VACUUM CLEANING SYSTEM

Abstract

A vacuum cleaning system comprises a vacuum cleaner and a docking station. The docking station comprises a dirt storage chamber and an interface configured to mate with a dirt bin of the vacuum cleaner such that dirt expelled from the dirt bin through a bin opening is ejected into the dirt storage chamber of the docking station. A vacuum generator evacuates air from the dirt storage chamber when the vacuum cleaner is docked. In a dirt bin emptying mode, the system operates the vacuum generator to generate a partial vacuum in the dirt storage chamber and, opens a dirt bin door once a sufficient negative pressure level has been generated, and operates an air valve arrangement to admit a pulse of air into the dirt bin to eject dirt from the dirt bin through the bin opening and into the dirt storage chamber.

Claims

1. A vacuum cleaning system comprising a vacuum cleaner and a docking station, wherein the docking station comprises a dirt storage chamber and an interface configured to mate with a dirt bin of the vacuum cleaner such that dirt expelled from the dirt bin through a bin opening is ejected into the dirt storage chamber of the docking station, wherein the vacuum cleaning system further comprises a suction generator configured to evacuate air from the dirt storage chamber when the vacuum cleaner is docked with the docking station, wherein the system is configured to operate in a dirt bin emptying mode comprising: operating the suction generator to generate a partial vacuum in the dirt storage chamber, once a negative pressure level has been generated, opening a dirt bin door of the vacuum cleaner and operating an air valve arrangement to admit a pulse of air into the dirt bin of the vacuum cleaner thereby to eject dirt from the dirt bin through the bin opening and into the dirt storage chamber.

2. The system of claim 1, wherein the air valve arrangement is configured to generating a swirling air flow through the dirt bin.

3. The system of claim 1, wherein the vacuum cleaner is configured such that a flow of the admitted pulse of air passes through or over at least one separating system of the vacuum cleaner during the dirt bin emptying mode to clean dirt from that respective separating system.

4. The system of claim 3, wherein the one or more separating system includes at least one of a surface filter and a depth filter.

5. The system of claim 4, wherein the surface filter comprises a shroud filter located in the dirt bin.

6. The system of claim 1, wherein the air valve arrangement is located in at least a portion of a dirt bin wall distal from the dirt bin opening.

7. The system of claim 1, wherein the air valve arrangement has a total area that is configured to be not more than the minimum cross sectional area of the dirt bin.

8. The system of claim 1, wherein the air valve arrangement is configured to be operated by differential pressure between the dirt bin and ambient environment.

9. The system of claim 1, wherein the air valve arrangement is configured to be operated repeatedly during sustained operation of the suction generator, thereby permitting a plurality of sequential air pulses to flow through the dirt bin.

10. The system of claim 1, further including an intermediate chamber upstream of the dirt storage chamber.

11. The system of claim 10, wherein the intermediate chamber and the dirt storage chamber are separated by a one way valve to allow dirt to pass into the dirt storage chamber from the intermediate chamber.

12. The system of claim 10, wherein the intermediate chamber includes one or more air flow apertures to allow air to flow into it during the dirt bin emptying mode.

13. The system of claim 12, wherein the one or more air flow apertures are configured to generate a swirling air flow around the intermediate chamber.

14. The system of claim 1, wherein the dirt storage chamber comprises a porous dirt bag.

15. The system of claim 1, wherein the suction generator creates a negative pressure level in the dirt storage chamber by drawing air from the dirt storage chamber through the vacuum cleaner.

16. The system of claim 1, wherein the vacuum cleaner includes an inlet nozzle that is at least in part surrounded by the bin door.

17. The system of claim 1, wherein the docking station includes two or more interfaces, each of which is configured to mate a different type of vacuum cleaner to the docking station.

18. The system of claim 1, wherein the suction generator forms part of the vacuum cleaner.

19. A method of operating a vacuum cleaner system, the system comprising a vacuum cleaner and a docking station, wherein the docking station defines an interface configured to mate with a dirt bin of the vacuum cleaner such that dirt expelled from the dirt bin through a bin door is ejected into a dirt storage chamber of the docking station, wherein the system further comprises a suction generator configured to evacuate air from the dirt storage chamber, wherein the method comprises: generating a partial vacuum in the dirt storage chamber; opening a bin door of the dirt bin of the vacuum cleaner; and admitting a pulse of air into the dirt bin of the vacuum cleaner such that dirt stored in the dirt bin is ejected into the dirt storage chamber of the docking station.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a side view of a handheld vacuum cleaner;

[0022] FIG. 2 is another side view of the handheld vacuum cleaner of FIG. 1 showing internal detail;

