"LIQUID BATH FILTER DEVICE FOR A VACUUM CLEANER APPARATUS" * * * * * FIELD OF THE INVENTION The present invention concerns a liquid bath filter device for a vacuum cleaner apparatus, comprising a container into which the particles of dust and dirt are sucked in by means of a suction motor, together with the so- called primary air, through a first pipe. The dust sucked in is hit by a spray of steam and then separated from the air by means of a spray of water, which makes it fall into the container. The filter device is designed so that the spray of water is caused by the mixture of water and so-called secondary clean air, which is introduced into the container through a second pipe, thanks to the depression present inside the container, or by means of ventilation means.

BACKGROUND OF THE INVENTION The state of the art includes a liquid bath filter device for a vacuum cleaner apparatus which comprises an accumulation container connected with a suction motor, which sucks in dust and particles of dirt together with primary air through a first suction pipe. The device also comprises an assembly to generate a fluid arranged immediately downstream of the aperture of the suction pipe for primary air and able to generate a jet of steam, which hits the particles of dust and dirt to encourage them to fall into the accumulation container.

This conventional device has the disadvantage, however, that some particles of dust and dirt may not be hit and made heavier enough by the steam sprayed, and so it is not always possible to ensure that they all fall completely into the container.

The state of the art also includes a filter device, without the assembly to generate steam, connected to a fan

which generates a flow of so-called secondary air, different from the flow of primary air.

To be more exact, the flow of secondary air is introduced into the container through a second introduction pipe, arranged near the first introduction pipe. This second introduction pipe is connected to and coaxial with the inside of a water conveyor pipe, which sits lower in the liquid of the container. The upper open end of the conveyor pipe has a restriction which, due to the Venturi effect, makes the air passing in the second introduction pipe suck in water through the conveyor pipe and generate a vertical spray which hits the dust possibly sucked in with the flow of primary air. The dust is absorbed by the sprayed water and falls into the same container from which the conveyor pipe has sucked the water to be sprayed.

This last conventional filter device has the disadvantage that it is always dirty water which is sprayed, mixed with the dust previously fallen. Consequently the conveyor pipe is continually subject to the risk of deposits of dirt and therefore of incrustations, which can impede an efficient suction and also definitively obstruct the passage of the water to be sprayed.

Another disadvantage is due to the fact that, in this filter device, the second introduction pipe for the secondary air and the conveyor pipe are arranged coaxial and very near each other, so that they make it very difficult to perform the normal and necessary cleaning operations of the container.

The Applicant has devised and embodied the present invention to overcome these shortcomings of the state of the art, and to obtain further advantages.

SUMMARY OF THE INVENTION The present invention is set forth and characterized in

the main claim, while the dependent claims describe other innovative characteristics of the invention.

One purpose of the present invention is to achieve a liquid bath device in which, along a determinate suction path, the dust and particles of dirt are hit both by a spray of a fluid, such as for example a liquid in the form of steam, and also by a spray of water which allows to guarantee that the particles of dust and dirt are all completely knocked down, even those which are not hit enough and knocked down by the fluid.

Another purpose of the invention is to achieve a liquid bath filter device for a vacuum cleaner apparatus by means of which the dust sucked in, together with the primary air, inside a container, is knocked down continuously by means of a spray of water which is always clean, so as to prevent deposits of dirt or dust in the zones through which the water which forms the spray passes.

In accordance with these purposes, a filter device according to the present invention, for a vacuum cleaner apparatus, comprises a water accumulation container into which the primary air, sucked in by suction means through a suction pipe, is able to be introduced. In correspondence with the suction pipe, there are first introduction means to introduce a fluid, advantageously steam, which is able to knock down the dust into the container. According to a characteristic of the present invention, the device comprises second introduction means to introduce secondary air arranged downstream of said first introduction means and able to introduce secondary air into the water contained in the container so as to generate a spray of water against the dust sucked in and already hit by the fluid. Advantageously the second introduction means are able to make the secondary air bubble in the water.

In one embodiment of the present invention, the secondary air is introduced into the container thanks to the depression generated by the suction means inside the accumulation container.

According to a variant, the secondary air is able to be introduced into the accumulation container by means of means to generate secondary air, such as for example ventilation means.

