CA2342673A1

CA2342673A1 - Air cleaner with coarse filter

Info

Publication number: CA2342673A1
Application number: CA002342673A
Authority: CA
Original assignee: GBD Corp
Priority date: 2001-03-30
Filing date: 2001-03-30
Publication date: 2002-09-30
Also published as: WO2002078505A3; AU2002242553A1; WO2002078505A2

Abstract

A vacuum cleaner that includes a cyclone separator has a coarse filter disposed in the path of air flowing towards the outlet of the cyclone separator, for holding back hair that would otherwise tend to clog the vacuum cleaner, while minimizing impedance to air flow. In a preferred embodiment, the coarse filter comprises a disc-shaped lattice structure of barrier elements that are arranged to "catch" the animal hair.

Description

Title: AIR CLEANER WITH COARSE FILTER
FIELD OF THE INVENTION
This invention relates generally to air cleaners of the type that include at least one cyclone separator for removing dirt from air that flows through the air cleaner.
BACKGROUND OF THE INVENTION
The invention has been devised primarily, though not exclusively, in the context of vacuum cleaners that include at least one cyclone separator for cleaning air that flows through the vacuum cleaner.
Cyclone separators, which are sometimes referred to merely as cyclones, are devices that use centrifugal force and low pressure caused by spinning motion, to separate materials of differing density, size and shape. Vacuum cleaners that include cyclone separators are disclosed, for example, in United States Patents Nos. 3,425,192, 4,593,429 and 4,643,748.
PCT Publication No. WO 00140135 published July 13, 2000 discloses a vacuum cleaner that includes a cyclone separator in combination with a downstream electrostatic precipitator for removing fine particulate matter from the air that passes through the cyclone separator.
As disclosed in this publication, the cyclone separator is removable from the vacuum cleaner as a unit and the unit includes a bin for collecting dirt that has been removed by the cyclone. The bin can be separated from the remainder of the cyclone and emptied.
Elongate filaments such as hair, particularly animal hair, represents a particular problem for vacuum cleaners. Animal hairs tend to matt together and clog or sometimes even completely block air flow through a vacuum cleaner. U.S. Patent No. 4,643,748 referred to previously discloses the use of a disc upstream of an air outlet from a cyclone separator for blocking hair filaments. However, the disc has the disadvantage that it interferes significantly with normal air flow through the cyclone.

