To smoothly roll rollers on a guide rail by extending a belt between a pair of front and rear rollers, and rolling these rollers on the guide rail through the belt.

A pair of roller guides 9 arranged on the front and rear sides of an under carriage 3, have a plate-like support bracket fixed to an under carriage 2 through a square pipe. A pair of rollers 14 and 15 are rotatably installed through a support shaft on both front and rear both ends of a support plate swingably installed on the lower end of the support bracket through a support shaft. In the roller 15, a V groove is formed on an outer periphery, and a V groove is similarly formed on the roller 14. A synthetic resin-made V belt 19 is extended between a pair of rollers 14 and 15. Therefore, the rollers 14 and 15 roll on a blade part 2a of a guide rail 2 through the V belt 19 like a caterpillar. Therefore, these comparatively smoothly roll even in the initial stage of operation of a skewing elevator.