VACUUM CLEANER

Abstract

A vacuum cleaner operable between ON and OFF states includes a cyclonic dust separation device operable, when the vacuum cleaner is in the ON state, to provide separation of dust from an airflow through the vacuum cleaner; a motor that generates airflow through the vacuum cleaner having a motor cover provided with at least one fluid opening which defines a part of a fluid flow path for fluid originating from a serviceable filter assembly; and a valve assembly operable to open and close, respectively, the at least one fluid opening in the motor cover. The valve assembly can be configured such that, when the vacuum cleaner is in the ON state, the valve assembly is in the closed position to prevent the airflow through the at least one fluid opening, and, when the vacuum cleaner is in the OFF state, the valve assembly is in the open position to open the fluid flow path through the at least one fluid opening.

Description

The present invention relates to a vacuum cleaner. Aspects of the invention relate to a vacuum cleaner and to a motor assembly for use in a vacuum cleaner. In particular, the invention relates to a vacuum cleaner which operates on the basis of cyclonic separation of dust from an airflow through the vacuum cleaner.

A vacuum cleaning appliance or, more simply, “vacuum cleaner”, typically comprises a main body which is equipped with a suction motor, a dust separation device, and a cleaner head connected to the dust separation device usually by a separable coupling. The dust separation device is the main mechanism by which the vacuum cleaner removes dirt and debris from the airflow through the machine, and this applies whether the dust separation device relies on a cyclonic separation system or otherwise.

Although dust separators are generally very efficient at removing dirt and debris from the airflow, fine particles remain in the airflow that exits the dust separator and travels towards the suction motor. It is important that the suction motor is protected from these fine particles as they can be potentially damaging to some of its components. It is also important to make the exhaust airflow that is discharged from the vacuum cleaner as clean as possible. Thus, typically, a vacuum cleaner includes two filters: a first filter, also called a “pre-motor filter” or “pre-filter”, which is located in the airflow through the machine downstream of the dust separation device but upstream of the suction motor; and a second filter, also called a “post-motor filter” or “post-filter”, that is located in the airflow downstream of the suction motor, before the airflow exhausts from the machine.

It is known to house the pre-motor filter in a filter assembly which can be removed easily by the user for cleaning purposes. Typically, once the filter assembly is removed the filter medium for the pre-filter can be removed from the assembly, washed, and dried, and then replaced in the assembly. It remains a challenge however to ensure that the user handles the filter medium correctly once it has been removed and that once washed the filter medium is thoroughly dried before it is re-inserted into the filter assembly. For example, any moisture remaining in the filter medium once it has been re-inserted into the filter assembly can cause problems due to its location relative to the electronic components of the vacuum cleaner, so that it is desirable to avoid inserting a filter medium which is not fully dried into the assembly.

It is an object of the invention to address the aforementioned problem.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a vacuum cleaner for use with a serviceable filter assembly, wherein the vacuum cleaner is operable between ON and OFF states and comprises a cyclonic dust separation device which is operable, when the vacuum cleaner is in the ON state, to provide separation of dust from an airflow through the vacuum cleaner; a motor for generating the airflow through the vacuum cleaner, the motor having a motor cover provided with at least one fluid opening which defines a part of a fluid flow path for fluid originating from the serviceable filter assembly; and a valve assembly operable between open and closed positions to open and close, respectively, the at least one fluid opening in the motor cover.

Preferably, the valve assembly is configured such that, when the vacuum cleaner is in the ON state, the valve assembly is in the closed position to prevent the airflow through the at least one fluid opening, and when the vacuum cleaner is in the OFF state the valve assembly is in the open position to open the fluid flow path through the at least one fluid opening.

When the serviceable filter assembly of the vacuum cleaner is removed for washing, for example, there is a possibility that the filter assembly will not be completely dry when it is reassembled into the vacuum cleaner after servicing. The present invention provides the advantage that should this occur, when the vacuum cleaner is in the OFF state and typically stored in an upright position, the valve assembly is operable to control the flow of fluid (such as water or other cleaning fluid) through the fluid flow path to ensure that contact with or exposure of critical components to fluid is substantially avoided. For example, the valve assembly is operable to open when the vacuum cleaner is turned off (OFF state), thereby opening up a fluid flow path through the vacuum cleaner which routes any fluid flow away from the printed circuit board which supports the controller for the motor. In addition, when the vacuum cleaner is turned on (ON state) and an airflow is drawn through the appliance, the valve member is closed to ensure that no air can flow pass the valve assembly causing damage to the downstream motor.

