To establish sure motions of a tumble preventive frame to emerge and retract interlocking with moving racks.

Arrangement according to this invention is equipped with stationary cam rails 26 installed for respective moving racks 1A, cam follower means 27 installed on the side with the tumble preventive frame 3, pushing tools 28 installed for respective moving racks 1A, and rack drawout hindering stoppers 29 installed in line for the respective moving racks 1A, wherein each cam follower means 27 is furnished with a pair of cam follower arms 36 and 37 energized in the closing motion direction and a driven member 40 supported swingably only in the intermediate region of the two cam follower arms, and when the frame 3 is in the limit position of emerging and retracting, the cam follower arms 36 and 37 pinch the front angle part 26b or the rear angle part 26c of the stationary cam rail 26, while the pushing tools 28 work only between the two angle parts 26b and 26c of the rail 26 for propelling the frame 3 through the driven member 40 and the cam follower arm 36 or 37 on the moving direction side where the driven member 40 abuts.