SUMMARY OF THE INVENTION
An object of the present invention is to address the problem of hairs or other elongate filaments clogging an air cleaner, white avoiding the disadvantages encountered by the invention of the 748 patent.
The present invention provides an air cleaner having a dirty air inlet, a clean air outlet spaced from the dirty air inlet, an air flow path extending from the dirty air inlet to the clean air outlet and at least one cyclone separator disposed in the air flow path for receiving air from the dirty air inlet. The cyclone separator has a cyclone chamber with a side wall having a generally cylindrical inner surface and bottom wall. A cyclone inlet is arranged to direct in-coming dirty air generally tangentially against an upper region of the inner surface of the chamber side wall so as to cause the in-coming dirty air to spiral down the inner surface of the side wall to the bottom wall. Cyclone outlet means is arranged generally centrally of an upper region of the chamber, to which air flows upwardly from the bottom wall of the chamber. Coarse filter means is disposed in the path of air flowing upwardly from the bottom wall to the cyclone inlet, inwardly of the spiral air flow adjacent the side wall of the chamber. The coarse filter means includes a plurality of barrier elements that are dimensioned and spaced so as to minimize impedance of air flowing to the cyclone outlet means while tending to obstruct and retain in the cyclone chamber, elongate filaments that would otherwise enter the cyclone outlet means.
Spaced barrier elements of the form provided by the invention have been found effective to hold back or knock out of the air flowing to the cyclone outlet means, elongate filaments such as animal hair while not substantially affecting air flow overall.
The coarse filter means may be in the form of a disc-shaped structure comprising a lattice of barrier elements. In this embodiment, the barrier elements may be shaped to define a plurality of spaced concentric rings with straight barrier elements extending angularly outwardly and connecting the rings. In a further embodiment, the disc-shaped lattice structure may be provided with a depending skirt of lattice form for preventing migration of hair or other filaments outwardly around the disc-shaped structure.
BRIEF DESCRIPTION OF DRAWINGS
In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate a number of preferred embodiments of the invention by way of example, and in which:
Fig. 1 is a perspective view of an upright vacuum cleaner in accordance with the present invention;
Fig. 2 is a perspective view of the filter assembly of the vacuum cleaner;
Fig. 3 is a partial vertical sectional view through the filter assembly shown in Fig. 2, showing the coarse filter element of the invention; and, Fig. 4 is a perspective view illustrating an alternative embodiment of coarse filter element.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings, Fig. 1 shows an upright vacuum cleaner in accordance with a preferred embodiment of the present invention.
The vacuum cleaner and its manner of operation are generally in accordance with the disclosure of PCT Publication No. WO 00140135 referred to previously, to which reference may be made for specific details not found in the present disclosure.
The vacuum cleaner is generally denoted by reference numeral 20 and includes a floor cleaning head 22 that is mounted on wheels, one of which is visible at 24, for movement over a floor surface. A
dirty air inlet in the underside of the head is indicated at 26 and usually will accommodate a driven rotary brush or beater bar (not shown). Extending upwardly from a rear portion of the head 22 is a support structure 28 for a filter assembly 30 that is removable as a unit from the vacuum cleaner. The filter assembly is shown separately in Fig. 2.
Above the filter assembly, the support structure 28 carries an upper body portion 32 of the vacuum cleaner that incorporates a fan and motor assembly (not shown) for drawing air through the vacuum cleaner and delivering cleaned air to a clean outlet 34 at the top of body portion 32.
A handle for manoeuvring the vacuum cleaner is indicated at 36.
Referring now more particularly to Fig. 2, the filter assembly 30 includes a cyclone separator generally denoted by reference 38 and an electrostatic air filter 40 enclosed in a housing 42. A cyclone chamber C is defined by a dirt collection bin 44. Bin 44 has a cylindrical side wall 46 that is transparent. Visible through the side wall of the bin is the internal structure 48 of the cyclone separator. This includes a main inlet pipe 50 that extends upwardly centrally of bin 44 and through which dirty air enters the cyclone from the floor cleaning head 22 of the vacuum cleaner.
Pipe 50 extends upwardly and then laterally to a cyclone inlet opening 52 that directs air tangentially with respect to the internal surface of the side wall 46 of bin 44. When the vacuum cleaner is in use, air entering bin 44 from inlet 52 spirals downwardly on the internal surface of bin side wall 46 until it reaches a lower baffle member 54 (Fig. 2), which deflects the air inwardly and upwardly adjacent the outer surface of inlet pipe 50.
Member 54 forms a bottom wall of the cyclone chamber C. The air then passes through a coarse filter element F (to be described) before entering openings 56 in an upper housing 58 of the cyclone separator and then flowing upwardly through the electrostatic filter 40. This air flow is generally indicated by the ghost outline arrows 60. The air then travels upwardly through filter 40 and leaves the filter assembly 30 through an opening 62 in the top of filter housing 42.
