Filter unit for a vacuum cleaner

Abstract

A filter unit (115) for a vacuum cleaner comprises a first filter (205) with a longitudinal axis (215); a second filter (210) surrounding the first filter (205); and a cleaning element (245) which is rotatably arranged in the first filter (205) about the longitudinal axis (215) and is configured to sweep along the first filter (205). The cleaning element (245) is torque-locked to the second filter (210).

Description

[0001] The invention relates to a filter unit for a vacuum cleaner. In particular, the invention relates to the cleaning of such a filter unit.

[0002] A vacuum cleaner consists of a suction nozzle, a filter unit, and a fan. Air entering through the suction nozzle is cleaned of dirt in the filter unit and expelled into the environment. The filter unit can be single-stage or multi-stage. A cordless vacuum cleaner, in particular, whose components are preferably small and lightweight, can place high demands on the efficiency of the filter unit.

[0003] The filter unit typically includes a depth filter through which contaminated air flows. Dirt adhering to the surface of the depth filter can be tapped off at regular intervals, for example, when emptying the vacuum cleaner's dust container. Manual tapping is often not very effective and may require the user to touch a dirty surface. Tapped dust is often not collected in a targeted manner, so a previously cleaned area can become contaminated again. Loose or stirred-up dust can be problematic for allergy sufferers.

[0004] EP 1 547 510 A2 shows a filter unit comprising a single filter. The filter is surrounded on its outer surface by three brushes mounted on brush holders. There are gaps of approximately 120° between the three brush holders, allowing unobstructed air access to the filter.

[0005] GB 2 556 180 B proposes equipping the filter unit with a mechanism that provides a defined impulse to knock dust out of a depth filter. The mechanism comprises a rotatable element that is axially pre-tensioned to the axis of rotation by an elastic element. Rotation deflects the element axially against the elastic element on a helical surface, and at a predetermined point, it is released from the helix, striking the filter unit axially like a hammer.

[0006] However, the mechanism requires a handle for the user, positioned in an axial air outlet of the filter. This can reduce the filter element's permeability, and dirt can become trapped on the handle during vacuuming.

[0007] One of the problems underlying the present invention is to provide an improved filter element for a vacuum cleaner and an improved vacuum cleaner. The invention solves these problems by means of the subject matter of the independent claims. Dependent claims describe preferred embodiments.

[0008] A filter unit for a vacuum cleaner comprises a first filter with a longitudinal axis; a second filter surrounding the first filter; and a cleaning element rotatably arranged within the first filter about its longitudinal axis and configured to sweep along the first filter. The cleaning element is torque-locked to the second filter.

[0009] The circumferential movement of the cleaning element allows for gentle and efficient cleaning of the first filter. Dirt, particularly dust, accumulated on a surface can be scraped or tapped off the first filter. The torque-locking connection allows the cleaning element to be actuated by means of the second filter. The second filter is easily accessible and handled by an operator. The filter unit is preferably designed to allow potentially contaminated air to flow through it from the outside in. The second filter can be configured to remove larger particles from the air than the first filter. In a preferred embodiment, the second filter is designed as a screen filter. The first filter can comprise a paper or nonwoven filter.

[0010] The first filter can comprise a pleated filter, with the cleaning element configured to sweep along the pleats in the circumferential direction. The pleated filter can have a number of pleats extending radially in a star-like pattern. The cleaning element can sweep along the radially inner ends of the pleats sequentially. The cleaning element can be dimensioned radially such that, when rotated about its longitudinal axis, it first deflects a pleat in the circumferential direction and then suddenly releases it, thus imparting an impulse to the first filter.

[0011] Dust on the surface of the first filter can be loosened in this way. The direction of rotation of the cleaning element can be arbitrary, and cleaning with alternating directions of rotation is possible. At its axial ends, the first filter can be closed off by an element that may be in the form of a ring or a circular disc.

