PATENT ABSTRACT
An upright vacuum cleaner includes a nozzle base having a main suction opening formed in an underside thereof. A housing is hingedly connected to the nozzle base. The housing includes a dirt separation chamber and a dirt receptacle for receiving dirt and dust separated by the dirt separation chamber. A conduit connects the nozzle base to the housing. A suction source is located in one of the housing and the nozzle base. The suction source is in fluid communication with the dirt separation chamber. A generally conically shaped filter extends into the dirt separation chamber along a longitudinal axis of the dirt separation chamber.

PATENT DESCRIPTION
This application is a continuation of U.S. application Ser. No. 10/339,829 which was filed on Jan. 10, 2003 and is still pending. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to vacuum cleaners. More particularly, the present invention relates to stick type vacuum cleaners that employ a dust cup. 
   Upright vacuum cleaners are very well known in the art. One type of upright vacuum cleaner which has become common in the marketplace is a stick type vacuum cleaner in which a dust cup is employed for holding dirt and dust separated from an airstream. In most stick type vacuum cleaners, a nozzle base travels across a bare floor, carpet or other surface being cleaned. Pivotally mounted to a nozzle base is an upright housing portion. Often this is formed as a rigid plastic housing having a socket for accommodating the dust cup. As is well known, a suction source such as a motor and fan assembly is mounted to either the nozzle base or the upright housing of the vacuum cleaner. 
   It is now also known in the art of vacuum cleaners to use cyclonic action to separate particles from a stream of dirt laden air. To this end, the dirt laden air is directed tangentially into the dust cup and flows in a swirling motion in the dust cup. Dirt particles are flung outwardly toward the side wall of the dust cup while air is withdrawn along a longitudinal axis of the dust cup. 
   One known type of stick type vacuum cleaner employing a dust cup with cyclonic airflow utilizes an inverted truncated cone positioned within the dust cup. A baffle extends outwardly from an outer surface of the cone. The baffle cooperates with the cone for directing a stream of dirt laden air in a cyclonic manner about the outer surface wall of the cone. In order to remove dust from the dust laden airstream, a filter is positioned outside the dust cup and mounted thereto. This design is disadvantageous from the standpoint that two different elements are needed to provide the cyclonic airflow and to filter the dirt from the airstream. It would be beneficial to have a design wherein the filter element can be positioned in the dust cup rather than being forced out of the dust cup due to the presence of a structure for generating a cyclonic airflow within the dust cup. 
   Accordingly, it has been deemed desirable to develop a new and improved stick type vacuum cleaner which would overcome the foregoing difficulties and others while providing better and more advantageous overall results. 
   BRIEF SUMMARY OF THE INVENTION 
   In accordance with one aspect of the present invention, an upright vacuum cleaner is provided. More particularly, in accordance with this aspect of the invention, the vacuum cleaner comprises a nozzle base including a main suction opening formed on an underside thereof. An upright housing is hingedly connected to the nozzle base. The housing includes a dirt separation chamber and a dirt receptacle for receiving dirt and dust separated by the dirt separation chamber. A conduit connects the nozzle base to the housing. A suction source is located in one of the housing and the nozzle base and is in fluid communication with the dirt separation chamber. A generally conically shaped filter extends into the dirt separation chamber along a longitudinal axis of the dirt separation chamber. 
   According to another aspect of the present invention, a vacuum cleaner is provided. In connection with this aspect of the invention, the vacuum cleaner comprises a nozzle base and a housing pivotally mounted on the nozzle base. The housing defines a cyclonic airflow chamber for separating contaminants from a suction airstream. The housing further comprises an inlet for the cyclonic airflow chamber and an outlet for the cyclonic airflow chamber. A dirt container is selectively mounted in the housing and defines at least a portion of the cyclonic airflow chamber for receiving and retaining dirt and dust separated from the suction airstream in the cyclonic airflow chamber. An airstream suction source is mounted to one of the housing and the nozzle base. The suction source is in fluid communication with the cyclonic airflow chamber and has an inlet disposed downstream from the cyclonic airflow chamber outlet. A filter assembly is selectively mounted to the dirt container and extends into the dirt container. The filter assembly includes a longitudinal axis and a support member including a handle. The longitudinal axis passes through the handle. 
