GB2624189A

GB2624189A - A separation system

Info

Publication number: GB2624189A
Application number: GB2216680.5A
Authority: GB
Inventors: William Drewett George; Howard Percy-Raine Charles; Andrew Buchanan Harker Anthony; Alexandre Goncalves Ashley
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2022-11-09
Filing date: 2022-11-09
Publication date: 2024-05-15
Also published as: GB202216680D0; WO2024100483A1

Abstract

A separation system 16 for a vacuum cleaner (10, fig.1), comprising first and second parallel cyclonic separators 50, 56, each preferably including a plurality of separators 48, 54, and a movable member 62 movable between a first position permitting airflow through a first inlet 66 of the first cyclonic separator and a second inlet 72 of the second cyclonic separator, and a second position permitting airflow through the first inlet and inhibiting airflow through the second inlet. The movable member may move by inflation and deflation via a valve (30, fig.4) between spaced from and in contact with a sealing member 60 in an inlet duct 46, possibly via a user actuator (104, fig.6) or input (26, fig.1), a switch (404, fig.9), an electric actuator (24, fig.1), and/or a drive motor (208, fig.7). The separators may have first and second dirt collection chambers 52, 58. The inlets may be in an annular array. The vacuum cleaner may be operable in first and second modes having different flow rates, which correspond to the position of the moveable member.

Description

A SEPARATION SYSTEM

Field of the Invention

The present invention relates to a separation system for a vacuum cleaner, and a vacuum cleaner comprising such a separation system.

Background of the Invention

Vacuum cleaners rely on a suction generator to generate an airflow, which is used to pick up dirt from a surface to be cleaned. The airflow is passed through one or more separation stages to separate dirt from the airflow before the airflow is ejected from the vacuum cleaner. Some vacuum cleaners utilise cyclonic separators as a separation stage.

Summary of the Invention

According to a first aspect of the present invention there is provided a separation system for a vacuum cleaner, the separation system comprising: a first cyclonic separator comprising a first inlet; a second cyclonic separator comprising a second inlet, the second cyclonic separator arranged in parallel with the first cyclonic separator; and a movable member movable between a first position in which the movable member permits airflow through the first and second inlets, and a second position in which the movable member permits airflow through the first inlet and inhibits airflow through the second inlet.

Use of the movable member to selectively permit or inhibit airflow through the second inlet may provide increased separation efficiency compared to arrangements where airflow always needs to flow through the second cyclonic separator when also flowing through the first cyclonic separator. In particular, vacuum cleaners having a wide range of power modes may have a similarly large variation of flow rate across those power modes. Cyclonic separators can typically only be designed for an optimal balance of separation efficiency and restriction for a single flow rate, or a small range of flow rates. For a typical separation system having one cyclonic separator, or two cyclonic separators that are always fluidically connected in parallel, when the flow rate through the separation system changes, the separation efficiency and restriction through the separation system also changes. This may mean that the vacuum cleaner is unable to function at peak separation and energy efficiency in all modes and with all flow rates.

Reduced separation efficiency can reduce a lifetime of a filter downstream of the cyclonic separators, for example as a result of more dirt or debris remaining in the air and passing through to the filter, and may result in a user needing to perform maintenance, such as washing the filter, more often. Increased airflow restriction may result in more energy being required by the motor to draw a same volume of air, and therefore a reduction in battery life where the vacuum cleaner is a battery-operated vacuum cleaner. Furthermore, increased airflow restriction may reduce airflow through a vacuum cleaner, which may reduce pick-up of dirt.

The separation system described herein may mitigate for the above by allowing for the second cyclonic separator to be selectively utilised via positioning of the movable member. In particular, this may allow for the first and second cyclonic separators to be tuned to give performance at peak separation efficiency in multiple power modes, and at multiple airflow rates. This may result in increased separation efficiency and reduced flow restriction in particular modes of operation.

