Upright vacuum cleaner with cyclonic airflow

<u style="single">Background of the Invention</u>

0001The present invention relates to vacuum cleaners. More particularly, the present invention relates to upright vacuum cleaners used for suctioning dirt and debris from carpets and floors.

0002Upright vacuum cleaners are ubiquitous. They are known to include an upper portion having a handle, by which an operator of the vacuum cleaner may grasp and maneuver the cleaner, and a lower cleaning nozzle portion which travels across a floor, carpet, or other surface being cleaned. The upper portion is often formed as a rigid plastic housing which encloses a dirt and dust collecting filter bag, although the upper portion may simply be an elongated handle with the filter bag, and an external cloth bag, being hung therefrom. The cleaning nozzle is hingedly connected to the upper handle portion such that the upper portion is pivotable between a generally vertical upright storage position and an inclined operative position. The underside of the nozzle includes a suction opening formed therein which is in fluid communication with the filter bag.

0003A vacuum or suction source such as a motor and fan assembly is enclosed either within the nozzle portion or the upper portion of the cleaner. The vacuum source generates the suction required to pull dirt from the carpet or floor being vacuumed through the suction opening and into the filter bag. A rotating brush assembly is typically provided in proximity with the suction opening to loosen dirt and debris from the surface being vacuumed.

0004To avoid the need for vacuum filter bags, and the associated expense and inconvenience of replacing the bag, another type of upright vacuum cleaner utilizes cyclonic airflow, rather than a filter bag, to separate a majority of the dirt and other particulates from the suction airstream. The air is then filtered to remove residual particulates, returned to the motor, and exhausted.

0005Such prior cyclonic airflow upright vacuum cleaners have not been found to be entirely effective and convenient to use. For example, with these prior cyclonic airflow vacuum cleaners, the process of emptying dust and dirt from the cyclonic chamber dirt collection container has been found to be inconvenient, and often resulted in the spillage of the cup contents. Likewise, with these prior units, replacement of the filter element has not been convenient. Other cyclonic airflow vacuum cleaners have been found to exhaust air which is not free of residual contaminants. For example, one prior unit filters the airstream after it passes through the cyclonic chamber, but thereafter passes the airstream through the motor assembly where it is potentially recontaminated by the motor assembly, itself, prior to its being exhausted into the atmosphere.

0006Because the cyclonic action of such vacuum cleaners does not completely remove all dust, dirt, and other contaminants from the suction airstream, it is necessary to include a filter downstream from the cyclonic chamber. As such, prior cyclonic airflow vacuum cleaners have heretofore included conventional filter elements including conventional media to filter the airstream after it passes through the cyclonic chamber. These prior filter elements have caused considerable difficulties. A conventional filter that is sufficiently fine to filter the airstream effectively unduly restricts airflow and decreases the effectiveness of the cyclonic action. On the other hand, a coarse filter does not effectively filter the airstream of residual contaminants. Further, conventional filter media, such as paper or fibrous media, has been found to clog readily, thereby unduly decreasing airflow rates over time. Thus, a need has been found for a cyclonic airflow vacuum cleaner with an effective filter positioned downstream relative to the cyclonic chamber for effectively filtering the airstream without clogging. A vacuum cleaner in accordance with the precharacterizing part of claim 1 is disclosed in EP-A-0 042 723.

0007Accordingly, it has been deemed desirable to develop a new and improved upright vacuum cleaner which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.

<u style="single">Summary of the Invention</u>

0008According to the present invention, a new and improved upright vacuum cleaner is provided. This is attained with the vacuum cleaner according to claim 1.

0009An upright vacuum cleaner includes a housing de-fining a cyclonic airflow chamber for separating conta-minants from a suction airstream. The housing includes a suction airstream inlet and a suction airstream outlet in fluid communication with the cyclonic airflow chamber. A nozzle base includes a main suction opening which is fluidically connected with said cyclonic airflow chamber inlet.

