WO2013114096A1

WO2013114096A1 - Washing device

Info

Publication number: WO2013114096A1
Application number: PCT/GB2013/050191
Authority: WO
Inventors: Andries Otten
Original assignee: Safeway Hygiene Services Limited
Priority date: 2012-01-30
Filing date: 2013-01-29
Publication date: 2013-08-08
Also published as: GB2502248A; GB201201492D0; GB2502248B

Abstract

There is disclosed a hand washing device including a washing chamber having an enclosed interior, the interior having an interior surface. The washing chamber has a forwardly and upwardly facing mouth through which a user's hand or hands may be inserted into the interior. The mouth has a lip that is directed inwardly into the enclosed interior. The mouth is sufficiently large to allow insertion of a user's hand or hands without touching the lip. The interior surface is smooth and without corrugations or similar dirt traps, and the interior of the washing chamber is configured as a funnel from the mouth towards a drain, the drain being located at a lowermost part of the interior. Spray nozzles are mounted in flush manner in the interior surface, and at least some of the spray nozzles are angled spray nozzles angled at an angle from 5° to 25° to a line substantially normal to the interior surface at the location of the respective nozzle, the angle being in a direction away from the mouth. The device further includes at least one exhaust port in the interior surface connected to an aspirator configured to generate an airflow through the interior from the mouth towards the at least one exhaust port, thereby to reduce egress of spray through the mouth.

Description

WASHING DEVICE

This invention relates to an apparatus for washing articles, in particular but not exclusively a user's hands and forearms, in particular but not exclusively for use in medical and food preparation applications. BACKGROUND

Hygiene in particular of the hands, is of great importance in today's world, and in particular in clinical or medical environments, or where food is being prepared. Germs or other foreign particles on the hands can be passed between individuals resulting in the spread of disease. Cuticles and nails are particular areas where germs and the like may be harboured. Conventional scrubbing or washing, involving mechanical action and friction, for example of one hand against another, to remove germs and dirt from these areas is not always entirely satisfactory or effective. In fact, scratches and abrasions produced as a result of scrubbing operations, for instance using a nail brush, may become more problematic in that they form further reservoirs where germs or other undesirables may lurk. The use of large volumes of antiseptics can create problems, from an environmental point of view, as these are flushed into public drainage systems. In addition, excessive use may result in the development of resistance amongst the microbe population.

In addition, persons with skin or joint or fracture problems or elderly can experience discomfort if hand or abrasive instruments are used to clean the hand surface or nail and cuticle.

US 3,757,806 discloses a hand washing device comprising a curvilinear manifold means arranged about a longitudinal axis, including fluid inlet and fluid outlet means, a pump for pumping a washing fluid at pulsating pressure, and means for conveying washing fluid from the pump to the manifold means. The manifold means are arranged to form a pair of generally cylindrical volumes, each for receiving a hand and forearm of a user. A large number of small holes are provided on the interior surfaces of the manifold to generate a pulsating spray of the washing fluid onto the user's hands. In order to prevent washing fluid from splashing out of the device, rubber diaphragms or iris rotating-type iris sleeve ports are provided through which a user must insert and withdraw his hands. Because the user's hands

P2232PC00 Jan 2013 will touch these parts upon withdrawal from the device after cleaning, it is very easy for the hands to become recontaminated with bacteria or microbes.

A similar device is known from US 5,924,148, which includes a pair of rubber gaskets through which a user must insert and withdraw his hands, and which are provided to reduce or prevent splashing.

US 5,265,628 discloses an automatic hand washer having a pair of rotating cylinders, each designed to receive a hand of a user. The cylinders are provided with nozzles on their internal walls arranged in a helical pattern for spraying a cleaning solution (for example chlorhexidine gluconate in water) onto the hands. The cylinders are configured to rotate about their axes, thus praying all sides of the hand without the need to move the hand or to rub the hands together. A ring of nozzles is provided at the mouth of each cylinder to generate a spray curtain, the intention being to help prevent washing solution from splashing out of the cylinders. However, it has been found that this is not always effective. Moreover, the device is mechanically complex, required drive mechanisms to rotate the cylinders and, more importantly, the inside surface of each cylinder is ribbed or stepped, the intention being to help prevent direct splashing washing solution towards the drain at the lower end of the cylinder. A disadvantage of such an arrangement is that any grooves or ridges or discontinuities in the surface constitute dirt traps and ideal breading grounds for bacteria and other microbes, since these dirt traps are very difficult to clean effectively. A very similar device is disclosed in WO 96/26795, which additionally provides an air knife for drying the after washing. Hot air dryers and air knives can form an additional source of contamination by blowing bacteria and other microbes onto hands that have just been cleaned.