The separation system may comprise an inlet duct for receiving an airflow, the inlet duct connected to the first and second inlets, and the movable member may be located within the inlet duct. By placing the movable member in the inlet duct, as opposed to the first inlet itself, increased flexibility in design of the movable member may be achieved, for example enabling use of a simpler movable member. In particular, the first inlet may typically be smaller than the inlet duct itself, with the inlet duct providing extra space for location of the movable member.

The first position may be a first position within the inlet duct. The second position may be a second position within the inlet duct.

The second inlet may be spaced from the first inlet along a length of the inlet duct.

This may enable the first and second cyclonic separators to be in a stacked, for example at least partially one above the other along the length of the inlet duct, which may provide a reduced form factor for the separation system in a radial direction. Spacing the second inlet from the first inlet along the length of the inlet duct may also facilitate inhibition of airflow through the second inlet, for example by enabling the movable member to provide at least a portion of a seal within the inlet duct between the first and second inlets of the first and second cyclonic separators. This is in contrast to an arrangement where the first and second inlets are located at a same length along the inlet duct. The length of the inlet duct may extend in a direction substantially parallel to a direction of bulk airflow through the inlet duct in use.

The separation system may comprise a sealing member extending about an inner surface of the inlet duct, and the movable member may be movable relative to the sealing member between the first and second positions such that the movable member is spaced from the sealing member in the first position, and the movable member contacts the sealing member in the second position. This may provide a relatively simple sealing arrangement compared to, for example an arrangement where sealing takes place at the second inlet itself. The sealing member may extend about substantially the entirety of the inner surface of the inlet duct. This may provide increased strength, for example hoop strength, of the sealing member in comparison to a sealing member that extends about only a portion of the inner surface of the inlet duct.

The inlet duct may be substantially cylindrical in form, the sealing member may be substantially annular in form, and the movable member may be substantially conical in form. The sealing member may be located within the inlet duct intermediate the first and second inlets. This may facilitate movement of the movable member between the first and second positions, for example as a result of a pressure difference between the second cyclonic separator and the inlet duct as the movable member moves between the first and second positions toward the sealing member.

The first cyclonic separator may have a different geometry to the second cyclonic separator. Thus the first and second cyclonic separators may facilitate provision of different restrictions and separation efficiencies when the movable member is in the first and second positions, which may enable optimisation of the separation system to provide different restrictions and separation efficiencies across different power modes of a vacuum cleaner that incorporates the separation system. The first cyclonic separator may have a different size and/or shape to the second cyclonic separator.

The separation system may comprise a user operable actuator to move the movable member between the first and second positions. This may allow a user to choose when to switch the movable member from the first position to the second position, or vice versa, which may provide improved control over efficiency and/or restriction when the separation system is utilised in a vacuum cleaner in use. The user operable actuator may comprise a switch actuable by a hand of a user.

The separation system may comprise an electrically operable actuator to move the movable member between the first and second positions. Use of an electrically operable actuator may facilitate automatic movement of the movable member between the first and second positions, for example in response to user selection of a mode of operation of a vacuum cleaner in which the separation system is incorporated.

The movable member may comprise an inflatable member movable, for example between the first and second positions, in response to inflation and deflation. Use of an inflatable member may facilitate movement between the first and second positions, for example by utilising existing airflow within the separation system in use. Inflation of the inflatable member may move the movable member from the first position to the second position. Deflation of the inflatable member may move the movable member from the second position to the first position.

The movable member may be movable between the first and second positions in 15 response to movement of a switch by a user. This may for example, enable a user to control when the second cyclonic separator is utilised. The inflatable member may inflate or deflate in response to movement of the switch by the user.

The separation system may comprise a first dirt collection chamber in fluid communication with the first cyclonic separator, and a second dirt collection chamber, different to the first dirt collection chamber, in fluid communication with the second cyclonic separator. This may inhibit flow leakage between the first dirt collection chamber and the second cyclonic separator when the movable member is in the second position.

The separation system may comprise: a plurality of first cyclonic separators, each comprising a respective first inlet; a plurality of second cyclonic separators, each comprising a respective second inlet, the plurality of second cyclonic separators arranged in parallel with the plurality of first cyclonic separators; and the movable member may permit airflow through the first and second inlets when in the first position, and movable member may permit airflow through the first inlets and inhibits airflow through the second inlets when in the second position. By providing a plurality of first and second cyclonic separators, separation efficiency may be improved in comparison to a separation system where only one first cyclonic separator and only one second cyclonic separator are utilised.

