Air-flow routing in the bottom part of a vacuum cleaner

[0001] Priority is claimed to German patent applications DE 102 46 674.2 and DE 102 46 675.0, the subject matters of both of which are hereby incorporated by reference herein. Moreover, the subject matter of all references cited herein are hereby incorporated by reference herein.

[0002] The present invention relates generally to vacuum cleaners, and particularly to a vacuum cleaner including a handle and a bottom part with two flows paths guided into a dust chamber via a common inlet opening.

BACKGROUND

[0003] A vacuum cleaner having a bottom-side suction opening and an additional suction opening for a suction hose is known from U.S. Pat. No. 6,317,920 B1. The known vacuum cleaner has an approximately square dust chamber that is bounded by dust-chamber walls and has an inlet opening formed in the front wall and rear wall for the air sucked in by the fan unit. The inlet opening in the front wall leads via a first flow path to the bottom-side suction opening whereas the inlet opening in the rear wall is in communication with the additional suction opening via a second separate flow path.

[0004] It is considered a disadvantage of this known vacuum cleaner that, due to the two inlet openings into the dust chamber, it is not possible to use conventional and inexpensive dust-collecting devices, in particular dust bags, having a single opening for feeding dirt- and/or dust-laden air. This disadvantage can be eliminated by a vacuum cleaner as disclosed in German Patent DE 1 208 457.

[0005] This vacuum cleaner has a Y-shaped elastic suction nozzle where flow paths from a bottom-side suction opening and from an additional and upwardly directed suction opening for connecting a suction hose jointly open into a short tubular member. This short tubular member extends into a dust chamber where it serves to receive a conventional dust-collecting device having a single inlet opening, in particular dust bags. In the first flow path from the bottom-side suction opening to the short tubular member, the suction nozzle contains a disk spring-like diaphragm upstream of the mouth, the disk spring-like diaphragm allowing manual closure of the air passage to the short tubular member. The user can move this diaphragm into its closed position by compressing the elastic suction nozzle and into its open position by expansion.

[0006] If the air passage from the bottom-side suction opening to the short tubular member is closed, the full suction power is available for vacuuming through the suction hose that is connected to the additional suction opening. However, at full suction power, thin textiles such as curtains, tablecloths, etc. can be vacuum cleaned only with difficulty because they are drawn into the suction hose due to the high suction power. When the air passage to the bottom-side suction opening is open, the suction power on the hose side is actually reduced, however, resulting in the disadvantage that heavy particles that are drawn in through the hose, due to their high kinetic energy, flow past the short tubular member opening into the dust-collection device and, via the first flow path through bottom-side suction opening, land on the floor. This danger is particularly high when the vacuum cleaner is turned off while vacuuming through the hose, or in the case of low suction power, for example, when the dust bag is full. In both cases, the heavy particles are moved through the suction hose and the bottom-side suction opening to the floor like on a chute due to their gravitational force.

SUMMARY OF THE INVENTION

[0007] It is therefore an object of the present invention to provide a vacuum cleaner in which particles that are drawn in through the suction hose are reliably conveyed into the dust chamber or the dust-collecting device inserted therein even at low suction power.

[0008] The present invention provides a vacuum cleaner <b>1</b> having a handle <b>5</b> and a bottom part <b>4</b>, the handle <b>5</b> being swivel-mounted to the bottom part <b>4</b> via an articulated joint <b>9</b> and the bottom part <b>4</b> containing at least one bottom-side suction opening <b>18</b>; a dust chamber <b>13</b> bounded by dust chamber walls <b>25</b>, <b>31</b>; a fan unit; and additional suction opening <b>19</b> for a suction hose <b>7</b>. A first flow path <b>20</b> through the bottom-side suction opening <b>18</b> and a separate parallel flow path <b>21</b> through the additional suction opening <b>19</b> are guided into the dust chamber <b>13</b> via a common inlet opening. The two flow paths <b>20</b>, <b>21</b> are arranged in the bottom part <b>4</b> and guided into the inlet opening together and approximately parallel to each other by a flow-guide element <b>28</b> located between the two flow paths <b>20</b>, <b>21</b>, the inlet opening being provided in one of the dust chamber walls <b>25</b>, <b>31</b>.

