Vacuum cleaning system

Abstract

A vacuum cleaning system includes a vacuum cleaner having a vacuum motor, a dust box, a primary separation system, a membrane filter, and an air valve arrangement configured to control airflow through at least the membrane filter. The vacuum cleaner is configured to be operable in a surface cleaning mode of operation and a self-cleaning mode of operation. In a surface cleaning mode of operation, the vacuum cleaner is configured such that the vacuum motor draws dirty air from the dirty air inlet through the dust box, the primary separation system and the membrane filter in a first airflow direction, and in a self-cleaning mode of operation, the vacuum motor draws dirty air from the dirty air inlet through the dust box, the primary separation system and the membrane filter in a second airflow direction. The vacuum cleaner is configured to allow air to flow from the air valve arrangement through the membrane filter in the second airflow direction to clean dirt from the membrane filter. Accordingly, it is useful that the airflow can pass through the vacuum cleaner in a second direction or "reverse" to remove agglomerated dirt from the membrane filter. The membrane filter may be used as a pre-motor filter located upstream of the vacuum motor, or as a post-motor filter located downstream of the vacuum motor, when considered from the airflow direction during the surface cleaning mode of operation.

Description

Background Art

[0001] Handheld vacuum cleaners and "stick vacuum cleaners" are popular household machines because they are lightweight and maneuverable compared to larger cylinder and upright vacuum cleaners that are connected to a power source. Useful portability is often achieved at least in part by battery power, and for convenience, many such machines are now bagless, so that the collected dirt is stored in an integrated dust box. Typically, handheld machines are used for frequent spot cleaning tasks, but, as battery technology improves, the trend is towards longer cleaning operations. The trend of handheld vacuum cleaners becoming the vacuum cleaner of choice in many households means that some users may prefer a larger dust box so that the vacuum cleaner can hold more dirt and debris between emptying the dust box. However, the smaller size of battery-powered vacuum cleaners means that users must perform regular maintenance, such as emptying the dust box, to maintain their optimal performance. In addition to emptying the box, users are also required to occasionally perform filter cleaning tasks in order to clean the fine air filter that such machines often include to filter the exhaust airflow. Such filters may meet HEPA filtration standards and therefore require regular cleaning to maintain their performance. Filter cleaning typically involves the user washing the filter in water and then allowing the filter to dry for an extended period of time, typically 24 hours or more, during which the vacuum cleaner cannot be used. It is hoped that the life of such filters can be extended without requiring the user to wash them. Summary of the invention

[0002] In a first aspect, an example of the invention provides a vacuum cleaning system, the vacuum cleaning system comprising a vacuum cleaner having a vacuum motor, a dust box, a primary separation system, a membrane filter and an air valve arrangement, the air valve arrangement being configured to control airflow through at least the membrane filter. The vacuum cleaner is configured to be operable in a surface cleaning mode of operation and a self-cleaning mode of operation. In the surface cleaning mode of operation, the vacuum cleaner is configured so that the vacuum motor draws dirty air from a dirty air inlet through the dust box, the primary separation system and the membrane filter in a first airflow direction, and in the self-cleaning mode of operation, the vacuum cleaner is configured to allow air to flow from the air valve arrangement through the membrane filter in a second airflow direction to clean dirt from the membrane filter.

[0003] Thus, usefully, airflow can be passed through the vacuum cleaner in a second direction to remove caked dirt from the membrane filter. When considered in terms of airflow direction during the surface cleaning mode of operation, the membrane filter can be used as a pre-motor filter upstream of the vacuum motor, or as a post-motor filter downstream of the vacuum motor.

[0004] In addition to the air valve arrangement that allows air to flow through the membrane filter in the self-cleaning mode of operation, it can also be configured to cause air to flow through the surface of the membrane filter in the self-cleaning mode. Here, air flowing through the surface of the membrane filter means that the air flows substantially parallel to the surface. By configuring the air valve arrangement to cause air to flow through the membrane filter, and to flow through the surface of the membrane filter during the self-cleaning mode of operation, the cleaning effect of the membrane filter is enhanced.

[0005] In some examples, the membrane filter is movably mounted within the vacuum cleaner, wherein the movement facilitates the removal of dirt from the membrane filter. During the movement, when the vacuum cleaner enters a self-cleaning mode of operation, the membrane filter may move from a first position to a second position to facilitate the removal of dirt from the membrane filter. The movement of the membrane filter may be combined with an impact from an impactor configured to provide a mechanical impact pulse to the membrane filter. This further improves the cleaning of the filter in the self-cleaning mode of operation.

[0006] The movement of the membrane filter can be triggered by various events. In one example, the movement of the membrane filter from the first position to the second position is caused by the operation of the air valve arrangement. In another example, the movement of the membrane filter from the first position to the second position is caused by the opening of the dust box door. In either example, a mechanical or electronic triggering mechanism can trigger the movement of the membrane filter. This movement can be powered by any suitable means, such as airflow through the membrane filter, or by a spring loaded mechanism.

[0007] Although the air backflow (in the second direction) through the membrane filter may be generated by the vacuum cleaner itself, in other examples of the present invention, the vacuum cleaning system further comprises a docking station, wherein the docking station comprises a dirt storage chamber and an interface, the interface being configured to cooperate with a dust box of the vacuum cleaner so that dirt discharged from the dust box through the box opening is discharged into the dirt storage chamber of the docking station. In the self-cleaning operating mode, the system is configured to: operate the vacuum generator to generate a partial vacuum in the dirt storage chamber, and once a sufficient negative pressure level has been generated, operate the air valve arrangement to cause a pulse of air to flow from the air valve arrangement through the membrane filter in the second air flow direction. In addition, the air valve arrangement can be adjusted so that when it is operated when a sufficient negative pressure level has been generated, the air valve arrangement causes a pulse of air to flow into the dust box of the vacuum cleaner, thereby discharging dirt from the dust box through the dust box opening and into the dirt storage chamber.

[0008] The vacuum motor of the vacuum cleaner is used to discharge dirt and dust in the vacuum cleaner into the dirt storage chamber of the docking station, which avoids the need to provide an additional vacuum motor in the docking station. This reduces the energy usage for the bin emptying operation, thereby improving the efficiency of the system. The air pulse function causes a high-speed air flow through the dust bin to ensure that the dust bin is emptied efficiently and that dirt adhering to the inner surface of the vacuum cleaner is removed during the emptying process.

[0009] Preferably, the dust box is associated with a centrifugal or cyclonic separator adapted to cause a circulating flow of air which separates entrained dirt from the airflow. In this case, in one example, the air valve arrangement is configured to generate a vortex airflow through the dust box. The vortex or rotating airflow increases the efficiency of emptying dirt from the dust box compared to an airflow that is usually directed axially through the dust box. Furthermore, this type of airflow again prevents dust from getting stuck in localized areas within the dust box.

[0010] The air valve arrangement may be operated by different methods. In one approach, the air valve arrangement may be electronically controlled and, as such, may be configured to communicate with a control system of the vacuum cleaner, the control system commanding the air valve arrangement to open and close intermittently in order to achieve the desired one or more air pulses. The time intervals for controlling the opening and closing of the air valve arrangement may be set at predetermined time periods. Alternatively, the time intervals may be controlled by a control system that senses the pressure within the dirt storage chamber of the docking chamber and activates the air valve arrangement when sufficient negative pressure is detected. However, in another example, the air valve arrangement is configured to operate by a pressure differential between the dust box and the surrounding environment.

[0011] Although a single pulse of high-speed air passing through the vacuum cleaner dust box may be sufficient to clear dust from the membrane filter and optionally discharge most of the dust, dirt and debris, preferably, the air valve arrangement is configured to operate repeatedly during the continuous operation of the vacuum generator, thereby allowing multiple consecutive air pulses to flow through the dust box. This is to more thoroughly clean the membrane filter of the vacuum cleaner and more effectively discharge dirt from the dust box. At this point, it should also be understood that during the self-cleaning operating mode, the air flow through the membrane filter can flow in the reverse direction, but can also flow in the first air flow direction, such as as part of the pulse operation, to help remove dirt / agglomerates from the membrane filter.

