Abstract:
An improved two-stage separator uses reusable containers for collecting particles separated by each separation stage. The reusable containers are constructed such that a user empties both reusable containers by the actions required to empty just one of the reusable containers.

Description:
[0001]    This application is a continuation of U.S. patent application Ser. No. 09/595,175 filed Jun. 16, 2000, which has been allowed, which is a continutation-in-part application of U.S. patent application Ser. No. 09/239,860 filed Jan. 29, 1999, which has been allowed. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to the transfer and removal of particles separated in multi-stage separators such as may be used by vacuum cleaners. In one particular application, the invention relates to the multi-stage separation having upstream and downstream separation stages wherein the position at which the separated particles exit from the downstream separation stage is positioned above the position at which the separated particles exit the upstream separation stage.  
         BACKGROUND OF THE INVENTION  
         [0003]    The use of multiple cyclones connected in parallel or series has long been known to be advantageous in the separation of particulate matter from a fluid stream. Typically, a relatively high speed fluid stream is introduced tangentially to a generally cylindrical or frusto-conical first stage cyclone separator, wherein the dirty air stream is accelerated around the inner periphery of the first stage cyclone separator. Fluid exiting the first stage cyclone separator is fed to the inlet of a second stage cyclone separator wherein the described separation process is repeated. Typically, successive separators are configured to remove ever-smaller particles from the fluid stream, until a desired cleaning efficiency is achieved. Particulate matter disentrained from the fluid flow is typically collected at the bottom of each stage.  
           [0004]    The advantages of multi-stage cyclonic separation are disclosed in U.S. Pat. No. 3,425,192 to Davis. As shown in FIG. 1, multi-stage separator  10  essentially comprises a large, lower first stage cyclone separator  12  connected in series with a plurality of smaller, parallel second stage cyclone separators  14  disposed over cyclone separator  12 . A motor (not shown) draws air through a cleaning head and into a dirty air inlet  16  of the first stage cyclone separator  12 . From first stage cyclone separator  12 , the air flows into second stage cyclone separators  14  and, from there, continues on through the vacuum motor to a clean air exhaust port (not shown). Particles separated from the fluid flow are deposited by first stage cyclone separator  12  into a primary collector  20 , while particles separated from the fluid flow by second stage cyclone separators  14  are deposited into a secondary collector  22 , vertically disposed over primary collector  20 . When primary and/or secondary collectors  20  and  22  become laden with deposited particles, and must therefore be emptied, two distinct emptying steps are required to clear the collectors of their contents.  
         SUMMARY OF THE INVENTION  
         [0005]    In accordance with the instant invention, there is provided a vacuum cleaner comprising a cleaner head having a dirty air inlet; and, a casing having a filtration member, the filtration member having an inlet in fluid flow communication with the dirty air inlet and an outlet in fluid flow communication with a source of suction, the filtration member comprising at least one upstream particle separator having an associated upstream particle collector and at least one downstream particle separator having an associated downstream particle collector, the particle collectors are configured such that the downstream particle collector is emptied by transferring its contents into the upstream particle collector.  
           [0006]    In one embodiment, at least a portion of the upstream particle separator is removable from the casing and the downstream particle collector is emptied into the upstream particle collector when the when the portion of the upstream particle collector is removed from the casing.  
           [0007]    In another embodiment, the vacuum cleaner further comprises a particle transfer member positioned between one of the particle separation members and its associated particle collector whereby particles separated by the said particle separation member are conveyed to said particle collector.  
           [0008]    In another embodiment, at least a portion of the particle transfer member is angled downwardly whereby particles travel to said particle collector at least partially under the influence of gravity.  
           [0009]    In another embodiment, the downstream particle separation member is chosen from the group of a cyclone, a Prandtl layer turbine and an electrostatic filter.  
           [0010]    In another embodiment, the downstream particle collector is positioned in the upstream particle separation member.  
           [0011]    In another embodiment, the downstream particle collector is pivotally mounted above the upstream particle collector.  
           [0012]    In another embodiment, the downstream particle collector has side walls and a bottom that is mounted for movement between a closed position and an open position and the bottom moves to the open position as the upstream particle collector is prepared for emptying.  
