GB2372436A

GB2372436A - A domestic vacuum appliance

Info

Publication number: GB2372436A
Application number: GB0109407A
Authority: GB
Inventors: Stephen Paul Organ
Original assignee: Dyson Ltd
Current assignee: Dyson Ltd
Priority date: 2001-02-24
Filing date: 2001-04-12
Publication date: 2002-08-28
Anticipated expiration: 2021-04-12
Also published as: GB2372436B; GB0104662D0; GB0109407D0; GB2372431B; GB2372431A

Abstract

A domestic vacuum appliance (10, Fig 16) having a motor and fan unit 48 for creating a flow of air through the appliance (10, Fig 16) and an airflow path for conducting the flow of air from an air inlet (18, 28a, Fig. 16) to the motor and fan unit 48, wherein the motor and fan unit 48 has a fan axis 32 and a fan inlet 48a and a filter 42 is arranged in the airflow path upstream of the fan inlet 48a, characterised in that the filter 42 is located in a housing 44 which forms part of a casing (14, Fig 16) of the appliance (10, Fig 16), the housing 44 being removable from the remainder of the casing (14, Fig 16) of the appliance (10, Fig 16) together with the filter 42.

Description

A Domestic Appliance The invention relates to a domestic appliance.

Particularly, but not exclusively, the invention relates to a vacuum cleaner and more particularly to a domestic vacuum cleaner. Vacuum cleaners are required to separate dirt and dust from an airflow in order to effect the cleaning of an environment, commonly a domestic environment. Dirt- and dust-

laden air is sucked into the appliance via either a floor-engaging cleaner head or a tool connected to the end of a hose and wand assembly and passed to a device for removing from the airflow as much dirt and dust as possible before the cleaned air is exhausted to atmosphere. Very many vacuum cleaners make use of a porous bag through which the dirty air is sucked so that the dirt and dust is retained in the bag whilst cleaned air is exhausted to the atmosphere. In other vacuum cleaners, cyclonic separators are used to separate dirt and dust from the airflow (see, for example, EP 0 042 723). Whichever type of separator is employed, there is commonly a risk of a small amount of dust passing through the separator and being carried to the fan and motor unit, which is used to create the flow of air through the vacuum cleaner whilst it is in operation. The exiting airflow is also made to flow past the motor so as to cool the motor and therefore the optimum operation of the motor is dependent on the airflow being maintained.

It is not desirable that dirt and dust particles are allowed to pass through the fan when the fan is arranged downstream of the separating apparatus of a vacuum cleaner because the fan could become damaged or unbalanced. In order to prevent this happening, some vacuum cleaners include a fine filter, separate from the main dirt and dust collecting apparatus, located between the separating apparatus and the fan (see, for example, GB 2 320 419 and EP 0 366 295). This is termed a "pre-motor filter" and extracts any fine dust particles remaining in the airflow after it has passed through the separating apparatus. Hence the risk of fine dust particles entering the fan is essentially eliminated.

Pre-motor filters commonly require to be either replaced or washed for reuse after a period of time. In known apparatus, the filter can be removed, either alone or with a collar or frame which provides structure to the filter (see, for example, the Dyson DC04 manufactured and sold by Dyson Limited). However, if the filter is overdue for washing or replacement, it is possible that the build-up of dirt and dust on the pre-motor filter will be such that simple removal of the filter will result in dirt and dust being dislodged from the filter before the user has had an opportunity to remove the filter to an appropriate location for disposal of the dirt and dust. It is then possible that the dirt and dust will be spilled on the floor or in another inconvenient place, which is undesirable. An object of the present invention is to provide a domestic appliance having a motor and fan unit for creating a flow of air through the appliance and a filter arranged upstream of the fan inlet, in which the risk of dirt and dust collected on the pre-motor filter becoming dislodged in an inappropriate place is minimised. Another object of the invention is to provide a domestic appliance in which the disadvantages of the prior art

are reduced or eliminated. A further object of the invention is to provide an improved vacuum cleaner.