[0012] The dirt storage chamber may comprise a first chamber portion and a second chamber portion separated by a one-way valve. Advantageously, this allows dirt to enter the second chamber portion and then be trapped in that position by the valve. This reduces the tendency for dust to be blown back from the docking station, particularly when the vacuum cleaner is detached from the docking station.

[0013] The second chamber portion of the dirt storage chamber may be removable or have a removable portion, such as a bin, bucket or container, which allows the dirt stored therein to be removed. One option is to provide a removable, breathable dust bag in the second chamber portion, which operates similarly to a conventional vacuum cleaner bag. Thus, when the docking station needs to be emptied, the user can simply remove the bag. Since the docking station does not need to be portable, the bag can be made much larger than a typical vacuum cleaner bag, so that it does not need to be emptied frequently, thereby providing particular convenience to the user.

[0014] In one example, the dirt storage chamber may include one or more airflow holes to allow air to flow into it during the dust bin emptying mode. This provides a clean air flow to enter the dirt storage chamber during the bin emptying cycle, thereby inhibiting backblowing of dust. Conveniently, the one or more airflow holes are located in the first chamber portion.

[0015] In order to improve the cleaning efficiency of the airflow in the dirt storage chamber, the one or more airflow holes are configured to generate a vortex airflow around the dirt storage chamber.

[0016] The vacuum generator can draw air from the dirt storage chamber through the vacuum cleaner itself, creating a negative pressure level in the dirt storage chamber, just like in normal vacuum cleaning operation. It is envisioned that the system works particularly well with a vacuum cleaner that has a vacuum nozzle, i.e., a suction port of the vacuum cleaner, which is at least partially surrounded by a box door. This means that the box door engages with the docking station and the vacuum nozzle enters the interior of the dirt storage chamber to exhaust air therefrom. However, other configurations are also acceptable. In this case, the interface between the vacuum cleaner and the docking station can be reconfigured to enable it to selectively cooperate with a second vacuum cleaner. The docking station can then be used with different vacuum cleaners owned by the same user.

[0017] Features described in conjunction with the first aspect of the invention are equally applicable to the other aspects of the invention, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a side view of a handheld vacuum cleaner;

[0019] Figure 2 yes Figure 1 Another side view of the handheld vacuum cleaner showing interior details;

[0020] Figure 3 It is a display Figure 1 and Figure 2 A view of how a dust box of a handheld vacuum cleaner can be emptied in a known manner;

[0021] Figure 4 and 5is a side view of a vacuum cleaner system including a handheld vacuum cleaner and a docking station, wherein Figure 4 The handheld vacuum cleaner is in the undocked position and Figure 5 The medium handheld vacuum cleaner is in the docking position;

[0022] Figure 6 , 7 and 8 is Figure 4 and 5 A schematic diagram of the valve arrangement of a hand-held vacuum cleaner showing its operating principle;

[0023] Fig. 9 and Fig.10 The two stages of the bin emptying or self-cleaning mode are shown when the handheld vacuum cleaner is docked on the docking station, wherein Fig. 9 The handheld vacuum cleaner is shown in an operating stage of exhausting air from a docking station, and wherein Fig.10 A handheld vacuum cleaner is shown discharging dirt from a dust box of the vacuum cleaner into a docking station;

[0024] Fig.11 is a schematic diagram of another example of a vacuum cleaner system, including another configuration of a handheld vacuum cleaner docked on a docking station;

[0025] Fig.12 is a schematic diagram of a pre-motor filter in the form of a membrane filter housed within the hand-held vacuum cleaner shown in the preceding figures, and includes illustrations showing components of the pre-motor filter in greater detail, including the valve arrangement;

[0026] Fig.13 is a schematic diagram of a pre-motor filter showing an arrangement of air valves for controlling air flow through the pre-motor filter when the handheld vacuum cleaner is operated in a self-cleaning mode;

[0027] Fig.14 is another schematic diagram of the pre-motor filter showing an air valve arrangement to control airflow through the pre-motor filter in an alternative route when the handheld vacuum cleaner is operated in a self-cleaning mode;

[0028] Fig.15 is another schematic diagram of a pre-motor filter, wherein the vacuum cleaner is operated in a self-cleaning mode, wherein the pre-motor filter is impacted by a mechanical agitation device or "impactor". DETAILED DESCRIPTION

[0029] Examples of the present invention relate to a vacuum cleaning system, which includes a vacuum cleaner, which in some examples can be matched, engaged, assembled or docked with a corresponding docking station. Typically, if the vacuum cleaner is battery-powered, this docking station is used as a power source for charging the vacuum cleaner. However, the docking station and vacuum cleaner of the present example are configured to facilitate the removal and storage of dirt and debris emptied from the vacuum cleaner into the docking station. The vacuum cleaner can be battery-powered, which is beneficial because it provides the advantage of portability, but this is not necessary. Although the vacuum cleaner according to the present example can be operated on the docking station to remove dirt and debris, in other examples, they can also be operated alone without being docked on the docking station.

[0030] Advantageously, the vacuum cleaning system of the present invention provides vacuum-assisted bin emptying functionality without requiring an additional vacuum generator in the docking station. This makes the overall system less expensive and more energy efficient.

[0031] Figures 1 to 3 Various views of a battery powered or cordless handheld vacuum cleaner 2 which may be used in the system of the present invention are shown to provide a useful background for the reader.

[0032] First reference Figure 1 and Figure 2 The handheld vacuum cleaner 2 comprises a body 4 with an elongated handle 6, a primary separation system in the form of a cyclonic separation unit 8 with a longitudinal axis X and a cleaning tool 10 in the form of a nozzle, which is fixed to the cyclonic separation unit 8. The cleaning tool 10 is detachable from the handheld vacuum cleaner, which means that it can be used for different cleaning tasks. Figure 1 , the cleaning tool 10 is in the form of a crevice tool. However, in other examples, the cleaning tool 10 may be in the form of an elongated tube or "stick" having a floor tool attached to one end distal from the vacuum cleaner 2. Thus, the cleaning tool 10 in this configuration allows the vacuum cleaner to be used as a stick vacuum cleaner. The specific form of the cleaning tool 10 used with the vacuum cleaner 2 is not important to the concepts of the present invention, but is shown in these figures for context and completeness.

[0033] The cyclonic separating unit 8 extends away from the handle 6 such that the cleaning tool 10 is located at an end of the cyclonic separating unit 8 furthest from the handle 6. The cleaning tool 10 extends away from the cyclonic separating unit 8 along a longitudinal axis X of the cyclonic separating unit 8.

[0034] The body 4 also includes a suction generator 11 including a motor 12 and an impeller 13 located above and toward the rear of the handle 6. The components of the suction generator 11 are located in a motor housing or casing 15. The motor housing 15 is located adjacent the cyclonic separation unit 8 so that the airflow leaving the cyclonic separation unit 8 flows into the motor housing 15 to be discharged from the vacuum cleaner 2. The motor housing 15 may include a pre-motor filter 19 located in front of or upstream of the motor 12 and the impeller relative to the direction of airflow through the machine so as to filter contaminants from the airflow that are not separated by the cyclonic separation unit 8. The pre-motor filter 19 is located in the Figure 2 Schematically shown in FIG, and various structural configurations may be adopted. When considering the direction of airflow through the cyclonic separation unit 8 and the pre-motor filter 19 in normal operation of the vacuum cleaner, the pre-motor filter 19 is located in the upstream direction of the motor 12. However, in some examples, in addition to the pre-motor filter 19 or instead of the pre-motor filter 19, a post-motor filter (not shown) may be provided.

[0035] The battery 14 is located just below the handle 6. An actuator in the form of a finger-operated trigger 16 is provided at an upper portion of the handle 6. A trigger guard 17 extends forwardly from the handle below the trigger 16. The handle 6 is arranged at an angle θ1 relative to the longitudinal axis X of the cyclonic separating unit 8 so that the handle 6 is in a handle grip configuration. In the example shown, the handle axis H is arranged at 110 degrees relative to the longitudinal axis X of the cyclonic separating unit 8. This angle is the angle between the longitudinal axis X extending forwardly of the handle 6 and the portion of the handle axis H extending through the handle 6.