[0012] The cleaning element can include a paddle located in an axially central region of the first filter. In the axial direction, the paddle is preferably just large enough to ensure reliable actuation of the first filter. Typically, the cleaning element is axially no more than approximately 1 / 4 or 1 / 5 the size of the first filter. The paddle is preferably flat and is further preferably positioned in a flow-optimized plane encompassing the longitudinal axis. In another embodiment, several paddles are provided, which can be distributed around a circumference around the longitudinal axis. In yet another embodiment, several axially offset paddles are provided.

[0013] The second filter and the cleaning element can be positively coupled to each other by means of engagement elements, but remain axially separable. Corresponding engagement elements can be provided on the elements for this purpose. The engagement elements can form a toothed coupling or be shaped like a regular polygon, for example, a hexagon. Other possibilities include a hexagonal recess, a multi-tooth recess, a slot, or a cross recess. Preferably, the male part of the engagement elements is provided on the first filter, and the female part on the second filter.

[0014] An engagement element can be rotationally fixed and axially displaceable, preferably incorporating an elastic element to move the engagement element axially towards the other engagement element. The entire cleaning element can be axially displaced, thus also moving the paddle axially. For example, a male engagement element can be rotationally fixed and axially displaceable on the first filter, while a female engagement element can be rigidly attached to the second filter. The torque-locking engagement between the second filter and the cleaning element can be maintained when the filters are separated by a predetermined amount in the axial direction. This allows the filters to be positioned in a first position, in which the filter unit is used for air filtering, and in a second position, in which dirt is removed from the filter unit.

[0015] The second filter can be attached to the first filter using a bayonet fitting. Once connected, the two filters form a separate, usable filter unit. The filters can be in their first position during this process. To release the bayonet fitting, the second filter is first moved axially towards the first, rotated by a predetermined angle, and then removed from the first filter in the opposite axial direction.

[0016] With the bayonet fitting open, the filters can be in the second position. In this position, the filters can be easily separated axially and removed from each other, releasing the torque connection between the engagement elements. For example, dirt loosened from one of the filters by activating the cleaning mechanism can then be easily emptied into a waste container after the filters are separated. The dirt simply sinks to the bottom and is not further agitated by the surrounding air, allowing for hygienic disposal.

[0017] The bayonet fitting and the engagement elements are preferably located at different axial ends of the filter unit. In particular, the bayonet fitting can be located on a radial outer surface of a filter material of the second filter. For this purpose, both second filters can have a radial flange by which they can be held together by means of the bayonet fitting. Preferably, several bayonet fittings are provided, which can be offset about the longitudinal axis.

[0018] The second filter can be closed at one axial end. The closed end is preferably located on the axial side where the engagement element is attached. The end can be closed by means of a circular disc. Alternatively, the closed end can be bowl-shaped, with a rim of a predetermined axial height adjoining the circular disc. The closed end is easily gripped by the user.

[0019] The first filter can have a flange for the axial outlet of purified air, the flange preferably being axially opposite the closed end of the second filter. The user can intuitively and securely grasp the first filter at the axially opposite flange. By twisting the grasped elements against each other, the cleaning element can be actuated to dislodge dirt from one of the filters.

[0020] The elements handled by the user may not contain any filter material and therefore may be only slightly or not at all contaminated. A mechanical drive for the cleaning element may be located outside an axial outlet of the first filter, which may be situated on the flange. The volume flow of purified air from the first filter may remain unaffected.

[0021] At least one of the filters can be cylindrical or conical. Such a filter can be easily manufactured and, if necessary, readily adapted to the available space where the filter unit is to be used on a vacuum cleaner.

[0022] The filter unit can be designed to be housed in a separator. The separator can also be cylindrical or conical and designed to collect dirt separated from the air flowing through it. In a particularly preferred embodiment, an airflow entering the separator is introduced radially outwards in a tangential direction, so that it travels along a circular or helical path along a surface of the separator. Following the principle of a cyclone, dirt in the air can be driven radially outwards, where it is slowed down by the separator and sinks axially downwards. The air can then flow radially into the second filter and from there into the first filter, exiting it axially.

