Abstract:
A dirt separation and collection container suitable for use in a bagless vacuum cleaner including two dirt separation and collection zones is provided. Dirty air enters the mid-section of the device and enters a first stage dirt separation zone including a cylindrical baffle spaced inwardly from the outer wall of the device with an inclined slot to allow coarse dirt particles and fibers to pass through and collect at the base of the outer wall of the device. The spinning air is then fed into a second stage conical separator for separating fine dirt particles and collecting them in an inner substantially cylindrical collection chamber. Air exits the conical separator and device opposite the cone opening before being drawn to the suction source. Elements may be oriented upwardly or downwardly depending upon the configuration of the housing for receiving the dirt separation and collection device.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to dirt separation and collection devices and vacuum cleaners and, more particularly to a vacuum cleaner including a collection vessel having a first stage separation zone including a slotted baffle for separating and collecting coarse dust particles and a second stage separating zone including a frusto-conical cyclone for separating and collecting fine dirt particles. 
     Cyclonic vacuum cleaners have been known for some time. For example, European Patent No. EP 0 042 723 and U.S. Pat. No. 4,593,429 to James Dyson disclose a vacuum suction cleaning device including two cyclone units in series operating successively to extract dirt particles from an air flow. One of the two cyclones has a substantially frusto-conical shape serving to increase the velocity of the dirt particles so that the cyclone is capable of depositing the fine dust particles in a small diameter collection chamber relative to the diameter of the cone opening. Prior to the air entering the cyclone, dirty air enters tangentially against the wall of a cylindrical outer chamber operating as a cyclone to remove coarse dirt particles from the dirty air entering the device. 
     In addition to devices wherein the successive cyclones are coaxial as in the above noted publications, Dyson in U.S. Pat. No. 4,373,288 places frusto-conical cyclones side by side. In this configuration, the device is designed to remove dirt through the two cyclones operating in series. The principal objective in all these devices is to avoid the need to utilize a bag as in conventional vacuum cleaners. In these conventional devices, air is drawn through the appliance by a fan that creates a large pressure drop as the bag fills with dirt. This increase in pressure drop lowers the cleaning efficiency of the unit. It is for this reason that configurations for bagless vacuum cleaners are extremely appealing. 
     A bagless cleaning device is disclosed in WO 99/42198 based on PCT/GB99/00507 by the applicant herein. The full text of this publication is incorporated herein by reference. In this device dirty inlet air is passed into the upper portion of a cyclone having a cylindrical cross-section and a lower frusto-conical section. This cyclone separation stage is designed to separate fine dirt particles in a collection chamber below the cone opening. The cylindrical portion of the device includes a transition zone connected to an adjacent side chamber for collection of coarse dirt particles. In another embodiment disclosed therein, coarse dirt is collected in an outer larger cylindrical chamber surrounding the inner frusto-conical cyclone separator. 
     Other bagless vacuum cleaner designs are shown in a series of related applications that issued to Royal Appliance Mfg. Co. based on an application that initially issued as U.S. Pat. No. 6,003,196 on Dec. 21, 1999. These patents disclose various types of upright vacuum cleaners including an air separation chamber that may be a cyclonic separation device. All the vacuum cleaners described in these patents include a filter disposed in the cyclonic air flow chamber or dirt cup upstream of the suction source. 
     U.S. Pat. No. 6,192,550 to Sanyo Electric Co., Ltd. also discloses a vacuum cleaning device having a rotatable filter disposed in a cyclonic air separation chamber. This device is particularly effective, because the rotatable feature of the filter allows removal of dirt entrained in the filter into the bottom of the dirt cup for easy disposal when the dirt cup is removed for cleaning. The contents of this patent are incorporated herein by reference. 
     While many of these bagless designs are improvements over conventional vacuums utilizing bag technology, it remains desirable to provide continued improvements and alternative designs to improve the separation of dirt particles from air without the need to include filters in the air separator chamber or in the dirt cup. 