The first inlets may be arranged in a first annular array, the second inlets may be arranged in a second annular array, and the first annular array may be spaced apart from the second annular array. This may provide a relatively simple arrangement for the movable member to inhibit airflow through the second cyclonic separator, for example where the sealing member is located in the inlet duct between the first and second annular arrays.

The separation system may comprise different numbers of first and second cyclonic separators. This may facilitate tailoring of the separation system for different flow rates in use.

The separation system may comprise a third separation system upstream of the first and second separation systems. This may, for example, enable initial filtration of the airflow within the separation system prior to the first and second cyclonic separators.

According to a second aspect of the present invention there is provided a vacuum cleaner comprising a separation system according to the first aspect of the present invention.

The vacuum cleaner may comprise an airflow generator for generating an airflow through the separation system, the vacuum cleaner may be operable in a first mode in which the airflow generator generates airflow at a first flow rate through the separation system, and a second mode in which the airflow generator generates airflow at a second flow rate, different to the first flow rate, through the separation system, and the movable member is in the first position in the first mode and in the second position in the second mode. Use of the movable member when the vacuum cleaner experiences different flow rates in different modes may provide improved flow restriction and/or improved separation efficiency when compared to a vacuum cleaner where both the first and second cyclonic separators are utilised for each mode of operation.

The second flow rate may be less than the first flow rate, for example with the second mode being a lower power mode of operation than the first mode.

The movable member may move automatically between the first and second positions based on a selected one of the first and second modes. This may provide improved performance of the vacuum cleaner in comparison to an arrangement where a user has to decide when to move the movable member between the first and second positions.

The movable member may comprise an inflatable member movable in response to inflation and deflation, and a valve assembly to cause inflation and deflation of the inflatable member, the valve assembly may comprise a first airflow path in fluid communication with a location upstream of the airflow generator, a second airflow path in fluid communication with a location downstream of the airflow generator, a third airflow path in fluid communication with the inflatable member, and a valve member movable to selectively allow airflow through only one of the first airflow path and the second airflow path. Such an arrangement may make use of existing airflow within the vacuum cleaner to move the movable member between the first and second positions. For example, pressure differences between different locations in the vacuum cleaner may be utilised to selectively inflate and deflate the inflatable member.

The second airflow path may be in fluid communication with ambient atmosphere external to the vacuum cleaner. The second airflow path may be in fluid communication with an interior of the vacuum cleaner downstream of the airflow generator. This may provide increased response time compared to an arrangement where the second airflow path is in fluid communication with ambient atmosphere external to the vacuum cleaner, for example as a result of a greater pressure internal to the vacuum cleaner when compared to ambient pressure external to the vacuum cleaner.

Airflow may be allowed through the first airflow path, and inhibited through the second airflow path, by the valve member, to deflate the inflatable member and place the movable member in the first position. Airflow may be allowed through the second airflow path, and inhibited through the first airflow path, by the valve member, to inflate the inflatable member and place the movable member in the second position.

Movement of the valve member may be electrically actuated. This may provide a relatively quick response time, for example compared to a manual actuation of the valve member. The valve assembly may comprise a solenoid valve assembly, for example with the valve member movable in response to a solenoid.

Movement of the valve member may be electrically actuated in response to 20 selection of one of the first and second modes by a user. This may enable the movable member to be moved automatically in response to selection of one of the first and second modes by a user.

The separation system may comprise a drive motor to drive movement of the movable member between the first and second positions. Use of a drive motor may provide more accurate positioning of the movable member than for example use of an inflatable member, where flow through the separation system can vary during use.

The drive motor may be actuated in response to selection of one of the first and second modes by a user. This may enable the movable member to be moved automatically in response to selection of one of the first and second modes by a user.

