EXTRACTION WITH TEMPORARY SUCTION INTERRUPT

摘要

A method of cleaning a surface comprising applying cleaning solution to a surface, applying suction to the surface to remove the applied cleaning solution from surface, and selectively interrupting the suction to the surface for a selected time to increase dwell time of the cleaning solution on the surface. In one embodiment, the suction is interrupted when a moveable duct door fluidly and selectively opens and closes a suction leak hole within the working air conduit. In another embodiment, the suction is interrupted when a actuator selectively moves the duct door between the first and second positions within the working air conduit to restrict the working air flow in the working air conduit. The suction reduction selectively increases the cleaning solution dwell time.