[0023] According to a second aspect of the present invention, a vacuum cleaner comprises a filter unit as described herein. It is further preferred that the vacuum cleaner comprises a described collection container in which the filter unit can be received. The vacuum cleaner can, in particular, be cordless and, more preferably, comprise a universal, handheld device (MUH: multi-use handstick).

[0024] The invention will now be described in more detail with reference to the accompanying figures, in which Figure 1 shows an exemplary vacuum cleaner; Figure 2 shows a filter unit for a vacuum cleaner; Figures 3 and 4 show a filter unit in two different operating states; and Figure 5 shows two filters of a filter unit. represents.

[0025] Figure 1Figure 1 shows an exemplary vacuum cleaner 100, exemplified as a MUH, in a longitudinal section. The vacuum cleaner 100 comprises a blower 105, which can be operated by means of electrical energy from an energy storage device 110, a filter unit 115, and a connection 120, which can be connected, for example, to a suction tube or a suction nozzle (not shown). An air duct 125 connects the filter unit 115 to the blower 105. In the arrangement shown, the filter unit 115 is located upstream of the blower 105; an embodiment with a downstream filter unit 115 is also possible. The filter unit 115 is arranged in a collection container 130.

[0026] During operation of the vacuum cleaner, potentially dirt-laden air flows through the connection 120 into the collection container 130, where, in particular, coarser dirt can be separated from the airflow by means of an eddy current separator or cyclone. The air enters the filter unit 115 in a radial direction and exits axially to reach the blower 105 via the air duct 125. The blower 105 accelerates the airflow and releases it into the surrounding environment. The illustrated installation position of the filter element 115 is not mandatory, and the vacuum cleaner can be operated in a different position than shown; however, it is assumed in the following that the filter element 115 has an upper and a lower axial end, which are connected in Figure 1 are clearly recognizable.

[0027] Figure 2Figure 1 shows a filter element 115 for a vacuum cleaner 100 in a first embodiment. The filter element 115 comprises a first filter 205, which is surrounded by a second filter 210. The filters 205 and 210 are, for example, cylindrically shaped and preferably extend concentrically along a longitudinal axis 215, which can also represent a longitudinal axis 215 for the filter element 115.

[0028] The first filter 205 comprises a nonwoven or paper filter, which is preferably folded multiple times, thus increasing the effective surface area of ​​the first filter 205 for the air flowing through it. The folds of the filter 205 are essentially the same size, and creases in the material preferably run parallel to the longitudinal axis 215, so that a section through the first filter 205 perpendicular to the longitudinal axis 215 shows a star-shaped figure. The filter material used is preferably bonded airtight in the circumferential direction.

[0029] A first end cap 225 is attached to the upper axial end of the first filter 205, and a second end cap 230 is attached to the lower axial end, each preferably being airtightly connected to the filter material. A flange 235 extends radially from the upper end cap 225 and can carry a seal 240 to ensure an airtight connection to the separator vessel 130.

[0030] A cleaning element 245 is rotatably mounted about the longitudinal axis 215 on the lower end cap 230. The cleaning element 245 comprises an axial shaft and a radially projecting paddle 250, which extends to the filter material of the first filter 205. Optionally, the shaft is mounted above the paddle 250 on the upper end cap 225.

[0031] A first engagement element 255 is torque-locked and axially displaceable with the shaft of the cleaning element 245 and is pressed axially downwards relative to the lower end cap 230 by means of an elastic element 260. The torque lock can be achieved, for example, by means of a toothed connection or a polygonal profile between the shaft of the cleaning element 245 and the engagement element 255.

[0032] The second filter 210 is designed as a cylindrical sieve filter and includes a closed bottom section to which a second engagement element 265 is attached or formed. This second engagement element is configured to engage with the first engagement element 255 in a torque-locking manner. For this purpose, the elements 255 and 265 can each, for example, have a polygonal profile, one of which can be axially inserted into the other. A flange 270 is attached to the upper end of the second filter 210 and is configured to bear axially against the flange 235 of the first filter 205.