           [0013]    In another embodiment, the bottom is maintained in the closed position by interaction between the bottom and a member positioned on a portion of the vacuum cleaner that is not removed with the upstream particle collector.  
           [0014]    In another embodiment, the downstream particle collector is disposed adjacent the upstream particle separation member.  
           [0015]    In accordance with another aspect of the instant invention, there is provided a separator for separating entrained particles from a fluid flow, the separator comprising a first particle separation member; a reusable particle collector disposed beneath the particle separation member, the particle collector having a moveable member movably mounted between a closed position and an open position; and, a particle receiving chamber disposed beneath the particle collector, wherein when the moveable member moves from its closed position to its open position, particles collected in the particle collector are substantially transferred to the particle receiving chamber.  
           [0016]    In accordance with another aspect of the instant invention, there is provided a separator comprising an inlet in fluid flow communication with a source of fluid having particles therein; a particle separation member; a first particle collector disposed below the particle separation member; and, a particle transfer member positioned between the particle separation member and the particle collector whereby particles separated by the particle separation member are conveyed to the particle collector.  
           [0017]    In accordance with another aspect of the instant invention, there is provided a separator for separating entrained particles from a fluid flow, the separator comprising first separating means for separating particles from the fluid flow; second separating means for separating particles from the fluid flow; first particle collecting means for collecting particles separated from the fluid flow by the first separating means; second particle collecting means for collecting particles separated from the fluid flow by the second separating means; and, directing means for directing particles from the first particle separating means to the first particle collecting means. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example to the accompanying drawings.  
         [0019]    The drawings show a preferred embodiment of the present invention, in which:  
         [0020]    [0020]FIG. 1 is a vertical cross section through a multi-stage cyclonic separator according to the prior art;  
         [0021]    [0021]FIG. 2 is a perspective view of a multi-stage separator according to the present invention;  
         [0022]    [0022]FIG. 3 a  is an exploded perspective view of the multi-stage separator of FIG. 2;  
         [0023]    [0023]FIG. 3 b  is an exploded perspective view of an alternate embodiment of the multi-stage separator of FIG. 2;  
         [0024]    [0024]FIG. 4 is a perspective view of the multi-stage separator of FIG. 2, with the second stage collector shown in a partially open position;  
         [0025]    [0025]FIG. 5 is a perspective view of a household vacuum cleaner according to the present invention;  
         [0026]    [0026]FIG. 6 is a perspective view of an alternate embodiment of a multi-stage separator having a particle transfer member according to the present invention;  
         [0027]    [0027]FIG. 7 is a perspective view of a further alternate embodiment of a multi-stage separator having a particle transfer member according to the present invention;  
         [0028]    [0028]FIG. 8 is a perspective view of a further alternate embodiment of a household vacuum cleaner having a particle transfer member according to the present invention;  
         [0029]    [0029]FIG. 9 is a perspective view of a further alternate embodiment of the second stage particle collector according to the present invention; and,  
         [0030]    [0030]FIG. 10 is an enlarged side view of the second stage particle collector of FIG. 9. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]    The present invention relates to multi-stage particle separation systems wherein the particles separated in a second (or downstream) separation stage are transported to a position wherein they may be removed from the multi-stage particle separation systems together with the particles separated in a first (or upstream) separation stage. The improvements may be used in any multi-stage separation system wherein material separated by a second stage separation process is to be stored in a storage container which is to be periodically emptied. The downstream separation stage may use any separation technique, eg a cyclone separator, a Prandtl layer turbine, an electrostatic precipitator or the like, which produces separated particles that must be handled in such a way that they will not be re-entrained in fluid flowing through the downstream separation stage (eg, stored in a reusable container). Preferably, the downstream and the upstream separation stages use such separation techniques.  
         [0032]    The preferred embodiment of the present invention is described in its use with a vacuum cleaner and in particular an upright vacuum cleaner. It will be appreciated that the improvements in multi-stage separation described herein may be used with canister vacuum cleaners, back pack vacuum cleaners, central vacuum cleaner systems as well as single and multi-stage separators of any sort, including industrial dust or particle collection systems wherein particles are to be removed from a fluid (i.e. a liquid and/or a gas).  
