An actuating mechanism includes first and second hollow outer shafts, two rotating wheels located between the first and second outer shafts, and an inner shaft received in the second outer shaft. Each of the first and second outer shafts forms a connecting portion at one end thereof. Each connecting portion defines two receiving holes. Each rotating wheel includes a body and a rod extending through the body. The bodies of the rotating wheels are in contact with each other. Two ends of the rod of each rotating wheel are correspondingly received in the receiving holes of the first and second outer shafts to connect the first and second outer shafts together. One end of the inner shaft contacts the rod of one rotating wheel. The inner shaft is rotatable in the second outer shaft to drive the two rotating wheels to rotate.