[0023] FIG. 3 is a view demonstrating how a dirt bin of the handheld vacuum cleaner of FIGS. 1 and 2 is emptied in a known manner;

[0024] FIGS. 4 and 5 are side views of a vacuum cleaner system including a handheld vacuum cleaner and a docking station, wherein in FIG. 4 the handheld vacuum cleaner is in an undocked position and wherein in FIG. 5 the handheld vacuum cleaner is in a docked position;

[0025] FIGS. 6, 7 and 8 are schematic views of a valve arrangement of the handheld vacuum cleaner in FIGS. 4 and 5 illustrating its principle of operation;

[0026] FIGS. 9 and 10 show two phases of a bin emptying mode when the handheld vacuum cleaner is docked onto the docking station, wherein FIG. 9 shows a phase of operation where the handheld vacuum cleaner operates to evacuate air rom the docking station, and wherein FIG. 10 shows the handheld vacuum cleaner ejecting dirt into the docking station from the dirt bin of the vacuum cleaner;

[0027] FIG. 11 is a schematic view of an alternative example of a vacuum cleaner system including an alternative configuration of handheld vacuum cleaner docked onto a docking station.

DETAILED DESCRIPTION

[0028] Examples of the invention relate to a vacuum cleaning system including a vacuum cleaner which can be mated, engaged with, fitted to, or docked, to a corresponding docking station. Typically such docking stations are used as a power source to recharge a vacuum cleaner if that vacuum cleaner is battery powered. However, the docking station and vacuum cleaner of the examples of the invention are configured to facilitate the removal and storage or dirt and debris that is emptied from the vacuum cleaner into the docking station. The vacuum cleaner may be battery powered, which is beneficial due to the portability advantages it provides, but this is not essential.

[0029] Advantageously the vacuum cleaning system of the examples of the invention provides a vacuum-assisted bin emptying function without the need for an additional vacuum generator in the docking station. This makes the overall system less costly and more energy efficient.

[0030] FIGS. 1 to 3 show various views of a battery-powered or cordless handheld vacuum cleaner 2 which may be used in the system of the invention, thereby providing the reader with useful context.

[0031] Referring firstly to FIGS. 1 and 2, a handheld vacuum cleaner 2 comprises a main body 4 having an elongate handle 6, a cyclonic separating unit 8 having a longitudinal axis X and a cleaning tool 10, in the form of a nozzle, which is secured to the cyclonic separating unit 8. The cleaning tool 10 is detachable from the handheld vacuum cleaner which means it can be used for different cleaning tasks. In FIG. 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 pipe or wand which has a floor tool attached to its end distal from the vacuum cleaner 2. The cleaning tool 10 in this configuration therefore allows the vacuum cleaner to be used as a stick vac. The specific form of cleaning tool 10 which is used with the vacuum cleaner 2 is not important to the inventive concept but is shown in these Figures for context and completeness.

[0032] The cyclonic separating unit 8 extends away from the handle 6 such that the cleaning tool 10 is at the end of the cyclonic separating unit 8 which is furthest from the handle 6. The cleaning tool 10 extends away from the cyclonic separating unit 8 along the longitudinal axis X of the cyclonic separating unit 8.

[0033] The main body 4 further comprises a suction generator 11 comprising a motor 12 and impeller 13 which are located above and towards the rear of the handle 6, and a battery 14 located directly 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 1 with respect to the longitudinal axis X of the cyclonic separating unit 8 such that the handle 6 is in a pistol grip configuration. In the embodiment shown, a handle axis H is arranged at 110 degrees with respect to the longitudinal axis X of the cyclonic separating unit 8. The angle is the included angle between the longitudinal axis X extending forward of the handle 6 and the portion of the handle axis H extending through the handle 6.

[0034] The cyclonic separating unit 8 comprises a primary cyclonic separator 18 and a plurality of secondary cyclonic separators 20 positioned downstream of the primary cyclonic separator 18. The primary cyclonic separator 18 is adjacent a first end of the cyclonic separating unit 8 and the secondary cyclonic separators 20 are adjacent a second end of the cyclonic separating unit 8 which is opposite the first end. The secondary cyclonic separators 20 are arranged in a circular array which extend about the longitudinal axis X of the cyclonic separating unit 8.

[0035] The primary cyclonic separator 18 comprises a separator body 22 in the form of a bin having a cylindrical outer wall 24 and an end wall 26. The cylindrical outer wall 24 defines a cyclonic separation chamber 28. In the embodiment shown, it is the axis of the cyclonic separation chamber 28 which defines the longitudinal axis X of the cyclonic separating unit 8. A central duct 30 extends from the end wall 26 to an inlet 32 of the cyclonic separation chamber 28.