Another similar device is known from US 4,817,651. In all of these rotating cylinder devices, cleaning fluid is pumped into an annular space between an outer cylinder and an inner cylinder. The inner cylinder is provided with nozzles, and when the cylinders are rotated at high speed, the cleaning solution is caused to be jetted out of the nozzles. The space between the inner and outer cylinders is not easily accessible for cleaning, and can itself be a significant dirt trap.

P2232PC00 Jan 2013 US 2008/0099043 discloses a hand washing device with a pair of cylinders that may be stationary, but which preferably rotate. The cylinders include internal brushes for cleaning the user's nails and fingertips. However, such brushes are notorious dirt traps and breeding grounds for bacteria and other microbes. US 6, 110,292 discloses a device that generates pulsating, swept jets of cleaning fluid that are intended to give rise to vibrational resonance when they strike human skin. The jets may be angled towards a drain of the washing chamber, and the mouth of the washing chamber through which the hand and forearm is inserted may be provided with an inflatable cuff to help reduce splashing. It is stated that the cuffs are deflated after washing so as to allow the hand to be withdrawn without touching the cuff, but this is a complex system, and the simple presence of a cuff that contacts unwashed skin can lead to contamination of the unit. Moreover, the nozzles project into the washing cavity, forming discontinuities that can act as dirt traps.

Accordingly, the prior art devices tend to be complex in design with many moving parts, or have projections, ribs or other discontinuities on the inner surfaces of the washing surfaces, or have cuffs or gaskets that seek to prevent splashing but actually give rise to a risk of contamination of cleaned hands as these are withdrawn from the washing chambers. Many of the prior art devices have all three of these shortcomings.

Moreover, in a closed washing environment as disclosed in the prior art references, there is a significant risk of cross-contamination if a first user has particularly contaminated hands and touches parts or surfaces within the closed washing environment. If the washing environment is not kept scrupulously clean, it is easy for contamination to spread to the hands of subsequent users.

Another consideration is that all hand washing methods have the potential to generate bacterial aerosols by the mechanical action of rubbing the hands together and the application of water. These bacterial aerosols can then settle on a user's clothing or on surfaces near the hand washing location and then be spread to other environments within a hospital or food processing facility.

BRIEF SUMMARY OF THE DISCLOSURE

P2232PC00 Jan 2013 In accordance with the present invention there is provided a hand washing device comprising: a washing chamber having an interior, the interior having an interior surface; the washing chamber having at least one mouth through which a user's hand or hands may be inserted into the interior; the interior of the washing chamber being provided with a drain; a plurality of spray nozzles; and at least one exhaust port in the interior surface connectable, or connected to an aspirator configured to generate an airflow through the interior from the mouth towards the at least one exhaust port, thereby to reduce egress of spray through the mouth. The device seeks to facilitate the removal of transient flora and microorganisms, as well as dirt, from the hands by massaging stationary pre-soaped hands with water or washing fluid sprays. Embodiments of the device seek to reduce the risk of cross-contamination both within and outside the device by way of ballistic droplet formation and gravimetric aerosol generation. Embodiments of the device also seek to provide a positive user outcome of improved hand wash compliant and reduction of occupational dermatological problems associated with frequent hand washing as required by modern healthcare and food preparation standards.