0010An airstream suction source is provided and has an inlet fluidically connected to said cyclonic airflow chamber outlet and a suction source exhaust outlet. The suction source selectively establishes and maintains a suction airstream from the nozzle main suction opening to the suction source exhaust outlet. A main filter assembly is positioned in fluid communication between the cyclonic airflow chamber and the suction source for filtering residual contaminants from the suction airstream downstream relative to the cyclonic airflow chamber. The main filter assembly comprises a filter element including high-density polyethylene porous filter media.

0011In accordance with an aspect of the invention, a vacuum cleaner includes an upright housing section including a handle. A nozzle base section is hingedly interconnected with the upright housing section and includes a main suction opening formed in an underside thereof. A cyclonic airflow chamber is defined in the upright housing section and separates dust and dirt from a suction airstream. A suction source is located in the upright section or the nozzle section and has a suction airflow inlet in fluid communication with the cyclonic chamber and a suction airflow outlet. A main filter assembly is located between the cyclonic chamber and the suction source for filtering residual dust and dirt from the suction airstream after the suction airstream passes through the cyclonic airflow chamber. A final filter assembly is located an either the housing or the nozzle base and is connected in fluid communication with the suction airflow outlet of the suction source for filtering the suction airstream exhausted by the suction source prior to the suction airstream being dispersed into the atmosphere.

0012A vacuum cleaner includes a nozzle section. A housing section is connected to the nozzle section and is in fluid communication with the nozzle section. A cyclonic airflow chamber is located in the housing section for separating dirt and dust from a suction airstream flowing into the housing section between an inlet located at a periphery of the housing section and an outlet located at an apex of the housing section. A filter chamber is located in the housing section between the cyclonic airflow chamber and the outlet of the housing section. The filter chamber includes a first filter housing and a first filter element mounted in the first filter housing. The first filter element and the first filter housing cooperate to define a tortuous flow path for air flowing from the cyclonic airflow chamber to the outlet of the housing section.

0013One advantage of the present invention is the provision of a new and improved vacuum cleaner.

0014Another advantage of the invention is found in the provision of a vacuum cleaner with a cyclonic airflow chamber through which the suction airstream flows for separating dust and dirt from the airstream and for depositing the separated dust and dirt into an easily and conveniently emptied dirt cup.

0015Still another advantage of the present invention resides in the provision of a cyclonic airflow upright vacuum cleaner with a main filter that effectively filters residual contaminants from the suction airstream between the cyclonic airflow chamber and the motor assembly without unduly restricting airflow and without premature clogging.

0016Yet another advantage of the invention is the provision of a cyclonic airflow upright vacuum cleaner with a final filter located downstream from the suction motor assembly for filtering the suction airstream immediately prior to its exhaustion into the atmosphere.

0017A further advantage of the invention is the provision of a vacuum cleaner with both a main filter and a final filter wherein both the main and final filter are easily removable and replaceable.

0018A still further advantage of the present invention is the provision of a vacuum cleaner with a filter element mounted in a filter housing wherein the filter element and filter housing cooperate to provide a tortuous flow path for air flowing therethrough.

0019Still other benefits and advantages of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description.