[0036] The cleaning tool 10 comprises a connector portion 33 and a nozzle portion 34 which define a duct 36 along the cleaning tool 10. The connector portion 33 has an outer diameter which is smaller than the inner diameter of the portion of the central duct 30 adjacent the end wall 26 such that the connector portion 33 can be inserted into the central duct 30 (as illustrated) thereby ensuring a rigid connection between the cleaning tool 10 and the cyclonic separating unit 8. This configuration is not essential, however, and the connector portion 33 may be configured in other ways to mate the cleaning tool 10 to the vacuum cleaner.

[0037] The cleaning tool 10 is provided with retaining features (not shown) which engage with the central duct 30 so as to secure the cleaning tool 10 to the central duct 30. The cleaning tool 10 further comprises an annular collar 43 that abuts the end wall 26 thereby holding the end wall 26 in the closed position, and so prevents accidental opening of the end wall 26 while the cleaning tool 10 is attached. The cleaning tool 10 has a manually operated catch 44 that is actuated in order to disengage the retaining features from the central duct 24 in order to remove the tool 10 form the cyclonic separating unit 8. Again, it should be noted that these mechanical details are only exemplary and, as such, 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.

[0038] The central duct 30 and the duct 36 through the cleaning tool 10 together define an inlet duct 30, 36 which extends coaxially with the longitudinal axis X and through the end of the cyclonic separating unit 8 which is furthest 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.

[0039] The inlet 32 of the cyclonic separation chamber 28 is spaced away from the end wall 26 and is located towards the end of the primary cyclonic separator 18 which is opposite the end of the cyclonic separating unit 8 to which the cleaning tool 10 is connected. The cyclonic separation chamber 28 therefore extends about or surrounds the portion of the inlet duct 26,30 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 which has both radial and circumferential components with respect to the cyclonic separation chamber 28 so as to promote rotational flow within the cyclonic separation chamber 28 during use.

[0040] The end wall 26 and the portion of the cylindrical outer wall 24 adjacent the end wall 26 define a dirt collector 38, which is in the form of a dirt collecting bin or more simply dirt bin, in which dirt separated from the incoming flow by the primary cyclonic separator 18 is collected.

[0041] 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 catch 42. The end wall 26 can be moved from the closed position, in which dirt is retained within the dirt collector 38, to an open position, in which dirt can be removed from the dirt collector 38, by releasing the catch 42 and pivoting the end wall 26 away from the end of the cylindrical outer wall 24. The end wall 26 can therefore be considered to be a bin door or the dirt bin 38 which closes bin opening 27 of the dirt bin 38.

[0042] A cylindrical shroud 45 is disposed centrally within the cyclonic separation chamber 28 and extends coaxially with the axis of the chamber 28. Apertures 46 provided through the shroud 45 define a fluid outlet from the cyclonic separation chamber 28.

[0043] A duct 48, which is formed in part by the shroud 45, provides fluid communication between the outlet from the cyclonic separation chamber formed by the apertures 46 and inlets 49 of the secondary cyclonic separators 20. Each secondary cyclonic separator 20 has a solids outlet 50 at one end which is in communication with a fine dust collector 51 that extends along the side of the primary cyclonic separator 18. A fluid outlet 52 at the end of each of the secondary cyclonic separators 20 opposite the solids outlet 50.

[0044] The cyclonic separating unit 8, suction generator 11 and battery 14 are expected to be the heaviest components of the vacuum cleaner 2. The separator 8 has a centre of gravity which is forward of the trigger guard 17 and so generates a clockwise moment about the trigger 16 and the trigger guard 17 (as viewed in FIGS. 1 and 2). The battery 14 has a centre of gravity which is rearward of the trigger guard 17. The battery 14 therefore exerts an anticlockwise moment about the trigger 16 and the trigger guard 17. The suction generator 11 also has a centre of gravity which is rearward of the trigger guard 17. The cyclonic separating unit 8, suction generator 11 and battery 14 are positioned such that the net moment of all of the components of the vacuum cleaner 2 about an axis that extends perpendicularly with respect to the handle 6 and the longitudinal axis X of the cyclonic separating unit 8 and which passes through a region immediately below the trigger guard 17 is zero. The centre of gravity of the vacuum cleaner 2 is therefore located within the region below the trigger guard 17 such that when the trigger 16 is released by a user, the handheld vacuum cleaner 2 is balanced about a point below the trigger guard 17 and so can be supported easily by the rest of the user's fingers on the handle 6 and the upper finger against the trigger guard 17 without tipping forwards or backwards. Furthermore, the vacuum cleaner 2 can be supported on the battery 14, which forms a base of the vacuum cleaner 2, without toppling over. Although these aspects provide ergonomic benefits for the user, it should be noted that they are only exemplary and the vacuum cleaner may be configured in other ways.