[0009] In in embodiment of the vacuum cleaner according to the present invention, provision is made for the flow-guide element located between the two flow paths to be formed by a dividing wall that divides the short tubular member into a first inlet region and a second inlet region, the first flow path opening into the first inlet region and the second flow path opening into the second inlet region. This design provides a flow-guide element in a simple and inexpensive manner.

[0010] A further embodiment of the present invention provides for one of the two flow paths to run parallel to a dust chamber wall at least in one region. Due to this flow path configuration, the dust chamber wall serves both to bound the dust chamber and to guide the air of the parallel flow path.

[0011] In an embodiment of the vacuum cleaner according to the present invention, in which the additional suction opening and the suction hose are in fluid communication and the suction opening of the suction hose can be closed by a closing element, provision is made for the suction hose to be in fluid communication with a secondary air device that allows adjustment of the vacuum in the second parallel flow path when the suction opening is closed, and thus, of the suction power at the bottom-side suction opening. This design allows the secondary air device to be placed at an ergonomically convenient location for the user, eliminating the need for it to be provided on the bottom part in the flow path to the bottom-side floor nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is elaborated upon below based on an exemplary embodiment with reference to the drawings, in which:

[0013]FIG. 1 is a side view of a vacuum cleaner including a handle with a parking fixture for a suction hose as well as a bottom part;

[0014]FIG. 2 is a perspective view of the lower shell of the bottom part of FIG. 1 with mounted articulated joint;

[0015]FIG. 3 shows the lower shell of FIG. 2 from a different perspective;

[0016]FIG. 4 is a perspective view of the lower shell of FIG. 3 without the articulated joint;

[0017]FIG. 5 is a side view of the parking fixture of the vacuum cleaner of FIG. 1 with the secondary air device in an open position; and

[0018]FIG. 6 is a schematic sectional view of the parking fixture.

DETAILED DESCRIPTION

[0019] Vacuum cleaner <b>1</b> shown in FIG. 1 has a bottom part <b>4</b> that can be rolled on front wheels <b>2</b> and rear wheels <b>3</b>, a handle <b>5</b> with a hand grip <b>6</b>, and a suction hose <b>7</b>. Handle <b>5</b> is swivel-mounted to bottom part <b>4</b> via a quiver <b>8</b> for holding suction hose <b>7</b> and an articulated joint <b>9</b> supported at the end face in the region of rear wheels <b>3</b>.

[0020] As shown in FIG. 1, bottom part <b>4</b> has a housing including a lower shell <b>10</b>, an upper shell <b>11</b> and two adjacent hinged covers <b>12</b>.<b>1</b>, <b>12</b>.<b>2</b>. Inside the housing, a dust chamber <b>13</b> containing a dust-collecting device is located below first cover <b>12</b>.<b>1</b>, and a receiving chamber <b>15</b> containing a fan unit is located below second cover <b>12</b>.<b>2</b> (see FIGS. 2, 3, <b>4</b>).

[0021]FIGS. 2 through 4 show lower shell <b>10</b> in a perspective view. In lower shell <b>10</b>, receiving chamber <b>15</b> for accommodating the fan unit and dust chamber <b>13</b> for receiving a dust-collecting device are formed by walls; dust chamber <b>13</b> and receiving chamber <b>15</b> being immediately adjacent to each other, and the front wall of receiving chamber <b>15</b> being formed by a portion of dust chamber rear wall <b>17</b>. Moreover, lower shell <b>10</b> has formed therein a bottom-side suction opening <b>18</b>, an additional suction opening <b>19</b> to which can be connected suction hose <b>7</b>, and two flow paths <b>20</b>, <b>21</b>. First flow path <b>20</b> and second flow path <b>21</b> connect dust chamber <b>13</b> to bottom-side suction opening <b>18</b> and to additional suction opening <b>19</b>, respectively.