[0036] The cyclonic separating unit 8 comprises a primary cyclonic separator 18 and a plurality of secondary cyclonic separators 20 located downstream of the primary cyclonic separator 18. The primary cyclonic separator 18 is adjacent to a first end of the cyclonic separating unit 8 and the secondary cyclonic separators 20 are adjacent to a second end of the cyclonic separating unit 8 opposite to the first end. The secondary cyclonic separators 20 are arranged in a circular array extending around a longitudinal axis X of the cyclonic separating unit 8.

[0037] The primary cyclone separator 18 comprises a separator body 22 in the form of a box having a cylindrical outer wall 24 and an end wall 26. The cylindrical outer wall 24 defines a cyclonic separation chamber 28. In the example shown, the axis of the cyclonic separation chamber 28 defines the longitudinal axis X of the cyclonic separation unit 8. A central duct 30 extends from the end wall 26 to an inlet 32 ​​of the cyclonic separation chamber 28.

[0038] The cleaning tool 10 includes a connector portion 33 and a nozzle portion 34, which define a conduit 36 ​​along the cleaning tool 10. The outer diameter of the connector portion 33 is smaller than the inner diameter of the portion of the central conduit 30 adjacent the end wall 26, so that the connector portion 33 can be inserted into the central conduit 30 (as shown), thereby ensuring a rigid connection between the cleaning tool 10 and the cyclonic separation unit 8. However, this configuration is not required, and the connector portion 33 can be configured in other ways to fit the cleaning tool 10 to a vacuum cleaner.

[0039] The cleaning tool 10 is provided with a retaining feature (not shown) which engages with the central conduit 30 so as to secure the cleaning tool 10 to the central conduit 30. The cleaning tool 10 also includes an annular collar 43 which abuts the end wall 26 so as to retain the end wall 26 in a closed position and thereby prevent the end wall 26 from accidentally opening when the cleaning tool 10 is attached. The cleaning tool 10 has a manually operated latch 44 which is actuated to disengage the retaining feature from the central conduit 24, thereby removing the tool 10 from the cyclonic separation unit 8. Again, it should be noted that these mechanical details are merely exemplary and therefore the cleaning tool 10 may take other forms and the cleaning tool 10 may be connected to the vacuum cleaner body 4 in other ways.

[0040] The central duct 30 and the duct 36 passing through the cleaning tool 10 together define an inlet duct 30, 36, which extends coaxially with the longitudinal axis X and passes through the end of the cyclonic separating unit 8 farthest from the handle 6. That is, through the end wall 26 of the separating unit. As shown here, the end wall 26 is perpendicular to the longitudinal axis X of the machine.

[0041] The inlet 32 ​​of the cyclonic separation chamber 28 is spaced from the end wall 26 and is located towards the end of the primary cyclone 18 which is opposite to the end of the cyclonic separation unit 8 to which the cleaning tool 10 is connected. Thus, the cyclonic separation chamber 28 extends around a portion of the inlet duct 30, 36 formed by the central duct 30. A first portion of the central duct 30 leading from the end wall 26 extends along the axis X of the cyclonic separation chamber 28. A second portion of the central duct 30 extends from the first portion to the inlet 32 ​​of the cyclonic separation chamber 28. The second portion extends in a direction having a radial and a circumferential component relative to the cyclonic separation chamber 28 so as to promote a rotational flow within the cyclonic separation chamber 28 during use.

[0042] The end wall 26 and the portion of the cylindrical outer wall 24 adjacent the end wall 26 define a dust collector 38 in the form of a dirt collection box or more simply a "dust box" in which dirt separated from the incoming flow by the primary cyclone separator 18 is collected.

[0043] The end wall 26 is connected to the cylindrical outer wall 24 by a pivot 40 and is held in a closed position by a user-operable latch 42. The end wall 26 can be moved from a closed position, in which dirt is retained within the dust box 38, to an open position, in which dirt can be removed from the dust box 38 by releasing the latch 42 and pivoting the end wall 26 away from the end of the cylindrical outer wall 24. Thus, the end wall 26 can be considered a door of the dust box 38 that closes the box opening 27 of the dust box 38.

[0044] A cylindrical shroud 45 is centrally disposed within the cyclone chamber 28 and extends coaxially with the axis of the chamber 28. A hole 46 disposed through the shroud 45 defines a fluid outlet for the cyclone chamber 28. Note that the hole 46 is located at Figure 2 4. The holes 46 are shown as distinct holes in FIG. 4, although it is contemplated that in other examples the holes 46 may be smaller and more numerous, such as as part of a fine mesh or perforated membrane.

[0045] A duct 48 formed in part by the shroud 45 provides fluid communication between the outlet of the cyclone chamber formed by the apertures 46 and the inlet 49 of the secondary cyclone 20. Each secondary cyclone 20 has a solids outlet 50 at one end which communicates with a fine dust collector 51 extending along the side of the primary cyclone 18. At the end of each secondary cyclone 20 opposite the solids outlet 50 is a fluid outlet 52.

[0046] In use, the handheld vacuum cleaner 2 is activated by the user pressing the trigger 16 with the index finger. Dirty air is drawn into the cyclonic separation chamber 28 by the suction generator 11 through the inlet ducts 30, 36 and through the inlet 32. The rotating flow promoted by the second portion of the central duct 30 within the cyclonic separation chamber 28 produces a cyclonic action that separates relatively heavy or large dirt from the air. Cyclonic vacuum cleaners with dual cyclone systems or multiple cyclone systems are well known in the art. Therefore, this discussion is provided for context and illustrates one type of vacuum cleaner suitable for use in examples of the present invention.

[0047] Typically, the vacuum cleaner 2 is held so that the cyclonic separation unit 8 points downward from the handle 6. Thus, the dirt separated in the cyclonic separation chamber 28 falls into the dust box 38 under the influence of gravity. Partially cleaned air passes through the holes 46 in the shroud 45 and is sucked into the secondary cyclone 20 along the duct 48. Smaller and lighter dirt particles are separated from the air by the secondary cyclone 20 and discharged into the fine dust collector 51 through respective solid outlets. The cleaned air leaves the secondary cyclone 20 through the pre-motor filter 19 and the suction generator 11 via the respective fluid outlets 52 of the secondary cyclone 20 and leaves the vent (not shown) at the rear of the main body 4.

[0048] Figure 3The vacuum cleaner 2 is shown being emptied in a known manner. To empty the dust box 38 and the fine dust collector 51, the user first detaches the cleaning tool 10. Then, while holding the handle 6, the user points the vacuum cleaner 2 towards a suitable container (e.g. a trash bin or a garbage bag) into which the dirt is to be emptied. The user then releases the catch 42 and the end wall 26 pivots from its closed position to its open position.

[0049] In an alternative arrangement, the inlet duct 30, 36 may be spaced apart from the axis of the cyclonic separating unit 8. However, the cyclonic separating unit 8 may be arranged to extend partially around a portion of the inlet duct, or completely around a portion of the inlet duct 30, 36. For example, the inlet duct 30 may be recessed into the side of the cyclonic separating unit 8 so that the duct extends within the outline of the cyclonic separating unit 8 when viewed along the axis of the cyclonic separating unit 8.

[0050] When the vacuum cleaner 2 is emptied, it will be appreciated that dirt and dust are discharged from the dust box 38 by gravity. It is also known to include a mechanical agitator, such as a piston, to push dirt out of the dust box 38. However, during the emptying operation, fine dust tends to float upwards, which is undesirable for the user. Some examples of the present invention are intended to address this problem.

[0051] Now go to Figure 4 and 5 , shows a schematic diagram of a handheld vacuum cleaner 2 that can be docked with a docking station 60 to define a vacuum cleaning system 62, although in other examples the vacuum cleaning system 62 may not require a docking station. Figure 4 and 5 The vacuum cleaner 2 shown is similar in structure to Figures 1 to 3 Therefore, the same reference numerals will be used to refer to the same or similar parts.

