GB2440903A

GB2440903A - Upstream coarse filter before cyclone in vacuum cleaner

Info

Publication number: GB2440903A
Application number: GB0616326A
Authority: GB
Inventors: David Benjamin Smith
Original assignee: Hoover Ltd
Current assignee: Hoover Ltd
Priority date: 2006-08-17
Filing date: 2006-08-17
Publication date: 2008-02-20
Anticipated expiration: 2026-08-17
Also published as: GB2440903B; GB0616326D0

Abstract

A vacuum cleaner comprises a filter 15 having end and side walls formed of mesh, 5 the filter 15 being arranged to filter and collect coarse dirt having a particle size of over 500 pm from the air flow through the cleaner. Parallel-connected high-efficiency cyclonic separators 17 are disposed downstream of the filter 15 for separating finer dirt and dust from the airflow. In use, the finer dirt and dust passes through the filter 15 and as such the filter 15 does not become clogged and suffer from the 10 consequent reduction in suction. The finer dirt and dust is then removed by the cyclonic separators 17, which are kept free of coarse dirt and fibrous matter by the upstream filter. In this manner, the risk of losing cyclonic action is avoided.

Description

I 2440903 Vacuum Cleaner This invention relates to a vacuum

cleaner.

Vacuum cleaners are well known appliances comprising a cleaning head having a dirty air inlet, through which dirt and dust is drawn into the cleaner along an air flow path by a motor/fan unit disposed inside the vacuum cleaner. A separation device is disposed in series with the air flow path for separating dirt and dust from the air flow One well known form of separation device comprises a porous bag or box arranged to filter the air flow and to collect the dirt and dust therein. Although such devices work well, they need to be changed or cleaned regularly in order that they do not obstruct the air flow and cause an increased pressure drop.

Cyclonic separators are another known form of separation device used in vacuum cleaners. A disadvantage of such devices is that they are not particularly suited to separating coarse dirt and fibrous matter from the air flow and as such, matter tends to build up inside the cyclone, preventing the cyclonic action.

We have now devised a vacuum cleaner which alleviates the above-mentioned problems.

In accordance with the present invention there is provided a vacuum cleaner comprising an inlet for dirty air, an outlet for cleaned air, an air flow path extending between the inlet and outlet, means for creating an airflow along the airflow path, and separation means disposed in the air flow path for separating dirt and dust therefrom, wherein said separation means comprises a filter arranged to filter coarse dirt and fibrous matter from the air flow and a cyclonic separator disposed downstream of said filter for separating finer dirt and dust from the air flow In use, the finer dirt and dust passes through the filter and as such the filter does not become clogged and suffer from the consequent reduction in suction associated with conventional vacuum cleaners comprising filter bags.

The finer dirt and dust is then removed by the cyclonic separator, which is kept free of coarse dirt and fibrous matter by the upstream filter. In this manner, the risk of losing cyclonic action is avoided.

The separation efficiency of cyclone separators is dependant upon the radial forces acting on the dirt and dust particles as they swirl around the separation chamber. It will be appreciated that the separation efficiency for finer dirt and dust particles can be maximised by decreasing the radius of the separation chamber.

Accordingly, the cyclonic separator preferably comprises a plurality of small-diameter high-efficiency cyclone separators connected in parallel with each other.

Preferably the filter is arranged to contain and collect the separated materials, the filter preferably being arranged for removal from the vacuum cleaner, in order to allow it to be emptied and cleaned.

Preferably the filter comprises a container having a three-dimensional side wall formed of a porous or apertured filter material.

Preferably the filter material is arranged to filter particles having a diameter of more than 500 pm.

Preferably the filter material comprises an open gauze or mesh.

An advantage of solely collecting coarse dirt and fibrous matter in the filter is that the collected material is compressed by the relatively unrestricted air flow through the filter, with the result that the filter is able to contain more material and therefore requires less frequent emptying.

The compression of the collected material means that the filter is easier and cleaner to empty. Furthermore, the compressed material collects and builds up at the downstream point of the filter, thereby keeping the remainder of the walls free of matter, so that there is no significant drop in air flow as the filter becomes full.

Another advantage of solely collecting coarse dirt and fibrous matter in the filter is that the collected material accumulates in an orderly manner from the most downstream point of the filter and as such it is relatively easy for users to gauge the fill level of the filter.

Preferably the filter is disposed in a chamber having first and second ends, the filter being arranged to filter air entering said chamber from said first end, the cyclonic separator being mounted at said second of the chamber.

Preferably, in use, said second end of the chamber is arranged above said first end, such that finer dirt and dust separated by the cyclonic separator falls under the influence of gravity to a collection point at said first end.

Preferably said first end of the chamber is provided with an opening for emptying the separated matter from the cleaner Preferably the chamber and filter comprise tubular side walls, which are spaced apart from each other, so that the air flows freely out of the filter into a surrounding void.

An embodiment of the present invention will now be described by way of an example only and with reference to the accompanying drawings, in which.

Figure 1 is a longitudinal-sectional view through an upright vacuum cleaner in accordance with the present invention; Figure 2 is an exploded perspective view of some components of the vacuum cleaner of Figure 1; and Figure 3 is a schematic view of the separation components of the vacuum cleaner of Figure 1.