The washing chamber is preferably provided with a substantially smooth interior surface that is substantially free of sharp edges and corners means that the interior surface is easy to keep clean, with a much reduced risk of the formation of dirt traps, which are areas where dirt can accumulate and act as a breeding ground for microbes and the like. In particularly preferred embodiments, the interior surface of the washing chamber presents no non-rounded corners or edges, but instead comprises flat or curved surfaces, or a single curved surface, with at least one mouth or opening through which a user's hands may be inserted. The interior surface of the washing chamber may be fabricated from glass, ceramic or polymer, and may additionally be treated with or have incorporated therein a biocide such as silver or other metal ions, or chemical biocides such as are known in those of ordinary skill in the art. The interior surface is preferably smooth, without ribs or corrugations, and without

P2232PC00 Jan 2013 sharp corners or internal edges so as to allow the surface to be cleaned easily and thoroughly, and to hinder the adhesion of microbes to the surface or hard-to-reach parts of the surface. Liquid glass technology (such as spray-on liquid silicon dioxide layering technology available from Nanopool® GmbH) maybe used to form a smooth interior surface. The washing chamber may be any appropriate shape, as may the interior of the washing chamber. In one embodiment, the interior surface of the washing chamber advantageously has ceiling portion and floor portion, either or both of which may, optionally be substantially flat. In that embodiment, the spray nozzles are preferably located in these substantially flat portions of the interior surface of the washing chamber. In another embodiment, the chamber may be provided with front and rear walls, the nozzles being provided in the front and rear walls.

It is preferred that the washing chamber, especially the interior surface of the washing chamber remains static during use. That is to say, the interior surface does not move during washing. But for the mouth, drain and exhaust, the interior is preferably substantially enclosed.

In currently preferred embodiments, a single mouth is provided to allow a user to insert both hands into the washing chamber. The mouth preferably has a width greater than its height, so as to allow both hands to be inserted side-by-side into the washing chamber at the same time. Suitable shapes for the mouth include oval (including Cassini-type ovals), elliptical, oblong (with rounder corners or ends), hourglass-type shapes, hippopedic shapes or dog-bone shapes. In all embodiments, it is desirable for the mouth to be configured so that the hands can easily be located in the washing chamber without accidentally touching the edge or lip of the mouth. Shapes that have a central constriction in height (in the manner of an hourglass on its side, or a dog-bone) are useful, since they encourage the user to insert his hands in a predetermined position within the washing chamber and to keep his hands separated from each other.

In alternative embodiments, a pair of mouths may be provided, one for each hand. The openings may be circular, rounded, oval or tear-drop shaped, and are configured to allow

P2232PC00 Jan 2013 a hand to be inserted into the washing chamber without touching the edge of the opening or orifice.

The mouth is preferably arranged ergonomically, so that a user standing in front of the washing device will find it easy and comfortable to insert his hands into the washing chamber, typically side-by-side rather than with one hand higher than the other. For example, the mouth may be arranged to face upwardly and/or forwardly from the interior of the washing chamber.

Preferably the mouth has a lip, directed towards the interior of the washing chamber. The mouth may advantageously be provided with a bezel. The bezel is shaped and/or configured so as to surround and overhang the mouth. Preferably, the bezel incorporates a lip that runs around the mouth and is configured to direct splashing or aerosolised washing fluid back into the washing chamber. The bezel may be made of the same material as the washing chamber, or of a different but similar material. The bezel may be configured to provide the lip that is directed inwardly into the enclosed interior. The bezel may have a portion that extends from top to bottom across its width, thereby to define a pair of openings. In this way, a washing chamber having a single mouth can be configured, with the bezel, to present a pair of openings for a user's hands.

In addition to being substantially smooth and without sharp edges or corners, the interior surface of the washing chamber may have a generally funnel-like shape. In embodiments having a single mouth, the funnel may have a cross-section similar to the shape to the mouth. The cross-section may remain substantially constant in area moving from the mouth towards a rear of the washing chamber before reducing in size as the washing chamber narrows towards a drain. The drain is positioned in the lower portion of the chamber, optionally in the floor of the chamber and/or at the rear of the chamber. The location of the drain may be selected according to the shape of the chamber itself.

Preferably, the washing chamber is arranged so that the mouth is higher than the drain washing chamber. The mouth may be vertically above the drain. In one embodiment, a line drawn from the centre of the mouth to the centre of the drain would preferably be at between 20° to 90° to the horizontal, more preferably from about 30° to about 80°. In some embodiments, the mouth is provided in the front of the chamber and the drain is found at the

P2232PC00 Jan 2013 rear of the chamber. In that embodiment, the chamber is angled such that the front part of the chamber is higher than the rear part. For example, an imaginary line drawn from the central part of the front of the washing chamber to a central part of the rear of the washing chamber will preferably be at an angle from 20° to 60° to the horizontal when the washing chamber is positioned for use, preferably from 30° to 50°, most preferably about 40°. This helps to keep the spray within the washing chamber.