[0052] exist Figure 4 In the embodiment, the handheld vacuum cleaner 2 is spaced apart from the docking station 60, and in Figure 5 , the vacuum cleaner 2 is docked on the docking station 60. As will become apparent from the following discussion, the vacuum cleaner 2 can be operated in a bin emptying and / or "self-cleaning" mode of operation in which dirt contained in the dust bin 38 is drawn into the docking station 60 due to the partial vacuum created by the vacuum cleaner 2 therein.

[0053] Reference will first be made to the docking station 60. In this example, the docking station 60 has a generally cylindrical body 64, and is taller than it is wide. More specifically, its vertical height (as viewed in the figure) is approximately three times its width (i.e., its diameter). It should be noted that the geometry shown here is merely exemplary, and therefore, the docking station 60 need not be cylindrical, and may be a different shape.

[0054] The body 64 of the docking station 60 is defined by a thin wall 66 having a bottom end 68 and a top end 70. The bottom end 68 rests on a floor (not shown) and is facilitated for stability by outwardly flared stands 72 or feet. The feet 72 are removable from the docking station 60 and are optional.

[0055] The top end 70 of the docking station 60 provides an interface 74 which is configured to engage with the vacuum cleaner 2. In principle, the interface 74 can be configured in various ways, but it should provide the functionality that the central duct 33 of the vacuum cleaner 2 can communicate with the interior of the docking station 60 and the pivotable end wall 26 of the dust collector 28 can open into the interior of the docking station 60, thereby exposing its contents.

[0056] In the example shown, the interface 74 is configured as an annular closure located on the top end 70 of the docking station 60. The interface 74 can be fixed to the body 64 of the docking station 60 so as to be removable and / or pivotable relative to the body 64. Alternatively, the interface 74 can be fixed, such as an integral part of the docking station 60, so that it cannot be removed, although this is not currently considered preferred. A removable interface 74 can allow for the replacement of an interface of a different configuration that is suitable for a vacuum cleaner of a different configuration, as will become apparent later.

[0057] The annular shape of the interface 74 defines a central opening 80, which is sized to be comparable to the size of the separator body 22 of the vacuum cleaner 2. Thus, the central opening 80 receives the separator body 22 of the vacuum cleaner 2. Preferably, the central opening 80 has a suitable sealing arrangement (not shown), such as a rubber lip seal or a rim that seals against the outer surface of the separator body 22, although this is considered optional.

[0058] Now turning to the interior of the docking station 60, Figure 4 and 5In the embodiment of the present invention, it can be understood that in this example, the docking station 60 has a divided internal volume. In particular, the docking station 60 is configured to define a dirt storage chamber 82 and an intermediate chamber or front chamber 84. The two chambers 82, 84 are surrounded by an internal volume 85, which is defined by the outer wall 66 of the docking station 60. The intermediate chamber 84 provides a spatial volume leading from the interface 74 of the docking station 60 to the dirt storage chamber 82. The intermediate chamber 84 has a chamber wall 86, which is shaped in the form of a tapered chute and therefore has a larger upper portion 87, which leads to a narrower throat 88. In the illustrated example, the vertical height of the throat 88 is less than the vertical height of the upper portion 86. However, in other examples, the length of the throat 88 can be longer than this, which can provide benefits in preventing dirt from flowing back from the dirt storage chamber 82.

[0059] The lower end of the throat 88 terminates in the dirt storage chamber 82. In this example, the dirt storage chamber 82 can be suspended or hung from the intermediate chamber 84, more specifically from the throat 88. Therefore, the dirt storage chamber 82 can be removably clamped or otherwise attached to the intermediate chamber 84. A valve 89 separates the intermediate chamber 84 (more specifically its throat 88) from the dirt storage chamber 82. In this example, the valve 89 is a one-way valve or "check valve" that is configured to allow dirt to enter the dirt storage chamber 82 from the intermediate chamber 84 under the influence of vacuum, which will be explained below. Once the pressure is normalized, the valve 89 closes to prevent dirt or dust from returning from the dirt storage chamber 82 to the throat 88.

[0060] The dirt storage chamber 82 is shown here as a generally oval cross-section. However, this is only for convenience, so the form of the dirt storage chamber 82 can be rigid or flexible. For example, it is envisioned that the dirt storage chamber 82 can be defined by a porous bag. The porous bag can be a woven or non-woven fabric, such as can be used in a conventional bag vacuum cleaner known in the art. Due to the porosity of the dirt storage chamber 82, dirt and debris can be sucked into it due to the vacuum in the internal volume 85, and when air can pass through the holes in the walls of the dirt storage chamber 82, the dirt and debris are trapped inside. Instead of a porous bag, it is envisioned that the dirt storage chamber 82 can have a more rigid structure, such as can be achieved by a porous fabric stretched on a skeleton or a porous fabric treated to have a certain rigidity. In either case, it is envisioned that the dirt storage chamber 82 can be removed from the docking station. In this way, the dirt storage chamber 82 can be emptied, such as in an outside trash can, or it can be replaced with an empty dirt storage chamber 82. Although not shown, suitable doors may be provided in the wall 66 of the docking station 60 so that the dirt storage chamber 82 may be removed and replaced.

[0061] The upper portion 86 of the intermediate chamber 84 is provided with a set of apertures 90 which allow air to enter the intermediate chamber 84 from the interior volume 85 of the docking station 60. This assists in creating a vacuum within the docking station 60 by the vacuum cleaner 2, as will be described.

[0062] The aperture 90 may be valved to allow air to flow in only one direction, i.e., from the interior volume 85 of the docking station 60 to the interior of the intermediate chamber 84. In the example shown, the aperture 90 may be configured to impart swirl to the air flow as it passes through the aperture 90 into the intermediate chamber 84. For example, the valve of the aperture 90 may be in the form of a slit valve of a flap valve.

[0063] As can be seen from the example shown, the dimensions of the intermediate chamber 84 are such that it allows the dust box door 26 to be fully pivoted outwardly and to hang vertically within the intermediate chamber 84 in the orientation of the figure.

[0064] As described above, the vacuum cleaning system 62 is configured such that the vacuum cleaner 2, when docked on the docking station 60, is operable to create a vacuum within the intermediate chamber 84 and the dirt storage chamber 82, which vacuum is capable of sucking dirt and debris from the dust box 38 of the vacuum cleaner 2. This functionality is achieved in a box emptying or self-cleaning operating mode. This mode can be a manual operation performed by a user, or it can be an automatic operation that requires substantially no user intervention. Broadly speaking, during the self-cleaning operating mode, the vacuum cleaner 2 creates a partial vacuum in the dirt storage chamber 82 of the docking station 60 compared to the ambient pressure level. To this end, air within the dirt storage chamber 82 is drawn into the intermediate chamber 84 through the internal volume 85 and through the aperture 90, and the air is drawn from the intermediate chamber 84 into the vacuum cleaner 2. During the air exhaust, the box door 26 can be in an open position, but is preferably closed. Opening of the box door 26 can be achieved by a suitable box opening mechanism 92. During Figure 4 and Figure 5 , the box opening mechanism is shown as an actuating member 94 slidably attached to the separator body 22. The actuating member 92 includes a push rod 96 that engages a portion of the box door 26. The sliding movement of the actuating member 94 drives the push rod 96 to move downward, as shown, which unlocks the box door 26 so that it can fall open under the influence of gravity and due to the pressure difference across the box door 26. Those skilled in the art will appreciate that the box opening function can be achieved in other ways. For example, an electronic system can be provided in which a servo actuator is operable to open the box door 26 in response to a user's button press, or a pneumatic device can be provided that uses the low pressure in the container to generate sufficient force to unlock the box lock 42.