   According to still another aspect of the present invention, a vacuum cleaner comprises a first housing member comprising a cyclonic airflow chamber adapted for separating entrained dirt and dust from the circulating airstream. A dust cup is releasably mounted to the first housing member. The dust cup, which includes an open first end and a closed second end, holds dirt and dust separated from the cyclonic airflow chamber. A second housing member defines a main suction opening. A first conduit fluidly connects the main suction opening of the second housing member to an inlet of the cyclonic airflow chamber. A generally conically shaped filter assembly is selectively mounted to the dust cup. It extends along a longitudinal axis of the dust cup. An airstream source is mounted to the first housing member and is positioned above the cyclonic airflow chamber. The airstream source is adapted for generating and maintaining an airstream flowing through the cyclonic airflow chamber. 
   In accordance with a further aspect of the present invention, a vacuum cleaner comprises a nozzle section and a housing section connected to the nozzle section and in fluid communication with the nozzle section. A dust cup is selectively mounted to the housing section. The dust cup holds dirt and dust separated from a suction airstream flowing into the housing section. A suction source is in fluid communication with the dust cup. A cyclonic airflow chamber is defined at least partially in the dust cup for separating particulate material entrained in an airstream flowing from the nozzle section towards the suction source. A tapered filter assembly extends into the dust cup for further separating dirt and dust from the suction airstream. 
   In accordance with yet another aspect of the present invention, a vacuum cleaner comprises a housing in communication with a suction opening and including a socket. A dust cup is removably mounted in the housing socket. The dust cup comprises an open first end, a closed second end and a side wall. A filter is selectively mounted to the dust cup first end and extends into the dust cup. A particle separation chamber is defined in the dust cup between an interior wall of the dust cup and the filter for separating particles from an airstream flowing from the suction opening through an inlet located in the dust cup side wall. A suction source is in fluid communication with the dust cup first end. The suction source is located in the housing for generating and maintaining a suction airstream from the suction opening through the filter. 
   Still further benefits and advantages of the present invention will become apparent to those of average skill in the art from a review of the following detailed description of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may take form in certain parts and arrangements of parts, preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: 
       FIG. 1  is a front elevational view of a vacuum cleaner according to the present invention; 
       FIG. 2  is a side elevational view thereof; 
       FIG. 3  is an enlarged exploded perspective view of a lower portion of the vacuum cleaner of  FIG. 1 ; 
       FIG. 4  is a rear perspective view of a dust cup of the vacuum cleaner of  FIG. 3 ; 
       FIG. 5  is an exploded perspective view of the dust cup of  FIG. 3  from above; 
       FIG. 6  is a top plan view of the dust cup of  FIG. 5 ; 
       FIG. 7  is an exploded perspective view of the dust cup of  FIG. 3  from below; 
       FIG. 8  is a cross sectional view of the vacuum cleaner of  FIG. 2  with an upright housing thereof tilted back for use; 
       FIG. 9  is a cross sectional view through the vacuum cleaner of  FIG. 2  along lines  9 - 9 ; 
       FIG. 10  is a bottom plan view of the vacuum cleaner of  FIG. 1 ; 
       FIG. 11  is a schematic view of a filter according to another embodiment of the present invention; and, 
       FIG. 12  is a schematic view of a filter according to a third embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the figures, wherein the showings are for purposes of illustrating several preferred embodiments of the invention only and not for purposes of limiting same,  FIG. 1  illustrates a stick vac A including a nozzle base  10  having on an underside thereof a suction opening  12 . As best shown in  FIG. 10 , also provided on the nozzle base are rollers  14 , located immediately behind the suction opening, and rear wheels  16 . With reference again to  FIG. 1 , supported on the nozzle base  10  is a housing  20 . Defined in the housing is a socket  22  ( FIG. 3 ) for selectively accommodating a dust cup  24 . Extending from an upper end of the housing  20  is a handle  26 . Positioned on a distal end of the handle is a hand grip  30  which supports a ring  32 . The ring can be used to, for example, hang the stick vac from a suitable peg or hook mounted on a wall or in a closet or the like since the stick vac is a relatively light weight appliance. 
