GB2189382A - Vacuum cleaner - Google Patents

Abstract

A hand-held, wet and dry vacuum cleaner comprising a suction fan/motor unit 1, 2, filter 8 for separating both liquid and solid material from air drawn towards the suction fan/motor unit, and a suction nozzle 5, 6, is characterised by an apertured baffle 10 disposed within the nozzle, the function of which is to inhibit flow towards portion 6 of the nozzle of any liquid drawn in. The filter may comprise an outer sheet 13 of metal gauze and an inner cap of expanded or foamed plastics. The motor may be battery-driven. <IMAGE>

Description

SPECIFICATION A wet and dry vacuum cleaner Field of the Invention The invention relates to an electrical, hand-held wet and dry vacuum cleaner capable of collecting both solid and liquid material.

Background Art Known wet and dry vacuum cleaners designed to tolerate the entrainment of water particles in the suction air stream comprise a motor; a suction fan driven by the motor and having inlet and outlet sides; an inlet suction nozzle, having an inlet portion and a body portion, connected to the inlet side of the suction fan to form an enclosure; filtering means disposed within the body portion of the suction nozzleforfiltering liquid and solid material from air drawn through the suction fan; and deflecting means disposed within the body portion of the suction nozzle for directing the flow of air through the suction nozzle along a non-rectilinear path.

In one wet and dry vacuum cleaner constructed in this way, the filtering means extend perpendicular to the axis of the suction nozzle and the deflecting means direct the suction air stream downwards, transversely of the axis of the suction nozzle, past the filtering means, so that the air stream must undergo a sharp change in direction before passing through the filtering means. This results in a centrifugal separation of liquid and solid particles from the air stream before the air stream passes through the filtering means. It is convenient, with this form of construction, to form the suction nozzle with an internal cavityforthe collection of the centrifugally separated liquid and solid particles.

However, there is a possibility that some liquid particles remain entrained in the air stream passing through the filtering means and this liquid can cause harm to the electric motor. In addition, if too much liquid collects in the suction nozzle, this can slop around as a result of movement of the vacuum cleaner during use and so the liquid can be brought into direct contact with the filtering means, thus increasing the possibility of damage to the electric motor and other electrical components. Similar danger occurs when a wet and dry vacuum cleaner is tilted so that liquid in the suction nozzle flows onto the filtering means.

One way to overcome this difficulty is to provide filtering means in the form of a fine filter for capturing fine particles and a coarse filter surrounding the fine filter in order to prevent larger particles from clogging up the fine filter. One such coarse filter comprises a sheet of textile fabric cloth.

This is quite effective in catching entrained liquid.

However, as this cloth becomes progressively damper with collected liquid, it becomes more and more impervious to the flow of air and this reduces the efficiency of the wet and dry vacuum cleaner and can result of overloading of the fan motor.

Moreover, the water collected by the textile fabric can be drawn into the motor with consequent damage thereto.

Disclosure of the Invention It is intended, by means of the present invention, to overcome the disadvantages of known wet and dry vacuum cleaners and, in particular, to provide a wet and dry vacuum cleaner with improved means for preventing liquid collected by the vacuum cleaner from damaging the electric motor for driving the suction fan of the vacuum cleaner.

This is achieved by providing deflecting means which comprise an apertured baffle extending transversely of the axis of the suction nozzle and cooperating with the body portion of the nozzle to inhibit the flow of liquid within the enclosure from the inlet portion of the suction nozzle towards the body portion of the suction nozzle.

Thus, according to the invention, there is provided a wet and dry vacuum cleaner, comprising a motor; a suction fan driven by the motor and having inlet and outlet sides; an elongate suction nozzle, having an inlet portion and a body portion, connected to the inlet side of the suction fan to form an enclosure; filtering means disposed within the enclosure in the body portion of the suction nozzle for filtering liquid and solid material from air drawn through the suction fan; and an apertured baffle disposed within the enclosure in the body portion of the suction nozzle and extending transversely of the axis of the suction nozzle, cooperating with the body portion of the suction nozzle to inhibit the flow of liquid within the enclosure from the inlet portion of the suction nozzle towards the body portion of the suction nozzle.

The baffle serves to reduce the extent to which liquid within the suction nozzle slops around and although liquid can pass through the aperture or apertures formed in the baffle, it will not normally do so unless the level of liquid within the suction nozzle rises to the level of the edge of at least one aperture as a result of backwards and forwards movement or tilting of the vacuum cleaner or by the accumulation of too much liquid. For this reason, it is normal to provide the baffle with a single central aperture. This ensures that the vacuum cleaner can be tilted equally in any direction without increasing the possibility of liquid flowing on to the filtering means.