In embodiments, the valve assembly includes a valve member which is received within the motor cover and is movable to open and close the at least one fluid opening in the motor cover when switching between the open and closed positions, respectively.

In embodiments, the valve member is received through a valve opening provided in the motor cover member.

In embodiments, the valve opening is positioned on a central longitudinal axis of the vacuum cleaner.

In embodiments, the valve member includes a stem portion and a sealing portion, wherein the stem portion is received within the valve opening and wherein the sealing portion has a surface which seals against the motor cover to close the at least one fluid opening when the valve assembly is in the closed position.

The stem portion and the sealing portion are configured in such a way that allows a strong seal against the motor cover when the valve is in the closed position.

In embodiments, the valve member is configured such that, when the vacuum cleaner is stowed in an upright position in the OFF state, the valve member is movable under a force due to gravity into the open position.

Advantageously, when the vacuum cleaner is stowed in an upright position, the valve member opens which allows any fluid to pass through the vacuum cleaner and into the primary cyclone. Importantly, water or any other fluid retained in the filter milter can be drained safely without collecting on the motor cover and risking damage other components (for example, a PCB).

In embodiments, the valve assembly includes a valve spring which serves to urge the valve member into the closed position to prevent the airflow past the valve member when the vacuum cleaner is in the ON state.

In embodiments, the vacuum cleaner further comprises retaining means to limit movement of the valve member when it moves into the open position.

In embodiments, the retaining means includes an annular flange carried on the valve member which engages with the motor cover to limit the extent of movement of the valve member.

In embodiments, the vacuum cleaner further comprises a plurality of fluid openings provided in the motor cover.

In embodiments, each of the plurality of fluid openings is of arc-shaped form.

In embodiments, the cyclonic dust separation device includes at least one vortex tube in communication with a primary cyclone, wherein at least one of the vortex tubes forms a part of the fluid flow path when the vacuum cleaner is in the OFF state and the valve assembly is in the open position.

In embodiments, the primary cyclone forms a part of the fluid flow path when the vacuum cleaner is in the OFF state and the valve assembly is in the open position.

In embodiments, the vacuum cleaner further comprises a printed circuit board including a controller for the motor, wherein the printed circuit board resides beneath the filter assembly when the vacuum cleaner is in a stowed position.

It will be appreciated that preferred and/or optional features of each aspect of the invention may be incorporated alone, or in appropriate combination, in the other aspects of the invention also.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention may be more readily understood, an embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a dust separation device for a vacuum cleaner known in the art, with the dust separation device in an in-use position;

FIG. 2 is a perspective view of the dust separation device in FIG. 1, when in a docked or stowed position;

FIG. 3 is a section view of a part of the dust separation device in FIGS. 1 and 2 when in the docked or stowed position (as in FIG. 2), to illustrate a fluid path through the device;

FIG. 4 is an exploded view of the dust separation device of an embodiment of the invention;

FIG. 5 is a perspective view of a part of the dust separation device in FIG. 4, to illustrate a motor of the device;

FIG. 6 is a perspective view of the motor cover in FIG. 5 together with a valve member for controlling a fluid flow through the device;

FIG. 7 is a perspective view of the valve member shown in FIGS. 5 and 6;

FIG. 8 is side view of the valve member in FIG. 7;

FIG. 9 is a section view of the valve member in FIGS. 7 and 8;

FIG. 10 is an enlarged cut-away view of the valve member in FIGS. 7 to 9;

FIG. 11 is cut-away view through the dust separation device in FIG. 4, looking towards the filter assembly, to illustrate the position of the valve member mounted in the motor cover;

FIG. 12 is a cut-away view through the dust separation device in FIG. 4, from a direction looking towards a cyclone assembly of the device, to illustrate the reverse side of the motor cover to that shown in FIG. 11;

FIG. 13 is an enlarged section view of a part of the dust separation device in FIG. 4 to illustrate a fluid flow path through the device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In order to understand a potential problem in the prior art, FIGS. 1 and 2 show a perspective view of a known dust separation device, referred to generally as 10, which is fitted with a filter assembly 12. The dust separation device 10 forms a part of a vacuum cleaner which includes, at one end of an elongate section (referred to as the wand-not shown), a cleaner head (also not shown). The dust separation device 10 is located at the other end of the wand to the cleaner head.