The interior surface of the washing chamber is provided with a plurality of nozzles or sprays that are designed to spray or jet water or other washing fluid onto the user's hands. The nozzles may be mounted in holes formed in the wall of the washing chamber so that they can be fed with fluid from outside the washing chamber and to spray or jet the fluid into the interior of the washing chamber. The nozzles are mounted in such a way that they are preferably substantially flush with the interior surface of the washing chamber and do not present dirt traps in which dirt can accumulate. Of particular importance is that the fluid nozzles are configured to spray or jet the washing fluid towards the drain of the washing chamber. For example, in some embodiments, the drain is found in the rear of the chamber and the nozzles are configured to spray the water towards the rear. This helps reduce splashing and unwanted egress of contaminated cleaning fluid through the mouth to the outside of the device and onto a user's arms and clothes, or into an environment that is intended to be aseptic. In particularly preferred embodiments, at least some of the spray nozzles are arranged or angled so as each to generate a fan-shaped spray that is angled at an angle of from 5° to 25° from a plane normal or perpendicular to the respective ceiling or floor portion or wall of the interior surface of the washing chamber. The washing chamber and its mouth and, where provided, the bezel are advantageously configured so as to encourage a user to insert his hands into the washing chamber with the palms flat and substantially parallel to the floor and ceiling portions or walls of the interior surface of the washing chamber. Accordingly, the sprays from the angled spray nozzles will tend to have a plane that is angled at an angle of from 5° to 25° from a plane normal or perpendicular of the skin or surface of the user's hand upon which they impinge when the user's hands is in the correct position within the washing chamber. The angle may be from 10° to 20°, preferably 10° to 15° and in currently preferred embodiments about 12° to the plane normal to the surface of the user's hand. By generating

P2232PC00 Jan 2013 a fan-shaped spray at these angles, a specific shear cleaning action is obtained. This is to be distinguished from the trampoline or skin resonance effect cleaning of prior art devices where cleaning fluid is jetted in a pulsed manner at an angle more perpendicular to the surface of the skin. As previously stated, the spray nozzles that are angled are angled so as to spray in a direction that has a resolved component toward the rear of the washing chamber, and not towards the mouth. This helps to reduced unwanted splashing.

The spray nozzles are configured to generate a fine spray of washing fluid consisting of fluid droplets of very small size. This increases the liquid surface area of the cleaning fluid, distributes the cleaning fluid over a predetermined area, and generals an shearing force and/or impact force (depending on the angle of incidence onto the skin) to help remove microbes, transient flora and other dirt from the user's hands. The use of a very fine spray or mist helps to promote thorough wetting of the skin surface.

The spray nozzles are preferably arranged in at least two different groups. A first group comprises angled spray nozzles configured to spray washing fluid at an angle of from 5° to 25° to a plane normal to the skin or surface of the user's hand, while a second group comprises spray nozzles configured to spray washing fluid at a more perpendicular angle to the skin or surface of the user's hand, particularly in the region of the user's cuticle and fingernails.

In a currently preferred embodiment, four angled spray nozzles are mounted in a ceiling of the washing chamber and four angled spray nozzles are mounted in a floor of the washing chamber (two spray nozzles above each hand, and two spray nozzles below each hand). Each group of four spray nozzles may be mounted in a quadrilateral arrangement. In a washing chamber designed to accommodate two hands at the same time, this embodiment will therefore have eight angled spray nozzles. A similar arrangement may be provided when the chamber has front and rear walls.

In addition to the angled spray nozzles, this embodiment further includes four spray nozzles configured to spray washing fluid at an angle substantially perpendicular to the floor portion of the washing chamber; two spray nozzles below the fingertips of each hand when the user's hands are in the correct position. These spray nozzles serve to remove dirt and microbes from the cuticles and from under the fingernails of the user.