Brief Description of the Drawings

Figure 1 is a schematic cross-sectional view of a first embodiment of a vacuum cleaner; Figure 2 is a schematic view of an actuator of the vacuum cleaner of Figure 1; Figure 3 is a schematic view of a secondary separation stage of the vacuum cleaner of Figure 1; Figure 4 is a schematic illustration of a combined first configuration of the actuator of Figure 2 and the secondary separation stage of Figure 3; Figure 5 is a schematic illustration of a combined first configuration of the actuator of Figure 2 and the secondary separation stage of Figure 4; Figure 6 is a schematic cross-sectional view of a first embodiment of a vacuum cleaner; Figure 7 is a schematic cross-sectional view of a first embodiment of a vacuum cleaner; Figure 8 is a schematic cross-sectional view of a first embodiment of a vacuum cleaner; and Figure 9 is a schematic cross-sectional view of a first embodiment of a vacuum 30 cleaner.

Detailed Description of the Invention

A vacuum cleaner 10 is illustrated schematically in Figure 1, and comprises a main body 12, a primary separation stage 14, and a secondary separation stage 16. Collectively the combination of the primary 14 and secondary 16 separation stages, along with appropriate ancillary components that facilitate operation of the primary 14 and secondary 16 separation stages, may be thought of as a separation system as discussed herein. Equally, the secondary separation stage 16, along with appropriate ancillary components that facilitate operation of the secondary separation stage, may be thought of as a separation system as discussed herein.

The main body 12 is shaped to define a handle 18, and houses a battery pack 20, a suction motor 22, and an actuator 24. A user input 26, in the form of a depressible button, is located on an exterior surface of the main body 12.

The actuator 24 is shown in isolation in Figure 2, and comprises a housing 28, a valve member 30 movable within the housing 28, a coil 32 for selectively moving the valve member 30, and first 34, second 36, and third 38 airflow paths in fluid 20 communication with the housing 28.

The valve member 30 takes the form of a solenoid core. The valve member is resiliently biased by a spring 31 to a position where the valve member blocks airflow through the first airflow path 34, and allows airflow through the second 36 and third 38 airflow paths. The valve member may comprise appropriate sealing surfaces. The coil 32 is energised in response to operation of the user input 26 to move the valve member 30. The first airflow path 34 is in fluid communication with a location slightly upstream of the suction motor 22. The second airflow path 36 is in fluid communication with a location downstream of the suction motor 22 within the main body 22. The third airflow path 38 is in fluid communication with an inflatable member 62 of the second separation stage 16, as will be discussed in more detail hereafter.

The primary separation stage 14 comprises a generally annular chamber 40, an air inlet 42, and an air outlet 44. The primary separation stage 44 can be thought of as an inertial separator, and in some examples a filter (not shown in Figure 1) is located between the air inlet 42 and the air outlet 44. Although not illustrated, in some examples the air inlet 42 has a connection formation for connecting to at least one of an elongate tube and a cleanerhead.

The secondary separation stage 16 is illustrated in isolation in Figure 3, and comprises an inlet duct 46, an array 48 of first cyclonic separators 50, a first dirt collection chamber 52, an array 54 of second cyclonic separators 56, a second dirt collection chamber 58, a sealing member 60, and an inflatable member 62.

The inlet duct 46 is generally cylindrical in form, and is in fluid communication with the air outlet 44 of the primary separation stage 44. The array 48 of first cyclonic separators 50 and the array 54 of second cyclonic separators 56 extend annularly about the inlet duct 46, with the array 54 of second cyclonic separators 56 spaced along the inlet duct 46 from the array 48 of first cyclonic separators 50. This may enable the second cyclonic separators 56 to be stacked relative to the first cyclonic separators 50, for example with the second cyclonic separators 56 spaced apart from the first cyclonic separators 50 along a length of the inlet duct 46, whilst also at least partially overlapping the first cyclonic separators 50.

