Abstract: A hob or shaper cutter for making a hub for a misalignment gear coupling having a hub and a sleeve. The hob or shaper cutter has cutting edges. Each cutting edge being inclined at a different angle to the center line of the tooth. The cutting edges are adapted to cut tooth flank surfaces having three adjacent involute shaped areas. Each involute shaped area having a different pressure angle than the involute area adjacent it. The involute areas of each tooth result in teeth with flanks that are generally cylindrical shaped, whereby hub treeth operate with a minimum of interferfence with sleeve teeth when operating with the hub misaligned with the sleeve.

Abstract: A coupling including a seal which has an outer periphery that is adapted to be pressed into the inner periphery of a hollow cylindrical sleeve of a gear coupling. An annular flange is integrally attached to the ring and the flange extends radially inwardly and toward and is adapted to underlie the external teeth on the hub of the coupling. The flange terminates in an inwardly directed sealing surface that is adapted to sealingly engage an external cylindrical surface on the hub. The sealing surface on the flange is adapted to be disposed on a plane passing through the center of curvature of the tips of the hub teeth perpendicular to the central axis of the coupling.