[0033] A bayonet fitting 275 can be provided for connecting the filters 205, 210 at their flanges 235, 270. The bayonet fitting 275 allows the filters 205, 210 to rotate relative to each other about the longitudinal axis 215 when the filters 205, 210 are pressed together axially against a preload force. In a first rotational position, the filters 205, 210 can be separated axially from each other; in a second rotational position, they are held together axially. A locking element can secure the filters 205, 210 against unintentional engagement or disengagement from this rotational position.

[0034] If the cleaning element 115 is removed from the collection container 130 after use of the vacuum cleaner 100, dirt may be present on the surfaces of the first filter 205 and / or the second filter 210. To remove this dirt from the surfaces, the bayonet fitting 275 can be released to separate the filters 205 and 210. To do this, a user can grasp the first filter 205 with one hand at the upper end cap 225 and the second filter 210 with another hand at the bottom section, compress axially, and twist the filters 205 and 210 relative to each other about the longitudinal axis 215. The twisting is limited to a predetermined amount before the filters 205 and 210 can be separated axially. When the axial compression force is released, the elastic element 260 pushes the filters 205 and 210 apart axially by a predetermined amount. In practice, this amount can be approximately...8 - 12 mm and is preferably sufficient to disengage the bayonet fitting 275 so that it is not closed when the filters 205, 210 are twisted against each other.

[0035] If filters 205 and 210 are now rotated relative to each other about the longitudinal axis 215, the cleaning element 245 rotates within the first filter 205, and the paddle 250 brushes over radially inward-facing folds in the filter material. This deflects a fold circumferentially until the force transmission to the paddle 250 breaks and the fold springs back. This exerts an impulse on the first filter 205, which can knock dirt off the surface of the filter material. The impulse can also be transferred to the second filter 210, so that dirt can also be shaken off its surface.

[0036] If the filter element 115 is held so that its longitudinal axis 215 runs vertically, the dirt can sink in the axial direction. Dirt shaken off the first filter 205 can collect between filters 205 and 210. After shaking, filters 205 and 210 can be separated axially to release the dirt into a waste container.

[0037] The filters 205 and 210 can then be reassembled into the filter element 115 in reverse order. To do this, the filters 205 and 210 are axially pushed together and, if necessary, twisted against each other until the engagement elements 255 and 265 engage. The filters 205 and 210 are then compressed further against the force of the elastic element 260 until the bayonet fitting 275 can engage. Further rotation and axial compression may be required to thread the bayonet fitting 275 into place. The filters 205 and 210 are then twisted against each other until the bayonet fitting 275 locks them. The axial compression force can then be released, and the filter unit 115 can be reinserted into the vacuum cleaner 100. Cleaning the filter element 115 can advantageously be carried out whenever the collection container 130 is emptied.

[0038] Figures 3 and 4The figures show filter element 115 in different operating states, each in a partial longitudinal section. Figure 3 The bayonet fitting 275 is open and the engagement elements 255, 265 are in mutual engagement, so that the cleaning element 245 can be rotated about the longitudinal axis 215 by means of the second filter 210. Figure 4 The bayonet fitting 275 is closed, so that the filter element 115 can be inserted into the vacuum cleaner 100.

[0039] In the form of representation of Figures 3 and 4 The cleaning element 245 has more paddles (250) than in Figure 1In this embodiment, a first pair of opposing paddles 250 is axially offset from a second pair of opposing paddles 250. In another embodiment, four paddles 250 are provided, which are attached to the shaft of the cleaning element 245 at 90° intervals. Here, the paddles 250 are preferably located axially essentially centrally between the end caps 225 and 230.

[0040] The bayonet fitting 275 is formed in this case by a mushroom element 305 projecting axially from the first end cap 225 and an elongated hole 310 in the flange 270. The elongated hole 310 extends circumferentially around the longitudinal axis 215 and is wide enough at one point to allow the head of the mushroom element 305 to pass through it. From this point onward, the elongated hole 310 is narrower, so that a shaft of the mushroom element 305 can be moved within the elongated hole 310, but the head cannot slide axially out of the elongated hole 310.

