GB2466625A

GB2466625A - Dust receptacle with dust compression means

Info

Publication number: GB2466625A
Application number: GB0823442A
Authority: GB
Inventors: Richard Waters; Philip Grove
Original assignee: Vax Ltd
Current assignee: Vax Ltd
Priority date: 2008-12-23
Filing date: 2008-12-23
Publication date: 2010-06-30
Anticipated expiration: 2028-12-23
Also published as: EP2375953A1; CN102300493B; EP2375953B1; CN102300493A; RU2011129396A; RU2553199C2; GB0823442D0; AU2009332757A1; WO2010073046A1; GB2466625B

Abstract

A dust receptacle for a vacuum cleaner comprises a dust collection chamber 14 and a pressing apparatus. The pressing apparatus includes a pressing member 22 movable within the chamber 14 for contacting and compressing dust therein, a hollow extendible element 30 which is operable to extend and contract lengthwise in response to a pressure differential between its interior and exterior, the exterior of the extendible element 30 being subject to air pressure inside the chamber, and means 40 for establishing a higher pressure within the interior of the extendible element 30 that than at the exterior thereof, thereby causing extension of the extendible element 30 to contact and compact the dust in the chamber 14. A valve 40 may constitute the means for establishing a higher pressure while a bleed valve may be provided for controlled equalisation of pressure between the interior and exterior of the extendible element 30. The pressing member 22 may in clued apertures in its surface so that any dust which falls on top of the pressing member may pass through so that it rests on the bottom of the container 14. The extendible member 30 maybe in the form of bellows.

Description

Title: Dust receptacle for a vacuum cleaner.

Description of Invention

This invention relates generally to the field of suction cleaners (which are commonly, and will herein be, referred to as vacuum cleaners), and more particularly to a dust receptacle for a vacuum cleaner.

Vacuum cleaners typically include a suction nozzle with which dirt, dust and the like is sucked into the cleaner, and a body containing a motor and an impeller, with which a suction force is generated. The dust-laden air flows from the nozzle to the body, wherein the dust is separated from the air by some means, such as a swirling motion in a cyclone unit, or a porous filter through which the dust particles cannot pass. The separated dust is retained in a collecting part of the separator unit, and may later be disposed of.

* *. In referring herein to dust, it is to be understood that what is sucked up and entrained in the air stream created by the vacuum cleaner can include particles of a very wide range of sizes, ranging from microns to millimetres.

Fibres, including animal and human hair, and scraps of fabric, paper, plastics, etc. are also likely to be sucked up. All such things are to be understood as included within the term "dust" used herein, and whatever system is utilised for dust separation and collection in a vacuum cleaner ought to be able to cope with all of them.

A problem arising with such systems is that the low density of the dust particles means that a relatively large volume is occupied by the dust collected in the body of the cleaner. This is particularly the use where the dust includes fibres and fluff. In cyclonic separator units, a large amount of space is required by the one or more cyclones, and so less space is available to store separated dust. The less dust storage space is provided, the more often the user must empty the collected dust from the vacuum machine.

In addition to the problems mentioned above, the process of emptying dust from the vacuum cleaner commonly results in loosely stored dust particles becoming airborne. This makes cleaning the components more difficult, and to some extent negates the removal of dust from the environment in the first instance. Additionally, the increase in airborne dust particles may affect people suffering with conditions such as asthma.

According to the present invention, we provide a dust receptacle for a vacuum cleaner, the receptacle including: a dust collection chamber having an inlet for dust, the dust inlet being in communication with an air flow to a source of suction; and a pressing apparatus, including: a pressing member movable within the chamber for contacting dust therein; a hollow extendible element which is operable to extend and contract lengthwise in response to a pressure differential between its interior and exterior, the exterior of the pressing element being subject to air pressure inside the chamber; and means for establishing a higher pressure within the interior of the extendible element than that at the exterior thereof, thereby causing extension of the extendible element for the pressing member to contact the dust in the chamber.

These and other features of the invention, and the advantages thereof, will now be described by way of example with reference to the accompanying drawings of which: Figure 1 is a side cross-section of a dust receptacle in connection with a dust separation chamber.

Figure 2 is a plan view of the arrangement shown in Figure 1.

Referring firstly to figure 1 of the drawings, a dust receptacle 10 for a vacuum cleaner comprises a dust collection chamber indicated generally at 14, alongside a dust separation chamber 12. The dust collection chamber 14 has an upper part 38 and a lower part 39, the lower part having a bottom wall 18 from which a circular peripheral wall 20 extends upwardly towards the upper part 38 of the chamber. As illustrated, the peripheral wall 20 tapers slightly from its bottom end to its top end, but it could be cylindrical. Adjacent the upper part 38 of the dust collection chamber 14 is a dust inlet 16 which connects the dust collection chamber to the dust separation chamber 12.

