Vacuum cleaner power nozzle having selectively introduced secondary airflow for operation on carpeted surfaces

Abstract

A vacuum cleaner power nozzle adjustable for use on low- and high-pile carpets. Vent openings across the front of the nozzle selectively open to introduce a secondary flow of air at the leading side of the roller brush of the nozzle. The secondary flow of air reduces resistance to movement of the power nozzle over high-pile carpet, and is drawn under the rotating roller brush to aid in displacement and removal of particulate from the carpet.

What is claimed is: 
     
         1 . A vacuum cleaner power nozzle assembly, comprising:
 an intake opening formed on a lower side of said vacuum nozzle assembly;   a powered lower brush mounted in said intake opening so as to extend generally transverse to a front-to-back direction of movement of said power nozzle assembly; and   at least one selectively openable passage that permits entry of a secondary flow of air into said intake opening on a front side of said roller brush, so that said secondary flow of air reduces down force exerted by a vacuum in said intake opening, and so that said secondary flow of air is drawn downwardly and under said roller brush by rotation of said roller brush so as to aid in dislodging and removing particulate matter from a carpet.   
     
     
         2 . The vacuum cleaner power nozzle assembly of  claim 1 , wherein said at least one passage that admits entry of said secondary flow of air to said intake opening comprises:
 at least one passage that communicates between said intake opening of said nozzle assembly and an exterior of said nozzle assembly so that said secondary flow of air is drawn from outside said nozzle assembly by said vacuum at said intake opening.   
     
     
         3 . The vacuum cleaner power nozzle assembly of  claim 2 , further comprising:
 a chamber into which said secondary flow of air is introduced from said at least one intake opening, said chamber extending across at least a portion of said front side of said roller brush.   
     
     
         4 . The vacuum cleaner power nozzle assembly of  claim 3 , wherein said chamber comprises:
 a flow restriction formed above said at least one intake opening so as to prevent said secondary flow of air from being drawn back over a top of said roller brush by vacuum in said intake opening.   
     
     
         5 . The vacuum cleaner vacuum assembly of  claim 4 , wherein said flow restriction is formed by a convergence between an upper portion of said roller brush and a forward wall of said chamber.