The invention provides a domestic appliance having a motor and fan unit for creating a flow of air through the appliance and an airflow path for conducting the flow of air from an air inlet to the motor and fan unit, wherein the motor and fan unit has a fan axis and a fan inlet and a filter is arranged in the airflow path upstream of the fan inlet, characterised in that the filter is located in a housing which forms part of a casing of the appliance, the housing being removable from the remainder of the casing of the appliance together with the filter. The provision of a removable housing forming part of the casing of the appliance allows the filter to be retained in a semi-closed environment until the filter can be removed to a location suitable for removing the filter from the housing. An appropriate location might be a waste disposal area, a utility room, a garage or a garden. In such a location, any dirt and dust spilled from the filter during its

removal from the housing will be of little or no consequence or, at least' will be relatively easy to clear away.

Preferably, the housing is open on the downstream side of the filter to allow the filter to be removed from the housing for replacement or cleaning purposes. More preferably, the housing comprises a cover which faces the upstream side of the filter. This ensures that the dirt- and dust-laden upstream surface remains enclosed by the cover whilst the removability of the filter from the housing remains easy and convenient for the user.

In a preferred embodiment of the invention, the cover is spaced away from the upstream side of the filter and the housing comprises an inlet for introducing air to the interior of the housing between the cover and the upstream side of the filter. More preferably, the housing is removable from the remainder of the casing of the appliance in a direction which is perpendicular to the axis of the filter such that, when the housing is removed from the remainder of the casing of the appliance, the inlet is directed upwardly at all times. This arrangement ensures that, when the housing is removed to allow the filter to be cleaned or replaced, any dirt and dust which has been captured on the upstream side of the filter is retained inside the housing until the user is ready to dispose of it at a convenient location. The fact that the housing and filter are removable from the remainder of the appliance allows the disposal of the filter to be carried out more hygienically than has hitherto been the case.

Further and advantageous features of the invention are set out in the subsidiary claims.

An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figures la and lb (collectively, Figure 1) are front and side views, respectively, of a domestic appliance according to the invention;

Figures 2a and 2b (collectively, Figure 2) are side and perspective views, respectively, of a portion of the appliance of Figure 1; Figure 3 is a sectional view, taken along the line III-III of Figure 2a, of some of the components of the portion of the appliance shown in Figure 2; and Figures 4a and 4b (collectively, Figure 4) are side and perspective views, similar to Figures 2a and 2b respectively, illustrating the removal of a component of the appliance.

Figures la and lb show a domestic appliance according to the present invention in the form of a vacuum cleaner 10 incorporating cyclonic separating apparatus 100. The vacuum cleaner 10 comprises an upstanding body 12 at a lower end of which is located a motor casing 14 which houses a motor and fan unit. A cleaner head 16 is mounted in a freely articulated fashion on the motor casing 14. A suction inlet 18 is provided in the cleaner head 16 and wheels 20 are rotatably mounted on the motor casing 14 to allow the vacuum cleaner 10 to be manoeuvered over a surface to be cleaned.

The cyclonic separating apparatus 100 is mounted on the upstanding body 12 above the motor casing 14. The cyclonic separating apparatus 100 is seated on a generally circular, horizontal surface formed by a filter cover 22. The filter cover 22 is located above the motor casing 14 and provides a cover for a post-motor filter (not shown). The post-motor filter is provided in order to prevent any particles emanating from the motor from being released to the atmosphere. The cyclonic separating apparatus 100 is also secured to the upstanding body 12 by means of a clip 24 located at the top of the cyclonic separating apparatus 100. The upstanding body 12 incorporates upstream ducting (not shown) for carrying dirty air to an inlet of the cyclonic separating apparatus 100 and downstream ducting 26 for carrying cleaned air away from the cyclonic separating apparatus 100.

The upstanding body 12 further incorporates a hose and wand assembly 28 which may be retained in the configuration shown in the drawings so as to function as a handle for

manocuvering the vacuum cleaner 10 over a surface to be cleaned. Alternatively, the hose and wand assembly 28 may be released to allow the distal end 28a of the wand to be used in conjunction with a floor tool (not shown) to perform a cleaning function, eg on stairs, upholstery, etc. The structure and operation of the hose and wand assembly 28 is not material to the present invention and will not be described any further here, other than to say that the general structure and operation of the hose and wand assembly 28 illustrated in Figures la and lb is similar to that described in US patent number Re 32,257 which is incorporated herein by reference. Also, several tools and accessories 30a, 30b, 30c, are releasably mounted on the upstanding body 12 for storage purposes between periods of use.