[0022] Bottom-side suction opening <b>18</b> is provided centrally on lower shell <b>10</b>, ahead of front wheels <b>2</b> in working direction A. Bottom-side suction opening <b>18</b> extends substantially vertically into lower shell <b>10</b> and opens into first flow path <b>20</b>.

[0023] Additional suction opening <b>19</b> is formed by a bearing for articulated joint <b>9</b> (see FIG. 4), articulated joint <b>9</b> having a through-channel for suction hose <b>7</b> through which the fluid communication can be established between additional suction opening <b>19</b> and suction hose <b>7</b>. Alternatively, additional suction opening <b>19</b> can be formed by a separate housing opening to which suction hose <b>7</b> can be connected in a manner known per se.

[0024] Rectangular-shaped dust chamber <b>13</b> is located at a short distance behind front wheels <b>2</b> in working direction A of vacuum cleaner <b>1</b>. In the left region of dust chamber rear wall <b>17</b> as viewed in working direction A, provision is made for an outlet opening <b>24</b> to receiving chamber <b>15</b> of the fan unit; the fan unit bearing against the outlet opening with the suction side when the vacuum cleaner is in the assembled state.

[0025] On right dust chamber wall <b>25</b> as viewed in working direction A, there is formed a short tubular member <b>26</b> as an inlet opening to dust chamber <b>13</b> which extends into dust chamber <b>13</b> and through which flow paths <b>20</b>, <b>21</b>, which run towards each other in the direction of flow (see FIG. 3), are guided into dust chamber <b>13</b> together and approximately parallel to each other. In order to insert both a dust bag and a firm dust container as a dust-collecting device into dust chamber <b>13</b>, short tubular member <b>26</b> extends into dust chamber <b>13</b>. In general, the short tubular member has a rigid design, but can also be made from an elastic material. Alternatively to the aforementioned short tubular member <b>26</b>, it is also possible to use only a hole in dust chamber wall <b>25</b> as an inlet opening to dust chamber <b>13</b> through which hole the two flow paths <b>20</b>, <b>21</b> are guided into dust chamber <b>13</b> approximately together and parallel to each other. The dust-collecting device to be inserted then seals against the inlet opening.

[0026] In order for even heavy particles to maintain their predetermined flow path <b>20</b>, <b>21</b> during vacuuming and not to flow past the inlet opening into the other flow path because of their high kinetic energy, the two flow paths <b>20</b>, <b>21</b> are separated from each other by a flow-guide element <b>28</b>. In the exemplary embodiment, flow-guide element <b>28</b> is formed by a straight dividing wall. Alternatively, flow-guide element <b>28</b> can also be formed by a contour that is more convenient in terms of fluid mechanics, for example, a radius.

[0027] As shown in FIGS. 2, 4, the dividing wall extends up and into short tubular member <b>26</b>, dividing it into a first inlet region <b>32</b><i>a </i>and a second inlet region <b>32</b><i>b</i>. Due to the attachment of the dividing wall in short tubular member <b>26</b>, the dividing wall is secured in a stable manner.

[0028] The alignment of a dust bag opening with respect to the inlet opening is normally accomplished in that a holding plate arranged around the dust bag opening is moved along the inlet opening toward dust chamber bottom <b>29</b> until the dust bag opening is level with the inlet opening. To prevent jamming of the holding plate with short tubular member <b>26</b> during the alignment described above, the lower portion of the straight dividing wall is designed as a guide slope that extends at an angle from the center of the short tubular member toward the dust chamber bottom, the lower portion of the guide slope slightly projecting beyond short tubular member <b>26</b> into dust chamber <b>13</b> at the height of the bottom <b>26</b>.<b>1</b> of the short tubular member.