The dust separation device 10 includes a device housing 14 having a handle 16 for manipulation by the user. Typically, the handle 16 houses a battery pack inside one handle section 18 which may contain one or more replaceable or rechargeable batteries for powering the dust separation device 10. The device housing 14 houses various components of the dust separation device 10, as is known in the art, including a cyclone assembly 15 and a brushless electric motor (not visible in FIGS. 1 and 2). The dust separation device 10 utilises cyclonic separation to separate dirt and debris from an airflow through the device to enable the cleaning of a surface as the cleaner head is swept over the surface. The brushless electric motor is a direct current motor which is operated on a switched reluctance principle and is controlled by means of a printed circuit board (PCB) (not visible in FIGS. 1 and 2) which receives power from the battery pack 18.

The filter assembly 12 provides a pre-motor filter stage for the dust separation device 10 and connects to one end of the device housing 14 in a removable manner. The other end of the device housing 14 connects to the wand (not shown). The filter assembly includes a washable filter medium which allows the passage of air therethrough, but which prevents the passage of dirt or dust particles which would otherwise be drawn into the motor and may cause damage.

In FIG. 1, the dust separation device 10 is shown in a typical in-use orientation of the vacuum cleaner in which the longitudinal axis of the dust separation device is at an angle to the vertical direction. The user grasps the handle 16 of the dust separation device 10 and manoeuvres the device so that the cleaner head at the end of the wand is moved back and forth across the surface to be cleaned. When not in use, the dust separation device 10 is stowed in a docked or stowed position, as shown in FIG. 2, in which the longitudinal axis of the dust separation device is aligned with the vertical direction (i.e. the device is upright). This orientation is particularly convenient as it lends itself to stowing of the vacuum cleaner against a wall or in a cupboard to minimise intrusion into open space.

In order to clean the pre-motor filter assembly 12 it is necessary to first disconnect the filter assembly 12 from the dust separation device 10, as shown in FIG. 4. It is a known problem that during use the filter medium tends to become blocked with dirt and debris and therefore regular cleaning is required to ensure effective operation and prolonged service life for the vacuum cleaner. When the filter assembly 12 is removed from the dust separation device 10 it can be washed in order to clean it, typically running the filter medium under a running water tap or immersing it in water. The filter medium should then be dried fully before it is reassembled into the filter assembly 12, following which the filter assembly 12 can be re-connected to the dust separation device 10.

The problem which can be experienced in the dust separation device 10 arises when the filter medium of the filter assembly 12 is not fully dried before it is re-assembled with the dust separation 10 and the vacuum cleaner is stored in the stowed position of FIG. 2.

Referring also to FIG. 3, a longitudinal central axis of the vacuum cleaner, A-A, is identified and the position of a filter medium 20 of the filter assembly 12 relative to a printed circuit board (PCB) 22 for the motor of the dust separation device 10 can be seen clearly. The PCB 22 is positioned directly beneath the filter assembly 12 including the filter medium 20 and, therefore, under the force of gravity, any water which remains within the filter medium after washing is able to follow a water fluid path 24 downwards through the filter assembly, impinging on the PCB 22. To avoid failures resulting from the exposure of the PCB 22 to water or other cleaning liquid, the inventors have therefore devised an improvement to the dust separation device 10 which will be described with reference to the subsequent figures.

Similar parts to those described previously will be referred to with like reference numerals.