P2232PC00 Jan 2013 It will be understood that more or fewer than 12 spray nozzles may be provided, but it has been found by the applicant that 12 nozzles combines effective coverage at an acceptable consumption of washing fluid. While the rate of consumption of washing fluid may not be a particular issue where there is an ample supply (for example, a mains water supply), it is envisaged that mobile or portable embodiments will make use of a reservoir of washing fluid that requires periodic refilling. It has been found that a volume in the range of 1 to 2 litres of washing fluid, preferably around 1.5 litres of washing fluid, is sufficient for a complete 15 second wash cycle.

A pre-filter may be provided to remove mineral impurities and foreign particles from the washing fluid prior to the washing fluid being pumped to the spray nozzles.

The spray nozzles may be individually supplied with washing fluid by means of tubes or hoses on the outside of the washing chamber. A double-walled washing chamber construction is thus not required.

In preferred embodiments, the washing fluid is supplied to the spray nozzles at a pressure of 200 to 500 kPa (2 to 5 bar), preferably 270 to 400 kPa (2.7 to 4 bar). The pressure may be calibrated and varied by a programmable pressurised accumulator. The pressure may be varied during a wash cycle to provide appropriate cleaning action for different types and burdens of transient flora, microbes etc. in specific applications.

The washing fluid contained within the washing vessel during use is in the form of a fine spray or aerosol that coalesces on contact with the skin and the inner surface of the washing chamber as droplets. The interior surface of the washing chamber may have an ultrafine, smooth, hydrophobic surface, and is angled so as to promote directional flow of the fluid droplets towards the drain portion at the rear of the washing chamber. The angle is preferably from 20° to 60° to the horizontal when the washing chamber is positioned for use, preferably from 30° to 50°, most preferably about 40°.

The drain portion may include a substantially conical drain and an open, smooth aperture to promote discharge flow. In addition, the open, smooth aperture does not act as a dirt trap, and therefore reduces the likelihood of cross-contamination between users.

P2232PC00 Jan 2013 The aerosolised washing fluid is evacuated from the washing chamber by way of at least one exhaust port. The at least one exhaust port is preferably aspirated so as to be operable to suck the aerosolised washing fluid from the interior of the washing chamber. Preferably, two exhaust ports are provided, one on each sidewall of the washing chamber. The exhaust ports are preferably located near to the mouth of the washing chamber, for example behind the bezel. An aspirator pump and an exhaust manifold may be provided, and washing fluid and air may be separated by way of a filter or the like within the exhaust manifold. Used washing fluid may be directed to a holding sump. Waste washing fluid can be discharged to an exterior drain at the end of the washing cycle. The air may be exhausted by way of HEPA filter to the outside of the device, optionally by way of angled fins at a base of an exterior casing of the device. Aspiration (i.e. activation of the aspirator pump) preferably starts prior to the washing fluid being sprayed from the spray nozzles, and continues for a predetermined time after the end of spraying.

The exhaust manifold is configured to generate a directional airflow through the washing chamber from the mouth towards the at least one exhaust port, the airflow being sufficient to reduce or prevent ballistic droplet and aerosol dispersion of contaminated washing fluid through the mouth of the washing chamber without the need for special cuffs or gauntlets that may present a cross-contamination risk.

The washing chamber and the mouth and, where provided, the bezel are shaped and designed to integrate the various components described above within an ergonomic and functional unit to provide a comfortable, consistent and safe procedure and to contribute positively to hand wash compliance. The design of the mouth and of the interior of the washing chamber helps to direct air and washing fluid droplet/aerosol flow, substantially reducing the incidence of dispersion and cross contamination to users and the environment. A hand wash cycle may be activated by the user placing his hands into the washing chamber and breaking a visible light beam or infrared beam arranged across the washing chamber at a location corresponding to a correct position of the hands. The beam may be projected from one side of the interior of the washing chamber and impinge upon a photodetector on an opposed side of the interior of the washing chamber. More than one beam/photodetector pair may be provided in order to ensure that the hands are correctly position, the hand wash cycle starting only when all the beams are broken.

P2232PC00 Jan 2013 The device may be provided with an electronic control panel and electronic control circuitry. When the light or infrared beams are broken and the hand wash cycle commences, this is recorded in a memory in the control circuitry. In the user does not complete the preprogrammed hand wash cycle (for example, he removes his hands from the washing chamber before the cycle is complete), the photodetector will detect this and an incomplete wash will be recorded. This may activate an audible and/or visual alarm signal and optionally an RFID record.