According to a preferential form of embodiment of the invention, the container is divided into at least two zones, a first zone associated with the suction pipe, and a second zone, distinct from the first zone, in which clean water is able to be contained. Conveyor means are also provided to convey the clean water from the second zone to the first zone.

The second introduction means are connected to the conveyor means to introduce the secondary air into the latter and thus cause a spray of clean water onto the dust sucked in.

According to another characteristic of the present invention, the accumulation container is divided into the two above-mentioned zones by means of separation means consisting for example of a wall, by means of which it is possible to keep the clean water and the dirty water separate.

In a preferential embodiment this wall is provided with a through hole, so as to keep a constant level of water in the two zones.

In a first embodiment, the conveyor means for the clean water comprise, for example, a first elbow-shaped, open pipe, which is able to put the second zone in communication with the suction pipe which sucks in the primary air. The second introduction means to introduce secondary air

comprise a second pipe which, on one side, is open towards the outside of the accumulation container and, on the other side, is connected with the first pipe.

In this way the secondary air is sucked inside the container and is bubbled in the clean water present in the first open pipe, so as to generate the spray to knock down the dust.

Another purpose of the present invention is to achieve a filter device which is easy to dis-assemble in order to carry out normal cleaning operations.

In accordance with this purpose, in a preferred form of embodiment, the container comprises at least a base tank, where the water is contained, and a cover able to close the base tank. The cover comprises, in a single piece, the first open pipe and the wall, whereas the base tank comprises, in a single piece, the second introduction pipe to introduce secondary air. Therefore, by lifting the cover with respect to the base tank, the second introduction pipe to introduce the secondary air is dis-assembled simply and quickly from the first open pipe for the clean water, to facilitate possible cleaning or maintenance operations on the container.

BRIEF DESCRIPTION OF THE DRAWINGS These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein: - fig. 1 shows a general diagram of a filter device according to the present invention; - fig. 2 is a section of a first embodiment of the filter device in fig. 1; - fig. 3 is a section of a second embodiment of the filter

device in fig. 1; - fig. 4 is a section view of the filter device in fig. 3 in its dis-assembled condition DETAILED DESCRIPTION OF SOME PREFERENTIAL FORMS OF EMBODIMENT OF THE INVENTION With reference to fig. 1, a liquid bath filter device 10 according to the present invention, for a vacuum cleaner apparatus, of a conventional type and not shown in the drawings, comprises a container 18 consisting of a base tank 12 able to contain water and an upper portion, or cover 16.

The filter device 10 comprises a suction motor 15 connected to the container by means of a pipe 13 and an inlet pipe 19 through which dust 20 and other solid particles are sucked in.

In correspondence with the inlet pipe 19 there is a pipe 50, connected to a water steam generator, not shown in the drawings. A jet of steam is able to be introduced through the pipe 50 against the particles of dust 20 to allow a first absorption of water therein, in order to facilitate and optimize their fall into the base tank 12.

The air and possible dust 20 which are not filtered in the liquid bath are subsequently made to pass, through a grid 25a of the interchangeable type, arranged in the outlet pipe 13 and functioning as a dry filter.

The cover 16 comprises an introduction pipe 34, open above towards the outside and able to be arranged vertically inside the container 18, to allow the so-called secondary air to be introduced. To be more exact, the secondary air is introduced thanks to the depression generated by the suction motor 15 inside the container 18.

According to a variant, the secondary air is introduced by means of a fan 21.

The lower end 34a of the introduction pipe 34 is

immersed in the water so as to make the secondary air bubble therein and create a spray 46 of water against the dust 20.

In this way, any possible dust 20 hit both by a jet of steam and also by the spray 46 of water and fall completely into the base tank 12.

An adjustable platelet 51 is also arranged between the introduction pipe 34 and the introduction pipe 50 to introduce steam, in order to further deflect the particles 20 made heavy by the steam towards the base tank 12.

In a preferential form of embodiment shown in fig. 2, which is an improved version of the device 10 as described heretofore, the cover 16 also comprises, in a single piece, a vertical separating wall 22 able to divide the container 18 into two different zones.

A first zone 24 is able to contain dirty water, that is, into which the dust 20 and other solid particles arriving from the inlet pipe 19 are able to be deposited, whereas a second zone 26 contains only clean water.