     SUMMARY OF THE INVENTION 
     Generally speaking, in accordance with the invention, a dirt separation and collection device for a bagless vacuum cleaner including at least a first stage cylindrical separation zone formed of a baffle having an inclined slot is provided. The separation and collection device has an elongated cylindrical container including the first stage slotted separation zone and a second stage inner frusto-conical cyclone fine dust separating cyclone, both coaxially mounted within the cylindrical container. The first stage separator is a slotted baffle or shroud with an inclined slot that removes coarse dirt particles from the dirty inlet air before the air is fed into the fine dirt cyclone separator. The slotted baffle is disposed coaxially about the cyclone separator within the dirt collection container. Dirty air enters tangentially into the interior of the slotted baffle disposed at the upper portion of the container and extends only a portion of the length of the container. Coarse dirt and fibrous materials pass through the slot thereby depositing the coarse dirt particles in the bottom of the container. Air then enters the larger cone opening to the interior of the cyclone separator wherein fine dirt particles are removed through the smaller cone opening at the opposite end and clean exhaust air is withdrawn at the center of the larger cone opening. 
     The cyclone separator may be disposed within the baffle with the cone opening oriented towards the lower or upper directions. Dirty air may enter the first stage separator at the top or bottom of the baffle with the slot angle being oriented clockwise or counterclockwise from top or bottom. The cylindrical dirt separation container including and inlet in the sidewall into the baffle and a coaxial cyclone with clean air withdrawn at the top is particularly well suited for use in an upright vacuum cleaner of the type disclosed in U.S. Pat. No. 6,192,550. Dirt is removed by opening the container bottom in a similar manner as described in the patent. 
     Accordingly, it is an object of the invention to provide a dirt separation device for a vacuum cleaner that provides greater dirt separation over existing designs. 
     It is another object of the invention to provide a dirt separation device including a cyclone separator disposed coaxially within a cylindrical baffle having an inclined slot. 
     A further object of the invention is to provide a dirt separation device including a cylindrical dirt collection chamber having a baffle with an inclined slot for removing coarse dirt and fibrous materials from the incoming dirty air stream with an inner coaxial cyclonic separator within the dirt collection chamber. 
     Yet another object of the invention is to provide an air separation device including a cylindrical dirt cup with a cyclonic separation device disposed coaxially within the dirt cup and a slotted baffle disposed about the cylindrical axis for removal of coarse dirt particles and fibrous material prior to inlet air entering the cyclone separator for collection of fine dirt particles. 
     Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification. 
     The invention accordingly comprises the features of construction, combination(s) of elements, and arrangement of parts which will be exemplified in the construction(s) hereinafter set forth, and the scope of the invention will be indicated in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing(s), in which: 
         FIG. 1  is a side sectional view of an upright vacuum cleaner of the type disclosed in the prior art including a filter within a removable cylindrical cyclonic air separation and collection chamber; 
         FIG. 2  is a front sectional view of the upright vacuum cleaner illustrated in  FIG. 1 ; 
         FIG. 3  is a rear elevational view in section of a transparent dirt separation and collection container with a dirty air inlet to a first stage slotted separation zone and an inner second stage coaxial cyclone separation zone constructed and arranged in accordance with the invention; 
         FIG. 4  is a front elevational view of the dirt separation and collection device of  FIG. 3 ; 
         FIG. 5  is a right side elevation view in cross-section of the dirt separation and collection device of  FIGS. 3 and 4 ; 
         FIG. 6  is a sectional view of the dirt collection and separation device of  FIGS. 3–5  taken along line  6 — 6  of  FIG. 3 ; 
         FIG. 7  is a perspective view of the first stage separation zone of the device of  FIGS. 3–6 ; 
         FIG. 8  is a schematic view of a dirt separation and collection device with slotted first stage separation zone in accordance with another embodiment of the invention; and 
         FIG. 9  is a schematic view of a slotted first stage separation zone constructed and arranged in accordance with yet another embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 and 2  illustrate a side sectional view and a front section view of the upright vacuum cleaner of the type shown in U.S. Pat. No. 6,192,550, the disclosures of which is incorporated herein by reference. Here, a suction nozzle  2  for floors is formed at a lower portion of a main body  1  of the vertical type vacuum cleaner with a handle  3  for operating main body  1  at an upper portion thereof, all of which are formed in an uniform manner. 