         [0033]    An improved multi-stage separator according to the present invention is shown generally in the Figures at  30 . Referring to FIG. 2, separator  30  comprises a first stage cyclone  32  and a plurality of second stage cyclones  34 . First stage cyclone  32  has a first stage collector  36  and second stage cyclones  34  have a second stage collector  38 . First stage cyclone  32  and second stage cyclones  34  are housed within a housing  40  having a top  41 , a lower portion comprising container  66  and an upper portion comprising second stage assembly  51 . As shown in FIG. 2, top  41  comprises a mesh screen that is positioned upstream of a motor driven fan. However, it will be appreciated that second stage assembly  51  may be open or it may be closed if it is provided with a fluid outlet. First stage cyclone  32  has an fluid inlet  42 , fed by a fluid feed conduit  45 , and a fluid outlet  46 . Fluid outlet  46  feeds a transfer conduit  44  which is in fluid communication with a plurality of second stage cyclones  34  via a plurality of inlets  47 . Second stage cyclones  34  each have a fluid outlet  49  positioned beneath mesh screen  41 .  
         [0034]    As shown in FIG. 2, transfer conduit  44  extends above mesh screen  41  to engage a support member (not shown) to fix second stage cyclones  34  in position. The interior of conduit  44  is sealed to cause the air to enter second stage cyclones  43 . Alternately, transfer conduit  44  may terminate at inlets  47  and alternate support means may be provided to position second stage cyclones  34  in second stage assembly  51  (eg. by means of support members attached to the inner wall of second stage assembly  51 ).  
         [0035]    While the first and second stages are connected in series, it will be appreciated that the improvements disclosed herein may be used in a system wherein the first and second stages are connected in parallel. It will also be appreciated that additional separation stages may be positioned upstream, downstream or both upstream and downstream from the first and second separation stages. It will further be appreciated that first stage cyclone  32  may comprise a plurality of cyclones and/or that the second stage may comprise only one second stage cyclone  34  (see for example FIG. 7). The fluid may be propelled through separator  30  by any means known in the art. For example, a pump may be positioned upstream of separator  30  or, in the case of a vacuum cleaner, a source of suction (eg. a motor driven fan) may be positioned downstream from separator  30 .  
         [0036]    Beneath second stage cyclones  34  is a particle transfer member  48  which slopes downwardly to second stage collector  38 . Second stage collector  38  has side walls  50  and a bottom  52 . Referring to FIG. 3 a , bottom  52  is separable from side walls  50 .  
         [0037]    In the embodiment wherein separator  30  is used in a vacuum cleaner (see, for example, FIG. 5), a motor-driven fan draws particle-laden fluid via a feed conduit into first stage inlet  42  via fluid feed conduit  45 . The fluid flows cyclonically within a first stage cyclone  32  depositing particles in first stage collector  36  (which may be the bottom surface of container  66 ). The fluid exits first stage cyclone  32  via outlet  46  and is delivered by conduit  44  to the inlets  47  of second stage cyclones  34 . Cyclonic flow in second stage cyclones  34  further separates particles from the fluid flow, which particles fall on to particle transfer member  48  for transfer to second stage collector  38 . The fluid flow then exits second stage cyclones  34  via outlets  49 , and is expelled from separator  30 . The separated particles travel under the influence of gravity along particle transfer member  48  to second stage collector  38 .  
         [0038]    Preferably, as shown in FIG. 2, transfer member  48  comprises a helical ramp which slopes downwardly, around centre conduit  44 , to second stage collector  38 . Transfer member  48  is preferably angled sufficiently to cause the particles to slide easily down transfer member  48  to second stage collector  38  under the influence of gravity without substantially collecting on the surface of transfer member  48 . Preferably, the motor-driven fan is mounted as part of the casing in which separator  30  is mounted. Accordingly, vibration from the operation of the motor-driven fan may assist the particles to travel along particle transfer member  48  under the influence of gravity (in which case particle transfer member may be at a lesser incline).  