   With reference now to  FIG. 2 , also provided on the hand grip is a first cord hook  34 . This cooperates with a second cord hook  36  located on the housing  20  in order to allow a conventional electrical cord (not illustrated) to be wrapped around the cord hooks when the appliance is not in use. 
   With reference now to  FIG. 8 , the nozzle base  10  includes a hollow interior  40  which allows air to flow from the suction opening  12  towards a first conduit  42 . The first conduit includes a pivot area  44  at a first end  46  thereof. The first conduit extends out of the nozzle base  10  and terminates at a second end  48 . The first conduit second end  48  is received in a second conduit  50  extending from the housing  20 . To this end, the second conduit  50  has a first end  52  which slips over the fist conduit second end  48 . The two conduits are secured together by conventional means. The second conduit extends along a portion of the housing  20  and terminates at a curved second end  54  which, as is best illustrated in  FIG. 3 , leads to an opening  56 . 
   The opening  56  is located on an interior wall  60  of the housing  20  and is surrounded by an elastomeric gasket  62 . As best seen in  FIG. 9 , a tangential, swirling, flow path  64  is thus provided for air entrained dirt which flows from the suction opening  12  through the first and second conduits  42  and  50  and out the opening  56 . 
   An upper section  70  of the housing accommodates a motor/fan assembly  72 . This includes a fan  74  and a motor  76  positioned above the fan. Exhaust air from the fan flows out through exhaust vents  78  provided in the housing  20 . With reference again to  FIG. 2 , an on/off switch  80  is located on the housing upper section  70 . Also defined on the housing upper section is a catch  84  as best illustrated in  FIG. 3 . 
   With reference now to  FIG. 4 , the dust cup  24  includes an open first end  92  and a closed second end  94  as well as a side wall  96  extending between the two ends and an interior wall  97 . An opening  98  is defined in the side wall  96 . Extending from the second end  94  of the dust cup is a stub  100 . As best illustrated in  FIG. 8 , the stub  100  protrudes into a pocket  101  defined in the housing  20  in order to allow the dust cup  24  to be pivotally mounted on the housing. In other words, the stub  100  and pocket  101  define a hinge assembly for the dust cup on the housing. 
   With reference now to  FIG. 5 , a handle  102  is defined on the side wall  96  of the dust cup adjacent the first end  92  thereof. The handle accommodates a moveable, resilient, latch  104  having a finger grip  106 . As best illustrated in  FIG. 8 , when a downward force is exerted on the latch  104  at the finger grip  106 , the latch releases from the catch section  84  on the housing thereby enabling the dust cup upper end to be pulled away from the housing. During this time, the dust cup pivots on the housing via a cooperation of the stub  100  in pocket  101  to provide a hinge function. 
   Selectively positioned in the dust cup  24  is a filter assembly  110 . With reference now to  FIG. 7 , the filter assembly includes a first end  112  which is defined by a frame  114 . The frame has a top wall  116  ( FIG. 5 ) with a rim  117  and an outer skirt  118  depending therefrom. Spaced from the outer skirt is an inner skirt  119 . Defined in the top wall  116  is a handle  120  which is in the form of a bridge extending between a pair of apertures  122  and  124  in the top wall. Reenforcing the top wall are a plurality of spaced ribs  126  which extend from the outer skirt  118  to the rim  117 . A channel  127  is defined between the inner and outer skirts  119 ,  118 . The filter assembly  110  also has a second end  128  which is defined by an end cap  130  having a bottom wall  131 . With reference again to  FIG. 5 , extending from the bottom wall is an inner rim  132  and a skirt  134  defining an annular channel  136  therebetween. A filter  140  extends between the frame  114  and the end cap  130 . The filter can be made of a planar filter medium which can be pleated as at  142 . The filter has a first end  144  which is secured in the channel  127  of the frame  114  and a second end  146  which is secured in the channel  136  defined in the end cap  130 , as may best be seen in  FIG. 8 . 