     Suction nozzle  2  for floors has a suction inlet  4  at a bottom surface side and further incorporates therein a rotating brush  5  to face suction inlet  4 . Rotating brush  5  is connected to a rotating shaft of a motor fan  6  that is incorporated in the lower portion of main body  1  to be driven in a rotating manner. A pair of laterally arranged front wheels  7  are attached frontward of the bottom surface of suction nozzle  2  for floors, while a pair of laterally arranged rear wheels  8  are attached rearward of a lower portion of main body  1 . 
     A pipe  9  is attached on either side of the suction nozzle  2  for floors that communicates with suction inlet  4 . Pipe  9  extends upward along main body  1  to a tip end portion of a hose  10  in a freely attachable and detachable manner. Hose  10  is disposed to the rear surface side of the main body  1  by means of a holding portion  11  arranged on a rear surface side of the handle  3  for operating the main body and is connected to a suction cylinder  12  which is formed to be shifted to either side with respect to a center of the rear surface side. 
     A dust-collecting device (dust-collecting unit)  20  is fitted to a central portion on the front surface side of the main body  1  of the vacuum cleaner in a freely attachable and detachable manner. Dust-collecting device  20  includes cylindrical pre-filter  22  made of transparent resin or the like fitted into the interior of a substantially cylindrical dust-collecting case  21  made of transparent resin or the like, with a substantially cylindrical main filter  23  inside of pre-filter  22 . 
     Dust-collecting case  21  is provided with a grip  24  at a central portion on a side that faces to the front when being attached to main body  1 . Grip  24  is so arranged as to extend in a longitudinal direction in a successive manner downward to handle  3  for operating main body  1  with a groove  25  is formed on a surface of the grip  24 . 
     A handle  26  is rotatable for rotating the pre-filter  22  is attached to an upper side of grip  24  in such a manner that it is freely foldable in a transverse direction with respect to a rotating axis  27  thereof. Handle  26  can be accumulated in groove  25  of grip  24  while a knob  26   a  of handle  26  is fitted to a concave portion  25   a  formed in groove  25  of grip  24  to be fixed thereat. It is possible to discharge dust accumulated within dust-collecting case  21  by holding grip  24 , and the handle  26  can also be accumulated by efficiently utilizing the grip  24  which is not needed at the time of performing cleaning. 
     A clamp  28  is engaged with main body  1  when dust-collecting device  20  is fitted to main body  1  is provided on an upper side of the handle  26  of the dust-collecting device  20 . 
     A bottom lid  32  is attached which is arranged to be freely openable and closeable by a hinge  31  provided in a lower portion of grip  24 . Bottom lid  32  is so arranged that by pushing a lever  33  provided in a lower portion of the grip  24 , a clamp  34  formed on an opposing side of the dust-collecting case  21  to be connected to the lever  33  is disengaged from an engaging jaw  35  to thereby release a discharge outlet  36  for the dust. 
     A spiral rib  52  is formed as to extend in vertical directions on an outer periphery of the pre-filter  22 . The spiral rib  52  is disposed about pre-filter  22  so that dust which has accumulated and compressed within dust-collecting case  21  is pushed out in a direction of the discharge outlet when bottom lid  32  is opened for rotating the filter is rotated in a rightward direction. 
     Air that has been filtered of dust within dust-collecting device  20  exits through the aperture on the lower portion side of cylindrical body  40  of main filter  23  to the exterior of dust-collecting case  21 . Filter air is taken in by motor fan  6  via a filter  56  shown in  FIG. 1  to be exhausted through an exhaust outlet  58  formed on a lower portion of a front surface of main body  1  to the exterior by being passed from motor fan  6  through an exhaust filter  57 . 
     Dust which has been scraped up by rotating brush  5  of the suction nozzle  2  for floors passes through pipe  9  and hose  10  into dust-collecting case  21  through suction cylinder  12  located to be shifted in either direction with respect to a center of the rear surface side of main body  1  and is made to flow downward by being revolved along the inner wall thereof while large-sized dust (coarse dust) is deposited on the bottom. 