Brief Description of the Drawings

0020The invention may take form in certain components and structures, preferred embodiments of which will be illustrated in the accompanying drawings wherein: <ul id="ul0001" list-style="none" compact="compact"><li>FIGURE 1 is a perspective view illustrating a cyclonic airflow upright vacuum cleaner in accordance with the present invention;</li><li>FIGURE 2 is a front elevational view of the vacuum cleaner illustrated in FIGURE 1;</li><li>FIGURES 3 and 4 are left and right side elevational views, respectively, of the vacuum cleaner shown in FIGURE 1;</li><li>FIGURE 5 is a rear elevational view of the vacuum cleaner of FIGURE 1, further showing the required suction hose assemblies in broken lines for clarity;</li><li>FIGURE 6 is a bottom plan view of the vacuum cleaner of FIGURE 1;</li><li>FIGURE 7 is a front elevational view of the upright body portion of the vacuum cleaner of FIGURE 1;</li><li>FIGURE 8 is a partial side view in cross-section of the vacuum cleaner illustrated in FIGURE 1, and further diagrammatically illustrating the suction airstream flow;</li><li>FIGURE 9 is a perspective view of the upright body portion shown in FIGURE 7, with the dirt cup and main filter housing removed for clarity;</li><li>FIGURE 10 is an exploded perspective view of the main filter, main filter housing, and dirt cup;</li><li>FIGURE 11 is a perspective view of the final filter assembly in accordance with the present invention;</li><li>FIGURES 12A and 12B are rear elevational and bottom plan views, respectively, of the upper portion of the main filter housing;</li><li>FIGURE 13A is a perspective view of a main filter in accordance with the present invention;</li><li>FIGURE 13B is a bottom plan view of the main filter;</li><li>FIGURE 13C is a cross-sectional view of the main filter along line C-C of FIGURE 13B;</li><li>FIGURE 13D is a cross-sectional view of an alternative main filter element in accordance with the present invention; and,</li><li>FIGURE 14 is a front elevational view, partially in cross-section along line E-E of FIGURE 8, illustrating the upright body portion of the vacuum cleaner of FIGURE 1.</li></ul>

<u style="single">Detailed Description of the Preferred Embodiments</u>

0021Referring now to the FIGURES, wherein the showings are for purposes of illustrating preferred embodiments of the invention only and not for purposes of limiting the same, FIGURES 1-6 illustrate an upright vacuum cleaner <b>A</b> including an upright housing section <b>B</b> and a nozzle base section <b>C.</b> The sections <b>B,C</b> are pivotally or hingedly connected through the use of trunnions or another suitable hinge assembly D so that the upright housing section <b>B</b> pivots between a generally vertical storage position (as shown) and an inclined operative position. Both the upright and nozzle sections <b>B,C</b> are preferably made from conventional materials such as molded plastics and the like. The upright section <b>B</b> includes a handle <b>20</b> extending upward therefrom by which an operator of the vacuum <b>A</b> is able to grasp and maneuver the vacuum.

0022During vacuuming operations, the nozzle base <b>C</b> travels across the floor, carpet, or other subjacent surface being cleaned. The underside <b>24</b> (FIGURE 6) of the nozzle includes a main suction opening <b>26</b> formed therein which extends substantially across the width of the nozzle at the front end thereof. The main suction opening <b>26</b> is in fluid communication with the vacuum upright body section <b>B</b> through a passage <b>30</b> and a connector hose assembly <b>34</b> (FIGURE 5). A rotating brush assembly <b>36</b> is positioned in the region of the nozzle main suction opening <b>26</b> for contacting and scrubbing the surface being vacuumed to loosen embedded dirt and dust. A plurality of wheels <b>38</b> support the nozzle on the surface being cleaned and facilitate its movement thereacross.

0023The upright vacuum cleaner <b>A</b> includes a vacuum or suction source for generating the required suction airflow for cleaning operations. With reference particularly to FIGURES 5 and 9, a suitable suction source, such as an electric motor and fan assembly <b>E,</b> generates a suction force in a suction inlet <b>40</b> an exhaust force in an exhaust outlet <b>42.</b> The motor assembly airflow exhaust outlet <b>42</b> is in fluid communication with a final filter assembly <b>F</b> for filtering the exhaust airstream of any contaminants immediately prior to its discharge into the atmosphere. The motor assembly suction inlet <b>40,</b> on the other hand, is in fluid communication with an elongated suction conduit <b>46</b> which extends upward from the motor/fan assembly <b>E</b> to an upper region of the upright section <b>B</b> where it communicates with the cyclonic suction airflow dust and dirt separating region <b>G</b> of the vacuum <b>A</b> to generate a suction force therein.

