Vacuum cleaner having two cyclonic cleaning stages

Abstract

A vacuum cleaner has a first and second cyclonic cleaning stages in series. The second cyclonic cleaning stage has a plurality of second stage cyclones. A conduit connects the first cyclonic cleaning stage outlet and the second stage cyclone inlets.

1 . A vacuum cleaner comprising: 
 a) a dirty air inlet and a source of suction to draw air containing particulate matter into the dirty air inlet and produce an air stream in the vacuum cleaner;    b) a first cyclonic cleaning stage comprising a cyclone having a first cyclonic cleaning stage inlet and a first cyclonic cleaning stage outlet;    c) a second cyclonic cleaning stage positioned in series with the first cyclonic cleaning stage, the second cyclonic cleaning stage comprising a plurality of second stage cyclones, each of the second stage cyclones having a second stage cyclone inlet and a second stage cyclone outlet; and,    d) a passage connecting the first cyclonic cleaning stage outlet and the second stage cyclone inlets, and the passage is configured to inhibit settling out of particulate matter from the air stream.    
     
     
         2 . The vacuum cleaner as claimed in  claim 1  wherein the second stage cyclones at least partially surround the passage.  
     
     
         3 . The vacuum cleaner as claimed in  1  wherein the passage is at least partially defined by the second stage cyclones.  
     
     
         4 . The vacuum cleaner as claimed in  claim 1  wherein the passage has a cross sectional area which is approximately the same as the cross sectional area of the first cyclonic cleaning stage outlet.  
     
     
         5 . The vacuum cleaner as claimed in  claim 1  wherein the passage is substantially free of horizontal spaces that are transverse to the direction of fluid flow through the passage.  
     
     
         6 . The vacuum cleaner as claimed in  claim 1  wherein the passage is substantially free of any dead air spaces.  
     
     
         7 . The vacuum cleaner as claimed in  claim 1  wherein the passage is substantially free of regions that are adapted to separate particulate matter from the air stream.  
     
     
         8 . The vacuum cleaner as claimed in  claim 1  wherein the passage is defined by a single conduit.  
     
     
         9 . A vacuum cleaner comprising: 
 a) a dirty air inlet and a source of suction to draw air containing particulate matter into the dirty air inlet and produce an air stream in the vacuum cleaner;    b) a first cyclonic cleaning stage comprising a cyclone having a first cyclonic cleaning stage inlet and a first cyclonic cleaning stage outlet;    c), a second cyclonic cleaning stage positioned in series with the first cyclonic cleaning stage, the second cyclonic cleaning stage comprising a plurality of second stage cyclones, each of the second stage cyclones having a second stage cyclone inlet and a second stage cyclone outlet; and,    d) a passage extending from the first cyclonic cleaning stage outlet to the second stage cyclone inlets, and the passage is substantially free of any dead air spaces.    
     
     
         10 . The vacuum cleaner as claimed in  claim 9  wherein the second stage cyclones at least partially surround the passage.  
     
     
         11 . The vacuum cleaner as claimed in  claim 9  wherein the passage is at least partially defined by the second stage cyclones.  
     
     
         12 . The vacuum cleaner as claimed in  claim 9  wherein the passage has a cross sectional area which is approximately the same as the cross sectional area of the first cyclonic cleaning stage outlet.  
     
     
         13 . The vacuum cleaner as claimed in  claim 9  wherein the passage is substantially free of horizontal spaces that are transverse to the direction of fluid flow through the passage.  
     
     
         14 . The vacuum cleaner as claimed in  claim 9  wherein the passage is substantially free of regions that are adapted to separate particulate matter from the air stream.  
     
     
         15 . The vacuum cleaner as claimed in  claim 9  wherein the passage is defined by a single conduit.  
     
     
         16 . A vacuum cleaner comprising: 
 a) a dirty air inlet and a source of suction to draw air containing particulate matter into the dirty air inlet and produce an air stream in the vacuum cleaner;    b) a first cyclonic cleaning stage comprising a cyclone having a first cyclonic cleaning stage inlet and a first cyclonic cleaning stage outlet;    c) a second cyclonic cleaning stage positioned in series with the first cyclonic cleaning stage, the second cyclonic cleaning stage comprising a plurality of second stage cyclones, each of the second stage cyclones having a second stage cyclone inlet and a second stage cyclone outlet; and,    d) a conduit extending from the first cyclonic cleaning stage outlet to the second stage cyclone inlets.    
     
     
         17 . The vacuum cleaner as claimed in  claim 16  wherein the second stage cyclones at least partially surround the passage.  
     
     
         18 . The vacuum cleaner as claimed in  claim 16  wherein the passage is at least partially defined by the second stage cyclones.  
     
     
         19 . The vacuum cleaner as claimed in  claim 16  wherein the passage does not increase in cross sectional area in a downstream direction.  
     
     
         20 . The vacuum cleaner as claimed in  claim 16  wherein the passage has a cross sectional area which is approximately the same as the cross sectional area of the first cyclonic cleaning stage outlet.  
     
     
         21 . The vacuum cleaner as claimed in  claim 16  wherein the passage is substantially free of horizontal spaces that are transverse to the direction of fluid flow through the passage.  
     
     
         22 . The vacuum cleaner as claimed in  claim 16  wherein the passage is substantially free of regions that are adapted to separate particulate matter from the air stream.  
     
     
         23 . The vacuum cleaner as claimed in  claim 16  wherein the passage is substantially free of any dead air spaces.