The dust separation chamber 12 is a cyclonic chamber having a tangential inlet 48 for airflow with dust entrained in it, the tangential orientation of the inlet 48 causing air to swirl within the chamber 12 about an upright central axis thereof, so that dust is separated from the air and is expelled transversely from the chamber through an exit passage 13 leading to the inlet 16. Air from which the dust has been separated leaves the chamber by way of an exit 42 at the top of the chamber 12 on the central axis thereof. S...

S

At the upper end of the peripheral wall 20 of the chamber 14, spaced a short * distance above the dust inlet 16, is a radially inwardly extending annular wall *:** 36. Above the wall 36 there is a wall portion 37 which as illustrated is frusto *..* conical and another annular wall followed by an upwardly extending slightly tapering wall forming a housing part 46. At the top of the receptacle, there is a top wall 32 closing off the top of the housing part 46. The dust collection chamber 14 is provided with a pressing apparatus, including a hollow extendible element 30 and a pressing member 22. The pressing member 22 is circular in configuration and has an upper surface 26 and lower surface 24, with a connection portion 28 extending upwardly from the centre of its upper surface 26. The pressing member 22 is movable upwardly and downwardly within the chamber 14 between an upper limiting position and a lower limiting position. In the upper limiting position, the upper surface 26 of the pressing member contacts the annular wall portion 36, whilst in the lower limiting position the lower surface 24 of the pressing member contacts the bottom wall 18. In the upper limiting position, the pressing member 22 fits closely within the circumferential waIl 20 of the chamber, whilst in the lower limiting position it is spaced by a small distance from the circumferential wall 20, in consequence of the slight upward taper of the wall 20.

The pressing apparatus further comprises a hollow extendible element 30 which is connected between the connection portion 28 of the pressing member and a connection fitting on the top wall 32 of the chamber. The extendible element is contracted when the pressing member is in its uppermost limiting position and extended as shown in broken lines in figure 1 when the pressing member is in its lower limiting position. The extendible element 30 is resilient so that when it is not subjected to any external forces it contracts to pull the pressing member 22 to its uppermost position. The extendible element is generally of bellows configuration, and conveniently may be constituted by a ". portion of extendible suction hose such as are well known for use on vacuum S...

cleaners: such a hose typically comprises a flexible plastics material supported on a helical resilient wire element so that normally it is in the S.....

* contacted condition but is able to extend when subjected to lengthwise tension. S... IS * * S *

* 25 The pressing member 26 is a circular element, and has a number of apertures extending between its upper surface 26 and lower surface 24. The apertures in the member allow dust and debris to pass through the plate when, as described below, the pressing member is at a position within the collection chamber beneath the dust inlet 16. Thus dust may rest in the lower part 39 of the chamber, on the lower wall 18. For emptying the chamber, lower waIl 18 may be openable e.g. by pivoting relative to the wall 20 of the chamber.

The apertures in the pressing member may be of any suitable shape and size, but must provide for particles of dust as large as the vacuum cleaner is capable of handling to pass through the pressing member to reach the lowermost part of the chamber. Disposed on the top wall 32 of the chamber is a device by which the interior of the extendible element 30 can be connected to the external atmosphere, and hence be at atmospheric pressure. This may comprise a valve 40 operable to open and close an aperture in the top wall 32.

When the vacuum cleaner is operating, because of the air flow drawn through the separating chamber 12 by the source of suction of the cleaner, the air pressure within the dust collection chamber 14 will typically be some 10 to 20 kilopascals below atmospheric pressure, and possibly a greater difference in pressure may be created if there is any blockage of the inlet to the cleaner.

The exterior of the extendible element 30 is, of course, subject to the sub-atmospheric pressure in the chamber 14 when the vacuum cleaner is operating.

The extendible element 30 is of impermeable material, but a small bleed aperture is provided to enable air to pass at a predetermined rate between its interior and exterior. The bleed aperture may be provided in the wall of the extendible element, or possibly in the connection portion 28 of the pressing member 22. When air passes between the interior and exterior of the * extendible element, any differential in pressure between the two is reduced in the absence of any other influences. *** ** * * * *

* 25 The valve 40 may take various forms. It may be operated to open and allow air at atmospheric pressure into the interior of the extendible element 30 by a member provided on the pressing member 22, so that the valve is opened when the pressing member is at or very near its uppermost position and be closed when the pressing member has moved a predetermined distance downwardly from its uppermost position. For example, an elongate rod may be provided inside the extendible element 30, connected so as to extend upwardly from the connecting part 28 of the pressing member. Such an elongate rod may engage a flap valve to push it open when the pressing member is at its highest point. Closure of the flap valve element after the pressing element has moved downwardly from its uppermost position may be damped, so that after the pressing member has descended so that elongate rod is disengaged from the valve element, the valve element remains open for a short additional time, e.g. about 0.3 seconds.

