Linear motion guide apparatus equipped with a plurality of rows of ball chains

A linear motion guide device, provided with a plural ball row chain, which comprises a track rail and a movable block mounted to the track rail to be movable through a number of balls, said movable block comprising a movable block body provided with a loaded ball rolling groove corresponding to a loaded ball rolling groove formed to the track rail and a non-loaded ball return passage disposed in parallel to the loaded ball rolling groove of the movable block body and also provided with a direction changing passage forming members formed at both ends of the movable block body and constituting ball direction changing passages forming an endless ball circulation passage communicating the loaded ball rolling groove and the rolling member return passage, said balls being composed of at least one set of two ball rows in parallel to each other with a predetermined space and said two ball rows being supported by a belt-shaped plural ball row chain enabling the balls to circulate the endless ball circulation passage, said plural ball row chain being composed of a flexible connection member disposed between the two ball rows and spacers disposed at both side edges of the connection member and adapted to be inserted into adjacent balls,

• wherein a ball retainer portion is disposed to the movable block body so that the balls in respective ball rows along the loaded ball rolling groove are engaged at a time of removing the movable block from the track rail and the balls are prevented from falling off through an assembling of the ball retainer portion and the plural ball row chain.