Abstract:
A cyclone system for a vacuum cleaner includes an array of two or more primary cyclone chambers, an array of two or more secondary cyclone chambers situated downstream of the primary cyclone chambers, and a manifold situated downstream of and communicating with the primary cyclone chambers and upstream of and communicating with the secondary cyclone chambers.

Description:
BACKGROUND OF THE INVENTION  
       [0001]    The present invention relates to vacuum cleaners. More particularly, although not exclusively, the invention relates to “bagless” vacuum cleaners having cyclonic filtering chambers. 
         [0002]    Cyclonic chamber vacuum cleaners are known. Some such vacuum cleaners employ both a primary cyclonic chamber for removing large particulate material from an air stream, and a secondary cyclonic chamber housed within the primary chamber for separating smaller particulate material from the air stream after passing through the primary chamber. 
         [0003]    Some cyclone vacuum cleaners comprise a long exit tube extending into the cyclonic chamber and around which a cyclonic flow is induced. 
         [0004]    Such known cyclonic vacuum cleaners have limited particulate-removal efficiency and indeed the location of a secondary chamber within a primary chamber, or the extension of an elongated exit tube into the cyclonic chamber diminishes desirable natural vortex which might otherwise be induced in the chamber. 
       OBJECTS OF THE INVENTION 
       [0005]    It is an object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages and/or more generally to provide an improved sequential cyclonic vacuum cleaner. 
       DISCLOSURE OF THE INVENTION 
       [0006]    There is disclosed herein a cyclone system for a vacuum cleaner, comprising:
       an array of primary cyclone chambers,   an array of secondary cyclone chambers situated downstream of the primary cyclone chambers, and   a manifold situated downstream of and communicating with the primary cyclone chambers and upstream of and communicating with the secondary cyclone chambers.       
 
         [0010]    Preferably, the manifold communicates with each primary cyclone chamber via an air-extraction exit tube extending into the primary cyclone chamber. 
         [0011]    Preferably, each exit tube comprises an inlet through which air from the primary chamber passes en route to the manifold and a particulate screen across the inlet. 
         [0012]    Preferably, each primary cyclone chamber comprises a dirty air inlet port directed tangentially into the chamber and the exit tube extends sufficiently into the chamber such that its inlet is not in the direct flow path of the dirty air inlet port, but not substantially therepast, thereby leaving a major axial portion of the primary cyclone chamber unobstructed by the exit tube. 
         [0013]    Preferably, the secondary chambers each comprise an air-extraction exit tube extending into the secondary chamber and via which air is drawn from the secondary chamber. 
         [0014]    Preferably, the cyclone system further comprises a respective fine particulate receptacle associated-with each secondary cyclone chamber, and wherein each secondary cyclone chamber is frusto-conically tapered inwardly toward the respective fine particulate receptacle. 
         [0015]    Preferably, the cyclone system further comprises a pair of said primary cyclone chambers and a trio of said secondary cyclone chambers. 
         [0016]    There is further disclosed herein a cyclone chamber for a vacuum cleaner, comprising:
       a dirty air inlet port directed tangentially into the chamber,   an air-extraction exit tube extending into the cyclone chamber and having an inlet through which air is extracted from the chamber, the exit tube extending sufficiently into the chamber such that its inlet is not in the direct flow path of the dirty air inlet port, but not substantially therepast, thereby leaving a major axial portion of the cyclone chamber unobstructed by the exit tube.       
 
         [0019]    Preferably, the cyclone chamber further comprises a particulate screen situated across the inlet of the air-extraction exit tube. 
         [0020]    There is further disclosed herein a cyclone system for a vacuum cleaner, comprising:
       a primary cyclone chamber for receiving dirty air and having an exit port,   a secondary cyclone chamber situated outside of and downstream of the primary cyclone chamber and having an inlet port receiving airflow from the exit port of the primary chamber.       
 