The device may be fitted with a soap or detergent dispenser externally to the washing chamber. The soap or detergent dispenser is preferably a "no touch" dispenser provided with a passive infra-red or other type of proximity detector that senses the presence of a user's hand and dispenses a pre-determined volume of soap or detergent onto the hand. The soap or detergent dispenser may be linked to the control circuitry in such a way that a hand wash cycle cannot be activated until a successful dispensation has been recorded. In addition, the control circuitry may be configured to require that a user inserts his hands into the washing chamber within a predetermined time after activation of the soap or detergent dispenser, for example, within 1 minute. It is to be understood that preferred embodiments of the present device require a user to apply soap or detergent to his hands outside the washing chamber, and to perform a predetermined sequence of cleaning actions (for example, the hand soaping actions specified by the NHS National Patient Safety Agency and the World Health Organization Guidelines on Hand Hygiene in Health Care) before inserting his hands into the washing chamber.

The electronic control panel may include a display, and the display may provide status information and prompt actions from the user. For example, the display may show various hand soaping actions, each for a predetermined period of time, encouraging the user to follow the correct hand soaping protocol.

The sprays in the washing chamber are configured to rinse the hands and to remove soap/detergent, dirt and microbes that have already been loosed from the skin by the hand soaping actions. This is in contrast to prior art hand washing devices that seek to apply soap or detergent within the washing chamber to try to dispense with the step of rubbing the hands together prior to rinsing. It has been found that omitting the hand rubbing steps leads to

P2232PC00 Jan 2013 poorer hand hygiene and requires more complex machinery and a greater risk of contamination due to egress of droplets and aerosols from the washing chamber.

The control circuitry may incorporate an RFID or similar user identification system that makes use of RFID tags or badges worn by users. This allows hand washing compliance by individual users to be monitored and recorded, and for additional training to be given to users who consistently fail to comply with the proper procedure.

Preferably, the washing chamber is mounted in a housing and positioned so as to be comfortable for use by users of a wide variety of different lengths.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

Figure 1 shows a washing chamber in three quarter view;

Figure 2 is a front elevation of the washing chamber of Figure 1;

Figure 3 is a side elevation of the washing chamber of Figure 1;

Figure 4 is a rear elevation of the washing chamber of Figure 1;

Figure 5 is a top view of the washing chamber of Figure 1;

Figure 6 is a bottom view of the washing chamber of Figure 1.

DETAILED DESCRIPTION

Figure 1 shows a washing device of a first embodiment, comprising a washing chamber 1 which may be mounted on a base unit containing various pumps and control electronics as will be described later in more detail, and may additionally contain a supply of washing fluid (such as water) and a supply of soap or detergent. In the embodiment shown, the device is provided with a connection 3 to a supply of mains water. The washing chamber

P2232PC00 Jan 2013 1 of this embodiment has a mouth comprising two openings 4 each surrounded by a bezel 5. The washing chamber 1 is also provided with a bracket 6 that secures the washing chamber 1 to the base unit 2 at an angle of about 40° to the horizontal. A housing or console (not shown) is preferably provided for the washing chamber 1 and the base unit 2 in order to give an aesthetically pleasing finish to the device as a whole. An electronic display 7 is provided on the front of the base unit 2, although the display 7 may be provided in the housing or console (not shown).

The washing chamber 1 is shown in more detail in Figures 2 to 6. The bezel 5 is mounted at the mouth 4 of the washing chamber 1. The washing chamber 1 has a generally flat ceiling portion 8 and a generally flat floor position 9, the ceiling and floor portions 8, 9 being generally parallel to each other and angled at around 40° to the horizontal by the bracket 6. The washing chamber 1 also has a pair of side walls 10, 11 that are generally parallel to each other at the mouth 4 of the washing chamber, but converge at a rearward portion of the washing chamber 1, where a drain 12 is located. Four angled spray nozzles 13 are mounted in the ceiling portion 8 of the washing chamber, and another four angled spray nozzles 13' are mounted in the floor portion 9, the nozzles 13, 13' being positioned in opposed locations. The nozzles 13, 13' are angled towards the rearward portion of the washing chamber 1 at an angle of between 10° and 15° to a line normal to the ceiling and floor portions 8, 9. The spray nozzles 13, 13' are arranged to generate fan-shaped sprays of washing fluid onto the hands of a user (from above and below) when the hands are placed in the washing chamber 1. The fan-shaped sprays of washing fluid (e.g. water) impinge upon the skin of the hands at an angle of between around 10° and 15°, this leading to an efficacious shearing effect to help remove microbes and soap/detergent from the skin. A further four spray nozzles 14 are provided at the floor portion 9 of the washing chamber 1, these being arranged in a line across the width of the washing chamber 1 further towards the drain 12. These spray nozzles 14 are not angled, but instead are configured to spray washing fluid in a direction substantially normal to the floor portion 9 of the washing chamber 1. Two spray nozzles 14 are provided for each hand, and are positioned so as to spray washing fluid at the fingertips and under the fingernails of the user.