[0045] In use, the handheld vacuum cleaner 2 is activated by a user pressing the trigger 16 with an index finger. Dirty air is drawn by the suction generator 11 through the inlet duct 30, 36 and through the inlet 32 into the cyclonic separation chamber 28. The rotational 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 cyclonic systems or a plurality of cyclonic systems are well-known in the art. Therefore, this discussion is provided for context and to illustrate a type of vacuum cleaner that is suitable for use within the examples of the invention.

[0046] Typically, the vacuum cleaner 2 is held such that the cyclonic separating unit 8 points downwardly from the handle 6. Dirt separated in the cyclonic separation chamber 28 therefore falls under the influence of gravity into the dirt collector 38. The partially cleaned air passes through the apertures 46 in the shroud 45 and is drawn along the duct 48 to the secondary cyclones 20. Smaller and lighter particles of dirt are separated from the air by the secondary cyclones 20 and expelled through the respective solids outlets into the fine dust collector 51. The cleaned air exits the secondary cyclones 20 via the respective fluid outlets 52 of the secondary cyclones 20 through the suction generator 11 and out of vents (not shown) at the rear of the main body 4.

[0047] FIG. 3 shows the vacuum cleaner 2 being emptied in a known way. In order to empty the dirt collector 38 and the fine dust collector 51, the user first disconnects the cleaning tool 10. Then, whilst gripping the handle 6, the user points the vacuum cleaner 2 towards a suitable receptacle (e.g. a waste bin or bag) into which the dirt is to be emptied. The catch 42 is then released by the user and the end wall 26 pivoted from its closed position into its open position. Since the cyclonic separating unit 8 is pointed away from the user, there is no need for the user to adopt a different grip or posture from that which is adopted during normal cleaning. Here, it should be appreciated that the catch 42 is positioned close to the end of the bin. However, in other configurations the catch 42 may be operated from a remote position through the use of a suitable linkage which is operated by an activating switch (not shown in this example).

[0048] In an alternative arrangement, the inlet duct may be spaced from the axis of the cyclonic separating unit 8. Nevertheless, the cyclonic separating unit may be arranged to extend partly around a portion of the inlet duct or to entirely surround a portion of the inlet duct. For example, the inlet duct may be recessed into the side of the cyclonic separating unit such that duct extends within the profile of the cyclonic separating unit when viewed along the axis of the cyclonic separating unit.

[0049] When emptying the vacuum cleaner 2, it will be appreciated that dirt and dust is ejected from the dirt collector through the action of gravity. It is also known to include a mechanical agitator such as a plunger to urge the dirt out of the dirt collector. However, in an emptying operation, fine dust tends to float upwards which is undesirable for the user. The examples of the invention are directed to address this issue.

[0050] Turning now to FIGS. 4 and 5, there is shown a schematic representation of the handheld vacuum cleaner 2 that is dockable with a docking station 60 thereby to define a vacuum cleaning system 62. The vacuum cleaner 2 shown in FIGS. 4 and 5 is similar in configuration to that shown in FIGS. 1 to 3. Therefore the same reference numerals will be used to refer to the same or similar parts.

[0051] In FIG. 4, the handheld vacuum cleaner 2 is spaced from the docking station 60, whereas in FIG. 5 the vacuum cleaner 2 is docked onto the docking station 60. As will become apparent from the discussion that follows, the vacuum cleaner 2 is operable in a bin emptying mode of operation during which dirt contained in the dirt collector 38 is sucked into the docking station 60 due to a vacuum therein which has been generated by the vacuum cleaner 2.

[0052] Reference firstly will 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 orientated in the Figures) is approximately three times its width, i.e. its diameter. It should be noted that the geometry shown here is only exemplary and as such the docking station 60 need not be cylindrical and may be differently shaped.

[0053] The body 64 of the docking station 60 is defined by a thin wall 66 having a base end 68 and a top end 70. The base end 68 rests on the floor (not shown) and stabilisation is benefitted by a flared stand 72 or foot. The foot 72 may be removable from the docking station 60 and is optional.

[0054] The top end 70 of the docking station 60 provides an interface 74 that is configured to engage with the vacuum cleaner 2. In principle the interface 74 may be configured in various ways, but it should provide the functionality that the central duct 33 of the vacuum cleaner 2 is able to communicate with the interior of the docking station 60 and that the pivotable end wall 26 of the dust collector 28 is able to open into the interior of the docking station 60 thereby exposing its contents.

