Patent ID: RE39715

Claim:
A tripot universal joint comprising: an outer drive member having a first longitudinal axis and three longitudinal drive channels disposed parallel to the longitudinal axis and equally spaced circumferentially from one another, each one of the three longitudinal drive channels defined by two opposing concave side surfaces and a back surface, the back surface of each drive channel facing radially inward with respect to the outer drive member, the opposing concave side surfaces of each drive channel disposed parallel to one another and separated circumferentially with respect to the outer drive member by the back surface of that drive channel ; an inner drive member having a second longitudinal axis and three radial trunnions equally spaced circumferentially from one another and on respective coplanar radial axes which intersect the second longitudinal axis at a spider center, each one of the three trunnions having a circular convex surface disposed in the a respective one of the longitudinal drive channels and being in confronting relation with the opposing concave surfaces of said respective one of the longitudinal drive channels of the outer drive member; three ball assemblies , each said ball assembly constructed and arranged to rotate and wobble about the radial axis of the a respective one of the trunnion s , each one of the three said ball assemblies assembly contacting and encircling the circular convex surface of the its respective trunnion, and each said ball assembly having a semi-spherical outer ball being in rolling contact with one of the two opposing concave side surfaces of a said drive channel of the outer drive member , each said outer ball having a central axis about which it rotates and a radial side wall facing radially outward with respect to the outer drive member; and wherein the back surface of the each said drive channel having has a guide rail projecting radially inward and extending longitudinally lengthwise to the channel, the guide rail being spaced circumferentially between the two opposing side surfaces so that of the channel, the radial side wall of the each outer ball contacts the contacting its respective guide rail longitudinally at one of two spaced positions along the guide rail positions longitudinally spaced therealong at one of two locations on said outer ball radial side wall depending upon the direction the ball assembly tilts relative to and along said first longitudinal axis of said outer drive member as it pivots about an X-axis disposed coplanar to the radial axes of the three trunnions and disposed perpendicular to the radial axis of the respective trunnion , said two locations on the side wall being on opposite sides of said outer ball central axis .