[0029] First flow path <b>20</b> runs along the outer face of dust chamber front wall <b>31</b> and along dust chamber wall <b>25</b>, which is to the right as viewed in working direction A, so that these dust chamber walls <b>31</b>, <b>25</b> serve both as boundary walls for dust chamber <b>13</b> and for guiding first flow path <b>20</b>. Analogously, second flow path <b>21</b> uses the rear portion of right dust chamber wall <b>25</b> as viewed in working direction A.

[0030] During the operation of the vacuum cleaner <b>1</b>, the full suction power is only available at floor nozzle <b>18</b> when the handle-side suction opening of suction hose <b>7</b> is closed, since suction hose <b>7</b> and floor nozzle <b>18</b> are simultaneously in fluid communication with the fan unit and dust chamber <b>13</b> via separate flow paths <b>20</b>, <b>21</b>.

[0031] Therefore, a closing element that is designed as a parking fixture <b>33</b> is secured on the telescoping handle <b>6</b> near hand grip <b>6</b><i>a </i>for closing suction hose <b>7</b>, it being possible for the suction-side suction hose end <b>34</b> or the accessory <b>35</b> connected thereto to be received or parked in the closing element in a positive-locking, substantially airtight and detachable manner.

[0032] As shown in FIG. 6, parking fixture <b>33</b> includes a receiving region <b>36</b> which is positive locking on the peripheral side with respect to accessory <b>35</b> and which has a receiving opening <b>37</b>. Receiving opening <b>37</b> points in a direction facing away from hand grip <b>6</b><i>a</i>. When the accessory <b>35</b> connected to suction hose <b>7</b> is inserted in receiving opening <b>37</b>, suction-side hose end <b>34</b> extends in an approximately straight line as shown in FIG. 1.

[0033] As shown in FIG. 6, receiving region <b>36</b> is spring-biased and designed in such a manner that it can be moved in the direction of hand grip <b>6</b><i>a </i>against the force of spring <b>38</b>. When receiving region <b>36</b> is pushed up into its upper end position in the direction of hand grip <b>6</b><i>a </i>against the force of spring <b>38</b>, the positive connection to accessory <b>35</b> is released. When the user releases the pushed-up receiving region <b>36</b>, the receiving region is returned down to its original position by the force of spring <b>38</b>, thus securing the accessory <b>35</b> parked as shown in FIGS. 1, 5 and <b>6</b>.

[0034] A secondary air device in the form of a secondary air slide <b>39</b> is arranged at receiving region <b>36</b>. As shown in FIG. 5, secondary air slide <b>39</b> is guided by its grooves <b>40</b> with their stop edges <b>41</b><i>a</i>, <b>41</b><i>b</i>, which are provided on the side walls, and by ribs <b>42</b> that are formed at receiving region <b>36</b> and engage with grooves <b>40</b>.

[0035] This design allows secondary air slide <b>39</b> to be gradually moved down to its lower end position in the direction of the handle end on the side of the articulated joint, in which position the ribs <b>42</b> abut against upper stop edges <b>41</b><i>a</i>. In doing so, a correspondingly large secondary air opening <b>43</b> is cleared. When secondary air opening <b>43</b> is cleared while vacuum cleaner <b>1</b> is in operation and suction hose <b>7</b> is connected and parked via accessory <b>35</b>, the fan unit sucks in air L through floor nozzle <b>18</b> and also through secondary air opening <b>43</b>, allowing the suction power at bottom-side suction opening <b>18</b> to be gradually adjusted by changing the size of secondary air opening <b>43</b> with secondary air slide <b>39</b>. This eliminates the need for a secondary air adjusting device at the floor nozzle.

[0036] The above-described arrangement of the secondary air device is not limited to the vacuum cleaner according to the present invention with the special design of the two flow paths. Rather, the secondary air device can be used on all vacuum cleaners which have a bottom-side suction opening and a suction hose, and in which the flow paths of the suction hose and the bottom-side suction opening are in parallel and in fluid communication.