| 摘要 |
<p>Traveling wheels 51 are provided rotatably at positions on both sides of a main body case 25 below the center of gravity of a cleaner main body 13. A rear wheel 52 which can advance to and withdraw from a floor surface F side is provided posterior to rotary shafts 57 of the traveling wheels 51 of the main body case 25. The rear wheel 52 is energized in a direction of advancing to the floor surface F so as to become contactable with the floor surface F in an advanced state. The rear wheel 52 comes into contact with the floor surface F at a proper contact pressure, so that without deteriorating the turnability of the cleaner main body 13, straight traveling performance can be made higher than in the case where the cleaner main body travels only by the traveling wheels 51.</p> |
