A fiber optic connector is disclosed capable of joining in proper alignment the uncentered ends of two optical fibers mounted in ferrules. Each ferrule is rotatably supported inside an eccentric bore of a connector sleeve by means of a rotatable cage whose balls or rollers have different diameters. The two cylindrical connector sleeves are capable of being mated in a connector receptacle with the optical fibers therein adjusted to exact lateral alignment.

A fiber optic splice includes two cylindrical ferrules of different diameters and having bores parallel to, but offset from, the major axes of the ferrules. The ferrules are inserted into a deformable housing where they rest in a V-groove. When external pressure is applied to the housing it is deformed in a predetermined manner, allowing the ferrules to rotate and when the pressure is removed, the ferrules are held in place.

To adjust an optical fiber radially in a connector element, the fiber is supported in a tube which is mounted near its mating end on a thin diaphragm with radial adjusting screws at the other end of the tube to rock the tube for adjustment purposes. Thus a relatively coarse screw movement gives fine adjustment to enable the fiber end to be accurately aligned with the fiber end of a mating connector element. The two elements are located with respect to each other by flats on the surface of one element which cooperate with a V-groove in an inner surface of the other element.

An optical fiber connector assembly using eccentric ferrule centering means for adjusting the concentricity of the optical fiber interface end with respect to the connector body perimeter. The eccentric ferrule or ferrules are in the form of elongated sleeves with the innermost sleeve extending from the connector body end the greatest amount. An external crimp sleeve of a relatively soft malleable metal has a generally conical shape with internal step-tapered diameter to fit over the eccentric ferrule exposed ends. Once the concentricity alignment of the optical core has been effected by relative rotation of the eccentric ferrule members (sleeves), crimping of the soft metal sleeve to each eccentric sleeve exposed extremity fixes the relative rotational position of these ferrules preserving the concentric alignment of the optical fiber in the connector body.

A casting is made of a corner having three mutually intersecting flat surfaces, one of which is perpendicular to the other two, while a fiber end is positioned against the corner in an orientation such that the end of the fiber butts against said one corner surface and the side surface of the fiber tangentially touches said other two corner surfaces. Two such castings, each carrying a fiber end, are aligned with each other in an alignment frame having two flat alignment surfaces which are oriented with respect to each other at the same orientation as the two corner surfaces which tangentially touch the fiber side surface. Since these orientations are the same, the castings fit precisely into the groove formed by the two flat alignment surfaces of the frame and can be moved toward each other until they touch. In this position the fiber ends carried by the castings are butt aligned.