[0065] Once a sufficient negative pressure level is generated, the air valve arrangement 100 of the vacuum cleaner 2 is operated to allow a pulse of air to enter the dust box 38, which has the effect of expelling dirt from the dust box 38 through the box opening 27 and into the intermediate chamber 84. The dirt passes downwardly through the throat 88 into the dirt storage chamber 82, where it is captured by the porous wall. The air flow passages within the vacuum cleaner 2 can be configured to ensure that the air pulses generate a high velocity airflow through the machine, which effectively expel dirt from the dust box 38.

[0066] Although the air valve arrangement 100 is Figure 4 and Figure 5 is roughly shown in Figure 6 , Figure 7 and Figure 8 is shown in more detail in .

[0067] In broad terms, the purpose of the air valve arrangement 100 is to allow controlled jets or pulses of air to flow into and through the dust box 38 and out of the box opening 27. Figures 6 to 8 As shown, the air valve arrangement 100 includes one or more holes 102 defined in an upper portion of the separator body 22 near the secondary cyclone separator 20 ( Figure 6 , 7 not shown).

[0068] Here, the holes 102 are shown extending in a circumferential array around the separator body 22. Other configurations are also acceptable, but the array as shown provides a uniform distribution of air allowed to enter the dust box 38 around the axis X of the separator body 22.

[0069] The opening state of one or more holes 102 is controlled by valve member 104. Valve member 104 can move between open and closed positions. In the closed position, valve member 104 covers holes 102 so that air cannot flow through them. In the open position, valve member 104 opens holes 102 to allow air to flow through them. Figure 6 The valve member 104 is shown in a closed position, while Figure 7 The valve member 104 is shown in an open position.

[0070] In the illustrated example, the valve member 104 is configured as a collar or sleeve extending around the exterior of the separator body 22. As shown, the valve member 104 covers the hole 102 in the closed position and can be moved downward (in the direction shown in the figure) a distance sufficient to expose the hole 102 so that air can flow through the hole. The valve member 104 can be biased to the closed position, such as by a suitably configured bias spring (not shown).

[0071] like Figure 8As shown, the aperture 102 may be configured to impart a rotational trajectory or swirl to the air flow entering the separator body 22. To this end, the aperture 102 may be defined by a series of vanes or grids 106 extending through the wall of the separator body 22, thereby defining apertures 104 in the spaces between the vanes 106. The vanes 106 extend in a direction that is angled relative to the radial direction of the central axis X. Here, the vanes 106 are shown as being at an angle of approximately 45 degrees, although it should be understood that this is merely exemplary.

[0072] The movements of the valve member 104 may be manually controlled by a user of the vacuum cleaner 2. Alternatively, they may be controlled by a suitable control system. The following discussion will focus on manual control of the valve member 104.

[0073] Having described the features of the docking station 60 and the vacuum cleaner 2, the discussion will now focus on how to operate the vacuum cleaner 2 to perform a self-cleaning operation, focusing on Fig. 9 and 10 .

[0074] exist Fig. 9 , the vacuum cleaner 2 is shown docked on the interface 74 of the docking station 60. The vacuum cleaner 2 is in operation, i.e. the vacuum cleaner has been switched on by the operator / user, causing the suction generator 11 to draw air along the inlet duct 30 of the vacuum cleaner 2, which draws air from the intermediate chamber 84 and from the internal volume 85 of the docking station 60, which draws air out of the dirt storage chamber 82. It can be seen that the air flows from the internal volume 85 through the apertures 90 in the intermediate chamber 84, which impart a swirling motion to the air flow as it circulates around the intermediate chamber 84 and enters the inlet duct 30 of the vacuum cleaner 2.

[0075] When sufficient negative pressure is generated within the docking station 60, the dust box door 26 of the vacuum cleaner opens. This can be achieved by the user activating the box opening mechanism 92. It is currently contemplated that the box emptying operation can be completed with the dust box door 26 open while the air in the docking station is being evacuated. However, it is believed that the best results will be achieved with the box door 26 closed until sufficient vacuum is generated in the docking station 60.

[0076] The vacuum level that is considered effective will depend on the power of the suction generator 11 and the volume or air within the docking station 60. However, it is envisaged that a sufficient vacuum level will be achieved between 0.5 and 2 seconds. For example, this can be achieved by the vacuum generator drawing approximately 20 liters per second to reduce the ambient pressure within the docking station from approximately 100 kPa to approximately 75 kPa. This represents a pressure drop of between 20 kPa and 30 kPa, more preferably a pressure drop of between 23 kPa and 28 kPa. While these pressure drop values ​​are believed to provide good results, it is still possible to achieve good function with a slightly lower pressure drop.

[0077] exist Fig.10 , the door 26 of the vacuum cleaner 2 has been opened. The interior of the dust box 38 is therefore exposed to the vacuum existing in the docking station 60, and more specifically the vacuum existing in the intermediate chamber 84. Furthermore, in this example, it will be noted that the vacuum generator 11 has been closed by the user / operator. At this point, the air valve arrangement 100 is open, as can be seen by the valve member 104 being shown in a lower or open position. This means that ambient air is forcefully drawn into the dust box 38 through the aperture 102, thereby causing a pulse of air to flow into the dust box 38 to expel the contents of the dust box 38 into the docking station 60, as shown. Fig.10 shown.

[0078] The airflow from the dust box 38 into the docking station 60 flows through the intermediate chamber 84 and opens the valve 89 into the dirt storage chamber 82. Thus, dirt and debris discharged from the dust box 38 of the vacuum cleaner 2 is captured by the dirt storage chamber 82. Although the valve 89 is optional, its presence in this example of the invention ensures that the dirt and debris are captured within the dirt storage chamber 82 and do not return toward the vacuum cleaner 2.

[0079] At this point, it should be noted that the open area or hole 102 should be configured to provide a high velocity airflow into the dust box 38. When configuring the open area of ​​the hole 102, the negative pressure present in the docking station should also be considered. It is believed that 3500mm 2 Up to 4500mm 2 The open area between the 2In order to ensure that the high velocity airflow maintains its flow rate through the dust box, one consideration is to ensure that the opening area of ​​the aperture 102 is not significantly larger than the minimum cross-sectional area of ​​the interior volume of the dust box 38 when taken in a plane perpendicular to the axis X of the separator body 22. If the cross-sectional area of ​​the dust box 28 is larger than the opening area of ​​the aperture 102 by more than a predetermined amount, this will cause the air flow to slow down as it passes through the dust box 38, which will reduce the efficiency of the air flow in expelling dirt and debris from the dust box 38. Therefore, preferably, the opening area of ​​the aperture 102 is configured to be no less than 0.5 times the cross-sectional area of ​​the dust box.

[0080] Due to the high pressure differential between the dust box 38 and the interior of the docking station, and the sufficiently large venting area of ​​the holes 102 arranged by the air valve, the air pulse entering the docking station has a very high flow rate, but only lasts for a short time. For example, it is believed that the above parameters can achieve about 200L / s with a pulse duration of less than 0.1s. This results in a peak flow rate of more than 200m / s. If the flow area of ​​the hole 102 is smaller than the cross-sectional area of ​​the dust box 38, this has the effect of reducing the flow rate through the dust box 38. However, even if the cross-sectional area of ​​the dust box is about twice the flow area of ​​the hole 102, a flow rate of more than 100m / s can still be achieved.

[0081] It should be noted that Fig. 9 and 10 Only a single "pulse" of air is shown, which is created by first operating the suction generator 11 to establish a negative pressure within the dust box 38 (eg, Fig. 9 ), then close the suction generator 11 and open the door 26 and the air valve arrangement 100 (as shown in FIG. Fig.10 100) to produce a high-speed airflow through the dust box 38. However, in order to provide a more efficient and complete box emptying operation, the operation can be performed more than once. It should be understood that the operation of the air valve arrangement 100 can be repeated when the box door 26 is in the open position; the box door 26 does not need to be closed between the actuations of the air valve arrangement 100. In addition, although it is envisioned that the vacuum generator 11 should be cycled open when the air valve arrangement 100 is closed, and cycled closed when the air valve arrangement 100 is open, it is believed that this is not important for acceptable performance of box emptying. Therefore, while the vacuum generator 11 is running, acceptable functionality can be achieved by opening and closing the air valve arrangement 100. Therefore, it should also be understood that during the self-cleaning operating mode, the vacuum cleaner can operate while the air valve arrangement 100 changes state. The airflow through the machine can flow in the opposite direction, but it can also flow in the first airflow direction.