For ease of manufacture and assembly, the baffle is spaced from the body portion of the suction nozzle and there is an unsealed gap between the baffle and the body portion of the suction nozzle.

Although this permits the flow of some liquid past the baffle, this only occurs at the periphery of the baffle and the filtering means can be spaced from this part of the baffle. However, it is also possible to position the baffle with its edge in engagement with resilient sealing means supported by the body portion of the suction nozzle.

In a preferred embodiment, the filtering means comprise a cylindrical sheet of coarse filtering material which is disposed on an axis which is parallel to the axis of the suction nozzle and a layer of fine filtering material disposed between the cylindrical sheet of coarse filtering material and the suction fan for capturing particles which are finer than those captured by the cylindrical sheet of coarse filtering material. The deflecting means of the preferred embodiment comprise a circular sheet which supports one end of the cylindrical sheet and extends perpendicular to the axis of the suction nozzle so as to face the or each aperture in the baffle.This permits the cylindrical sheet of coarse filtering material to be spaced from the inside of the body portion of the suction nozzle and also helps to separate the cylindrical sheet of coarse filtering material from the aperture or apertures formed in the baffle. Air passing axially along the suction nozzle through the or each aperture or through a gap between the baffle and the body portion of the suction nozzle must change direction before passing through the filtering means.

The coarse filtering material is preferably metal gauze because, if any liquid impinges on a metal gauze filter, it easily passes through and so does not cause airflow blockages and is not retained inside the filter. Any entrained liquid flowing through the coarse filtering material is captured in the layer of fine filtering material.

It is also advantageous to space the cylindrical sheet of coarse filtering material axially from the inlet side of the suction fan so that, when the vacuum cleaner is inverted, with the suction nozzle pointing upwards, liquid contained in the suction nozzle can be accommodated in the space between the inlet side of the suction fan and the filtering means so that the liquid does not impinge directly on the filtering means. Clearly, it is advantageous to proportion the vacuum cleaner so that the volume of the liquid accommodated in this way is the same as the volume of liquid which can safely be accommodated within the suction nozzle during use of the vacuum cleaner without causing liquid to flow on to the cylindrical sheet of filtering material.

A vacuum cleaner embodying the present invention is hereinafter described, by way of example, with reference to the accompanying drawings.

Brief Description of the Drawings Figure 1 is a side elevation of an embodiment of the invention in the form of a hand-held, battery driven wet and dry vacuum cleaner; Figures 2 and 3 are sectional side elevation and plan views of the vacuum cleaner shown in Figure 1; and Figure 4 is a sectional side elevation of the vacuum cleaner in its normally inclined position for use and showing liquid collected inside the vacuum cleaner.

Mode for Carrying Out the Invention As shown in Figure 1, the vacuum cleaner comprises a rear part 18 formed with a handle 19 incorporating a hinged control bar 20 which serves to switch the vacuum cleaner on and off. A suction nozzle 5 and 6 having an inlet portion 5 and a body portion 6 is attached to the rear part 18 of the vacuum cleaner. During operation, air and entrained liquid and solid particles are drawn through the apertured front end 15 of the vacuum cleaner and air is discharged from the vacuum cleaner through vents 21 on opposite sides of the vacuum cleaner.

As shown in Figures 2 and 3, the control bar 20 operates a switch 22 which controls the connection of battery cells 23 to a small electric motor 1 mounted on the outlet side 4 of a centrifugal fan 2.

An internal conduit 16 extends from the apertured front end 15 of the suction nozzle 5 and 6, along an axis parallel to the axis of the suction nozzle 5 and 6.

The inner end of the internal conduit 16 is shaped and provided with an internal aperture 17 for directing the air stream through the internal conduit 16 transversely of the axis of the suction nozzle 5 and 6.

A suction inlet conduit 24 is connected to the inlet side 3 of the suction fan 2 and supports filtering means 8 comprising a cylindrical sheet 13 of metal gauze and a layer 34 of expanded or foamed plastic filtering material. The cylindrical sheet 13 of metal gauze is mounted, at one end, on an annular plate 25 supported by the inlet conduit 24 and, at its other end, on an annular plate 14which is connected to the annular plate 25 by internal ribs 26. The layer 34 of expanded or foamed plastic filtering material forms a cap which is mounted on a cruciform frame 35.

The circular sheet 14, a baffle 10 formed with a central circular aperture 11, and four connected ribs 27 together form deflecting means 9 which cause the flow of air from the internal conduit 16 to the suction fan 2 to sharply change direction before passing through the filtering means 8. As a result, liquid and solid particles entrained in this air are centrifugally separated from the air. In addition, the baffle 10 inhibits the flow of liquid along the suction nozzle 5 and 6 from the inlet portion 5 towards the body portion 6. Any liquid which passes through the cylindrical sheet 13 of metal gauze and does not flow back is captured by the layer 34 of expanded or foamed plastic filtering material.

