| 摘要 |
<p>A floor care appliance is provided in which suction pressure (vacuum) of cleaner suction air may be discretely modified in a series of steps by selective stages of bleed of atmospheric air into the dirt-collecting bag containing partial vacuum chamber. A multi-pushbutton ensemble activates directly, movable valve members, permanently attached to pushbuttons, which port or close off or obstruct an aperture in the housing or a tunnel arrangement leading to the aperture and communicating with ambient air pressure.</p> |