In order for the vacuum cleaner 10 to be brought into operation, the motor located in the motor casing 14 is activated so that dirty air is drawn into the vacuum cleaner via either the suction inlet 18 or the distal end 28a of the hose and wand assembly 28. This dirty air (being air having dirt and dust entrained therein) is passed to the cyclonic separation apparatus 100 via the upstream ducting. After the air has passed through the cyclonic separation apparatus 100, it is ducted out of the cyclonic separating apparatus 100 and down the upstanding body 12 to the motor casing 14 via the downstream ducting 26.

The cleaned air is used to cool the motor located in the motor casing 14 before being exhausted from the vacuum cleaner 10 via the filter cover 22. The combination of the inlet formed by either the hose and wand assembly 28 or the cleaner head 16, the upstream ducting, the cyclonic separating apparatus 100 and the downstream ducting 26 forms an airflow path within the vacuum cleaner 10 for conducting the flow of air from an air inlet to the motor and fan unit.

The present invention is concerned with the arrangement of the airflow path immediately upstream of the motor casing 14. As can be seen from Figures 1, 2 and 3, the motor casing 14 is generally cylindrical in shape and is arranged so that the longitudinal axis 32 of the motor casing 14 lies generally horizontally and extends laterally across the cleaner head 16. Integrally moulded with the motor casing 14 on one side thereof are mouldings 34 designed and adapted to accommodate a duct (not

shown) for carrying dirty air entering the vacuum cleaner 10 via the suction opening 18 in the cleaner head 16. The mouldings 34 also provide one point of support for the cleaner head 16 and a further point of support for one of the wheels 20. These features do not form part of the present invention and will not be described any further here.

On the side of the motor casing 14 remote from the mouldings 34, a filterreceiving portion 36 is provided. The filter-receiving portion 36 is integrally moulded with the motor casing 14 and projects away therefrom in the direction of the axis 32. The filter-

receiving portion 36 has a generally part-cylindrical side wall 38, which extends generally parallel to the axis 32, and an end portion 40. The end portion 40 incorporates a second point of support 40a for the cleaner head 16 and a second point of support 40b for the second wheel 20. The configuration of the filter-receiving portion 36 is such that a recess is provided, the recess being open on the uppermost side thereof, so that a filter 42 and a housing 44 therefor may be received and supported in the filter-receiving portion 36. A circular divider portion 46 is provided between the motor casing 14 and the filter-receiving portion 36, the divider portion 46 essentially defining the boundary between the two aforesaid features.

The filter 42 may be a composite filter or may be formed from any other suitable filter material. It may be washable if desired and may also include a layer of HEPA grade filter material. The filter 42 shown here is annular in shape, having a cylindrical outer surface 42a and a cylindrical aperture 42b therethrough. The filter 42 may include a plastics collar 42c, particularly if the filter 42 is a composite, washable filter.

A filter housing 44 surrounds the filter 42. The filter housing 44 is generally cylindrical in shape having a cylindrical wall 44a and an end wall or cover 44b. The cylindrical wall 44a and the end wall 44b between them define an interior cavity 44c which is capable of receiving the filter 42 with the upstream side of the filter 42 facing the end wall 44b. The interior cavity 44c also provides an upstream chamber 44d between the filter 42 and the end wall 44b. The side of the filter housing 44 remote from the end wall 44b is open to allow the filter 42 to be introduced to the interior cavity 44c and

removed therefrom. The filter housing 44 also incorporates a dueling portion 44e which is provided on the end wall 44b and which communicates with the upstream chamber 44d. The external dimensions of the filter housing 44 are such that the filter housing 44 is able to be received without play in the filter-receiving portion 36. Hence, when the filter 42 is placed inside the filter housing 44 and the filter housing 44 is located within the filter-receiving portion 36, the filter housing 44 forms a part of the casing of the vacuum cleaner 10 by means of which the airflow path is defined. The ducting portion 44e is shaped and configured so that, when the filter housing 44 is located in the filter-

receiving portion 36, the ducting portion 44e abuts sealingly against and communicates with the lower end of the downstream dueling 26 (see Figure 2). As can be seen from Figure 2a, the dueling portion 44e is inclined upwardly when the filter housing 44 is thus located in the filterreceiving portion 36.