[0082] In the above example, the suction generator 11 and the air valve arrangement 100 are envisioned to be manually controlled by the user in order to achieve the box emptying operation. However, the vacuum cleaner can be configured to automatically perform the self-cleaning operation under the control of the control system. For example, a suitable user-operable button or trigger can be provided on the vacuum cleaner 2, which the user can press to drive the self-cleaning operation. Accordingly, the control system of the vacuum cleaner 2 can be configured to electronically control the operation of the box door 26, the air valve arrangement 100 and the suction generator 11 in an appropriate sequence to generate the required one or more high-speed air pulses through the dust box 38.

[0083] In another example, it is contemplated that the valve arrangement 100 may be responsive to the pressure within the dust box 38. For example, once negative pressure is established in the dust box 39 and the door 26 has been opened, the valve arrangement 100 may be configured to open when exposed to the pressure differential between the ambient pressure outside the vacuum cleaner and the negative pressure inside the dust box 38. Such a pneumatically driven system would improve the energy efficiency of the system as it would not require any electrical energy to drive.

[0084] In the above example, the air valve arrangement 100 is embodied as a valve member 104 in the shape of a sleeve or collar that surrounds the separator body 22 to selectively open and close the aperture 102. However, it should be understood that this particular configuration is merely an example and that the air valve arrangement may be implemented in a different manner. Essentially, the function of the air valve arrangement 100 is to allow a controlled flow of air into the dust box 38 to flush away debris. Therefore, any configuration that allows this function is acceptable. For example, it is conceivable to allow reverse airflow through the cyclone separator system to flow out of the cylindrical shroud 45 (see FIG. 4 ). Figure 2 ) into the dust box 38. The benefit of this is that the reverse airflow will help remove caked dust that may partially block the holes in the shroud 45. It should therefore be understood that the airflow through the dust box 38, whether flowing directly into the dust box 38 through the holes 90 or flowing into the dust box through the cyclone separator and the shroud 45 (which is a surface filter), can be considered to perform a cleaning action on at least one separation system of the vacuum cleaner 2. The reverse airflow through the machine can also be configured to flow through one or more fiber filters of the vacuum cleaner 2, such as a HEPA filter or a depth filter of the vacuum cleaner.

[0085] Fig.11 Another example of a vacuum cleaning system 62 according to the present invention is shown, which includes an alternative configuration of a docking station 60 and a vacuum cleaner 110. Fig.11 In this embodiment, the docking station 60 is substantially the same as described in the above examples, so for the sake of brevity, only the differences are described here.

[0086] Turning to the vacuum cleaner 110, it should be understood that the vacuum cleaner is a cyclonic or "bagless" vacuum cleaner, as has been described in the previous examples. Thus, the vacuum cleaner 110 of this example has a body 112, which includes a suction generator 114 and a handle 116. The handle depends downwardly from the body 112. A cyclonic separator 118 is removably attached to the body 112. The cyclonic separator 118 has an inlet duct 120, which extends so that dirt and debris are sucked into the vacuum cleaner 110 through the inlet duct 120. The cyclonic separator 118 is oriented along an axis Y, around which a circulating airflow is established during operation, as is well known in the art. It is noteworthy that the separator axis Y is transverse to the axis Z defined by the elongated inlet duct 118, and is vertical in this example. This is in contrast to the vacuum cleaner 2 described in the above example, in which the axis of the inlet duct is aligned with the axis of the cyclonic separator.

[0087] Those skilled in the art will understand that Fig.11 The vacuum cleaner 110 shown in FIG. 1 is of the same general construction as vacuum cleaners commercially available from Dyson Technology Ltd, for example as "DC16", "DC30", "V6" and "V8".

[0088] The docking station 60 has an interface 122 that is configured to dock with the vacuum cleaner 110. The interface 122 in this example performs the same function as the interface 74 in the previous example of the invention, but is configured to adapt the docking station 60 to a vacuum cleaner 110 of a different configuration.

[0089] As shown, the interface 122 includes a socket 124 sized to receive the lower end of the cyclonic separator 118 and allow its bin door 126 to open into the docking station 60. Because the inlet duct 120 is oriented transverse to the axis Y of the cyclonic separator 118, the interface 122 also includes an inlet duct connector 128. The inlet duct connector 128 extends from the top of the interface 122 and is coupled to the front end of the inlet duct 120 of the vacuum cleaner 110. In this way, when the suction generator 114 is working, air is sucked from the docking station 60 through the interface 122 and the inlet duct connector 128, and enters the cyclonic separator 118 through the inlet duct 120. This enables the bin emptying operation to be performed in the same manner as described above.

[0090] In the above examples, the suction generator as part of the vacuum cleaner achieves an advantage in that only one electric motor is required to drive the vacuum cleaner and drive the bin emptying operation. However, it is conceivable that in other examples, a separate suction generator may be positioned in the docking station to drive the bin emptying operation. A separate suction generator is also possible in addition to the suction generator in the vacuum cleaner itself. Thus, in such an example, the suction generator in the docking station may operate in the same manner as the suction generator in the above examples, while the valve arrangement in the vacuum cleaner operates to generate a pulsed airflow through the vacuum cleaner, thereby assisting in emptying the bin.

[0091] As described above, in some examples, the air valve arrangement 100 is configured to allow a controlled air flow into the dust box 38 to flush out debris. Therefore, any configuration that allows this function is acceptable. For example, it is contemplated to allow reverse air flow through the cyclone separator system to flow out of the cylindrical shield 45 (see Figure 2 ) into the dust box 38. The benefit of doing so is that the reverse airflow will help to remove caked dust that may partially block the holes in the shroud 45. It should be understood, therefore, that the airflow through the dust box 38, whether flowing directly into the dust box 38 through the holes 90 or flowing into the dust box through the cyclone separator and the shroud 45 (which is a surface filter), can be considered to perform a cleaning action on at least one separation system of the vacuum cleaner 2. The reverse airflow through the machine can also be configured to flow through one or more fiber or membrane filters of the vacuum cleaner 2, such as a HEPA filter of the vacuum cleaner. In addition, it is envisioned that the reverse airflow can be used to flow through the pre-motor filter or post-motor filter of the vacuum cleaner so as to provide a cleaning mechanism to fully or partially regenerate the filter, which will reduce the need for the user to regularly clean such filters.

[0092] Now refer to Figures 12 to 15 Another example describing this principle.

[0093] First reference Fig.12 , shows in schematic form the hand-held vacuum cleaner 2 already discussed in the previous example, and also shows more details of the contents of the motor housing 15. As can be seen from the illustration, the vacuum cleaner 2 comprises a vacuum motor 12 and an impeller 13 constituting a vacuum generator 11. During the "normal" or surface cleaning mode of operation, a pre-motor filter 19 is positioned before the vacuum motor 12 in the direction of airflow. In this mode, the direction of airflow is Fig.128, and from there to the vacuum motor 12 through the pre-motor filter 19, which can be considered the primary separation system of this example. As is well known, the function of the pre-motor filter 19 is to filter fine contaminants from the air flow that may not have been removed from the air by the cyclonic separation unit 8 or other primary separation system. Therefore, the pre-motor filter 19 provides a degree of protection for the vacuum motor 12 to protect it from fine contaminants as well as moisture.

[0094] The pre-motor filter 19 is in the form of a membrane filter. The membrane filter is a thin sheet of material, such as expanded polytetrafluoroethylene (ePTFE). The membrane filter can be supported on a suitable structure, such as a frame, to define any suitable shape. For example, Fig.12 Schematically, it can be arranged as a flat sheet, or bent into a cylindrical or barrel shape, or folded into a variety of other forms. It should be noted that expanded polytetrafluoroethylene is suitable for use as a membrane filter because it is a durable material and has a porosity that can be selected within a range of values.

