Desktop draft hood

The utility model relates to an experiment field especially relates to desktop draft hood. Contain the fume hood body, fume hood body avris contains the door discharge that can go up and down, connect lifting line on the door discharge, lifting line is around on the fixed pulley, and the fixed pulley can change to be installed on the bearing frame, still contains the connecting rod that passes bearing frame and fixed pulley, fixed mounting has from step -by -step belt drive wheel on the connecting rod, connects the step -by -step belt drive wheel of initiative from step -by -step belt drive wheel through step -by -step area, and the step -by -step belt drive wheel of initiative lies in step motor's power output shaft, and step motor fixes on the fume hood body, and the connecting rod rotational energy drives the fixed pulley and rotates, further drives the door discharge. Beneficial effect: step motor can drive the step -by -step belt drive of initiative and take turns the rotation, and the step -by -step bel