FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
A PROCESS AND DEVICE FOR CLEANING SUBSTRATES
HINDUSTAN UNILEVER LIMITED, a company incorporated under
the Indian Companies Act, 1913 and having its registered office
at 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India
The following specification particularly describes the invention and the manner in which it is to be performed.

Technical Field
The present invention relates to a process and a device for cleaning substrates. In particular the invention relates to an air-water jet device coupled to the motor of a conventional washing machine.
Background and Prior Art
Washing of fabric articles is a commonly used process throughout the world. A specific problem with all machine wash processes is that machine washing processes do not always removal stains on fabric articles. In hand wash processes special attention can be provided for stains, but in washing machines this attention is absent.
One way of making sure that stains are removed is the application of a pre-treatment composition onto a stain prior to the start of the washing process. Another way is to manually remove the stain before washing. Both methods are commonly used in the art.
Another way of pre-treatment is the use of a water spray to utilise hydrodynamic stress for the removal of stains. Sprays are generally defined as either high speed liquids e.g. water or a combination of water and air have generally been used to clean hard and non-porous surfaces e.g. cleaning automobiles, walls of buildings, metal vessels.
US4787404 (IBM, 1988) disclosed a low flow-rate pressure atomizer device which is so dimensioned and operated as to accelerate a gas to substantially sonic velocity and cause it to break up a cleaning liquid also input at a high pressure into small droplets and accelerate these droplets to at least half the velocity of said gas to create shear stress at a surface adjacent the exit end of said device, thereby to remove the contaminants or the like from said surface.

FR-B-1108989 discloses a process to clean a substrate by subjecting the substrate to an air-water spray generated by a spraying means comprising an air passage and a water passage.
US 2002/189641 discloses a device for cleaning a soiled surface, the device comprising a feed water container and an air compressor in communication with the spray nozzle Comprising a water passage and an air passage. Both of the above mentioned devices provide an air water spray that is mixed inside the device. The disadvantage of such system is that the water flow cannot be reliably regulated because the air pressure goes against the water flow direction. This is Especially problematic when a low water to air ratio (for instance in water air ratios of less than 1:9) is required or a low water flowrate. The nozzles of the prior art are not suitable for this purpose.
Another prior art US-A-3,108,465 discloses a vibration isolating arrangement and more particularly a suspension systems for machines, such as for washing machines, which Operate at a relatively slow speed to wash clothes and then centrifuge liquid out of the clothes at a relatively high speed. However this type of arrangement as discloses by this prior art is not energy efficient, not cost effective and more importantly not suitable for the present purpose. A specific way of bre-treatment, described in our co-pending application PCT/EP2009/050869 (published as WO2009/103595), is the use of an air-water jet to remove a stain from a fabric article. The air-water jet device as described comprises of a noozle design for the external mix of air and water and a compressor for providing the required air.
The drawback of this system and all other air-water spray devices is that such air compressors and the required motor drives are very expensive,
Washing machines are usually equipped with a fairly strong motor drive that is very suitable to power the compressor of an air-water jet device.

Since air-water jet devices, such as the device described in PCT/EP2009/050869, are very suitable for spot cleaning of stains on fabric articles, an integrated washing machine comprising an air-water jet device.
Thus, it is an object of the invention to provide an integrated washing machine and air-water jet device.
It is a further object that the washing machine motor can be utilised for either washing, or using the air-water jet device
Surprisingly it has been found that a coupling device connected to the shaft of the washing machine motor to alternatively engage the air compressor of an air-water jet device and the washing machine drum, meets at least one of the objects above.
Summary of the Invention
Accordingly to the present invention provides a washing machine comprising a motor having a shaft; a washing machine drum; an air compressor; and a coupling system characterised in that the coupling system is connected to the washing machine motor shaft and to both the washing machine drum and the air compressor, wherein the coupling system is disengageably engageable with at least one device with the rotating motor shaft.
These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify

the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.
Detailed description of the Invention
The invention provides a coupling system connected to the washing machine motor shaft and to both the washing machine drum and an air compressor.
Coupling system
The coupling system may be any kind of coupling system capable of engaging at least one device with a rotating motor shaft. Commonly available coupling systems, such as mechanical or magnetic couplings, preferably disc clutch, combined conical disk clutch, magnetic clutch, pneumatic coupling, are suitable for this purpose. Magnetic couplings are the most preferred.
It is preferred that the coupling system is a double or multiple coupling system, which means that not one, but two or more devices are simultaneously connected to the motor shaft and wherein the devices may be engaged individually or at the same time. It is preferred not to engage both devices at the same time. The couplings may be connected to the motor shaft or to the device shaft. The motor is preferably connected to a device by a pulley and belt system.
The coupling device may be made of any metal, or plastic. Clutches are preferably made of ferromagnetic material. For example, bronze, mild steel, iron etc. Clutch

