Ball coupling device with hinged connection for two sliding shafts

A steering column comprising:

• an inner shaft comprising an axial groove located in a bore of an outer shaft comprising an axial groove so that the two axial grooves define a channel and the inner and outer shafts positioned along a common axis;
• the axial groove of one of the inner and outer shafts including two concave support surfaces located on either side of a raised bottom surface that projects into the channel;
• a row of balls received between the two axial grooves in the channel;
• a rigid rolling track member comprising a convex pivot portion with a convex pivot surface and a bearing portion with a bearing surface provided in the channel on each side of a median plan defined by a line drawn through the common axis and a center of at least one of the balls with the convex pivot surface in contact with the concave support surface and the bearing surface bearing against each of said balls;
• an elastic member located in the channel and in contact with the raised bottom surface pushing the two rolling track members against the balls such that at rest, when there is no torque transmission, and in operation, when there is a torque transmission, each of said balls simultaneously contacts the two rolling track members and the axial groove of one of the inner and outer shafts;
• and
• wherein the convex pivot surface of each of the two rolling tracks comprises a radius that is greater than a radius of the concave support surface that it contacts so as to define two contact areas that determine a pivot axis parallel to the common axis.

A steering column comprising an inner shaft and an outer shaft, the inner and outer shafts sliding within each other along a common axis thereof, said steering column comprising one or more coupling interfaces, each comprising:

• an axial groove of the inner shaft;
• an axial groove of the outer shaft;
• a row of balls received between the axial groove of the inner shaft and the axial groove of the outer shaft;
• two rigid rolling track members cooperating with the axial groove of one of the inner and outer shafts so as to pivot in the axial groove of said one of the inner and outer shafts about a pivot axis parallel to the common axis, the axial groove of said one of the inner and outer shafts including two concave support faces located on either side of a median plan passing through the common axis and the balls, the two rolling track members being provided on either side of the median plan;
• wherein each of the two rolling track members has a bearing portion with a bearing face bearing against each of said balls and a pivot portion with a convex pivot face bearing against a corresponding one of the two concave support faces, the convex pivot face having a radius that is greater than a radius of the corresponding one of the two concave support faces so as to define two contact areas between the convex pivot face and the corresponding one of the two concave support faces, wherein the two contact areas determine the pivot axis, the pivot axis being closer to the contact areas than to each of said balls;
• and
• an elastic member that bears in the axial groove of said one of the inner and outer shafts and pushes the two rolling track members against the balls such that at rest, when there is no torque transmission, and in operation, when there is a torque transmission, each of said balls simultaneously contacts the two rolling track members provided in said one of the inner and outer shafts and the axial groove of said other of said inner and outer shafts;
• wherein the elastic member being located such that when torque is applied, a load application line goes through the centers of each of the balls and the pivot portion of one of the rolling track members, whereby torque is transmitted between the inner shaft and outer shaft through the balls and the rolling track members.