0024With reference particularly to FIGURES 7 and 8, the cyclonic suction airflow dust and dirt separating region G housed in the upright section <b>B</b> includes a main filter housing assembly 50 and a mating dust and dirt cup or container <b>52.</b> The sections <b>50,52</b> together define a generally cylindrical cyclonic airflow chamber <b>54.</b>

0025It may be seen with reference also to FIGURE 10 that the main filter housing assembly <b>50</b> is, itself, constructed from two mating sections - an upper fixed housing section <b>50a,</b> and a lower, detachable filter housing section <b>50b.</b> The lower detachable filter housing section <b>50b</b> receives and retains a main filter element or cartridge <b>H.</b> The filter housing section <b>50b</b> releasably connects with the upper housing section <b>50a</b> to secure the filter element <b>H</b> in an operative filtering position. More particularly, the section <b>50b</b> includes a plurality of tabs or tangs <b>54b</b> extending therefrom. Likewise, with reference also to FIGURE 12B, it is shown that the upper housing section <b>50a</b> includes mating tabs or tangs <b>54a.</b> Thus, those skilled in the art will recognize that the components <b>50a,50b</b> connect in a key-like fashion upon rotation of the filter housing section <b>50b</b> in relation to the upper housing section <b>50a</b> so that a filter element H is operatively secured in position. Of course, rather than the mating tabs <b>54a,54b,</b> the two housing sections <b>50a,50b</b> may alternatively include mating threads, clips, or other suitable cooperating fastening means. The filter housing section <b>50b</b> includes a plurality of apertures, slots, or other passages <b>56</b> formed therethrough, preferably in the lower half thereof, so that the suction airstream flows freely from the chamber <b>54</b> into the filter housing section <b>50b</b> and to the main filter element <b>H.</b>

0026The housing upper section <b>50a</b> includes a suction airflow outlet passage <b>60</b> (FIGURE 8) which communicates with the cyclonic chamber <b>54</b> through an aperture <b>62.</b> The outlet passage <b>60</b> also communicates with the elongated suction conduit <b>46</b> leading to the motor/fan assembly <b>E</b> when the main filter housing assembly <b>50</b> is operatively connected to the vacuum upright section <b>B.</b> FIGURES 8 and 9 show that the elongated suction conduit <b>46</b> extends from the motor/fan assembly <b>E</b> upward to communicate with the main filter housing suction outlet passage <b>60</b> so that the suction inlet of the motor/fan assembly <b>E</b> is able to fluidically communicate with the cyclonic chamber <b>54.</b> When the main filter housing assembly <b>50</b> is assembled and in the operative position as described, a mouth <b>66</b> (FIGURE 10) of the filter element <b>H</b> mates with the periphery of the aperture <b>62</b> in a fluid-tight relationship. As such, the suction airflow from the cyclonic chamber <b>54</b> to the motor/fan assembly suction inlet <b>42</b> is not able to bypass the main filter element <b>H,</b> but instead must pass therethrough and be filtered of residual contaminants. It is preferable that the aperture <b>62,</b> and thus the main filter element <b>H</b> be centrally located in the cyclonic chamber <b>54</b> to facilitate the cyclonic airflow in the chamber.

0027The suction airstream enters an upper portion of the cyclonic dust and dirt separation chamber <b>54</b> through a generally tangential suction airstream inlet 80. In the preferred embodiment, as shown in FIGURES 12A-12B, the cyclonic chamber airstream inlet <b>80</b> is formed in the upper section <b>50a</b> of the main filter housing assembly <b>50.</b> It is noted that the inlet <b>80</b> is disposed entirely on one side of a center line <b>81</b> of the upper housing section so as to induce a swirling flow around the filter housing section <b>50b.</b> The suction airstream inlet <b>80</b> of the chamber <b>54</b> is in fluid communication with a suction airstream hose <b>82</b> through a fitting <b>84.</b> As shown in FIGURE 5, the hoses <b>82,34</b> are fluidically connected via fitting <b>86.</b> As such, the main suction opening <b>26</b> formed in the nozzle underside <b>24</b> is in fluid communication with the cyclonic chamber <b>54</b> through the passage <b>30,</b> the hoses <b>34,82,</b> and the cyclonic chamber suction inlet <b>80.</b>

0028The dirt container <b>52</b> of the cyclonic airflow dust and dirt separating assembly <b>G</b> is constructed for large capacity and ease of emptying the contents as necessary. In FIGURE 8, it may be seen that the dirt container 52 defines over ½ the volume of the cyclonic chamber <b>54.</b> As such, the capacity of the container <b>52</b> is maximized to lengthen the operational time before the dirt container <b>52</b> must be emptied.