surfaces are covered with friction material in order to engage after gear change and to avoid slip. Friction materials that can be used are ceramic, sintered bronze and moulded graphite.
Air-water jet device
The air-water jet device comprises two nozzles wherein a first nozzle is in fluid communication with a feed water source; and a second nozzle connected to a source of compressed air.
The water source may be any water source, either provided to the air-water jet device straight from the water mains, through a pump, through a pressured container holding the water or by any other means, or even by gravity (i.e. by placing the water reservoir above the height of use of the air-water jet.
Similarly, the air source may be any air source, either provided through a compressor, separate from or built into the device, or through a compressed air line, such as often available in hospitals.
Both the first nozzle (water nozzle) and the second nozzle (air nozzle) are positioned relative to an imaginary central axis (NOR). The first nozzle is positioned at an angle (a) of between 1 and 60° relative to the central axis, preferably 10° to 30°; and the second nozzle is at an angle (Ψ) of between 1 and 45° relative to the central axis, preferably 15° to 30°.
The mouth of the second nozzle is positioned more forward in the direction of the flow along the direction of the central axis than the mouth of the first nozzle, wherein the offset (OS) distance between the mouth of the first nozzle and the second nozzle is between 0.5 and 5 mm in said direction, preferably 1-3 mm.
The best results are obtained when the first nozzle has an opening of between 0.05 and 10 mm2, preferably even at least 0.2 mm2, and not more than 7 mm2,

more preferably not more than 5 mm2 or even less than and 3 mm2. Similarly, the opening of the second nozzle is preferably between 0.2 and 3 mm2.
The scope of the present invention further includes configurations comprising two or more water nozzles directed at a single air nozzle. Although this adds to the complexity of the device, which is generally not preferred, it provides the additional benefit of point of action mixing or reacting different or incompatible ingredients.
For nozzles with a circular opening, the diameter of the first nozzle is preferably between 0.25 and 3.5 mm, preferably at least 0.5 mm, but preferably not more than 3 mm, more preferably not more than 2.5 mm, or even less than 3 mm; while the diameter of the second nozzle is preferably between 0.5 and 2 mm.
Without wishing to be bound by a theory, it is thought that the present invention derives its performance from the positioning of the nozzles relative to the imaginary axis and the offset of the water nozzle (first nozzle) relative to the air nozzle (second nozzle). Because of this positioning, the water coming from the water nozzle forms a film around the air nozzle and because of this gives a finer spray at a lower water to air ratio (i.e. using less water). The air flow from the air nozzle is thought to create a local under pressure that ensures that the water is driven in the direction of the air nozzle along the air nozzle tip regardless of in which direction the nozzle is pointed. Furthermore, the water flow is not affected by the the air pressure, due to the separation of the air and water nozzle openings, which is a common problem with internal mix nozzle designs.
It is therefore preferred that the water: air ratio is between 10:90 and 1:9999, more preferably less than 5:95, still more preferably less than 4:96, even more preferably less than 3:97, less than 2:98 or even less than 1:99, while the ratio is preferably higher than 3:9997, more preferably higher than 5:9995.

It is further preferred that there is only a short distance between the opening of the water nozzle and the side of the air nozzle, this distance is preferably less than 2 mm, more preferably less than 1 mm, or even less than 0.5 mm. It is most preferred that the opening of the water nozzle is touching the air nozzle.
It is preferred that the air nozzle does not co-axially surround the water passage. It is also preferred that the water nozzle does not co-axially surround the air nozzle
The air pressure of the air source preferably has a pressure in the range of 1 to 4 bar. The air preferably has a velocity of greater than 80 m/s at the exit of the nozzle (the nozzle opening), preferably greater than 120 m/s, more preferably greater than 180 m/s, most preferably greater than 250 m/s are preferred. Although the invention would work up to very high air speeds, it is preferred for constructional reasons and convenience for the user that the air speed is less than the speed of sound (i.e. less than 334 m/s). Depending on the nozzle diameter, and the airflow rate is preferably between 3 and 50 l/min, preferably more than 5 l/min or even more than 10 l/min. The airflow rate is preferably less than 40 l/min, more preferably less than 30 l/min or even less than 25 l/min.
The water flow rate is typically between 2 and 50 ml/min, preferably more than 5 ml/min or even more than 10 ml/min, while the water flow rate is preferably less than 40 ml/min, preferably less than 30 ml/min or even less than 25 ml/min. Configuration
The air and/or water sources may be incorporated into the device, or be fit in a separate unit. In the latter case a separate unit comprising a compressor, a compressed air cartridge or cylinder or another source of air and/or a water reservoir optionally connected to the water mains is provided that is connected to a hand held device by means of a tubing as air line and/or water line.