   The filter assembly  110  is frustoconical or tapered in its construction. Moreover, the filter material or medium  140  is also tapered in its shape as can be best seen in  FIGS. 5 and 7 . It is believed that the conical shape of the filter improves filtering efficiency, as compared with a right cylindrical shaped filter. This may be due, at least in part, to the increased efficiency of cyclonic airflow around the filter that is provided in the dust cup by the cooperation of the dust cup inner wall  97  and the filter. As is evident from  FIG. 8 , an approximately constant distance is defined between the filter and the inner wall of the dust cup so as to enhance the cyclonic flow of air around the filter and, hence, dirt separation. The conical filter shape also allows for an easier emptying of the dust cup  24  and may reduce the rate at which the filter  140  becomes clogged. 
   As is evident from  FIG. 8 , at the second or smaller diameter end  128  of the filter assembly, the end cap  130  is secured to the filter element  140 . Similarly, at the first or larger diameter end  112  of the filter assembly, the frame  114  is secured to the filter element  140 . The frame  114  includes the pair of apertures  122  and  124  which communicate with an interior  148  of the filter. With this construction, air must enter through the wall of the filter material  140  into the interior space  148 . In other words, the frame  114  and the bottom wall  130  prevent airflow from entering the interior  148  of the filter without passing through the filter medium  140 . 
   The generally conically shaped filter assembly  110  is mounted in the dust cup  24  such that the frame  114  selectively engages the interior wall  99  of the dust cup via an interference fit between the rim  117  of the top wall and the dust cup interior wall  97 . In this way, the filter assembly  110  is releasably, yet securely, retained in its operative position, even when the dust cup  24  is removed from the vacuum cleaner A. Once this is accomplished, the filter assembly  110  can be removed from the dust cup  24  simply by grasping the handle  120  and pulling upward. Thereafter, the dust cup can be inverted so as to remove the dirt and dust contained therein. Subsequently, the dust cup can be righted again, the filter assembly can be reinstalled and the dust cup returned to the housing  20 . This is accomplished by placing the stub  100  in the pocket  101  and then pivoting the dust cup back into position until the latch  104  engages the catch  84 . The latch will be depressed until a tip of the latch clears the backside of the catch and then resiliently snaps upward to hold the dust cup in position, as illustrated in  FIG. 8 . 
   The filter material or medium can be made from a suitable conventional planar thermoplastic material if so desired, so that the filter can be washed. Alternatively, the filter medium can be made from a suitable paper material. The frame  114  and end cap  130  can be made from a suitable conventional thermoplastic material. The filter  140  can be secured to the frame  114  and end cap  130  by conventional means, such as adhesive, sonic welding or the like. 
   In use, as best shown in  FIG. 8 , air entrained dirt and dust enter the vacuum cleaner via suction opening  12 . The air stream flows through the hollow interior  40  of the nozzle base  10  and into the first end  46  of the first conduit  42 . The air then flows through the first conduit and into the second conduit  50 . Air flows out of the second conduit at its curved second end  54 . The air is directed into a cyclonic swirling flow in the dust cup  24  via the curved second end  54  of the second conduit. The air impinges upon the filter assembly  110  and swirls around it. 
   Thus, a cyclonic airflow chamber  150  is defined in the dust cup between the filter assembly  110  and the interior wall  97  of the dust cup. Particles in the air stream, such as dirt, dust and the like are removed or separated from the suction airstream in the cyclonic airflow chamber. More specifically, the location and orientation of the inlet opening  56  and the generally cylindrical configuration of the cyclonic airflow chamber  150  causes the suction airstream to follow a swirling or cyclonic path within the chamber, as best shown in  FIG. 9 . Dirt and dust are flung outwardly by centrifugal force toward the interior wall  97  of the dust cup  90 . The removed particulate matter such as dirt, dust and the like then falls, via gravity, toward the bottom of the dust cup  24 . It is retained therein until the dust cup is emptied. 
