Rotary table

Claim 1

A rotary workpiece support table comprising, an annular base member having a central section and an outer peripheral support surface engaging section, a horizontally disposed rotatable table member mounted on said base member and adapted to support an object for rotation about a generally vertical rotational axis, said table member comprising a central section generally vertically aligned with said central section of said base member and a generally flat radially outwardly disposed section extending radially outwardly to a position overlying said outer peripheral section of said base member, said central sections of said table member and said base member being formed with vertically aligned bores arranged coaxially of said rotational axis, a generally cylindrically shaped hub member extending through said bores, an antifriction bearing assembly for rotatably supporting said table member on said base member and comprising a first bearing race on said table member, a second bearing race on said hub member, and a plurality of antifriction ball bearing elements disposed between said first and second bearing races and lying along a common horizontally disposed plane, one of said bearing races being defined in part bY a segment of an imaginary sphere having its center located on said axis of rotation and disposed above said horizontal plane, whereby to optimize concentricity and parallelism and minimize axial runout of said table member relative to said base member.