Compressor
The compressor, preferably provides at least 1 bar pressure and not more than 5 bar, preferably less than 4 bar. Thus, very low power compressors, typically in the range of 0.05 to 1 HP, can be used to achieve the above specifications. Due to a pressure drop in the tubing and the device, the pressure at the air nozzle will preferably be in the range of 1 to 4 bar, preferably 2 to 3 bar. A device with a means to set the pressure is also contemplated; in this case the user is for instance able to choose between soft, medium and hard cleaning. In one of the preferred embodiment, a vessel for storing compressed air may be included between the compressor and the air jet device. When a vessel is used, a compressor generating a higher pressure (e.g. 1-20 bar) and a and a reducing valve for reducing the pressure in the vessel to the operating pressure of 1-4 bar, preferably 2-3 bar before going to the air jet device is also envisaged.
Water
The water source may be the water mains, i.e. directly connected to the faucet, or be in the form of a separate reservoir. The water pressure for use with the device may be relatively low, preferably at least 0.05 bar, more preferably at least 0.1 bar, but preferably not more than 3 bar, more preferably less than 2.5 bar, still more preferably less than 2 bar.
When a separate reservoir is used as water source, said reservoir may be filled with water only, or a detergent composition. It is understood that in the context of this invention, terms like "water source", "water reservoir" and "water nozzle" are not limited to water, but include also detergent compositions, preferably aqueous detergent compositions. The water reservoir may be placed above the level of use of the cleaning device, such as to provide pressure, or may be pressured separately. When pressured separately, it is especially preferred that the reservoir is pressurised with compressed air from the compressed air source.

Brief Description of the Drawings
Figure-1 is a schematic drawing of a washing machine motor, coupling device, compressor and washing machine drum.
Figure 2 shows a schematic drawing of the air-water jet nozzles
Figures 3 and 4 show 3-D drawings of the air-water jet nozzles in different embodiments.
Detailed Description of the Drawings
Figure 1 shows an integrated washing machine, comprising a motor drive (4), connected by a belt which is connected to the drum coupling (1), connected to a drum. The motor drive is also connected to a belt connected to a compressor coupling (2) connected to a compressor (3). The air line (A) of the air-water jet device is connected to the compressor (3). The water line (W) of the air-water jet is connected to a water reservoir and control device (5)
Figure 2 shows a configuration wherein, the nozzle (N) has the outlet port for liquid (OPW) positioned away from the substrate relative to the outlet port for air (OPA), offset by a distance (OS). The angle of incidence of the outlet port for liquid with respect to the substrate (FS) is defined by the angle a. The angle of incidence of the outlet port for air with respect to the substrate (FS) is defined by the angle . The dashed line NOR represents an imaginary line which is normal to the surface of the substrate. As is apparent, in this embodiment of the nozzle the angle a is greater than the angle . The air exits from the nozzle through outlet port for air (OPA) and the liquid exits through the outlet port for liquid (OPW).

Figure 3 shows a 3-D view of the configuration of Figure 2
Figure 4 shows a 3-D view of a configuration with 1 air nozzle and 2 water nozzles.

CLAIMS
1. A washing machine comprising
a. a motor having a shaft;
b. a washing machine drum;
c. an air compressor; and
d. a coupling system
characterised in that the coupling system is connected to the washing machine motor shaft and to both the washing machine drum and the air compressor, wherein the coupling system is disengageably engageable with at least one device with the rotating motor shaft.
2. A washing machine according to claim 1, wherein the coupling system is operated by a switch to engage either the washing machine drum or the air compressor or both.
3. A washing machine according to anyone of the preceding claims, wherein the coupling system is operated by a switch to engage either the washing machine drum or the air compressor wherein two or more devices are simultaneously connected to the motor shaft and wherein the devices may be engaged individually..

4. A washing machine according to anyone of the preceding claims, wherein the air compressor is connected to an air-water jet device.
5. A washing machine according to claim 4, wherein the air-water jet device comprises two nozzles wherein
a. a first nozzle is in fluid communication with a feed water source; and
b. a second nozzle connected to the air compressor; and
further characterised in that
c. both nozzles are positioned relative to a central axis, wherein

i. the first nozzle is at an angle of between 1 and 60° relative to the central axis; and
ii. the second nozzle is at an angle of between 1 and 45°
relative to the central axis iii. wherein the mouth of the second nozzle is positioned more forward in the direction of the flow along the direction of the central axis than the mouth of the first nozzle, wherein the offset distance between the mouth of the first nozzle and the second nozzle is between 0.5 and 5 mm in said direction.