[0055] In the illustrated example, 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 to be pivoted with respect to the body 64. Alternatively the interface 74 may be a fixed e.g. integral part of the docking station 60 such that it cannot be removed, although currently this is not considered preferable. A interface 74 that is removable may permit the replacement of a differently configured interface that is adapted for a different configuration of vacuum cleaner, as will be made apparent later.

[0056] The annular shape of the interface 74 defines a central opening 80 that is dimensioned to be comparable to that of the separator body 22 of the vacuum cleaner 2. The central opening 80 therefore 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 that seals against the outer surface of the separator body 22 although this is considered optional.

[0057] Turning now to the interior of the docking station 60, in FIGS. 4 and 5 it can be appreciated that the docking station 60 has a compartmentalised interior volume, in this example. In particular, the docking station 60 is configured to define a dirt storage chamber 82 and an intermediate chamber or antechamber 84. Both of these chambers 82,84 are surrounded by the interior volume 85 that is bounded by the outer wall 66 of the docking station 60. The intermediate chamber 84 provides a volume of space that leads from the interface 74 of the docking station 60 to the dirt storage chamber 82. The intermediate chamber 84 has a chamber wall 86 that is shaped in the form of a tapered chute and, as such, has a larger upper portion 87 which leads to a narrower throat portion 88. The vertical height of the throat portion 88 is, in the illustrated example, less than the vertical height of the upper portion 86. However, in other examples, the length of the throat portion 88 may be longer than this, which may provide benefits in terms of preventing dirt blow back from the dirt storage chamber 82.

[0058] A lower end of the throat portion 88 terminates at the dirt storage chamber 82. The dirt storage chamber 82 may depend or hang from the intermediate chamber 84, more specifically from the throat portion 88, in this example. Thus, the dirt storage chamber 82 may be removably clipped or otherwise be attached to the intermediate chamber 84. A valve 89 separates the intermediate chamber 84, and more specifically the throat portion 88 thereof, from the dirt storage chamber 82. In this example the valve 89 is a one-way or check valve that is configured to permit dirt to travel into the dirt storage chamber 82 from the intermediate chamber 84, under the influence of a vacuum, as will be explained. Once pressure has normalised, the valve 89 closes to prevent dirt or dust travelling back into the throat portion 88 from the dirt storage chamber 82.

[0059] The dirt storage chamber 82 is shown here in the form of a generally oval shape, in cross section. However, this is for convenience only and as such the dirt storage chamber 82 may be either rigid or flexible in form. For example, it is envisaged that the dirt storage chamber 82 may be defined by a porous bag. The porous bag may be a woven or non-woven fabric, as may be used in conventional bagged vacuum cleaners which are known in the art. By virtue of the porosity of the dirt storage chamber 82, dirt and debris can be sucked into it due to vacuum in the interior volume 85 and whilst air can travel through the pores of the walls of the dirt storage chamber 82, dirt and debris is trapped inside. Instead of a porous bag, it is envisaged that the dirt storage chamber 82 may have a more rigid construction, for example as could be achieved by a porous fabric stretched over a skeletal frame or a porous fabric that is treated so as to have some rigidity. In either case, it is envisaged that the dirt storage chamber 82 is removable from the docking station. In this way, the dirt storage chamber 82 can be emptied, e.g. in a trash bin outside, or can be replaced with an empty dirt storage chamber 82. Although not shown in the figures, a suitable door may be provided in the wall 66 of the docking station 60 so that the dirt storage chamber 82 can be removed and replaced.

[0060] 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 facilitate the formation of a vacuum within the docking station 60 by the vacuum cleaner 2, as will be described.

[0061] The apertures 90 may be valved to permit air to flow in one direction only, that is from the interior volume 85 of the docking station 60 to the interior of the intermediate chamber 84. In the illustrated example the apertures 90 may be configured to impart a swirl to the flow of air as it passes through the apertures 90 into the intermediate chamber 84. The valves of the apertures 90 may be in the form of slit valves of flap valves, for example.

[0062] As can be seen in the illustrated example, the intermediate chamber 84 is dimensioned such that it allows the dirt bin door 26 to pivot outwardly fully and hang down vertically inside the intermediate chamber 84, in the orientation of the drawings.