Each of the first cyclonic separators 50 is generally frustoconical in form, and has an inlet 66, an air outlet 68 in the form of a vortex finder, and a dirt outlet 70. Each first cyclonic separator 50 is tapered toward the dirt outlet 70. The inlets 66 of the first cyclonic separators 50 are evenly spaced about a periphery of the inlet duct 46, and are located substantially in the same plane as one another. The air outlet 68 of each of the first cyclonic separators 50 is in fluid communication with the suction motor 22. The dirt outlet 70 of each of the first cyclonic separators 50 is in fluid communication with the first dirt collection chamber 52.

The first cyclonic separators 50 each have substantially the same size and shape, and are tuned to have optimal separation efficiency and flow restriction for a first, relatively low flow rate, mode of operation of the vacuum cleaner 10, as will be described in more detail hereafter.

Each of the second cyclonic separators 56 is generally frustoconical in form, and has an inlet 72, an air outlet 74 in the form of a vortex finder, and a dirt outlet 76.

Each second cyclonic separator 56 is tapered toward the dirt outlet 76. The inlets 72 of the second cyclonic separators 56 are evenly spaced about a periphery of the inlet duct 46, and are located substantially in the same plane as one another. The air outlet 74 of each of the second cyclonic separators 56 is in fluid communication with the suction motor 22. The dirt outlet 76 of each of the second cyclonic separators 56 is in fluid communication with the second dirt collection chamber 58.

The second cyclonic separators 56 each have substantially the same size and shape, and are larger than the first cyclonic separators 50. The second cyclonic separators 56 are tuned, along with the first cyclonic separators 50, to have optimal separation efficiency and flow restriction for a second, relatively high flow rate, mode of operation of the vacuum cleaner 10, as will be described in more detail hereafter.

The sealing member 60 is substantially annular in form, and is formed of a resiliently deformable material. The sealing member 60 extends annularly about an internal surface of the inlet duct 46, and is located between the inlets 66 of the first cyclonic separators 50 and the inlets 72 of the second cyclonic separators 56.

The inflatable member 62 is located in the inlet duct 46 downstream of the sealing member 60, and is hollow and formed of a resiliently deformable material such as rubber. The inflatable member 62 is shaped to allow linear extension and contraction by means of buckling, rolling, concertina, or other similar effects, and comprises an external sealing surface 78 for engaging with the sealing member 60. An interior of the inflatable member 62 is in fluid communication with the third airflow path 38 of the actuator 24.

During operation of the vacuum cleaner 10, the battery pack 20 provides electrical power to the suction motor 22 to generate an airflow through the vacuum cleaner 10. Dirt-laden air enters the primary separation stage 14 through the air inlet 42. Relatively large dirt is filtered from the airflow within the primary separation stage 14 via inertial separation, before the airflow leaves the primary separation stage via the air outlet 44.

Airflow enters the secondary separation stage 16 via the inlet duct 46, and depending on a mode of operation of the vacuum cleaner 10 enters either the array 48 of first cyclonic separators 50, or the array 48 of first cyclonic separators 50 and the array 54 of second cyclonic separators 56.

A first configuration of the actuator 24 and the secondary separation stage 16 is illustrated in Figure 4. When the vacuum cleaner 10 is intended to operate in a mode of operation with a relatively high flow rate, as selected by a user via the user input 26, the coil 32 is energised such that the valve member 30 of the actuator 24 moves to block airflow through the second airflow path 36, whilst airflow is permitted through the first airflow path 34 and the third airflow path 38.

As the first airflow path 34 is in fluid communication with a location slightly upstream of the suction motor 22, and airflow is permitted through the first airflow path 34 and the third airflow path 38, a suction force is generated that causes the inflatable member 62 to deflate. In a fully deflated configuration, the inflatable member 62 is located in a first, retracted, position, relative to the sealing member 60. In the first position the inflatable member 62 is not in contact with the sealing member 60, and airflow is free to enter the inlets 66 of the first cyclonic separators 50, and the inlets 72 of the second cyclonic separators 56.

Airflow then moves helically within the first 50 and second 56 cyclonic separators in parallel, where relatively fine dirt particles are filtered via cyclonic separation and collected in the respective first 52 and second 58 dirt collection chambers. The airflow leaves the first 50 and second 56 cyclonic separators via their respective air outlets 68,74, before passing through the suction motor 22 and being exhausted from the main body 12 via an outlet (not shown).

