Above floor air bleed

Abstract

A surface cleaning head for a surface cleaning apparatus includes a dirty air inlet, a dirty air outlet, and a dirty airflow path extending between the dirty air inlet and the dirty air outlet. The surface cleaning head also includes an automated valve assembly operable to open and place the dirty airflow path in fluid communication with ambient pressure. The automated valve assembly is adjustably opened based upon a suction level within the dirty airflow path. The automated valve assembly includes an adjustable valve, a sensor operable to measure the suction within the dirty airflow path, and a controller operable to control the adjustable valve based on the sensor measurement.

What is claimed is: 
     
         1 . A surface cleaning head for a surface cleaning apparatus comprising:
 a dirty air inlet;   a dirty air outlet;   a dirty airflow path extending between the dirty air inlet and the dirty air outlet; and   an automated valve assembly operable to open and place the dirty airflow path in fluid communication with ambient pressure,   wherein the automated valve assembly is adjustably opened based upon a suction level within the dirty airflow path, and   wherein the automated valve assembly includes an adjustable valve, a sensor operable to measure the suction within the dirty airflow path, and a controller operable to control the adjustable valve based on the sensor measurement.   
     
     
         2 . The surface cleaning head of  claim 1 , wherein the adjustable valve can be adjustably opened allowing an adjustable amount of airflow in fluid communication with the dirty airflow path. 
     
     
         3 . The surface cleaning head of  claim 2 , wherein the adjustable valve is opened further when the suction within the dirty airflow path increases in magnitude. 
     
     
         4 . The surface cleaning head of  claim 1 , wherein the sensor is positioned within the dirty airflow path. 
     
     
         5 . The surface cleaning head of  claim 1 , wherein the sensor is positioned remote from the dirty airflow path, with a measuring airflow path extending therebetween. 
     
     
         6 . The surface cleaning head of  claim 1 , wherein the controller operates the adjustable valve to keep the dirty airflow path within a desired range of suction using the sensor measurement as feedback. 
     
     
         7 . The surface cleaning head of  claim 1 , wherein the automated valve assembly includes an opening to fluidly communicate the dirty airflow path with ambient pressure, and wherein the opening is positioned above the surface to be cleaned.