The divider portion 46 includes a circular upstream surface 46a in which is located a central aperture 46b. When the fan and motor unit 48 is located in the motor housing 14, it adopts the position relative to the divider portion 46 as shown in Figure 3. As can be seen, the central aperture 46b leads directly into the fan inlet 48a of the fan and motor unit 48. As can also be seen from Figure 3, the fan rotates about the same axis 32 as that of the motor casing 14.

A bleed valve 50 is provided in the filter housing 44. The bleed valve 50 is housed in a duct 52 provided in the filter housing 44 and extending axially from the end wall 44b towards the divider plate 46. The duct 52 lies coaxially with the axis 32 of the motor casing 14 and extends as far as the free edge of the side wall 44a. Hence, when the filter 42 is located within the interior cavity 44c, the duct extends through the whole of the filter 42 and opens downstream thereof. The upstream end of the duct 52 is open to atmosphere via a plurality of apertures 54 forming a generally annular slot in the centre of which is formed a plug 56. The diameter of the generally annular slot is slightly less than the internal diameter of the duct 52.

The bleed valve 50 comprises a valve head 50a which is cup-shaped and adapted to abut in a sealing manner on one side against the end wall 44b so as to close the apertures 54.

The valve head 50a has a central aperture of the same diameter as the plug 56. When the valve head 50a is pressed against the end wall 44b, the plug closes the central aperture of the valve head 50a. One end of a compression spring 50b is seated against the side of the valve head 50a remote from the end wall 44b. The other end of the compression spring 50b is seated against an inwardly projecting shaping 52b formed in the downstream end of the duct 52. The strength of the spring 50b is selected so that, when a pressure drop sufficient to indicate that the filter is blocked occurs across the pre-

motor filter 42, the valve head 50a is able to move against the bias of the compression spring 50b.

When the vacuum cleaner 10 is operated under normal conditions, the motor and fan unit 48 is operated causing the fan to rotate about the axis 32. Dirty air is thus drawn into the vacuum cleaner 10 via one of the dirty air inlets, ie. either through the suction opening 18 in the cleaner head 16 or through the distal end 28a of the wand and hose assembly 28. The dirty air is passed to the cyclonic separating apparatus 100 via the upstream ducting and dirt and dust is separated from the airflow in the cyclonic separating apparatus 100. The cleaned air then travels down the downstream ducting 26 and passes along the dueling portion 44e of the filter housing 44. The air then enters the upstream chamber 44d and then passes through the pre-motor filter 42 before entering the fan inlet via the central aperture 46b of the divider portion 46. Any dirt and dust particles entrained within the airflow are thus retained in the pre-motor filter 42 so that the risk of damage to or unbalancing of the fan is minimised. The air passes around the motor and fan unit 48 before exiting the vacuum cleaner via a post-motor filter housed beneath the filter cover 22. As previously explained, the post-motor filter is provided so as to prevent any particles generated within the motor from being emitted to the atmosphere.

If the pre-motor filter 42 becomes clogged or blocked so that insufficient cooling air passes to the motor, the pressure drop across the pre-motor filter 52 will increase. The valve head 50a will then move away from the end wall 44b so as to open an airway along the duct 52. Atmospheric air is then allowed to pass through the apertures 54, through the central aperture in the valve head 50a and along the duct 52 so as to enter the airflow path immediately upstream of the motor and fan unit 48. The bled air then passes along the central aperture 46b of the divider portion 46 and directly into the motor and fan unit 48. Indeed, the atmospheric air which is bled into the vacuum cleaner 10 is introduced directly to the fan inlet 48a at the eye of the fan. This has the distinct advantage that the bled air is introduced to the motor along a very direct path having no tortuous bends so that any required cooling is provided as quickly as possible.