Referring to FIG. 4, the construction of the vacuum cleaner of an embodiment of the invention can be seen more clearly. The cyclone assembly 15 includes first and second cyclone stages; a primary cyclone chamber 15a and a plurality of secondary cyclone tubes 15b (only two of which are identified). The secondary cyclone tubes 15b are also referred to as vortex tubes and are carried on a plate 30 (referred to as the vortex plate). An annular cover 32 is provided for the vortex plate 30. The annular cover 32 is provided with a plurality of formations, one for each vortex tube 15b, so that the cover slots conveniently over the vortex plate 30 and protects the outer surfaces of the vortex tubes.

Referring also to FIG. 5, a motor assembly 36 is located adjacent to the annular cover 32. As described previously, the motor assembly 36 includes a brushless electric motor in the form of a direct current motor which is operated on a switched reluctance principle and is controlled by means of the PCB 22 (not visible in FIGS. 4 and 5). The motor is housed within a motor casing 40, which is attached to the handle 16. The motor assembly 36 is closed by a motor cover member 42 to protect the motor from fine dust particles which may be present within the airflow through the device. In operation, the motor is used to drive a fan (not shown) to drive a suction airflow through the vacuum cleaner which is drawn through the cleaner head, through the wand and into the cyclone assembly 15. As described previously, the filter assembly 12 for the motor is located at the rear end of the appliance, remote from the wand, and is removable to enable it to be washed during servicing.

Referring also to FIG. 6, the motor cover 42 has one surface (referred to as the cyclone-facing surface 45) which faces the cyclone assembly 15 and an opposed surface 47 (referred to as the motor-facing surface) which faces away from the cyclone assembly 15 and towards the motor assembly 36 itself. The motor cover 42 is provided with several mounting flanges 44 which enable the motor cover 42 to be affixed to the motor casing 40 by means of screws or other fixing means. The valve assembly, including a valve member 50, is mounted in the motor cover 42.

Referring also to FIGS. 7 to 9, it can be seen that the valve member 50 resembles an umbrella structure including a cover or sealing portion 52 and a stem portion 54. The sealing portion 52 has an upper surface 52a and a lower surface 52b and the stem portion 54 extends downwardly from the lower surface 52b of the sealing portion 52; the stem portion 54 and the sealing portion 52 are integrally formed. At the end of the stem portion 54 remote from the sealing portion 52, the stem portion 54 carries an annular flange 56 having an outer surface which tapers inwardly in the direction towards the end of the stem portion 54. A flat end surface 58 of the stem portion 54 is provided with a recess 60 for receiving a screw (not shown).

As can be seen most clearly in FIG. 9, the lower surface of the sealing portion 52 is shaped to define an inner annular sealing region 72 and an outer annular sealing region 74, with the outer annular sealing region extending slightly further towards the end face 58 of the valve member 50 than the inner annular sealing region 72. The outer annular sealing region 74 defines an outer sealing surface at the periphery of the valve member 50 which is of enlarged diameter compared to an inner sealing surface of the inner annular sealing region 72.

Referring also to FIG. 10, the motor cover 42 is provided with a central opening region 62 which is positioned within the motor cover 42 so as to align with the central longitudinal axis A-A of the vacuum cleaner. The central opening region 62 includes three radially extending spokes 64, which meet in a central disc region 66 of the motor core 42, to divide the central opening region 62 into three regular arc-shaped openings 68 which define openings for fluid flow (fluid openings) through the motor cover 42. The three spokes 64 provide support for the central disc region 66. The central disc region 66 is itself provided with a further opening 70 (referred to as the “valve opening”) which receives the stem portion 54 of the valve member 50 in a slidable manner. In other words, the valve member 50 is mounted to the motor cover 42 through the valve opening 70.

The orientation of the valve member 50 is such that, when the valve member 50 is received in the valve opening 70, the lower surface 52b of the sealing portion 52 faces the cyclone-facing surface 45 of the motor cover 42. When in a closed or sealed position of the valve member 50, the outer annular sealing region 74 seals against that region of the motor cover 42 surrounding the valve opening 70 and the inner annular sealing region 72 seals against the disc region 66. Although the outer annular sealing region projects slightly further downwards from the sealing portion 52 towards the end face 58 of the valve member 50, the degree of flexibility of the valve member 50 ensures that the outer annular sealing region 74 is splayed radially outwards slightly as it engages with the cyclone-facing surface 45 of the motor cover 42 so that the inner annular sealing region 72 also contacts with and seals against the disc region 66.