[0041] A locking element 315 can exert a radial force on the head of the mushroom element 305 and require an increased rotational force to engage the Figure 2 to assume or leave the fully locked position of filters 205, 210 as shown.

[0042] Figure 5 Figure 1 shows a first filter 205 and a second filter 210 of a filter unit 115. The filters 205 and 210 are shown separated from each other along a longitudinal axis 215 in the manner of an exploded view. The illustrated embodiment is equivalent to the components shown in Figure 1. Figures 2 to 4 The illustrated embodiments are compatible and can also be used on the vacuum cleaner 100. Figure 1 be used. Reference sign

[0043] 100 Vacuum cleaner 105 Blower 110 Energy storage 115 Filter unit 120 Connection 125 Air duct 130 Collection container 205 first filter 210 second filter 215 longitudinal axis 225 first (upper) end cap of the first filter 230 second (lower) end cap of the first filter 235 flange 240 seal 245 cleaning element 250 paddle 255 first engagement element (on the cleaning element) 260 elastic element 265 second engagement element (on the second filter) 270 flange 275 bayonet fitting 305Mushroom element 310Long hole 315Locking element

Claims

1. Filter unit (115) for a vacuum cleaner (100), wherein the filter unit (115) comprises the following: - a first filter (205) with a longitudinal axis (215); - a second filter (210) surrounding the first filter (205); characterised by - a cleaning element (245), which is arranged in the first filter (205) so as to be rotatable about the longitudinal axis (215) and is designed to extend along the first filter (205); wherein the cleaning element (245) is coupled to the second filter (210) in a torque-locking manner.

2. Filter unit (115) according to claim 1, wherein the first filter (205) comprises a folded filter and the cleaning element (245) is designed to extend along the folds of the fold filter in the peripheral direction.

3. Filter unit (115) according to claim 1 or 2, wherein the cleaning element (245) comprises at least one paddle (250), which is disposed in an axially central region of the first filter (205).

4. Filter unit (115) according to claim 3, wherein the cleaning element (245) also has an axial shaft and wherein the at least one paddle (250) projects in the radial direction and extends as far as a filter material of the first filter (205).

5. Filter unit (115) according to claim 3 or 4, wherein the first filter (205) and the second filter (210) can be twisted with respect to one another so that - the cleaning element (245) rotates within the first filter (205) and - the at least one paddle (250) extends beyond radially inwardly pointing folds of a filter material of the first filter (205).

6. Filter unit (115) according to one of claims 3 to 5, wherein the at least one paddle (250) has - a pair of two opposing paddles (250), - a first pair of two opposing paddles (250) and a second pair of two opposing paddles (250), which are axially offset with respect to the paddles (250) of the first pair, or - four paddles (250), which are attached to a shaft of the cleaning element at 90° intervals.

7. Filter unit (115) according to one of the preceding claims, wherein the second filter (210) and the cleaning element (245) are coupled to one another in a form-fitting manner by means of engaging elements (255, 265) but can be axially separated from one another.

8. Filter unit (115) according to one of the preceding claims, wherein the second filter (210) can be fastened to the first filter (205) by means of a Bayonet closure (275).

9. Filter unit (115) according to claim 8, wherein the Bayonet closure (275) and the engaging elements (255, 265) are disposed at different axial ends of the filter unit (115).

10. Filter unit (115) according to one of the preceding claims, wherein the second filter (210) is closed at an axial end.

11. Filter unit (115) according to claim 10, wherein the first filter (205) has a flange (235) for the axial discharge of cleaned air; wherein the flange (235) axially faces the closed end of the second filter (210).

12. Filter unit (115) according to one of the preceding claims, wherein the first and / or the second filter (205, 210) is designed to be cylindrical or conical.

13. Filter unit (115) according to one of the preceding claims, wherein the filter unit (115) is designed for reception in a separation container (130).

14. Vacuum cleaner (100), comprising a filter unit (115) according to one of the preceding claims.

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