As shown in Figure 4, the wet and dry vacuum cleaner contains the maximum amount of liquid 28 for which it is designed to operate safely. When the vacuum cleaner is held stationary, with the liquid level 29 horizontal, the liquid level 29 can be seen through a transparent panel forming a window 30 in the inlet portion 5 of the suction nozzle 5 and 6. The motor 1 can be switched off and the suction nozzle 5 and 6 removed from the rear part 18 of the vacuum cleaner and emptied of its collected contents.

However, if it is decided to continue using the vacuum cleaner, backwards and forwards movement in the direction of the arrows 31 will cause the liquid 28 to slop around inside the suction nozzle 5 and 6 and, on occasion, the liquid 28 will have a surface 32. However, as shown, the baffle 10 will restrict the amount of liquid flowing beyond the baffle 10, through the gap 12, into a region in which it can impinge on the filtering means 8.

Even if the angle of inclination of the vacuum cleaner is decreased, the amount of liquid flowing into this region will be restricted by the baffle 10.

If the vacuum cleaner is inverted with the apertured front end 15 of the suction nozzle 5 and 6 held uppermost, the liquid 28 can be accommodated in the shaded region 33 between the inlet side 3 of the suction fan 2 and the cylindrical sheet 13 of metal gauze so that none of this liquid impinges upon the cylindrical sheet 13 of metal gauze.

For small hand-held wet and dry vacuum cleaners such as this, the volume provided for accommodating collected liquid is conveniently of the order of a quarter of a litre (approximately 9 fluid ounces).

Claims (10)

1. A wet and dry vacuum cleaner comprising: a motor (1); a suction fan (2) driven by the motor and having inlet and outlet sides (3 and 4); an elongate suction nozzle (5 and 6), having an inlet portion (5) and a body portion (6), connected to the inlet side (3) of the suction fan (2) to form an enclosure (7); filtering means (8) disposed within the enclosure (7) in the body portion (6) of the suction nozzle (5 and 6) for filtering liquid and solid material from air drawn through the suction fan (2); and deflecting means (9) disposed within the enclosure (7) in the body portion (6) of the suction nozzle (5 and 6) for directing the flow ofairthrough the suction nozzle (5 and 6) along a non-rectilinear path; characterised in that:~ the deflecting means (9) comprise an apertured baffle (10) extending transversely of the axis of the suction nozzle (5 and 6) and cooperating with the body portion (6) of the suction nozzle (5 and 6) to inhibit the flow of liquid within the enclosure (7) from the inlet portion (5) of the suction nozzle (5 and 6) towards the body portion (6) of the suction nozzle (5 and 6).

2. A vacuum cleaner, according to Claim 1, in which the baffle (10) is formed with a single, central aperture (11).

3. A vacuum cleaner, according to Claim 1 or Claim 2, in which the baffle (10) is spaced from the body portion (6) of the suction nozzle (5 and 6) and there is an unsealed gap (12) between the baffle (10) and the body portion (6) of the suction nozzle (5 and 6).

4. A vacuum cleaner, according to any preceding claim, in which the filtering means (8) comprise a cylindrical sheet (13) of filtering material which is disposed on an axis which is parallel to an axis of the suction nozzle (5 and 6) and the deflecting means (9) comprise a circular sheet (14) which supports one end of the cylindrical sheet (13) and extends perpendicular to the axis of the suction nozzle (5 and 6) so as to face the or each aperture (11) in the baffle (10).

5. A vacuum cleaner, according to Claim 4, in which the filtering material is metal gauze.

6. A vacuum cleaner, according to Claim 5, in which the filtering means (8) comprise a further layer (34) of filtering material capable of capturing finer particles than the metal gauze.

7. A vacuum cleaner, according to any one of Claims 4 to 6, in which the cylindrical sheet (13) of filtering material is axially spaced from the inlet side (3) of the suction fan (2).

8. A vacuum cleaner, according to any preceding claim in which the inlet portion (5) of the suction nozzle (5 and 6) tapers from the body portion (6) and has an apertured front end (15) and an internal conduit416) extending from the apertured front end (15) towards the body portion (6) along an axis parallel with the axis of the suction nozzle (5 and 6) and in which the internal conduit (16) has an internal aperture (17) for directing air from the internal conduit (16) transversely of the axis of the suction nozzle (5 and 6).

9. A vacuum cleaner, according to any one of the preceding claims, wherein the motor is powered by batteries accommodated in the vacuum cleaner.

10. A wet and dry vacuum cleaner substantially as hereinbefore described with reference to the accompanying drawings.