Referring back to Fig. 1, the flow path of air from the dirty air inlet 26 of head 22 to the clean air outlet 34 of the vacuum cleaner is indicated at 64. To summarize, the air travels upwardly through inlet pipe 50 of the cyclone separator to the inlet 52 of the cyclone, from where it spirals downwardly adjacent the inner surface of the side wall 46 of the cyclone bin.
The air then travels back up adjacent the outer surface of inlet pipe 50 and into the openings 56 of the housing 58 of the cyclone assembly. The air then travels upwardly through filter 40, and through the upper body portion 32 of the vacuum cleaner to outlet 34.
Filter assembly 30 (Fig. 2) is removable from the remainder of the vacuum cleaner in the manner disclosed in the PCT application referred to previously, by slightly depressing the filter assembly and then pulling it outwardly. As best seen in Fig. 3, the filter assembly housing 42 has a top surface that is angled upwardly to the right and that is shaped to provide a handle 66 that projects forwardly of the vacuum cleaner in the assembled condition, as best seen in Fig. 1. Thus, the user grasps the handle 66, depresses the filter assembly slightly and pulls it forwardly and outwardly using the handle. Fig. 2 shows the filter assembly as it would appear after removal from the remainder of the vacuum cleaner in this fashion.
When the vacuum cleaner is in operation, dirt that is removed from the air flowing through the vacuum cleaner by the cyclonic action of the cyclone separator accumulates in bin 44. The upper housing 58 of the cyclone assembly and the housing 42 of the filter 40 fit together to form a ub-assembly that also includes the inlet pipe 50 of the cyclone separator s and baffle 54 (Fig. 2). The housings 42 and 58 have the same cylindrical exterior configuration and fit together so that the sub-assembly forms a cylindrical closure that is a push-fit inside the upper portion of cyclone bin 44. The sub-assembly can be separated from the cyclone bin 44 by lifting the sub-assembly from the bin. Bin 44 can then be emptied of accumulated dirt.
In accordance with the present invention, a coarse filter F
(referred to previously) is provided in the path of air flowing upwardly from a bottom wall 54 of the cyclone chamber to the cyclone outlet represented th by the openings 56 in the upper housing 58 of the separator. The coarse filter includes a plurality of barrier elements that are dimensioned and spaced so as to minimize impedance of air flowing to the cyclone outlet while tending to obstruct and retain in the cyclone chamber C, elongate filaments such as animal hairs that would otherwise enter the cyclone outlet. Filter F in effect tends to knock the hairs out of the air that is flowing to the cyclone outlet and retain the hairs in bin 44 for disposal.
In the particular embodiment illustrated in Fig. 2, the filter F
comprises a disc-shaped lattice structure that is mounted at the top of the cyclone inlet tube 50 as best shown in Fig. 3. The barrier elements take the form of a series of spaced concentric ring-shaped barrier elements 68 connected by a series of straight barrier elements 70 that extend radially outwardly with respect to inlet pipe 50. For example, the lattice structure representing filter F may be a plastic moulding and the barrier elements may be relatively fine circular section plastic strands or filaments.
As best seen in Fig. 3, the filter F has an external diameter that is sufficiently less than the internal diameter of bin 44 so as not to significantly interfere with in-coming air that enters the cyclone chamber C
through inlet 52 and then spirals down the internal surface of bin 44.
Fig. 4 shows an alternative embodiment of the invention in which the disc-shaped lattice structure of Fig. 2 is provided with a depending skirt 72 which is itself made up of a lattice of barrier elements, comprising vertically spaced circular elements 74 and angularly spaced upright barrier elements 76 that connect the circular elements 74. It is believed that, in some applications, the skirt 72 will inhibit migration of hairs outwardly around the edge of the filter F.
It has been found in practice that the provision of coarse filter means including a plurality of barrier elements of the form provided by the invention minimizes impedance to air flowing to the cyclone outlet while tending to obstruct and retain in the cyclone chamber, hairs and other elongate filaments that would otherwise enter the cyclone outlet. This in turn avoids or minimizes any tendency for the hairs to matt and clog the air flow through the vacuum cleaner.
The coarse filter may have a shape other than the shapes specifically shown for filter F, for example an umbrella, bell or other curved shape.
It is to be understood that the preceding description relates to particular preferred embodiments of the invention only and that various additions and modifications are possible, some of which have been indicated previously and others of which will be apparent to a person skilled in the art. In particular, it is to be noted that the inv~:ntion is applicable to any type of vacuum cleaner whether upright (as illustrated), canister vacuum cleaner or central vacuum cleaner or the like. The dirty air stream which is processed may be collected, for example, by a wand or rotating brush positioned in the head of the vacuum cleaner as is known in the art. The invention may also be used with a wetldry vacuum cleaner.
The filter assembly may include more than one cyclone separator.
Finally, it should be noted that, while the disclosure with reference to the drawings is directed exclusively to vacuum cleaners, the invention may be applied to other forms of air cleaner, for example a room air cleaner. In this latter context, an air filter assembly, for example, of the form shown in Fig. 2 could form part of a room air cleaner in which air is caused to flow upwardly through the filter assembly and out into the room through opening 62.