P2232PC00 Jan 2013 The nozzles 13, 13 ', 14 are supplied with washing fluid by way of hoses (not shown) that are connected to a washing fluid pump (not shown) located in the base unit 2.

Two exhaust ports 15 are provided, one on either sidewall 10, 11 of the washing chamber 1 near the mouth 4. The exhaust ports 15 are connected to an exhaust manifold 16 that passes along the outside of the washing chamber 1 and then to an exhaust pipe 17. The exhaust pipe 17 is connected to an aspirator pump (not shown) located in the base unit 2. The aspirator pump causes a suction to be applied at the exhaust ports 15, and this suction generates an airflow in the region of the mouth 4 that helps to prevent spray from exiting through the mouth 4 of the washing chamber 1. Air and washing fluid are separated from each other either in the exhaust manifold 16, or the exhaust pipe 17 or the aspirator pump. Waste air can be expelled by way of HEPA or other types of filter, and waste cleaning fluid can be held in a sump (not shown) or passed to a drain.

Washing fluid that is not extracted by the exhaust ports 15 will tend to flow towards the drain 12, since this is located at the lowermost point of the washing chamber. A light beam or infra-red beam and photodetector arrangement 18 is provided towards the rear of the washing chamber 1 so as to detect when a user has placed his hands correctly in the washing chamber 1. The arrangement 18 is located so that when the light beam or infra-red beam is broken by the user's fingers, a washing cycle is started by the control electronics. It is to be noted that this will only happen when the user's hands are fully inserted in the washing chamber 1, with the fingertips extending over the spray nozzles 14. An additional light beam or infra-red beam and photodetector arrangement 19 can be provided between the exhaust ports 15 so as to ensure that the user's wrists are at the correct elevation in the washing chamber.

The interior of the washing chamber, including the drain 12 and the exhaust ports 15, is designed to be smooth and without sharp corners or other dirt traps. This means that the washing chamber 1 can be effectively self-cleaning, while also being easy to clean with a sterile cloth or the like as part of a regular maintenance routine.

In an alternative embodiment, not shown, the bezel 5 defines one opening in the mouth 4 of the washing chamber 1. The embodiment having two openings is somewhat

P2232PC00 Jan 2013 preferred, though, as by providing two openings 20, the bezel 5 encourages the user to locate his hands in the correct position inside the washing chamber 1 so that the hands do not touch each other, nor do they touch the interior surface of the washing chamber 1.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of them mean "including but not limited to", and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

P2232PC00 Jan 2013

Claims

1. A washing chamber having an interior, the interior having an interior surface; the washing chamber having at least one mouth through which a user's hand or hands may be inserted into the interior; the interior of the washing chamber being provided with a drain; a plurality of spray nozzles; and at least one exhaust port in the interior surface connectable to an aspirator configured to generate an airflow through the interior from the mouth towards the at least one exhaust port, thereby to reduce egress of spray through the mouth.

2. A hand washing device according to claim 1, wherein the washing chamber is enclosed.

3. A hand washing device according to claim 1 or claim 2, wherein the washing chamber is static in use.

4. A hand washing device according to any preceding claim, wherein the mouth is upwardly and/or forwardly facing.

5. A hand washing device according to any preceding claim, wherein the mouth has a lip that is directed inwardly into the enclosed interior.

6. A hand washing device according to any preceding claim, wherein the mouth is sufficiently large to allow insertion of a user's hands or hands without touching the lip.