[0095] At present, expanded polytetrafluoroethylene membrane filter media are considered useful because such media provide good chemical resistance, low pressure drop and high filtration efficiency, which makes them particularly suitable for harsh use in vacuum cleaners while achieving low emissions in line with HEPA standards. This is mainly achieved by fibrillating a continuous PTFE membrane into a very fine nanofiber network, which enters a no-slip flow state. This eliminates the boundary layer around the fiber, greatly reduces resistance, and thus reduces pressure drop. The fine characteristics of the fiber (especially less than 50nm, less than 100nm) and the close spacing also make particles of various sizes have a high capture efficiency and form a clean filter cake on the filter surface. Although ePTFE is used as an example here, similar results can be obtained with other polymers such as PU (polyurethane), PP (polypropylene), polyamide or PVDF (polyvinylidene fluoride). In addition, nanofibers produced by a series of manufacturing techniques can be used, including but not limited to electrospinning, forced spinning and ePTFE known nanofibrillation methods. Typically these filters are designed to provide efficiencies in the 99.99% @ 0.1 or 0.3 um range, however existing membranes can be as low as 75% or even 50% at this particle size. Fibril diameter can be determined by known techniques such as transmission electron microscopy (TEM) understood by those skilled in the art.

[0096] The pre-motor filter 19 is contained within a filter chamber 150 defined by a filter housing 151. The filter housing 151 may be the motor housing 15, or may be a separate component and removable therefrom.

[0097] from Fig.12 As will be appreciated in the drawings, the pre-motor filter 19 is configured to have an annular shape that divides the filter chamber 150 into a first (outer) chamber portion 152 and a second (inner) chamber portion 154. The outer chamber portion 152 and the inner chamber portion 154 are separated by the pre-motor filter 19, which is supported within the chamber 150 by a suitable filter support 156. The precise structure of the filter support 156 is not critical, but its function is to support the pre-motor filter 19 within the motor housing 15 in a secure manner so that the pre-motor filter 19 can effectively perform its filtering function. The outer chamber portion 152 receives incoming air from the cyclonic separation unit 8, which then enters the outer filter chamber portion 152 through the inlet 158 ​​and then passes through the pre-motor filter 19 to the vacuum motor 12.

[0098] An air valve arrangement 200 is also provided to control airflow through the filter chamber 150, thereby controlling airflow to the pre-motor filter 19. As shown, the air valve arrangement 200 includes at least one first valve element 160 that controls airflow through the outer chamber portion 152 and at least one second valve element 162 that controls airflow through the inner chamber portion 154. The functions of the first and second valve elements 162 will become apparent in the following discussion. At this point, it should be noted that the presence of the second valve element 162 is not required, but is provided as a potential enhancement to the overall functionality of the air valve arrangement 200.

[0099] Fig.12 The air valve arrangement 200 in the embodiment has the same function as the air valve arrangement 100 discussed in the previous example. That is, when the vacuum cleaner 2 is in the self-cleaning operating mode, the air valve arrangement 200 is operable to enable a high velocity airflow to pass through the vacuum cleaner 2 in a direction opposite to the direction of airflow through the machine in the surface cleaning operating mode. In particular, the air valve arrangement 200 allows the high velocity airflow to flow through the pre-motor filter 19 in the opposite direction, so that the pre-motor filter 19 is cleaned, thereby significantly restoring the pressure drop, which is beneficial to the filtering efficiency. This means that the pre-motor filter 19 will require much less cleaning than would normally be the case, and potentially, the need for filter cleaning will be avoided altogether.

[0100] At this point, it should be understood that during the self-cleaning mode of operation, the air flow through the membrane filter in the reverse direction may be combined with the air flow in the first air flow direction, which is the air flow direction in the floor cleaning mode of operation. This may occur due to repeated cycling of the air valve arrangement while the vacuum motor continues to operate.

[0101] Fig.13A first example of such functionality is shown, where the air valve arrangement 200 is operated to allow air to flow in the reverse direction through the pre-motor filter 19. In this figure, at least one first valve element 160 is in a closed state, thereby preventing air flow directly into the outer chamber portion 152, while at least one second valve element 162 is in an open state, thereby allowing air to flow in the reverse direction into the inner chamber portion 154 and into the outer chamber portion 152 through the pre-motor filter 19. From the outer chamber portion 152, the air flows through the inlet 158 ​​and reaches the cyclonic separation unit 8.

[0102] At this point it should be noted that the open and closed operating states of at least one first and second valve element 160, 162 are schematically shown, and thus the valve elements may be operated in any suitable manner. For example, they may be electromagnetically operated or pneumatically operated. In addition, they may be operated by a pressure differential across the respective valve elements.

[0103] from Fig.13 As can be seen in the figure, the pre-motor filter 19 has a layer of dirt on its dirty side. Since the pre-motor filter 19 is a membrane filter, in this example, the dirt is captured on its surface forming a layer or "cake". This surface clumping is in contrast to thicker filter elements such as depth filters, where dirt particles tend to accumulate in the interstices of the filter fibers, which is often referred to as "depth loading".

[0104] like Fig.13 As shown, the reverse flow of air through the pre-motor filter 19 effectively removes such surface filter cake because the airflow blows the filter cake off the surface of the pre-motor filter 19, whereupon the filter cake can be removed to a suitable location in the vacuum cleaner. For example, the surface filter cake can be discharged into the dust box of the vacuum cleaner and from there moved to the docking station (if the docking station is connected).

[0105] Fig.14 Shows the Fig.13 A modification of the example shown, in which the reverse airflow is directed through the inner chamber portion 154 and the pre-motor filter 19 by at least one second valve element 162 being in an open state, while at least one first valve element 160 is in a closed state. Fig.14 In the example of FIG. 1 , it will be noted that both the at least one first valve element 160 and the at least one second valve element 162 are in an open state. This means that high-speed air flow is allowed to enter the inner chamber portion 154 and pass through the pre-motor filter 19, thereby having the effect of back-flushing the pre-motor filter 19, but the high-speed air flow is also allowed to enter the outer chamber portion 152 directly.

[0106] from Fig.14As can be appreciated, the air flow entering the outer chamber portion 152 flows in a direction substantially parallel to the outer surface of the pre-motor filter 19. Thus, the air flows across the surface of the pre-motor filter 19, which has the effect of clearing accumulated filter cake from the pre-motor filter 19. Thus, the air flow through the pre-motor filter 19 from the at least one second valve element 162 and the air flow through the pre-motor filter 19 from the at least one first valve element 160 act together to enhance the cleaning effect of the reverse airflow during the self-cleaning mode of operation.

[0107] Note that in the orientation of the drawing, the airflow is shown as being downward through the outer chamber portion 152. Although there may be some turbulence in the airflow, it should be understood that the high-speed airflow through the outer chamber portion 152 will flow substantially in the direction shown from the at least one first valve element 160 of the outer chamber portion 154 to the inlet 158, which are axially aligned in the example shown.

[0108] exist Fig.15 A further enhancement is shown in the example. Fig.15 The structure shown is similar to the above reference Figures 12 to 14 Examples of descriptions, so for the sake of brevity only the differences are described.

[0109] exist Fig.15 In the example of FIG. 1 , the pre-motor filter 19 is movably mounted within the filter housing 151, such movement assisting in removing dust from the pre-motor filter 19. As shown, the pre-motor filter 19 is resiliently mounted to the filter support 156, which function is illustrated here by one or more compression springs 170, although other resilient mounting devices may also be suitable.

[0110] Fig.15 15. The pre-motor filter 19 is shown in a second (lower) position in which the pre-motor filter has been moved away from the filter support 156. Although not shown, it should be noted that the pre-motor filter 19 can be moved from a first position to a second position in which the pre-motor filter 19 is in a relatively higher position compared to the second position so that the end of the pre-motor filter 19 abuts the filter support 156.

[0111] It should be noted at this point that the resilient mounting of the pre-motor filter 19 provided by the filter support 156 may be provided by an annular spring integrated into the air-tight membrane to ensure that air does not bypass the pre-motor filter 19 .