Figure 4 illustrates the manner in which the filter housing 44 may be introduced to and released from the filter-receiving portion 36. A simple method of achieving this would be simply to move the filter housing 44 in a lateral direction indicated by arrow 58 in Figure 2a. However, it is preferable to provide a more reliable method of locating the filter housing 44 quickly and accurately in the filter-receiving portion 36. To this end, a projection 60 is provided on the cylindrical wall 44a of the filter housing 44 in a position which allows the projection 60 to abut against the edge of the side wall 38 of the filter-receiving portion 36. In this way, the filter housing 44 can be moved pivotally with respect to the filter-receiving portion 36 about the point of contact between the projection 60 and the cylindrical wall 38. The movement then required to release the filter housing 44 from the filter-receiving portion 36 is illustrated by arrows 62 in Figures 4a and 4b. The dueling portion 44e provides a convenient gripping portion by means of which the filter housing 44 can be moved into and out of the filter-receiving portion 36. As the filter housing 44 is moved in the direction of the arrows 62, the dueling portion 44e is lifted so that its angle of inclination to the horizontal increases as the ducting portion 44e is moved upwards. Also, a clip, snap-fit release means or other suitable retainer can be provided to ensure that the filter housing 44 remains held fixed in position at all times at which this is required.

Once it has been established that the filter 42 requires washing or replacement, the filter housing 44 is released from the reminder of the casing of the vacuum cleaner 10 by carrying out the operation described above. The filter 42 remains housed within the filter housing 44 during this operation. The upstream side of the filter 42 thus remains enclosed within the housing 44 and any dirt or dust which may be dislodged from the upstream surface of the filter 42 will be retained within the casing 44 itself. The fact that the dueling portion 44e remains upwardly directed at all times during this operation means that any dislodged dirt and dust cannot escape accidentally from the interior cavity 44c. The filter housing 44 can be carried to an appropriate location in which the filter 42 may be carefully removed from the filter housing 44 without any inconvenience to the user.

When the filter 42 has been replaced or washed or otherwise made ready for reuse, the filter 42 is replaced in the filter housing 44 and the filter housing 44 is then replaced in the filter-receiving portion 36 by reversing the removal operation described above. The vacuum cleaner 10 is then ready for further operation.

It will be appreciated that the invention is not to be regarded as limited to the details of the embodiment described above. Variations and alternative constructions will be understood to fall within the scope of the present invention. For example, the shape of the filter need not be cylindrical, although this shape is preferred for the embodiment described. Furthermore, the filter and filter housing need not be located immediately upstream of the fan as described in the embodiment but can be located at any convenient location between the main separating apparatus and the fan. For the purposes of the present application, the bleed valve described above may be omitted.

Claims

Claims:

1. A domestic appliance having a motor and fan unit for creating a flow of air through the appliance and an airflow path for conducting the flow of air from an air inlet to the motor and fan unit, wherein the motor and fan unit has a fan axis and a fan inlet and a filter is arranged in the airflow path upstream of the fan inlet, characterized in that the filter is located in a housing which forms part of a casing of the appliance, the housing being removable from the remainder of the casing of the appliance together with the filter.

2. A domestic appliance as claimed in claim 1, wherein the housing is open on the downstream side of the filter to allow the filter to be removed from the housing for replacement or cleaning purposes.

3. A domestic appliance as claimed in claim 1 or 2, wherein the housing comprises a cover which faces the upstream side of the filter.

4. A domestic appliance as claimed in claim 3, wherein the cover is spaced away from the upstream side of the filter and the housing comprises an inlet for introducing air to the interior of the housing between the cover and the upstream side of the filter.

5. A domestic appliance as claimed in any one of the preceding claims, wherein the filter is cylindrical and has a longitudinal axis.

6. A domestic appliance as claimed in claim 5, wherein the axis of the filter lies coaxially with the fan axis.

7. A domestic appliance as claimed in claim 5 or 6, wherein the housing is removable from the remainder of the casing of the appliance in a direction which is perpendicular to the axis of the filter.

8. A domestic appliance as claimed in claims 4 and 7, wherein, when the housing is removed from the remainder of the casing of the appliance, the inlet is directed upwardly at all times.

9. A domestic appliance as claimed in claim 7 or 8, wherein the housing is removable from the remainder of the casing of the appliance by sliding or rotational movement.

10. A domestic appliance as claimed in any one of the preceding claims, wherein the housing defines a part of the airflow path.

11. A domestic appliance as claimed in any one of the preceding claims, wherein the domestic appliance is a vacuum cleaner.

12. A domestic appliance as claimed in claim 11, wherein cyclonic separating apparatus is located in the airflow path for separating dirt and dust from the air flowing through the appliance.

13. A domestic appliance substantially as hereinbefore described with reference to the accompanying drawings.