A second configuration of the actuator 24 and the secondary separation stage 16 is illustrated in Figure 5. When the vacuum cleaner 10 is intended to operate in a mode of operation with a relatively low flow rate, as selected by a user via the user input 26, the coil 32 is not energised, and the spring 31 biases the valve member 30 to a position where the valve member 30 blocks airflow through the first airflow path 34, whilst airflow is permitted through the second airflow path 36 and the third airflow path 38.

As the second airflow path 36 is in fluid communication with a location downstream of the suction motor 22, and airflow is permitted through the second airflow path 36 and the third airflow path 38, a pressure is passed to the interior of the inflatable member 62 that causes the inflatable member 62 to inflate. In a fully inflated configuration, the inflatable member 62 is located in a second, deployed, position, relative to the sealing member 60. The inflatable member 62 is generally conical in form when engaged with the sealing member 60. In the second position the external sealing surface 78 of the inflatable member 62 is in contact with the sealing member 60, and airflow is free to enter the inlets 66 of the first cyclonic separators 50, but inhibited from entering the inlets 72 of the second cyclonic separators 56.

Airflow then moves helically within the first 50 cyclonic separators, where relatively fine dirt particles are filtered via cyclonic separation and collected in the respective first 52 dirt collection chamber. The airflow leaves the first 50 cyclonic separators via their respective air outlets 68, before passing through the suction motor 22 and being exhausted from the main body 12 via an outlet (not shown).

In such a manner, use of the inflatable member 62 to selectively permit or inhibit airflow through the second cyclonic separators 56 may provide increased efficiency compared to arrangements where airflow always needs to flow through the second cyclonic separators 56 when flowing through the first cyclonic separators 50. In particular, this may allow for the first and second cyclonic separators 50,56 to be tuned to give performance at peak efficiency in multiple power modes, and at multiple airflow rates. This may result in increased separation efficiency and reduced flow restriction in particular modes of operation. use of the inflatable member 62 may also utilise existing airflow through the vacuum cleaner 10 to selectively close off the second cyclonic separators 56.

A second embodiment of a vacuum cleaner 100 is illustrated schematically in Figure 6, where like reference numerals are used for sake of clarity.

The second embodiment 100 of the vacuum cleaner differs from the first embodiment 10 of the vacuum cleaner in the form of the actuator 102, and the presence of a user operated trigger 104. The actuator 102 does not comprise a coil. Here the actuator 102 is manually actuated, with the valve member 30 movable in response to movement of the trigger 104. In particular, the valve member 30 is movable in response to manual operation of the trigger 104 to enable inflation and deflation of the inflatable member 62, and hence selective operation of the second cyclonic separators 56, in a similar manner to that described in relation to the first embodiment 10 of the vacuum cleaner described above. In some examples, a sensor is provided to sense a position of the trigger 104, and to communicate a position of the trigger 104 to a controller that can automatically control a mode of operation of the vacuum cleaner 100 based on the position of the trigger 104.

A third embodiment of a vacuum cleaner 200 is illustrated schematically in Figure 7, where like reference numerals are used for sake of clarity.

The third embodiment 200 of the vacuum cleaner differs from the first 10 embodiment 10 of the vacuum cleaner in the form of the actuator 202 and presence of a movable, but not necessarily inflatable, member 204.

The actuator 202 comprises a controller 206, a drive motor 208, a pinion 210 and a rack 212. The controller 206 is configured to control the drive motor 208 in response to selection of a mode of operation of the vacuum cleaner 200 via the user input 26. The pinion 210 is coupled to an output of the drive motor 208, and is meshed with the rack 212. The rack 212 is coupled to the movable member 204.

The movable member 204 is fixedly attached at one end to a wall of the main body 12 of the vacuum cleaner 200. The movable member 204 is located in the inlet duct 46 downstream of the sealing member 60, and formed of a resiliently deformable material such as rubber. The movable member 204 generally has the form of a rolling diaphragm seal, and comprises an external sealing surface for engaging with the sealing member 60.

