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.