Claims

I/WE CLAIM:

1.~An air cleaner having a dirty air inlet, a clean air outlet spaced from the dirty air inlet, an air flow path extending from the dirty air inlet to the clean air outlet, and at least one cyclone separator disposed in said air flow path for receiving air from said dirty air inlet;

wherein the cyclone separator comprises a cyclone chamber having a side wall with a generally cylindrical inner surface and a bottom wall, a cyclone inlet arranged to direct in-coming dirty air generally tangentially against an upper region of said inner surface of the chamber side wall so as to cause said in-coming dirty air to spiral down said inner surface of the side wall to said bottom wall, cyclone outlet means arranged generally centrally of an upper region of said chamber, and to which air flows upwardly from said bottom wall, and coarse filter means disposed in the path of air flowing upwardly from said bottom wall to said cyclone outlet inwardly of said spiral air flow adjacent said side wall of the chamber, said coarse filter means including a plurality of barrier elements that are dimensioned and spaced so as to minimize impedance to air flowing into said cyclone outlet means while tending to obstruct and retain in the cyclone chamber, elongate filaments that would otherwise enter said cyclone outlet means.

2. An air cleaner as claimed in claim 1, wherein said coarse filter means comprises a disc-shaped lattice structure defined by said barrier elements.

3. An air cleaner as claimed in claim 2, wherein said barrier elements comprise a series of spaced concentric circular barrier elements connected by an angularly spaced series of elements that extend radially of the cyclone chamber.

4. An air cleaner as claimed in claim 3, wherein the coarse filter further comprises a skirt that depends from the outer perimeter of said disc-shaped lattice structure and that itself comprises a series of spaced barrier elements.

5. An air cleaner as claimed in claim 4, wherein said barrier elements defining the skirt comprise a series of vertically spaced circular elements interconnected by a series of angularly spaced vertical elements.

6. An air cleaner as claimed in any one of claims 2 to 5, wherein the coarse filter comprises a plastic moulding which includes said barrier elements.

7. An air cleaner as claimed in any one of claims 2 to 6, wherein said cyclone separator includes an air inlet pipe that extends upwardly centrally of the cyclone chamber to said cyclone inlet, and wherein said filter element is carried by said pipe.

8. In a vacuum cleaner having a dirty air inlet, a clean air outlet spaced from the dirty air inlet, an air flow path extending from the dirty air inlet to the clean air outlet and at least one cyclone separator disposed in the air flow path for receiving air from said dirty air inlet, the cyclone separator having air inlet and outlet means;
the improvement comprising coarse filter means disposed in the path of air flowing to said cyclone outlet means, the coarse filter means including a plurality of barrier elements that are dimensioned and spaced so as to minimize impedance to air flowing to said cyclone outlet means while tending to obstruct and hold back, elongate filaments that would otherwise enter the cyclone outlet means.

9. A filter assembly for an air cleaner, which includes a cyclone separator comprising a cyclone chamber having a side wall with a generally cylindrical inner surface and a bottom wall, a cyclone inlet arranged to direct in-coming dirty air generally tangentially against an upper region of said inner surface of the chamber side wall so as to cause said in-coming dirty air to spiral down said inner surface of the side wall to said bottom wall, cyclone outlet means arranged generally centrally of an upper region of said chamber, and to which air flows upwardly from said bottom wall, and coarse filter means disposed in the path of air flowing upwardly from said bottom wall to said cyclone outlet inwardly of said spiral air flow adjacent said side wall of the chamber, said coarse filter means including a plurality of barrier elements that are dimensioned and spaced so as to minimize impedance to air flowing into said cyclone outlet means while tending to obstruct and retain in the cyclone chamber, elongate filaments that would otherwise enter said cyclone outlet means.