     Mesh  51  of pre-filter  22  for sucking air is formed to be located downward within dust-collecting case  21 . Dust that has entered together with air through suction hole  30  located upward within the dust-collecting case  21  is pushed downward by being revolved at a high speed so as to be deposited on the bottom surface (bottom lid  32 ) of dust-collecting case  21  in a pressed condition. 
     Further, small-sized dust (minute dust) enters into pre-filter  22  by passing through mesh  51  arranged in the lower portion of pre-filter  22  and is filtered by the pleat-like main filter  23 . Thus, only clean air enters main filter  23  to flow downward through the motor fan  6  to be finally exhausted through the exhaust outlet  58  to the exterior. 
     Discharge of dust which has been accumulated in the dust-collecting case  21 , by holding grip  24  of dust-collecting case  21  and drawing the case out with pushing an operating portion of clamp  28  disposed above the grip  24  upward, the dust-collecting case  21  is detached from the main body  1  of the vacuum cleaner. 
     By pushing a lever  33  provided in the lower portion of the dust-collecting case  21 , clamp  34  is detached whereby bottom lid  32  is released to enable discharge of dust that has been accumulated in dust-collecting case  21 . At this time, especially flock-like dust adheres to the inner wall of dust-collecting case  21  in a compressed state so that dust does not easily come off as it is. Thus, handle  26  is rotated in a specified direction (in this case in a rightward direction) for rotating pre-filter  22  in a specified direction whereby spiral rib  52  provided on outer periphery of pre-filter  22  acts to push out dust such as flock-like dust in a compressed state so that easy discharge is enabled. 
     In an effort to eliminate the need for a filter in the dirt collection chamber in the type of upright vacuum shown in  FIGS. 1 and 2 , a two stage dirt separation and collection device  101  as shown  FIG. 3  constructed in accordance with the invention may be substituted for dust collecting case  21  in main body  1 . Dirt separation and collection container  101  is shown in  FIGS. 3–5 . 
     Referring now to  FIGS. 3 and 4 , dirt separation and collection container  101  includes a cylindrical collection vessel  102  formed with a substantially cylindrical sidewall  103 , a selectively openable base  104  and a removable cap  105  having a carrying handle  106 . A release button  112  mounted in handle  106  releases container  101  from main body  1 . Base  104  is secured to sidewall  103  by a hinge  108  and s opened by a latch  109  operatively connected by a connecting rod  111  for cleaning in the same manner as described in connection with the vacuum cleaner of  FIGS. 1 and 2 . 
     Dirty air enters container  101  through an inlet  113  in sidewall  103  and enters a first stage separation zone  114 . Coarse dirt separated in zone  114  is collected in the outer portion of vessel  102 . A second stage cyclone separation zone  124  is coaxially disposed in a center column  117  in which fine dirt particles are collected. 
       FIG. 5  is a cross-sectional view of the dirt separation elements contained in dirt separation and collection container  101 . These include a first stage separation zone  114  that is a cylindrical baffle or shroud mounted about the central axis of vessel  102  and extending only a portion of the length of vessel sidewall  103 . Air entering the first stage separator rotates in the annular space between baffle  114  and column  117  with large dirt particles expelled through an inclined slot  118  shown in  FIGS. 4 and 7 . Expelled particles are collected on the base  104  of vessel  102 . A number of paddles or baffles  116  are placed on the inside surface of base  104  to prevent re-entrainment of dirt during operation of the separation device. 
     Air circulating in first stage separator  114  passes through a section of column  114  having a plurality of holes  119  or a screen mesh. It then travels upwardly to a series of directional vanes  123  in a domed vane cover  110  and is directed into a second stage frusto-conical separator  124  coaxially oriented within vessel  102 . Second stage conical separator  124  has a large cone opening  126  at the top and a smaller cone opening  127  at the bottom. The separation elements may be oriented in any direction so that the second stage separation zone may be inverted as shown in the embodiment shown in  FIG. 8.9 . 
