Linear ball bearing for carriage of machine tool

In a linear ball bearing comprising a carriage having first and second adjacent longitudinal races, said linear ball bearing having a support with first and second guideways for receiving first and second endless rows of balls arranged to circulate in adjacent planes, whereby said first and second guideways respectively include first and second longitudinal raceways for loaded balls with open sides toward said first and second carriage races, respectively, and first and second reversal raceways for at least partly enclosing unloaded balls, said reversal raceways respectively connecting the ends of said first and second raceways for carrying loaded balls, and guide means fastened to said support to extend over said first and second raceways for loaded balls for guiding the loaded balls from the sides thereof away from said first and second raceways, the improvement wherein the balls of said first row and second row are arranged with the successive balls of each row laterally meshing in the interstices of the successively arranged balls of the other row and wherein said guide means comprises a longitudinally extending guiding rib arrangement having at least a first rib for laterally guiding the loaded balls, said rib being directly connected to a longitudinal retaining edge of said guide means for partly encompassing the loaded balls, said raceways for loaded balls partially surrounding said balls.