Referring to the drawings, there is shown an upright vacuum cleaner 10 comprising a wheeled floor-engaging head portion 11 and a body portion 12 pivotally mounted to the head portion 11.

An inlet 13 for dirty air is provided on the underside of the head portion 11. Typically a rotary agitator brush (not shown) extends across the inlet 13. The inlet 13 is connected via a duct 14 to the lower end of the body portion 12 of the cleaner, the duct 14 leading into the interior of a tubular filter 15.

The tubular filter 15 comprises side and upper end walls, which are formed of a gauze or mesh material. The lower end of the tubular filter 15 is sealed against the body 12 of the cleaner in an airtight manner The filter is disposed inside a tubular-walled compartment 16, having side walls which are spaced apart from the side walls of the filter 15.

A plurality of high-efficiency parallel-connected cyclone separators 17 are mounted in an annular array above the filter 15 at the top of the compartment 16. The cyclone separators comprise tangential air inlets at their lower ends, which are in direct fluid communication with the interior of the compartment 16. The tangential air inlets lead into respective frusto-conical separation chambers, which taper inwardly towards their upper ends. The upper ends of the cyclonic separators 17 are connected to a manifold 18, which is connected via a downwardly-extending duct 19 to a collection tube 20 disposed at the bottom of the body 12 of the cleaner, alongside the filter 15.

The lower ends of the cyclone separators 17 comprise axially-extending outlet ducts or so-called vortex finders, which are connected via an elongate duct 21 to a motor/fan unit 22 disposed inside the head portion 11 of the cleaner. The motor/fan unit 22 communicates with an outlet 23 disposed on the upper surface of the head portion 11 of the cleaner.

In use, when the motor/fan unit 22 is energised, an air flow is created through the cleaner from the inlet 13 to the outlet 23. Any coarse dirt and fibrous matter in the air flow is separated and retained by the mesh filter 15. The finer dirt and dust particles pass through the walls of the filter 15 into the surrounding compartment 16 The particles are then drawn out of the compartment 16 into respective cyclone separators 17.

The cyclonic air flow inside each of the cyclonic separators 17 throws the finer dirt and dust particles against the interior surface of their respective frusto-conical side walls, where they are then carried upwardly by the air flow towards the upper ends of the separators 17 and into the manifold 18. The particles then fall under the influence of gravity through the duct 19 into the collection tube 20.

The cleaned air is then drawn through the duct 21 and through the motor/fan unit, whereupon it exits the cleaner through the outlet 22.

The bottom end wall of the body portion 12 the cleaner comprises a closure 24, which can be opened to allow the coarse dirt and fibrous matter to be emptied from the filter 15 and also to allow the finer dirt and dust particles to be emptied from the collection tube 20. The coarse dirt and fibrous matter agglomerate at the upper end of the filter 15, with the air flow serving to compact the matter upwardly, thereby prolonging the times between which the filter needs to be emptied.

A vacuum cleaner in accordance with the present invention is relatively simple and inexpensive in construction yet has a high separation efficiency and is not susceptible to blockages or loss of suction.

Claims

Claims 1. A vacuum cleaner comprising an inlet for dirty air, an outlet

for cleaned air, an air flow path extending between the inlet and outlet, means for creating an airflow along the airflow path, and separation means disposed in the air flow path for separating dirt and dust therefrom, wherein said separation means comprises a filter arranged to filter coarse dirt and fibrous matter from the air flow and a cyclonic separator disposed downstream of said filter for separating finer dirt and dust from the air flow.

2. A vacuum cleaner as claimed in claim 1, in which the cyclonic separator comprises a plurality of small-diameter high- efficiency cyclone separators connected in parallel with each other.

3. A vacuum cleaner as claimed in claims 1 or 2, in which the filter is arranged to contain and collect the separated materials.

4. A vacuum cleaner as claimed in claim 3, in which the filter is arranged for removal from the vacuum cleaner, in order to allow it to be emptied and cleaned.

* 5. A vacuum cleaner as claimed in claims 3 or 4, in which the filter comprises a container having a three-dimensional side wall formed of a porous or **** apertured filter material.

6. A vacuum cleaner as claimed in any of claims 3 to 5, in which the filter S..

* material is arranged to filter particles having a diameter of more than 500 pm. * S * * S S...

** * 7. A vacuum cleaner as claimed in any of claims 3 to 6, in which the filter * .: 30 material comprises an open gauze or mesh.

8. A vacuum cleaner as claimed in any preceding claim, in which the filter is disposed in a chamber having first and second ends, the filter being arranged to filter air entering said chamber from said first end, the cyclonic separator being mounted at said second of the chamber.

9. A vacuum cleaner as claimed in claim 8, in which said second end of the chamber is arranged above said first end in use, such that finer dirt and dust separated by the cyclonic separator falls under the influence of gravity to a collection point at said first end.

10. A vacuum cleaner as claimed in claim 9, in which said first end of the chamber is provided with an opening for emptying the separated matter from the cleaner.

11. A vacuum cleaner as claimed in any preceding claim, in which the chamber and filter comprise tubular side walls, which are spaced apart from each other, so that the air flows freely out of the filter into a surrounding void.

12. A vacuum cleaner substantially as herein described with reference to the accompanying drawings. * S. * . S *SSI **.S * S *.S. * S S S. S *S.

S * * *S S * .5S S. S S S5 * S.