[0063] As has been discussed above, the vacuum cleaning system 62 is configured such that the vacuum cleaner 2 is operable, when docked on the docking station 60, to generate a vacuum within the intermediate chamber 84 and the dirt storage chamber 82 which is able to draw dirt and debris from the dirt bin 38 of the vacuum cleaner 2. This functionality is achieved during a bin emptying mode of operation. Such a mode may be a manual operation, as carried out by a user, or it may be an automatic operation which happens substantially without user intervention. In a broad sense, during a bin emptying mode of operation, the vacuum cleaner 2 operates to generate a partial vacuum, compared to the ambient pressure level, in the dirt storage chamber 82 of the docking station 60. To this end, air within the dirt storage chamber 82 is drawn through the interior volume 85 and through the apertures 90 into the intermediate chamber 84, from where it is drawn into the vacuum cleaner 2. During this air evacuation process, the bin door 26 may be in an open position, but preferably it is closed. Opening of the bin door 26 may be achieved by a suitable bin opening mechanism 92. The bin opening mechanism is shown in FIGS. 4 and 5 as an actuating member 94 that is slidably attached to the separator body 22. The actuating member 92 includes a push rod 96 that engages with a part of the bin door 26. Sliding movement of the actuating member 94 drives the push rod 96 in a downwards direction, as shown in the drawings, which unlatches the bin door 26 so it can fall open under the influence of gravity and due to the pressure differential across the bin door 26. The skilled person would appreciate that the bin opening function may be achieved in other ways. For example, an electronic system may be provided in which a servo-actuator is operable to open the bin door 26 in response to a button push by a user, or a pneumatic device that uses low pressure in the container to generate enough force to un-latch the bin catch 42.

[0064] Once a sufficient negative pressure level has been generated, an air valve arrangement 100 of the vacuum cleaner 2 is operated to admit a pulse of air into the dirt bin 38 which has the effect of ejecting dirt from the dirt bin 38 through the bin opening 27 and into the intermediate chamber 84. Dirt travels downwardly though the throat portion 88 and into the dirt storage chamber 82 where it is trapped by the porous walls. The airflow passages within the vacuum cleaner 2 can be configured to ensure that the pulse of air results in a high speed airflow through the machine that is effective at ejecting dirt from the dirt bin 38.

[0065] Although the air valve arrangement 100 is shown generally in FIGS. 4 and 5, it is shown in more detail in FIGS. 6, 7 and 8.

[0066] In a broad sense, the purpose of the air valve arrangement 100 is to allow a controlled burst or pulse of air to flow into and through the dirt bin 38 and out of the bin opening 27. As shown in FIGS. 6 to 8, the air valve arrangement 100 comprises one or more apertures 102 defined at an upper part of the separator body 22, near to the secondary cyclonic separators 20 (not shown in FIGS. 6, 7).

[0067] Here, the apertures 102 are shown extending about the separator body 22 in a circumferential array. Other configurations would be acceptable but an array as shown provides an even spread of air to be admitted into the dirt bin 38 about the axis X of the separator body 22.

[0068] The opening state of the one or more apertures 102 are controlled by a valve member 104. The valve member 104 is movable between opened and closed positions. In the closed position the valve member 104 covers up the apertures 102 so that air is not able to flow through them. In the open position the valve member 104 uncovers the apertures 102 to allow air to flow through them. FIG. 6 shows the valve member 104 in the closed position whereas FIG. 7 shows the valve member 104 in the open position.

[0069] In the illustrated embodiment the valve member 104 is configured as a collar or cuff that extends about the exterior of the separator body 22. As illustrated, the valve member 104 covers up the apertures 102 in the closed position and is moveable downwards (as oriented in the figures) by a distance sufficient to uncover the apertures 102, whereupon air is able to flow through the apertures. The valve member 104 may be biased into the closed position, for example by a suitably configured biasing spring (not shown).

[0070] As shown in FIG. 8, the apertures 102 may be configured to impart a rotational trajectory or swirl to the flow of air that enters the separator body 22. To this end, the apertures 102 may be defined by a series of vanes or louvres 106 that extend through the wall of the separator body 22 thereby defining the apertures 104 in the spaces between the vanes 106. The vanes 106 extend in a direction that is angled with respect to the radial direction from the central axis X. Here, the vanes 106 are shown as angled by approximately 45 degrees, although it should be appreciated that is only exemplary.

[0071] The movement of the valve member 104 may be controlled manually by the user of the vacuum cleaner 2. Alternatively, they may be controlled by an appropriate control system. The following discussion will focus on manual control of the valve member 104.

[0072] Having described the features of the docking station 60 and the vacuum cleaner 2, the discussion will now focus on how the vacuum cleaner 2 may be operated in order to carry out a bin emptying operation, with a focus on FIGS. 9 and 10.

[0073] In FIG. 9, the vacuum cleaner 2 is shown docked onto the interface 74 of the docking station 60. The vacuum cleaner 2 is operating, that is the vacuum cleaner has been turned on by an operator/user, such that the suction generator 11 is drawing air along the inlet duct 30 of the vacuum cleaner 2 which evacuates air from the intermediate chamber 84, and also from the interior volume 85 of the docking station 60, which draws air out of the dirt storage chamber 82. As can be seen, air flows from the interior volume 85 through the apertures 90 in the intermediate chamber 84 which impart a swirling motion to the flow of air as it circulates around the intermediate chamber 84 and into the inlet duct 30 of the vacuum cleaner 2.