The separating wall 22 is substantially impermeable to water, except in correspondence with a lower portion where there is a through hole 23, made in proximity with a bottom wall 27 of the container 18, and in correspondence with an upper portion where there are apertures 30, partly closed by deflectors 32. It should be noted that the clean water is kept separate from the dirty water because the dust 20 is deposited in a zone below the through hole 23.

The through hole 23 is able to let the water pass between the first zone 24 and the second zone 26 so as to keep a constant level in the two zones, whereas the apertures 30 allow the air to flow from the first zone 24 to the second zone 26 as far as a cage 25 which contains a float 42, connected to the outlet pipe 13.

The base tank 12 comprises, in a single piece, a

conveyor pipe 36 for clean water, elbow-shaped and comprising a vertical portion 36a and a horizontal portion 36b, arranged astride the separating wall 22. To be more exact, the horizontal portion 36b is open towards the second zone 26, to convey the clean water into the first zone 24.

The introduction pipe 34 is solid with the base tank 12 and is able to be inserted between mating housing walls 37, arranged around a corresponding cavity 38 made in the cover 16.

The introduction pipe 34 is arranged in the second zone 26 and is connected to the horizontal portion 36b of the conveyor pipe 36.

The liquid bath filter device 10 according to this form of embodiment functions as follows.

The secondary air passes into the clean water contained in the conveyor pipe 36 and causes turbulence and bubbling, sufficient to generate the spray 46 in proximity with the inlet pipe 19, so as to further capture the dust 20, already hit by the steam.

The dust 20 therefore falls due to gravity onto the bottom 27 of the base tank 12, but only into the first zone 24.

The filter device 10 has the advantage that the spray 46 consists only of clean water and that the inner surfaces of the conveyor pipe 36 and of the introduction pipe 34 are not subject to incrustations due to possible deposits of dust 20 or other solid particles, since the latter are able to be deposited only on the bottom of the first zone 24.

It should also be noted that the inlet pipe 19 of the container extends as far as the upper end of the vertical portion 36a of the conveyor pipe 36. In this way the secondary air, arriving from the introduction pipe 34, "directs"the spray 46 of clean water directly against the

particles of dust 20.

The vertical portion 36a of the conveyor pipe 36, moreover, exceeds in height a pre-defined maximum level Lmax of water inside the container 18, to prevent the dirty water contained in the first zone 24 from entering accidentally into the conveyor pipe 36 and mixing with the clean water.

In fact, for safety's sake, downstream of the liquid bath filter device 10, there is the float 42 of a conventional type, able to block the suction motor 15 when the level of water inside the container 18 has reached said bmax- Above the through hole 23, on the contrary, there is defined a minimum level Lr,, in below which the filter device 10 does not function because the level of water is under the conveyor pipe 36.

According to another form of embodiment of the invention, as shown in figs. 3 and 4, it is the cover 116 which comprises the conveyor pipe 136 and the separating wall 122, which is able to be inserted between mating housing walls 137 made on the bottom 127 of the base tank 112.

The cover 116 also comprises a bell element 140, able to deflect the flow of secondary air into the conveyor pipe 136.

The introduction pipe 134 is arranged in the first zone 24 and is able to be arranged inside the bell element 140 through a through cavity 139 made in the horizontal portion 136b of the conveyor pipe 136, equipped with a sealing ring 141, of the O-Ring type.

In this embodiment, the secondary air passes in a path defined between the introduction pipe 134 and the bell element 140 and between the latter and the pipe 136.

According to a variant not shown in the drawings, the

introduction pipe 134 is able to be coupled in the through cavity 139 by means of conical coupling.

A further advantage of the filter device is that it is easy to clean or maintain the container 18, simply by dis- assembling the cover 16,116 of the base tank 12,112.

To be more exact, fig. 4 shows the dis-assembly of the filter device 110 in accordance with this last form of embodiment. With the removal of the cover 116, the separating wall 122, the conveyor pipe 136 and the bell element 140 are all dis-assembled from the introduction pipe 134 and the base tank 112.

It is clear however that modifications and/or additions of parts may be made to the filter device 10,110 as described heretofore, but these shall remain within the field and scope of the present invention.