   Air, however, flows radially inward toward an axis  152  of the dust cup and then upward around the bottom cap  130  and then radially inward through the filter medium  140  into the interior space  148  thereof. Air then flows upward again through the apertures  122  and  124  around the handle  120  and into the fan  74 . The suction airstream then flows into the fan  74  and out of the housing  20  via the exhaust vents  78 . Thus, a clean air-type vacuum cleaner is here disclosed. 
   As previously noted, the conical or tapered shape of the filter assembly  110  enhances the removal effect of the cyclonic airflow path. Residual particulate matter, i.e., that which is not removed from the suction airstream as a result of the cyclonic action, normally lighter, smaller particles, are filtered by the filter element or medium  140  as the airflow path passes therethrough. The filter assembly  110  extends along the axis  152  of the dust cup such that the filter assembly is centrally positioned in the dust cup. Also, the axis  152  passes through the handle  120 , as may be evident from  FIG. 8 . Thus, the filter assembly  110  is concentrically disposed in the dust cup  24 . 
   The location and orientation of the opening  56  in the housing and the opening  98  in the dust cup will effect the direction of cyclonic airflow. However, it is contemplated that the openings could be located and arranged differently. For example, the direction of cyclonic airflow could be reversed. Thus, the cyclonic airflow direction could be clockwise or counter clockwise depending upon the location and arrangement of the aligned openings  56  and  98 . Also, the location of the dust cup side wall opening  98  could be changed if desired. All such orientations and arrangements are considered within the scope of the present invention. 
   Moreover, those skilled in the art will recognize that the term cyclonic as used herein is not meant to be limited to a particular direction of airflow rotation. Rather, the cyclonic action discussed in the present invention is merely intended to separate a substantial portion of the entrained dirt and dust from the suction airstream and cause such dirt and dust to be deposited in the dust cup  24 . The suction airstream then passes through the filter element or medium  140 , so that residual contaminants are removed, and exits the cyclonic airflow chamber, as well as the dust cup, through the two openings  122  and  124  in the frame  114 . 
   One potential disadvantage of the design illustrated in  FIG. 8  is that the same portion of the filter medium  140  is exposed to the airstream entering the dust cup  24 . Over time, the dust particles in the airstream may wear the filter material due to prolonged use of the vacuum cleaner. With reference now to  FIG. 11 , one way of addressing this issue is to lengthen the skirt of the frame so that the airflow hits the skirt and not the filter medium. More particularly,  FIG. 11  illustrates a filter assembly  160  having a first end  162  which is provided with a frame  164 . Extending away from the frame is a skirt  168 . The skirt has a lower end  170 . A filter medium  180  includes an upper end  182  which is in contact with and secured to the skirt lower end  170  along a securement line  184 . The filter medium also has a lower end  186  which is covered by a bottom cap  188 . 
   In the design illustrated in  FIG. 11 , the airflow, as depicted by arrow  190 , entering the dust cup (not shown) contacts the thermoplastic material of the skirt  168  and swirls around the skirt rather than directly contacting the filter medium  180 . The material of the frame  164  is less prone to wear than is the material of the filter medium  180 . While  FIG. 11  illustrates a design in which the filter is protected from the incoming airstream, a disadvantage of the design illustrated in  FIG. 11  is that the filter itself is somewhat shorter, hence, affording less filtration area. 
   With reference now to  FIG. 12 , another design is there illustrated. In this design, a filter assembly  200  includes a first end  202  having a frame  204 . Extending from the frame is a skirt  208 . The skirt has a lower end  210 . A filter medium  220  extends away from the frame  204 . The filter medium has an upper end  222  which is secured via a securement line  224  to an inside periphery of the skirt. The filter medium also has a lower end  226  which is covered by a bottom cap  228 . With the design illustrated in  FIG. 12 , the airflow, depicted by arrow  230 , contacts the skirt  208 , but yet the length of the filter medium  220  is not shortened. This is accomplished by extending the filter medium upwardly into the skirt until the upper end  222  of the filter is fastened to the skirt via the securement line  224 . 
   The invention has been described with reference to several embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding specification. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims, or the equivalents thereof.