[0074] When a sufficient negative pressure is generated within the docking station 60, the dirt bin door 26 of the vacuum cleaner is opened. This may be achieved by the user actuating the bin opening mechanism 92. Currently it is envisaged that the bin emptying operation can be accomplished with the bin door 26 opened whilst the air within the docking station is being evacuated. However, it is believed that optimum results will be achieved with the bin door closed until a sufficient vacuum has been generated in the docking station 60.

[0075] The level of vacuum that is considered to be efficient will depend on the power of the suction generator 11 and the volume or air within the docking station 60. However, it envisaged that a sufficient level of vacuum will be achieved between 0.5 and 2 seconds. For example, this could be achieved with a vacuum generator pumping approximately 20 litres per second in order 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 and 30 kPa, and more preferably a pressure drop between 23 and 28 kPa. Whilst these values of pressure drop are considered to provide good results, it is possible for good functionality still to be achieved with a somewhat lower pressure drop.

[0076] In FIG. 10, the bin door 26 of the vacuum cleaner 2 has been opened. As a result, the interior of the dirt bin 38 is exposed to the vacuum present in the docking station 60, more specifically the intermediate chamber 84. Also, in this example, it will be noted that the vacuum generator 11 has been turned off by the user/operator. At this point, the air valve arrangement 100 is opened as can be seen by the valve member 104 being shown in a down or open position. This means that ambient air is drawn forcefully into the dirt bin 38 through the apertures 102, thereby causing a pulse of air to flow into the dirt bin 38 to eject the contents of the bin 38 into the docking station 60, as can be seen in FIG. 10.

[0077] The flow of air from the dirt bin 38 into the docking station 60 flows through the intermediate chamber 84 and opens the valve 89 into the dirt storage chamber 82. The dirt and debris ejected from the dirt bin 38 of the vacuum cleaner 2 is therefore captured by the dirt storage chamber 82. Although the valve 89 is optional, its presence in this example of the invention ensures that dirt and debris is captured within the dirt storage chamber 82 and cannot travel back towards the vacuum cleaner 2.

[0078] At this point it should be noted that the open area or the apertures 102 should be configured to provide a high speed flow of air into the dirt bin 38. In configuring the open area of the apertures 102, account should also be taken of the negative pressure present in the docking station. It is believed that an open area of between 3500 mm.sup.2 to 4500 mm.sup.2 would provide a suitable air flow, and more preferably approximately 4000 mm.sup.2. To ensure that the high speed air flow maintains flow speed through the dirt bin, one consideration is to ensure that the open area of the apertures 102 is not more than the minimum cross sectional area of the volume inside the dirt bin 38, when taken in a plane perpendicular to the axis X of the separator body 22. If the cross sectional area of the dirt bin 28 is greater than the open area of the apertures 102, this will result in the flow of air slowing down as it progresses through the dirt bin 38 which could reduce the effectiveness of the air flow in ejecting the dirt and debris from the dirt bin 38. Therefore, it is preferred to configure the open area of the apertures 102 to be not smaller than 0.5 times the cross sectional area of the dirt bin 38

[0079] Due to the high pressure differential between the dirt bin 38 and the docking station interior, and a large enough air bleed area through the apertures 102 of the air valve arrangement, the pulse of air into the docking station has a very high flow rate but only for short period of time. For example, it is believed that the above parameters are able to achieve a peak flow rate of around 200 l/s of peak flow rate with a pulse duration of below 0.1 s. This results in a peak flow velocity of above 200 m/s. If the flow area of the apertures 102 is smaller than the cross sectional area of the dirt bin 38, this has the effect of slowing down the flow speed through the dirt bin 38. However, even if the cross section area of the dirt bin is around twice that of the flow area of the apertures 102, flow speeds of above 100 m/s are still achievable.

[0080] It should be noted that FIGS. 9 and 10 illustrate only single pulse of air, which is achieved by, firstly, operating the suction generator 11 to establish a negative pressure within the dirt bin 38 (as illustrated by FIG. 9), and then shutting off the suction generator 11 and opening the bin door 26 and the air valve arrangement 100 (as depicted in FIG. 10) to generate a high speed airflow through the dirt bin 38. However, the operation may be performed more than once in order to provide a more effective and complete bin emptying operation. It should be appreciated that operation of the air valve arrangement 100 may be carried out repeatedly while the bin door 26 is in the open position; the bin door 26 is not required to be closed between actuations of the air valve arrangement 100. Furthermore, although it is envisaged that the vacuum generator 11 should be cycled on when the air valve arrangement 1000 is closed, and cycled to off when the air valve arrangement is open, it is believed that this is not essential for acceptable performance of bin emptying. Therefore, acceptable functionality may be achieved by opening and closing the air valve arrangement 100 whilst the vacuum generator 11 is operating.

