endless chain, with the path of travel having a straight section in the work zone portion of its travel,
• guide rollers carried on opposite sides of each link of said endless chain for guiding the chain in its path of travel about said housing,
• a first series of rollers positioned in parallel rows along said straight section of the work zone for supporting said bearing surfaces of the links of said endless chain as the endless chain travels through the work zone,
• gib means secured along both sides of said straight section of said housing for engaging said guide rollers as the chain links enter the work zone portion of the chain travel to thereby press the endless chain into firm contact with said first series of rollers as the endless chain moves through the work zone, and
• a second series of rollers positioned in parallel rows in the straight section of said housing for contacting and guiding opposite sides of the depending rack portions of said links of the endless chain to prevent unwanted side-to-side deflections of the endless chain as it moves through the work zone.