When the vacuum cleaner starts to operate with the pressing member in its uppermost position, when a sub-atmospheric pressure is established in the chamber 14 while the interior of the extendible element is at atmospheric pressure, the pressing member begins to descend. When the pressing member has descended to the point at which the valve element has closed, the interior pressure of the extendible element will begin to equalise with the pressure in the collecting chamber by way of the bleed aperture above described. The pressing member will continue to descend until the force exerted as a result of the reduced pressure difference is balanced by the **. tension in the extendible element. When the pressures have equalised, the pressing member will be raised by virtue of the tension force exerted by the extendible element when it is extended. As long as the vacuum cleaner continues to operate, the pressing member will be lowered then raised causing S.....

* the dust beneath it to become compacted to some extent. As above mentioned, there are apertures in the pressing member 22 so that dust can fall through the pressing member in the chamber 14. Since the pressing member is not guided accurately within the collecting chamber, each time it reaches the lowermost point of its travel within the collection chamber it is likely to do so in slightly different orientations, so the effect will be a degree of compaction of all the dust at the bottom part of the chamber.

Instead of a valve operated mechanically in response to the position of the pressing member, it may alternatively be operated by a solenoid mechanism, e.g. by a timer or otherwise. Alternatively a valve could be operated on a timed basis by an electric motor or the like, e.g. a rotary valve.

The rate at which the pressing member descends is determined by the cross sectional area of the extendible element and the difference in pressure between its interior and exterior. The speed at which it returns to the top of the collecting chamber will depend on the rate at which air bleeds out of the bleed aperture associated with the extendible element and hence the rate at which the pressure differential between its interior and exterior decreases.

If large items of debris fall into the dust collection chamber 14 and become lodged below the pressing member 22, this may prevent the lower surface 24 of the pressing member 22 from contacting the dust as effectively as it would otherwise do. However, in the embodiment above described, the pressing member is not fixed in a horizontal position and may tilt within the chamber so that it is still effective in compacting, to some extent, the collected dust.

It may, in some cases, be preferable for the pressing member to be stabilised * so that it remains in an approximately horizontal orientation throughout its upwards and downwards movement within the collecting chamber. Guide means for this purpose may be provided. For example, the pressing member * may be provided with a number of spaced guide formations which extend upwardly and/or downwardly from its periphery, to maintain its orientation by **** contact with the peripheral wall of the chamber. Alternatively, the pressing member may be provided with a peripheral skirt formation, extending upwardly and/or downwardly from the pressing member to contact the peripheral wall of the chamber if the pressing member tilts significantly from the horizontal.

In yet a further alternative, one or more upright guide formations may be provided within the peripheral wall of the chamber, engaging corresponding formations in the pressing member for guiding the latter. Yet further, a cylindrical guide may be provided centrally in the dust collection chamber, extending up from positions at or adjacent the uppermost and lowermost limits of movement of the pressing member within the chamber. Such a guide may be of smaller diameter than the inside diameter of the extendible element, so that as the pressing member descends the extendible element receives the guide within its interior. The pressing member may have a formation which engages the guide sufficiently closely to control the orientation of the pressing member.

Although, as described, a cyclonic separator of the "throw-off' type is disposed alongside the dust collection chamber, other types of separator may be utilised in the invention.

The invention is applicable to vacuum cleaners of both the "upright" type and the "cylinder" or "canister" type When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

* The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a ***.

*:*. means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

Claims 1. According to the present invention, we provide a dust receptacle for a vacuum cleaner, the receptacle including: a dust collection chamber having an inlet for dust, the dust inlet being in communication with an air flow to a source of suction; and a pressing apparatus, including: a pressing member movable within the chamber for contacting dust therein; a hollow extendible element which is operable to extend and contract lengthwise in response to a pressure differential between its interior and exterior, the exterior of the extendible element being subject to air pressure inside the chamber; and means for establishing a higher pressure within the interior of the extendible element than that at the exterior thereof, thereby causing extension of the extendible element for the pressing member to contact the dust in the chamber. * ** * * .
2. A dust receptacle according to claim 1, wherein the means for establishing a higher pressure within the interior of the extendible element, *:*. comprises a valve operable to admit ambient atmosphere to the interior. * S
3. A dust receptacle according to claim 1 or claim 2, comprising a bleed :::: : aperture providing for controlled equalisation of pressure between the interior * 25 and exterior of the extendible element.
4. A dust receptacle according to any one of the preceding claims, wherein the pressing member comprises apertures extending between its upper and lower surfaces.
5. A dust receptacle according to any one of the preceding claims, wherein the extendible element is of bellows configuration of flexible material.
6. A dust receptacle according to claim 5, wherein the extendible element is of flexible plastics material supported on a helical wire.
7. A dust receptacle according to any one of the preceding claims, comprising a guide means for retaining the pressing member in a generally constant orientation within the chamber.
8. A dust receptacle according to claim 2 or any claim appendent thereto, wherein the valve is operated by the pressing member when it is at or adjacent a starting position.
9. A dust receptacle substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
10. A vacuum cleaner having a dust receptacle according to any one of the * ** preceding claims. *** * * ****
11. Any novel feature or novel combination of features described herein * and/or in the accompanying drawings.****** * * * ** * * S S * SS