In use, the controller 206 controls the drive motor 208 in response to selection of a mode of operation of the vacuum cleaner 200 via the user input 26. The drive motor 208 drives rotation of the pinion 210, which in turn causes linear motion of the rack 212. Movement of the rack 212 can cause movement of the movable member 204 between first and second positions in which the movable member is either disengaged from, or engaged with, the sealing member 60, in a manner similar to that described in relation to the first embodiment 10 of the vacuum cleaner described above.

A fourth embodiment of a vacuum cleaner 300 is illustrated schematically in Figure 8, where like reference numerals are used for sake of clarity.

The fourth embodiment 300 of the vacuum cleaner differs from the first embodiment 10 of the vacuum cleaner in the form of the actuator 302 and presence of a user operated trigger 304 and a movable, but not necessarily inflatable, member 306.

The actuator 302 comprises a first rack 308, a rotatable member 310, and a second rack 312. The first rack 308 is connected between the trigger 304 and the rotatable member 310, and drives motion of the rotatable member 310 in response to actuation of the trigger 304. The rotatable member 310 is meshed with the second rack 312. The second rack 312 is coupled to the movable member 306.

The movable member 306 is fixedly attached at one end to a wall of the main body 12 of the vacuum cleaner 300. The movable member 306 is located in the inlet duct 46 downstream of the sealing member 60, and formed of a resiliently deformable material such as rubber. The movable member 306 generally has the form of a rolling diaphragm seal, and comprises an external sealing surface for engaging with the sealing member 60.

In use, a user actuates the trigger 304, which, via the first rack 308, drives rotation of the rotatable member 310, which in turn causes linear motion of the second rack 312. Movement of the second rack 312 can cause movement of the movable member 306 between first and second positions in which the movable member is either disengaged from, or engaged with, the sealing member 60, in a manner similar to that described in relation to the first embodiment 10 of the vacuum cleaner described above. In some examples, a sensor is provided to sense a position of the trigger 304, and to communicate a position of the trigger 304 to a controller that can automatically control a mode of operation of the vacuum cleaner 300 based on the position of the trigger 304.

A fifth embodiment of a vacuum cleaner 400 is illustrated schematically in Figure 9, where like reference numerals are used for sake of clarity.

The fifth embodiment 400 of the vacuum cleaner differs from the first embodiment 10 of the vacuum cleaner in the form of the actuator 402 and presence of a user operated switch 404, a movable, but not necessarily inflatable, member 406, and a latch 408.

The actuator 402 comprises a mechanical linkage 410 connected between the switch 404 and the movable member 406.

The movable member 406 is fixedly attached at one end to a wall of the main body 12 of the vacuum cleaner 400. The movable member 406 is located in the inlet duct 46 downstream of the sealing member 60, and formed of a resiliently deformable material such as rubber. The movable member 406 generally has the form of a rolling diaphragm seal, and comprises an external sealing surface for engaging with the sealing member 60.

The latch 408 automatically engages the mechanical linkage 410 to hold the movable member 406 in place when a user moves the switch 404. The latch 408 is disengagable, for example either when a user moves the switch 404 in an opposite direction, or in response to selection of a mode of operation of the vacuum cleaner 400 via the user input 26.

In use, a user moves the switch 404, which, via the mechanical linkage 410, which can cause movement of the movable member 406 between first and second positions in which the movable member is either disengaged from, or engaged with, the sealing member 60, in a manner similar to that described in relation to the first embodiment 10 of the vacuum cleaner described above. The latch 408 can be used to selectively hold the movable member 406 in place.

In each of the embodiments described above, a movable member, including where an inflatable member moves as a result of inflation and deflation, moves between first and second positions to selectively enable or disable airflow through inlets 72 of the second cyclonic separators 56.

Whilst particular examples and embodiments have thus far been described, it should be understood that these are illustrative only and that various modifications may be made without departing from the scope of the invention as defined by the claims.