0029The dirt container <b>52</b> is connected to the vacuum upright section B through use of a hinge assembly <b>90</b> which allows the dirt container <b>52</b> to pivot as indicated by the arrow I between an operative upright position and an open forwardly tilted position. As shown herein, the hinge <b>90</b> comprises a first component <b>92</b> connected to the dirt container <b>52</b> and a second mating component <b>94</b> formed on the upright section <b>B.</b> Once the dirt container <b>52</b> is pivoted to the open position, it may be pulled upward and away from the section <b>B</b> and separated therefrom for ease of emptying the dirt container. Of course, after the dirt container is emptied, the foregoing procedure is reversed so that the dirt container is once again in the operative position. A handle <b>96</b> is provided on the exterior of the container <b>52</b> to facilitate operator movement of the container between the operative, -open, and removed position. A resiliently biased latch <b>98</b> retains the dirt container in the operative position. The latch <b>98</b> is biased through use of a spring or other resilient member, or via the natural resiliency of the plastic from which it is molded.

0030With continuing reference to FIGURE 8, the dirt container upper edge <b>100</b> defining an open upper end of the container <b>52</b> is preferably inclined downwardly in the direction away from the handle <b>96</b> or front of the container <b>52.</b> The main filter housing assembly section <b>50</b> is formed with a complimentary mating inclined edge <b>102,</b> and a seal such as a gasket or other structure (not shown) is provided between the edges <b>100,102</b> to prevent air leakage into the cyclonic airflow chamber <b>54.</b> The inclined upper edge <b>100</b> of the dirt container <b>52</b> also ensures that, when the container is pivoted to the open position, the upper edge <b>100</b> lies in a substantially horizontal plane. As such, the contents of the container are much less likely to spill when the container is opened during emptying operations. Preferably, the angle at which the upper edge <b>100</b> is inclined from horizontal is selected, in combination with the maximum distance the container is able to be pivoted on the arc I when opened, such that when the container is fully opened, the upper edge lies in a substantially horizontal plane.

0031As is shown in FIGURES 13A-13C, the main filter element H is preferably generally frusto-conical in overall configuration, converging in the direction away from the filter mouth <b>66</b> toward an opposite filter end <b>110.</b> However, those skilled in the art will recognize that a cylindrical or other filter configuration may be advantageously employed without departing from the scope and overall intent of the invention.

0032The preferred filter media comprises Porex® brand high density polyethylene-based open-celled porous media available commercially from Porex Technologies Corp., Fairburn, Georgia 30213, or an equivalent foraminous filter media. This preferred filter media is a rigid open-celled foam that is moldable, machinable, and otherwise workable into any shape as deemed advantageous for a particular application. Most preferably, to optimize filtration but also to allow sufficient airflow rates, the preferred filter media has an average pore size in the range of 45µm to 90µm. As is shown in FIGURES 13A-13C, the filter <b>H</b> is most preferably formed in a convoluted or circuitous configuration to maximize an outer surface area 112 of the filter. The maximized surface area <b>112</b> allows for the filter media to have a smaller pore size without unduly restricting the airflow therethrough. Most preferably, the filter media is formed into at least two elongated and concentric cylinders and/or frustums <b>114a,114b</b> with a deep annular passage <b>116</b> defined therebetween. Preferably, a deep central passage <b>118</b> is defined in the innermost cylinder or frustum <b>114a.</b> However, it should be appreciated that other filter designs could also be used if so desired. For example, it is possible to use a filter element not having a deep central passage. FIGURE 13D illustrates such an alternative configuration of the main filter element <b>H'.</b> Like components relative to the main filter element <b>H</b> are identified with like numerals including a primed (') suffix. The filter element <b>H'</b> is formed by concentric cylindrical portions <b>114a',114b'</b> separated by a deep annular passage <b>116'.</b> However, unlike the main filter element <b>H</b>, the element <b>H</b>'. does not include a deep central passage formed in the inner cylinder <b>114a'.</b>