7. A hand washing device according to any preceding claim, wherein the interior surface is substantially smooth.

P2232PC00 Jan 2013

8. A hand washing device according to any preceding claim, wherein the interior of the washing chamber is configured as a funnel from the mouth towards a drain, the drain being located at a lowermost part of the interior.

9. A hand washing device according to any preceding claim, wherein the nozzles are mounted or formed in substantially flush manner in the interior surface.

10. A hand washing device according to any of the preceding claims, wherein at least some of the spray nozzles being angled spray nozzles angled at an angle from 5° to 25° to a line substantially normal to the interior surface at the location of the respective nozzle, the angle being in a direction away from the mouth.

11. A hand washing device according to any preceding claim, wherein the lip is provided by a bezel that is provided at the mouth of the washing chamber.

12. A hand washing device as claimed in claim 11, wherein the bezel defines a single opening.

13. A hand washing device as claimed in claim 11, wherein the bezel defines a pair of openings.

14. A hand washing device as claimed in any preceding claim, wherein the interior surface of the washing chamber is made of glass, ceramic or polymer.

15. A hand washing device as claimed in any preceding claim, wherein the interior surface of the washing chamber has a substantially flat ceiling portion and a substantially flat floor portion, the ceiling and floor portions being substantially parallel.

16. A hand washing device as claimed in any preceding claim, wherein some of the spray nozzles are normal spray nozzles angled at an angle normal to the interior surface at the location of the respective nozzle.

17. A hand washing device as claimed in any preceding claim, comprising a pair of exhaust ports, one on each side of the mouth.

P2232PC00 Jan 2013

18. A hand washing device as claimed in any preceding claim, comprising an exhaust manifold connecting the exhaust port or ports to the aspirator.

19. A hand washing device as claimed in any preceding claim comprising a first plurality of angled spray nozzles in a ceiling of the washing chamber and a second plurality of angled spray nozzles in a floor of the washing chamber.

20. A hand washing device as claimed in claim 19, wherein the angled spray nozzles in the ceiling of the washing chamber are located in substantially opposed relationship to the angled spray nozzles in the floor of the washing chamber.

21. A hand washing device as claimed in claim 19 or 20, further comprising a third plurality of normal spray nozzles in the floor of the washing chamber.

22. A hand washing device as claimed in claim 21, wherein the normal spray nozzles are located between the drain and the second plurality of angled spray nozzles.

23. A hand washing device as claimed in claim 21, wherein the normal spray nozzles are arranged in a substantially straight line.

24. A hand washing device as claimed in any one of claims 21 to 23, comprising four angled spray nozzles in the ceiling of the washing chamber, four angled spray nozzles in the floor of the washing chamber, and four normal spray nozzles in the floor of the washing chamber.

25. A hand washing device as claimed in any preceding claim, wherein the angled spray nozzles are angled at an angle from 10° to 15°, optionally substantially 12°, to a line substantially normal to the interior surface at the location of the respective nozzle, the angle being in a direction away from the mouth.

26. A hand washing device as claimed in any preceding claim, comprising a reservoir of washing fluid connected to the spray nozzles by way of a pump.

27. A hand washing device as claimed in any one of claims 1 to 26, comprising a pump connected to the spray nozzles, and an inlet to the pump for connection to a supply of washing fluid.

P2232PC00 Jan 2013

28. A hand washing device as claimed in any preceding claim, further comprising a soap or detergent dispenser located outside the washing chamber.

29. A hand washing device as claimed in claim 28, comprising control electronics to prevent the device from commencing a wash cycle unless a successful dispense of soap or detergent has been recorded.

30. A hand washing device as claimed in any preceding claim, comprising at least one light gate comprising a light or infra-red source and a photodetector, the light gate being arranged to extend across the interior of the washing chamber, and comprising control electronics to commence a wash cycle when the light gate is interrupted by a user's hand.

31. A hand washing device as claimed in any preceding claim, further comprising electronic means to identify a user and to record successful or unsuccessful wash operations for that user.

32. A hand washing device as claimed in claim 31, wherein the electronic means includes an RFID tag reader.

33. A hand washing device substantially as hereinbefore described with reference to or as shown in the accompanying drawings.

P2232PC00 Jan 2013