         [0039]    Deposited particles accumulate in second stage collector  38  and, eventually, second stage collector  38  must be emptied. In accordance with one aspect of the instant invention, second stage collector is configured so that it is emptied when first stage collector  36  is emptied. For example, as shown in FIGS. 3 a ,  4 ,  9  and  10  second stage collector may be constructed so that the contents of second stage collector  38  are emptied into first stage collector when container  66  is removed from second stage assembly  51 . Alternately, as shown in FIGS. 3 b ,  6  and  7 , second stage collector  38  is constructed so that it is emptied when first stage collector  36  is emptied (eg. by inverting container  66 ). Container  66  may completely contain first stage cyclone  32 , or may comprise only a portion thereof. It will be understood that container  66  need only comprise first stage collector  36  and such additional portion as necessary to permit collectors  36  and  38  to be emptied and removed as described herein.  
         [0040]    As illustrated in FIG. 3 a , second stage collector  38  is separable into two components, namely side walls  50  and bottom  52 . Bottom  52  is affixed to the interior of container  66  while side walls  50  are affixed to second stage assembly  51 , such as to first stage outlet  46  or the lower surface of particle transfer member  48 . Referring to FIG. 4, to empty the contents of second stage collector  38  into first stage collector  36 , container  66  is rotated in the direction of arrow A so that bottom  52  moves relative to side walls  50  thereby causing the contents of second stage collector  38  to fall into first stage collector  36  which acts as a particle receiving chamber. Container  66  may then emptied by inverting container  66  over a garbage container. Thus, only a single emptying step is required to empty separator  30 .  
         [0041]    Referring again to FIG. 4, side wall  50  preferably has a lower edge  54  which moves over the surface of bottom  52 , as bottom  52  moves away from side walls  50 , to sweep the surface of bottom  52  to assist in removing particles therefrom. Bottom  52  may optionally also be canted relative to the horizontal (not shown) to encourage particles thereon to slide off into first stage collector  36  when bottom  52  is moved away from side walls  50 .  
         [0042]    In the embodiment of FIGS. 9 and 10, bottom  52  is hingedly connected to side walls  50  by a hinge  56 , rather than completely separable therefrom. A cam  58  positioned on the inner surface of container  66  is moveable (when container  66  is rotated relative to assembly  51 ) between a closed position in which it is positioned beneath bottom  52  (FIG. 9) and an open position in which it has been moved away from bottom  52  (solid lines in FIG. 10). When container  66  is rotated in the direction of Arrow B in FIG. 10, cam  58  is moved to a position beneath side walls  50  and bottom  52  follows cam  58  into a position beneath side walls  50  (as illustrated in dotted outline in FIG. 10), thereby closing second stage collector  38 . When cam  58  is moved away from side walls  50 , by the rotation of container  66 , bottom  52  is permitted to swing freely to its open position due to gravity thereby dumping the contents of second stage collector  38  into first stage collector  36 .  
         [0043]    In the embodiment of FIG. 3 b , second stage collector  38  is affixed to the inner surface of container  66 . In this embodiment, when assembly  51  is removed from container  66 , second stage collector  38  is positioned inside container  66 . Thus when first stage collector  36  is emptied, eg. by inverting container  66 , second stage collector  38  is also emptied.  
         [0044]    Referring to FIG. 5, upright vacuum cleaner  200  has a cleaner head  202  with rear wheels  204  and front wheels (not shown) for moving cleaner head  202  over a floor, a casing  206  which is pivotally mounted to cleaner head  202  and a handle  208  for moving of vacuum cleaner  200  over the floor. Casing  206  houses separator  30  according to the present invention. Vacuum cleaner  200  may be of any construction provided that container  66  is removable from vacuum cleaner  200  for emptying. Air inlet  42  of separator  30  communicates with a dirty air inlet (not shown) adjacent the floor in the lower surface of cleaner head  202 . Container  66  is removable from main casing  206 , via a handle  212 , for the periodic emptying of the particles therein. It will be understood by one skilled in the art that only the lower portion of first stage cyclone  32  (i.e. the portion with collector  36 ) may be removable from housing  40  provided that the contents of second stage collector  38  are emptied into first stage collector  36  prior to the removal of first stage collector  36  from vacuum cleaner  200 . Accordingly, neither second stage collector  38 , second stage cyclones  34  nor the entirety of first stage cyclone  32  need be disposed interior of the portion of container  66  which is removable from housing  40 , but rather may be fixedly located in main casing  206  above the portion of container  66  which is removable from housing  40 . In this embodiment, first stage collector  36  comprises a chamber positioned below first stage cyclone  32  and separated therefrom by a plate  68  having a plurality of openings  69  therein.  