     Air then rotates downwardly along the inside wall of cone  124  and then turns upwardly to exit through an outlet  128  and passes through exhaust or outlet conduits  129  formed on the outside of sidewall  103  of vessel  102 . Fine dirt is expelled through lower cone opening  127  and collected in an isolated collection zone  131  at the base of column  117 . Exiting clean air then passes along the outside of base  104  through a filter, such as a HEPA filter, to a suction source such as motor fan  6  in the vacuum cleaner of  FIG. 1 . A vortex baffle  132  is placed at the outside of small cone opening  127  to increase efficiency of the separation in conical separator  124 . 
     In the embodiment illustrated in  FIGS. 3–7 , slot  118  is shown positioned about 180 degrees from inlet  113  and is inclined in the direction of airflow from the upper portion of baffle wall  114  to the bottom portion. Slot  118  in baffle wall  114  is shown at an angle of about 30 degrees from vertical inclined in the direction of flow. The angle of incline may vary from 0 to 60 degrees. A wide variety of shapes and orientation of the slot may be utilized. For example, the slot may be a spiral extending about a portion of or the entire circumference of the cylindrical wall, or may be an incline as shown. It may also be inclined or spiraled in the opposite direction. 
     Baffle wall  114  is also formed with an inwardly facing lower flange  133  that does not extend to central column  117 . Flange  133  together with a helical vane  134  on central column  117  prevents re-entrainment of dirt into first stage separator  114 . 
     During operation coarse particles and fibers are separated from the dirty inlet air in first stage separator  114 . These coarse particles are collected in the base of vessel  102 . Fine dirt particles separated in second stage cyclonic separator  124  are collected in second stage collection zone  131 . 
     Dirt separation and collection chamber  101  was designed specifically to be interchangeable and usable with the vacuum cleaner as illustrated in  FIGS. 1 and 2 . Here, dirty air enters towards the middle to upper portion of vessel  102  and exits through cap  106  and is transported to motor fan  6  at the base of main body  1 . 
     The concept of a first stage separation zone having a slotted baffle in accordance with the invention is suitable for a wide variety of machine configurations. These include entry in the mid-point of a collection chamber into the lower portion of a first stage separator and passing into the upper portion of a conical separator where dirty air travels downward and exhausts at the upper portion of the separation and collection chamber. This configuration is similar to the embodiment of  FIGS. 3–7  and is illustrated in schematic in  FIG. 8 . In this embodiment, a dirt separation and collection chamber  151  includes a first separation zone or chamber  152 , a cylindrical sidewall  153 , a base  154 , an upper portion or cap  156  and a dirty air inlet  155 . First stage separator is formed of a cylindrical wall  157  extending only a portion of the length of sidewall  153  and having a slotted spiral  158  through which coarse particles and fibrous materials are expelled into the outer annular portion of vessel  151 . Fine particles are separated a second stage conical separator  159  and are collected in an isolated dirt collection chamber  161 . Clean air exhaust at an outlet  162  formed in cap  156 . 
     Referring now to  FIG. 9 , a further embodiment of a dirt separation and collection device constructed and arranged in accordance with the invention is shown in schematic. Here, a dirt separation and collection chamber  171  includes a cylindrical sidewall  172 , a base  173  having a central outlet  174  and a top wall  176 . A dirty air inlet  177  enters a first stage separator formed with a baffle  178  that is formed with a slotted spiral  179  for separating coarse particles from inlet air. Large dirt particles are collected within the outer portion of collection chamber  171 . 
     Air exiting baffle  178  passes through a perforated screen  181  where it is directed into a circular channel  183  and passes through vanes  184  before entering an inverted conical second stage cyclone separator  186  having an inner wall  187  and an upper opening  188  spaced from top wall  176 . Dirty air circulates helically along the surface of inner wall  187  with fine dirt particles being expelled out of small cone opening  188  into a cavity  189  before returning downward through the axis of second stage separator  186  to exhaust  174 . 
     In view of the fact that air enters mid-way into chamber  171  and exhausts at the base, such a separation and collection chamber would also be suitable for use with a vacuum cleaner  1  of  FIGS. 1 and 2 . Collected dirt is removed by top wall  176  and base  173 . 
     It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction(s) without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing(s) shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention that as a matter of language, might be said to fall therebetween.