As can be seen most clearly from FIG. 11, when the valve member 50 is in its closed position against the cyclone-facing surface 45 of the motor cover 42, the sealing portion 52 completely covers the disc opening region 62 to seal against the periphery of the arc-shaped openings 68 (which are not visible in FIG. 11). This can also be seen from the reverse view of the motor cover 42 in FIG. 12, where the lower surface of the sealing region 52 of the valve member 50, which is closed against the motor cover 42, is visible through the arc-shaped openings 68.

Operation of the vacuum cleaner will be familiar to the skilled person and will not be described in detail here, except insofar as it is relevant to the operation of the valve assembly 50 which provides an important functionality for the device. In general, however, it is worth noting that, in use, when the vacuum cleaner is in the ON state, a suction airflow is generated by the motor assembly 36 driving the fan which draws air up through the cleaner head, through the wand and into the primary cyclone 15a and the secondary cyclones 15b. The suction airflow draws dirty air into the cyclones 15a, 15b, where dirt and debris are separated from the airflow as the air swirls violently around these chambers. Dirt and debris are discharged from the secondary cyclones 15b and collect within the volume of the primary cyclone 15a, whilst cleaner air gets sucked, upwardly, out of the secondary cyclones 15b, through the filter assembly 12, through the motor assembly 36 and exits the device. Dirt and debris can be later removed from the appliance by detaching the cyclone assembly 15 and emptying the dirt and debris from a collection chamber.

FIG. 13 shows the vacuum cleaner in the stowed position (as in FIG. 2) in which the longitudinal axis A-A of the appliance is aligned with the vertical direction (i.e. the appliance is said to be upright). In this orientation the opposed surfaces of the motor cover 42 are such that one surface is downwardly facing (the cyclone-facing surface 45) and the opposed surface (the motor-facing surface 47) is upwardly facing. With the vacuum cleaner in this orientation, the valve member 50 is urged downwards, under a force due to gravity, so that the sealing portion 52 of the valve member 50 moves away from the cyclone-facing surface 45 of the motor cover 42, uncovering and opening up the arc-shaped openings 68. The extent to which the valve member 50 is able to move away from the cyclone-facing surface 45 of the motor cover 42 is limited by engagement of the annular flange 56 on the stem portion 54 of the valve member 50 with the motor-facing surface 47 via the disc region 66. The provision of the annular flange 56 on the valve member 50 provides a retention means for the valve member within the valve opening 70 and engagement between the annular flange 56 and the motor cover 42 ensures that the valve member 50 cannot drop completely through the valve opening 70. Importantly, the uncovering of the arc-shaped openings 68 allows any fluid that is present within the device, originating from the filter assembly 12, to pass through the openings 68, so that the arc-shaped openings 68 define a part of a fluid flow path (identified as dashed lines 80 in FIG. 13) through the appliance. The fluid flow path 80 flows radially outwards so that it passes over the vortex plate 30 and downwards through the vortex tubes 15b into the primary cyclone 15a. The fluid flow path comprises a number of separate, parallel flow routes for fluid, each passing through a respective one of the vortex tubes 15b into the primary cyclone 15a. If the valve member 50 were to remain closed against the motor cover 42 at this time, any water or other cleaning fluid retained in the filter medium would otherwise pass downwardly through the device, with fluid collecting on the motor cover 42 with the risk of damage to the PCB 22.

When the vacuum cleaner is in the ON state and air is being sucked through the appliance by means of the motor-driven fan, pressure beneath the motor cover 42 is greater than that above the motor cover 42, and the pressure drop across the motor cover 42 ensures that the valve member 50 remains closed against the cyclone-facing surface 45 of the motor cover 42 at all times. The airflow thus serves to maintain the valve member 50 in the closed position when the vacuum clearer is in the ON state, regardless of the orientation of the vacuum cleaner. Because the valve member 50 remains closed, no airflow is able to reach the internal components of the motor, behind the motor cover 42, and the only airflow route through the appliance is through the vortex tubes 15b and around the outside of the motor assembly 36. Hence, the motor is protected from airflow exiting the cyclone assembly 15 which may still carry a small amount of fine dirt and debris.

