To improve safety of engagement of a strut and a slide pipe by forming an engaging claw which is pivotally supported in the vicinity the upper end opening port of the strut of a stand in a hook shape, and notching a recessed groove engaged with an engaging claw on the slide pipe, in an elevating device for restricting the slide of the slide pipe of an electric fan.

In case of assembly of an electric fan, a slide pipe 12 is pushed down in a strut 21, the slide pipe 12 is fixed by operation of an elevating device, and work is carried out. In this case, when the slide pipe 12 is pushed down, an operating lever 14 energized on the upper end of a rated load spring 19 is rotated in a clockwise direction on a place where the engaging claw 15 of the operating lever 14 and the recessed groove 17 of the slide pipe 12 are matched with each other, and the engaging claw 15 and the recessed groove 17 are engaged with each other. In the engaging condition, since a clearance meeting looseness is generated by the weight of the impeller mounted on the slide pipe 12, a motor, and the like, when a push button 16 is pushed, the operating lever 14 is rotated in a anti-clockwise direction, and engagement of the engaging claw 15 and the recessed part 17 is released comfortably.