         [0045]    In the embodiment of FIG. 6, second stage collector  38  comprises a side container  70  having an inlet at an upper portion thereof and a bottom  72  positioned at a location beneath the inlet. As shown in FIG. 6, bottom  72  is substantially planar with the bottom of first stage collector  36 . Side collector is preferably a one piece assembly with container  66  so that container  66  and side container  70  are removed as a one piece assembly from casing  206 . Thus container  70  may be have a lower portion  71  that is integrally formed with container  66 . Alternately, the may be individually moulded and then assembled together to form a one piece unit. In either case, when first stage collector  36  is removed from casing  206  for emptying, eg. by inverting container  66 , lower portion  71  of container  70  is also removed from casing  206  and emptied.  
         [0046]    Particle transfer member  48  is configured to convey particles separated by the second stage to second stage collector  38 . It will be apparent to one skilled in the art that the configuration of transfer member  48  will vary depending upon the position of second stage collector  38 . For example, referring to FIG. 6, transfer member  48  comprises a disc canted to direct deposited particles laterally to side container  70 . In this embodiment, guide or spout  74  is optionally provided to direct particles from transfer member  48  to side container  70 . It will also be apparent that collector  38  is disposed below particle transfer member  48  so that particles may travel across transfer member  48  and be deposited into collector  38 .  
         [0047]    Referring to FIG. 7, transfer member  48  is shown used with advantage in a multi-stage separator  300  having its filtration stages arranged in a side-by-side configuration. Here, separator  300  comprises a first stage cyclone  32  and a second stage cyclone  34 , the first stage and second stage being connected in series. First stage cyclone  32  has an fluid inlet  42  and a fluid outlet  46  which is in fluid flow communication with conduit  44  which is in fluid communication with second stage cyclone  34  via inlet  47 . Second stage cyclone  34  has a fluid outlet  49  in communication with a conduit leading to a driving member (eg. a motor-driven fan which is not shown). Particle transfer member  48  is positioned at the bottom of first stage cyclone  32  and comprises a sloped member canted to direct deposited particles substantially laterally from first stage separator  32  to second stage collector  38  (which is also positioned at the bottom of second stage separator  34 ) via opening  78  in assembly  51 . Thus, in essence, in this embodiment first stage collector  36  and second stage collector  38  are one and the same. A spout member  74  is optionally provided to assist in transferring particles from transfer member  48  to collector  36 / 38  and, thus, it is only necessary to remove collected particles from the one collector  36 / 38 . It will be apparent that collector  36 / 38  is disposed below particle transfer member  48  so that particles may travel across transfer member  48  and be deposited onto collector  36 / 38 .  
         [0048]    The present invention can also be used advantageously with a single stage filtration means wherein it is desirable to transfer the contents of the single stage collector to a more accessible position prior to emptying. For example, referring to FIG. 8, vacuum cleaner  220  has a single stage of cyclonic cleaning, namely a cyclone  32  having an adjacent external container  70 . Struts  222  extend between the upper and lower portions of casing  206 . Transfer member  48  transfers particles deposited by the cyclone to side container  70 . Side collector  70  is separable from container  66  and casing  206 , thereby permitting the user to empty particles collected by cleaner  220  simply by detaching external container  70  from the container  66  and appropriately emptying its contents.  
         [0049]    Therefore, the transport member according to the present invention advantageously provides convenience in transporting collected particles to a collector for more convenient emptying thereof. The convenience added by the present invention permits a wider configuration of multi-stage separation devices to be used conveniently in domestic and household applications.  
         [0050]    The collector according the present invention also advantageously increases the flexibility of various multi-stage separation mechanisms for facilitating ease-of-use and convenient operation of household vacuum cleaners. As stated above, the upstream and downstream separation stages may use any separation technique which produces separated particles that must be handled in such a way that they will not be re-entrained in fluid flowing out of the separation stage (ie. the stage is capable of depositing and storing separated particles in a reusable container) such as, for example, a cyclone separator, a Prandtl layer turbine, an electrostatic filter, a fibre filter or the like.  
         [0051]    While the above description constitutes the preferred embodiments, it will be appreciated that the present invention is susceptible to modifications and change without departing from the fair meaning of the proper scope of the accompanying claims.