[0112] A suitable trigger mechanism may be provided to enable the pre-motor filter 19 to move from the first position to the second position. The trigger mechanism may be activated by the high velocity airflow starting to rush through the motor housing 15, the air valve arrangement 200 and the pre-motor filter 19. Additionally or alternatively, another trigger mechanism may be provided to unlock the pre-motor filter 19 from the first position.

[0113] Although it is obvious, Fig.15 The air valve arrangement 200 shown in FIG. 1 is configured such that at least one first valve element 160 is in a closed state and at least one second valve element 12 is in an open state, but it should be understood that both valve elements 160 and 162 can be in an open state, thereby enabling the airflow to "reverse" through the pre-motor filter 19 and to "wash" the surface of the pre-motor filter, as described above with reference to FIG. Fig.14 described.

[0114] As can be understood from the above discussion, when the reverse flow of high-speed air flows through the pre-motor filter 19, the sudden movement of the pre-motor filter 19 can help remove the caked dirt accumulated on its surface. In order to enhance this effect, a device can be provided to transmit an impact force to the pre-motor filter 19 when the pre-motor filter 19 moves from the first position to the second position.

[0115] This effect can be achieved by a suitable impactor 172, which is Fig.15 1 and 12. The motor filter 19 is shown in the form of a raised stop 174 axially positioned below the pre-motor filter 19. The raised stop 174 is shown schematically, so it should be understood that it can take any suitable structural form to provide the desired function. For example, the raised stop 174 can be a fixed structure protruding from the filter housing 151, and its size and position are such that after the pre-motor filter 19 has begun to move from the first position to the second position, the pre-motor filter 19 hits the raised stop 174 after a predetermined travel distance, thereby causing a sharp deceleration of the pre-motor filter 19 to promote the removal of any filter cake layer from the filter surface.

[0116] In other examples, it is contemplated that the impactor 172 may be configured so that a mechanical impulse may be delivered to the pre-motor filter 19 without moving from its first position. For example, the filter housing 151 may be equipped with a motorized scintillator or similar mechanism to impact the pre-motor filter 19.

[0117] Various modifications to the illustrated examples have been described. It will also be appreciated by those skilled in the art that other modifications may be made to the illustrated examples without departing from the invention as defined in the claims.

[0118] For example, in the above Figures 12 to 15In the depicted example, the vacuum cleaner 2 includes a pre-motor filter 19 in the form of a membrane filter to filter contaminants remaining in the airflow from the primary separation system 8. However, in other examples, it is envisaged that such a membrane filter may also be positioned as a post-motor filter. "Post-motor" refers to a filter that is located downstream of the airflow motor 12 in the direction of airflow when the vacuum cleaner 2 is in a surface cleaning operating mode. Further, it is envisaged that one or more membrane filters may be located downstream and upstream of the airflow motor 12. Thus, such a system would be considered to have at least one pre-motor filter and at least one post-motor filter.

[0119] It should also be noted that although Figures 12 to 15 In the example of FIG. 5 , the vacuum cleaner 2 is envisaged to be used with the docking station 60 described in the previous example, but it is also envisaged that Figures 12 to 15 The vacuum cleaner 2 in the embodiment may be used in a self-cleaning mode without using the docking station 60 .

[0120] Furthermore, although in the above examples the primary separation system is described as comprising a cyclonic separation unit 8, it should be noted that the primary separation system may comprise a different separation device, such as a bagging system or a non-cyclonic separator. Further, as an option there may be only a single separation system, rather than the primary and secondary separation systems of the illustrated embodiment. For example, the separation system may comprise a dirt collection chamber having a filter disposed therein, the filter being a membrane filter for separating dirt and debris from the airflow through the machine.

Claims

1. A vacuum cleaning system comprising a vacuum cleaner having a vacuum motor, a dust box, a primary separation system, a membrane filter and an air valve arrangement, the air valve arrangement being configured to control airflow through at least the membrane filter; wherein the vacuum cleaner is configured to be operable in a surface cleaning mode of operation and a self-cleaning mode of operation; wherein in the surface cleaning operating mode, the vacuum cleaner is configured such that the vacuum motor draws dirty air from a dirty air inlet in a first airflow direction through the dust box, the primary separation system and the membrane filter, and Wherein in the self-cleaning operating mode, the vacuum cleaner is configured to allow air to flow from the air valve arrangement through the membrane filter in a second air flow direction to clean dirt from the membrane filter.

2. The vacuum cleaning system of claim 2, wherein the air valve arrangement is further configured to flow air across the surface of the membrane filter during the self-cleaning mode.

3. The vacuum cleaning system according to any one of the preceding claims, wherein the membrane filter is selected from the group consisting of: ePTFE membrane, PP membrane, PU membrane, polyamide membrane and PVDF membrane.

4. The vacuum cleaning system of claim 3, wherein the filter element has a filtration efficiency of at least 50% at a particle size of 0.3 microns.

5. The vacuum cleaning system of claim 3 or 4, wherein the filter element has an average fibril diameter of less than 100 nm.

6. The vacuum cleaning system of any one of claims 1 to 5, wherein the membrane filter is movably mounted within the vacuum cleaner, wherein the movement facilitates removal of dirt from the membrane filter.

7. The vacuum cleaning system of claim 6, wherein the membrane filter is movable from a first position to a second position when the vacuum cleaner enters the self-cleaning mode of operation to assist in removing dirt from the membrane filter. 8 . The vacuum cleaning system of claim 7 , wherein during movement from the first position to the second position, the membrane filter contacts an impactor configured to provide a mechanical impact pulse to the membrane filter.

9. The vacuum cleaning system of any one of claims 6 to 8, wherein movement of the membrane filter from the first position to the second position is caused by operation of the air valve arrangement.

10. The vacuum cleaning system according to any one of claims 6 to 8, wherein movement of the membrane filter from the first position to the second position is caused by opening of a dust box door.

11. The vacuum cleaning system of any one of the preceding claims, wherein the membrane filter is at least a pre-motor filter such that the membrane filter is located upstream of the vacuum motor when considered in the direction of air flow in the surface cleaning operating mode.

12. The vacuum cleaning system of any one of the preceding claims, wherein the membrane filter is at least a post-motor filter such that the membrane filter is located downstream of the vacuum motor when considered in the second air flow direction in the surface cleaning operating mode.

13. The vacuum cleaning system according to any one of the preceding claims, further comprising a docking station, wherein the docking station comprises a dirt storage chamber and an interface, the interface being configured to cooperate with a dust box of the vacuum cleaner so that dirt discharged from the dust box through the box opening is discharged into the dirt storage chamber of the docking station, wherein the vacuum cleaner is configured to exhaust air from the dirt storage chamber when docked with the docking station, wherein in the self-cleaning mode, the vacuum cleaning system is configured to: operating the vacuum motor to create a partial vacuum in the dirt storage chamber, and Once the negative pressure level is generated, the air valve arrangement is operated to cause a pulse of air to flow from the air valve arrangement through the membrane filter in a second air flow direction.

14. A vacuum cleaning system according to claim 13, wherein once a negative pressure level has been generated, the air valve arrangement is operated to cause a pulse of air to flow into the dust bin of the vacuum cleaner, thereby expelling dirt from the dust bin through the dust bin opening and into the dirt storage chamber.

15. A vacuum cleaning system according to claim 13 or 14, wherein the vacuum cleaner is configured so that pulses of air admitted into the dust box during the self-cleaning mode first flow through the membrane filter.

16. The vacuum cleaning system of claim 15, wherein the primary separation system comprises at least one of a surface filter, a depth filter, and a cyclone separator.

17. The system of any one of the preceding claims, wherein the air valve arrangement has a total area configured to be no less than 0.5 times the cross-sectional area of ​​the dust box.

18. A system according to any preceding claim, wherein the air valve arrangement is configured to be operated by a pressure differential between the dust box and the surrounding environment.

19. A system according to any preceding claim, wherein the air valve arrangement is configured to operate repeatedly during continued operation of the suction generator, thereby allowing a plurality of consecutive air pulses to flow through the dust box.

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