Claims

Claims 1. A separation system for a vacuum cleaner, the separation system comprising: a first cyclonic separator comprising a first inlet; a second cyclonic separator comprising a second inlet, the second cyclonic separator arranged in parallel with the first cyclonic separator; and a movable member movable between a first position in which the movable member permits airflow through the first and second inlets, and a second position in which the movable member permits airflow through the first inlet and inhibits airflow through the second inlet.
2. A separation system as claimed in Claim 1, wherein the separation system comprises an inlet duct for receiving an airflow, the inlet duct connected to the first and second inlets, and the movable member is located within the inlet duct
3. A separation system as claimed in Claim 2, wherein the second inlet is spaced from the first inlet along a length of the inlet duct.
4. A separation system as claimed in Claim 2 or Claim 3, wherein the separation system comprises a sealing member extending about an inner surface of the inlet duct, and the movable member is movable relative to the sealing member between the first and second positions such that the movable member is spaced from the sealing member in the first position, and the movable member contacts the sealing member in the second position.
5. A separation system as claimed in any preceding claim, wherein the first cyclonic separator has a different geometry to the second cyclonic separator.
6. A separation system as claimed in any preceding claim, wherein the separation system comprises a user operable actuator to move the movable member between the first and second positions.
7. A separation system as claimed in any of Claims 1 to 5, wherein the separation system comprises an electrically operable actuator to move the movable member between the first and second positions.
8. A separation system as claimed in any preceding claim, wherein the movable member comprises an inflatable member movable in response to inflation and deflation.
9. A separation system as claimed in any of Claims 1 to 8, wherein the movable member is movable between the first and second positions in response 15 to movement of a switch by a user.
10. A separation system as claimed in any preceding claim, wherein the separation system comprises a first dirt collection chamber in fluid communication with the first cyclonic separator, and a second dirt collection chamber, different to the first dirt collection chamber, in fluid communication with the second cyclonic separator.
11. A separation system as claimed in any preceding claim, wherein the separation system comprises: a plurality of first cyclonic separators, each comprising a respective first inlet; a plurality of second cyclonic separators, each comprising a respective second inlet, the plurality of second cyclonic separators arranged in parallel with the plurality of first cyclonic separators; and wherein the movable member permits airflow through the first and second inlets when in the first position, and movable member permits airflow through the first inlets and inhibits airflow through the second inlets when in the second position.
12. A separation system as claimed in Claim 11, wherein the first inlets are arranged in a first annular array, the second inlets are arranged in a second annular array, and the first annular array is spaced apart from the second annular array.
13. A separation system as claimed in Claim 11 or Claim 12, wherein the separation system comprises different numbers of first and second cyclonic separators.
14. A vacuum cleaner comprising a separation system as claimed in any preceding claim. 15
15. A vacuum cleaner as claimed in Claim 14, wherein the vacuum cleaner comprises an airflow generator for generating an airflow through the separation system, the vacuum cleaner is operable in a first mode in which the airflow generator generates airflow at a first flow rate through the separation system, and a second mode in which the airflow generator generates airflow at a second flow rate, different to the first flow rate, through the separation system, and the movable member is in the first position in the first mode and in the second position in the second mode.
16. A vacuum cleaner as claimed in Claim 15, wherein the movable member comprises an inflatable member movable in response to inflation and deflation, and a valve assembly to cause inflation and deflation of the inflatable member, wherein the valve assembly comprises a first airflow path in fluid communication with a location upstream of the airflow generator, a second airflow path in fluid communication with a location downstream of the airflow generator, a third airflow path in fluid communication with the inflatable member, and a valve member movable to selectively allow airflow through only one of the first airflow path and the second airflow path.
17. A vacuum cleaner as claimed in Claim 16, wherein movement of the valve member is electrically actuated.
18. A vacuum cleaner as claimed in Claim 17, wherein movement of the valve member is electrically actuated in response to selection of one of the first and second modes by a user.
19. A vacuum cleaner as claimed in Claim 14 or Claim 15, wherein the separation system comprises a drive motor to drive movement of the movable member between the first and second positions.
20. A vacuum cleaner as claimed in Claim 19, wherein the drive motor is actuated in response to selection of one of the first and second modes by a user.