To stop rapidly and surely a support pedestal in a desired position on a floor by providing a brake means to stop the move of the support pedestal floated up movably on the floor due to jets of high pressure air from an air blower.

When a brake lever is operatively pivoted, pivotal links 16 are pivoted respectively about support shafts 14 through an oblique link bar 28. Thus, a link bar 20 is moved leftward, while operational links 12 are pivoted counterclockwise about the support shaft 14 and the other end is lowered drawing a gentle arc. A pivot 10 is lowered along a slot 4 of a guide tube 5 by the lowering action, and a vertically movable tube 9 and a vertically movable bar 8 supported pivotally by the pivot 10 are lowered. Thus, a rubber pad 6 mounted to a support member 7 at the lower end of the vertically movable bar 8 is lowered to contact a floor surface. By this action a support pedestal receiving large frictional resistance between the rubber pad 6 and the floor surface is rapidly stopped.