0033As mentioned, the subject vacuum <b>A</b> also comprises a final filter assembly <b>F</b> for filtering the suction airstream downstream from the motor/fan assembly and immediately prior to its exhaustion into the atmosphere. The preferred final filter assembly <b>F</b> is illustrated most clearly in FIGURE 11 and comprises a suction airstream inlet <b>120</b> which is connected in fluid communication with the exhaust outlet <b>42</b> of the motor and fan assembly <b>E.</b> The inlet <b>120</b> is itself in fluid communication with an elongated plenum <b>122</b> that opens to the atmosphere and houses filter media. A protective grid or grate structure is snap-fit or otherwise effectively secured over the plenum <b>122</b> to secure the filter media in place. The filter media is preferably a high efficiency particulate arrest (HEPA) filter element in a sheet or block form. The filter media is retained in position in the plenum by the grid <b>124,</b> but is easily replaced by removing the grid. As such, those skilled in the art will recognize that even if the motor/fan assembly causes contaminants to be introduced into the suction airstream downstream from the main filter element H, the final filter assembly F will remove the same such that only contaminant-free air is discharged into the atmosphere.

0034Referring primarily to FIGURES 8 and 14, the operation of the vacuum cleaning apparatus <b>A</b> is illustrated, with the flow of the suction airstream indicated by use of arrows <b>J.</b> The motor/fan assembly <b>E</b> or other suction generator establishes a suction force at its suction inlet <b>42,</b> in the elongated suction conduit <b>46,</b> and thus in the cyclonic separation chamber <b>54.</b> This suction force or negative pressure in the chamber <b>54</b> is communicated to the main suction opening <b>26</b> formed in the nozzle underside <b>24</b> through the hoses <b>82,34</b> (FIGURE 5) and associated fittings. This, then, in combination with the scrubbing action of the rotating brush assembly <b>36</b> causes dust and dirt from the surface being cleaned to be entrained in the suction airflow J and pulled into the upper portion of the chamber <b>54</b> through the generally tangential inlet <b>80.</b>

0035The location of the inlet <b>80,</b> the outlet passage <b>60,</b> and the generally cylindrical configuration of the chamber <b>54</b> causes the suction airstream to follow a swirling or cyclonic path downward within the chamber <b>54</b> and then to move upward through a central portion of the chamber <b>54</b> toward the centrally located main filter housing section <b>50b.</b> The orientation of the inlet <b>80</b> will affect the direction of cyclonic airflow, and the invention is not meant to be limited to a particular direction, i.e, clockwise or counterclockwise. Those skilled in the art will certainly recognize that the term "cyclonic" as used herein is not meant to be limited to a particular direction of airflow rotation. This cyclonic action separates a substantial portion of the entrained dust and dirt from the suction airstream and causes the dust and dirt to be deposited in the dirt cup or container <b>52.</b> The suction airstream then passes through the apertures <b>56</b> formed in the main filter housing section <b>50b,</b> passes through the main filter element <b>H</b> so that residual contaminants are removed, and exits the cyclonic chamber <b>54</b> through the suction airstream outlet passage <b>60</b> formed in the main filter housing section <b>50a.</b> The suction airstream is communicated to the motor/fan assembly <b>E</b> and exhausted through the outlet <b>42</b> (as indicated by broken arrows) to the final filter assembly <b>F</b> where it is filtered again by the HEPA filter to remove any contaminants that passed through the chamber <b>54</b> and the filter <b>H,</b> and any contaminants in the airstream due to its passage through the motor/fan assembly E.

0036The main filter element <b>H</b> can be cleaned by washing it, either manually or in a dishwasher -- since it is dishwasher-safe -- to remove dust or dirt particles adhering to the filter element. It is, however, important that the filter <b>H</b> be dried before it is used again. The final filter media of the filter assembly <b>F,</b> however, can not be cleaned and must be replaced when it becomes clogged.

0037The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. 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.