In the embodiment of the invention described with reference to the aforementioned Figures, the valve member 50 relies on the pressure crop across the motor cover 42 to retain the valve member 50 in the closed position when the vacuum cleaner is in the ON state. In other embodiments, the valve member 50 may be provided with a lightly-biassed valve spring which serves to urge the valve member 50 into the closed position to close the arc-shaped openings 68. It is only when the vacuum cleaner is turned to the OFF state and moved into the stowed (upright) position that the spring force of the valve spring is overcome by gravity and the valve member 50 is caused to moved away from the openings 68, to open up the fluid flow path 80 through the motor cover 42 and away from the PCB 22.

It will be appreciated that various other modifications to the invention may be made within departing from the scope of the invention as set out in the accompanying claims.

Claims

1: A vacuum cleaner for use with a serviceable filter assembly, wherein the vacuum cleaner is operable between ON and OFF states and comprises; a cyclonic dust separation device which is operable, when the vacuum cleaner is in the ON state, to provide separation of dust from an airflow through the vacuum cleaner;a motor for generating the airflow through the vacuum cleaner, the motor having a motor cover provided with at least one fluid opening which defines a part of a fluid flow path for fluid originating from the serviceable filter assembly; anda valve assembly operable between open and closed positions to open and close, respectively, the at least one fluid opening in the motor cover.

2: The vacuum cleaner as claimed in claim 1, wherein the valve assembly is configured such that, when the vacuum cleaner is in the ON state, the valve assembly is in the closed position to prevent the airflow through the at least one fluid opening, and when the vacuum cleaner is in the OFF state the valve assembly is in the open position to open the fluid flow path through the at least one fluid opening.

3: The vacuum cleaner as claimed in claim 1, wherein the valve assembly includes a valve member which is received within the motor cover and is movable to open and close the at least one fluid opening in the motor cover when switching between the open and closed positions, respectively.

4: The vacuum cleaner as claimed in claim 3, wherein the valve member is received through a valve opening provided in the motor cover member.

5: The vacuum cleaner as claimed in claim 4, wherein the valve opening is positioned on a central longitudinal axis of the vacuum cleaner.

6: The vacuum cleaner as claimed in claim 3, wherein the valve member includes a stem portion and a sealing portion, wherein the stem portion is received within the valve opening and wherein the sealing portion has a surface which seals against the motor cover to close the at least one fluid opening when the valve assembly is in the closed position.

7: The vacuum cleaner as claimed in claim 3, wherein the valve member is configured such that, when the vacuum cleaner is stowed in an upright position in the OFF state, the valve member is movable under a force due to gravity into the open position.

8: The vacuum cleaner as claimed in claim 3, wherein the valve assembly includes a valve spring which serves to urge the valve member into the closed position to prevent the airflow past the valve member when the vacuum cleaner is in the ON state.

9: The vacuum cleaner as claimed in claim 3, further comprising retaining means to limit movement of the valve member when it moves into the open position.

10: The vacuum cleaner as claimed in claim 9, wherein the retaining means includes an annular flange carried on the valve member which engages with the motor cover to limit the extent of movement of the valve member.

11: The vacuum cleaner as claimed in claim 1, comprising a plurality of fluid openings provided in the motor cover.

12: The vacuum cleaner as claimed in claim 11, wherein each of the plurality of fluid openings is of arc-shaped form.

13: The vacuum cleaner as claimed in claim 1, wherein the cyclonic dust separation device includes at least one vortex tube in communication with a primary cyclone, wherein at least one of the vortex tubes forms a part of the fluid flow path when the vacuum cleaner is in the OFF state and the valve assembly is in the open position.

14: The vacuum cleaner as claimed in claim 13, wherein the primary cyclone forms a part of the fluid flow path when the vacuum cleaner is in the OFF state and the valve assembly is in the open position.

15: The vacuum cleaner as claimed in claim 1, further comprising a printed circuit board including a controller for the motor, wherein the printed circuit board resides beneath the filter assembly when the vacuum cleaner is in a stowed position.