[0081] In the example described above, the suction generator 11 and the air valve arrangement 100 are envisaged to be controlled manually by the user in order to achieve a bin emptying operation. However, the vacuum cleaner could be configured such that a bin emptying operation is performed automatically under the control of a control system. For example, a suitable user-operable button or trigger may be provided on the vacuum cleaner 2 which the user may depress in order to drive a bin emptying operation. Correspondingly, a control system of the vacuum cleaner 2 may be configured to control electronically the operation of the bin door 26, the air valve arrangement 100 and the suction generator 11 in an appropriate sequence in order to generate the required one or more pulses of high speed air through the dirt bin 38.

[0082] In another example, it is envisaged that the valve arrangement 100 may be responsive to the pressure within the dirt bin 38. For example, once a negative pressure has been established in the dirt bin 39 and the bin door 26 has been opened, the valve arrangement 100 may be configured to open when exposed to a pressure differential between the ambient pressure outside of the vacuum cleaner and the negative pressure inside the dirt bin 38. Such a pneumatically-driven system would improve energy efficiency of the system as it would not require any electrical energy to power it.

[0083] The above discussion has explained some variants and modifications that may be made to the illustrated examples without departing from the scope of the invention as defined by the claims. Other variants will now be described.

[0084] In the above examples, the air valve arrangement 100 is embodied as a cuff or collar-shaped valve member 104 that encircles the separator body 22 to selectively open and close the apertures 102. However, it should be appreciated that this specific configuration is just an example and the air valve arrangement could be embodied in different ways. In essence, the function of the air valve arrangement 100 is to permit a controllable flow of air to enter into the dirt bin 38 to flush out debris. So any configuration that permits this functionality would be acceptable. For example, it is envisaged that a reverse airflow could be permitted though the cyclonic separator system so as to flow out of the cylindrical shroud 45 (see FIG. 2) into the dirt bin 38. The benefit of this is that the reverse airflow would assist in removing caked on dust that may partially block the pores of the shroud 45. It will therefore be appreciated that the flow of air through the dirt bin 38, whether it flows directly into the dirt bin 38 through the apertures 90, or whether it flow into the dirt bin through the cyclonic separator and the shroud 45 (which is a surface filter), can be considered to perform a cleaning action on at least one separating system of the vacuum cleaner 2. The reverse flow of air through the machine can also be configured to flow through one or more fibrous filters of the vacuum cleaner 2, for example through a HEPA filter or depth filter of the vacuum cleaner.

[0085] FIG. 11 illustrates a further example of a vacuum cleaning system 62 in accordance with the invention comprising a docking station 60, and an alternative configuration of vacuum cleaner 110. In FIG. 11, the docking station 60 is substantially as described in the above examples, so only the differences will be described here for brevity.

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

[0087] The skilled person would appreciate that the type of vacuum cleaner 110 shown in FIG. 11 is the same general configuration as vacuum cleaners available commercially from Dyson Technology Ltd, known as for example the 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 examples of the invention, but is configured to adapt the differently configured vacuum cleaner 110 to the docking station 60.

[0089] As can be seen, the interface 122 includes a socket 124 that is sized to accept the lower end of the cyclonic separator 118 and to allow a bin door 126 thereof to open into the docking station 60, as shown in the Figure. Since the inlet duct 120 is oriented to be 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 couples to the front end of the inlet duct 120 of the vacuum cleaner 110. In this way when the suction generator 114 is operated, air is drawn from the docking station 60 through the interface 122 and inlet duct connector 128, into the cyclonic separator 118 through the inlet duct 120. This enables a bin emptying operation to be performed in the same way as described above.

[0090] In the examples described above, an advantage is gained by the suction generator being part of the vacuum cleaner, such that only one electric motor is needed to power the vacuum cleaner but also to drive the bin emptying operation. However, it is envisaged that in other examples a separate suction generator may be positioned in the docking station to drive the bin emptying operation. The separate suction generator would be in addition to a suction generator within the vacuum cleaner itself. Therefore, in such an example, the suction generator in the docking station may be operated in the same way as the suction generator in the above described examples whilst the valve arrangement in the vacuum cleaner operates to generate the pulse air flow through the vacuum cleaner to assist in bin emptying.