         [0023]    Preferably, the primary and secondary chambers are each substantially cylindrical with a major longitudinal axis and wherein the axes of the respective chambers are substantially co-linear. 
         [0024]    There is further disclosed herein an upright vacuum cleaner comprising the above disclosed cyclone system and in which the secondary chamber is situated above the primary chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: 
           [0026]      FIG. 1  is a schematic plan illustration of a multi-chamber cyclone system, 
           [0027]      FIG. 2  is a schematic elevation of a dual cyclone chamber system, and 
           [0028]      FIG. 3  is a schematic elevation of an upright vacuum cleaner incorporating a dual cyclone chamber system. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    In  FIG. 1  of the accompanying drawings there is depicted schematically a cyclone system  9  for a vacuum cleaner. The system  9  includes a pair of primary cyclone chambers  11   a  and  11   b  and a common manifold  13  connecting the primary chambers to a trio of secondary cyclone chambers  14   a ,  14   b  and  14   c.    
         [0030]    Each primary cyclone chamber  11  is substantially cylindrical in form and comprises an inlet port  12  at the top end which extends tangentially therefrom. Each inlet port  12  would be connected via appropriate manifolding and suction ducting to a vacuum cleaning head or suction hose for example. The tangential transition of the dirty air inlet port  12  to the cylindrical chamber induces a cyclonic flow within the chamber. The chamber  11  includes at its bottom a large particulate receptacle area  17 . 
         [0031]    Whilst  FIG. 2  depicts a second system  10  incorporating only single primary cyclone chamber  11  and single secondary cyclone chamber  14 , the details shown in the figure can apply equally to the embodiment of  FIG. 1 . In the embodiment depicted in  FIG. 2 , the manifold  13  is replaced by a single connecting tube  21  between the cyclones. 
         [0032]    The manifold  13  (or connecting tube  21 ) receives airflow from the/each primary chamber  11  via a short exit tube  19  which extends down into the respective primary chamber  11  only a short distance. This distance is sufficient to clear the vertical space requirement of the inlet port  12  so that particulate material entering the primary chamber  11  via inlet port  12  is not drawn in directly by the exit tube. However, the exit tube  19  does not extend significantly further into the primary chamber  11  where it would otherwise adversely affect the natural vortex of airflow within the chamber. A particulate screen  16  is fitted over the exit tube  19  as an additional barrier to the direct ingress of large particulate material to the exit tube. 
         [0033]    In the embodiment of  FIG. 1 , the manifold  13  feeds into three individual secondary cyclone chambers  14   a ,  14   b  and  14   c . In the embodiment of  FIG. 2 , of course there is only a single secondary cyclone  14 . The-or each secondary cyclone chamber (as the case ma be)  14  also includes an exit tube  20  of similar design to exit tube(s)  19 , but typically without a particulate screen. The air flow from  13  or  21  feeds tangentially into the/each secondary cyclone chamber  14  in much the same way as does the dirty airflow into inlet port  12  of the primary chamber(s). 
         [0034]    The or each secondary cyclone chamber  14  at some point tapers conically toward a fine particulate receptacle  18  situated therebelow. Each exit tube  15  would be connected via appropriate manifolding and ducting to a motor-driven suction pump. 
         [0035]      FIG. 3  depicts an upright vacuum cleaner  30  in which the dual chamber system of  FIG. 2  is incorporated. The upright vacuum cleaner  30  typically includes a handle  25 , a cleaning head  23  and a suction pump  22  connected via ducting  24  to the exit tube  20  of the secondary cyclone  14 . Air from the suction pump  22  is exhausted as shown by the large arrow. In the example of  FIG. 3 , the primary and secondary cyclones  11  and  14  are mounted substantially coaxially. Moreover, the respective longitudinal axes of the cylindrical cyclone chambers are co-linear as indicated by common axis A in the figure. The smaller secondary cyclone is positioned above the larger primary cyclone. As seen in the figure, a single connecting tube  21  extends upwardly from exit tube  19  to the inlet port  15  of the secondary cyclone chamber  14 . 
         [0036]    In use, the motor-driven suction pump  22  would be activated to induce suction at the exit tube  15  of the or each secondary cyclone chamber  14 . As clean air is extracted from the secondary chamber(s)  14 , suction is induced in the manifold  13  (or connecting tube  21 ) and fine particle-laden air is drawn thereinto from the primary chamber(s)  11 . Similarly, as fine particle-laden air is extracted from the primary chamber(s)  11 , suction is induced at the inlet port(s)  12 . 
         [0037]    It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, particulate screens could be added to the exit tube(s)  20  to stop very fine particulate material, and any number of primary and secondary cyclone chambers can be attached to a single manifold.