GB2392826A - A method and apparatus for steam cleaning a surface - Google Patents

Abstract

A method of cleaning a surface with steam comprises supplying steam from a steam source, to a cleaning head which includes steam delivery means and a member 40 mounted thereon, passing steam from steam delivery means to the member 40 which is mounted on the steam delivery means so as to inhibit its displacement on receipt of steam, rotating said member 40 and passing steam through an outlet 64 in the member, thus cleaning a surface in the proximity of the outlet 64. There is preferably at least two outlets 64 which trace different paths on the surface to be cleaned. The cleaning head may further comprise a shroud 72 that encloses the member. The shroud preferably comprises a plurality of holes 74 therein to inhibit the device from sticking to the surface being cleaned. Suction means 16 may also be provided to remove any dirty material from the surface being cleaned.

Description

METHODS AND APPARATUS FOR CLEANING A SURFACE WITH

STEAM FIELD OF THE INVENTION

The present invention relates to a method of cleaning a surface with steam, an apparatus for use in the method, a cleaning head for use with the apparatus, methods of manufacturing parts of the cleaning head, to particular uses of the apparatus, to a method of cleaning a flooded lead acid battery, to an apparatus for delivering steam 0 for cleaning purposes and to a device for delivering steam for cleaning purposes.

BACKGROUND TO THE INVENTION

Steam is particularly useful as a cleaning agent for a number of reasons.

5 Firstly its gaseous nature means that it is able to penetrate crevices and small areas that would otherwise be difficult to clean with conventional methods. The high temperature (typically approximately 1 70 C) of the steam means that extra energy is available beyond the latent heat necessary to convert water to steam so that most kinds of oils, fats, grease and other detritus can be removed easily. This is because 20 the steam softens and also applies a physical force to remove the detritus. Very shortly after being applied to a surface the steam condenses to water that contains the loosened detritus, some of which is suspended in the water, and in which oils and grease are held in liquid form having been heated by the steam. This mixture can readily be removed by a wet vacuum process leaving the surface substantially clean.

25 Thus it is not necessary to use any chemicals to assist the steam cleaning process, although they can be used. Further advantages of steam cleaning are that it can be carried out in the vicinity of almost all electrical equipment and can remove proteins, drug resistant pathogenic bacteria and viruses from hospitals and medical research establishments for example. Steam cleaning can be used in almost any situation, as 30 long as the surface will not be adversely affected by the high temperature and moisture. There are a number of types of steam generator intended for generating steam for cleaning and sterilizing purposes. In general these can be broken in to three 35 classes: electric, fire-tube and water-tube boilers, the last being a type of flash steam

À e À À À e À ae..ee. e e À e eee e..e boiler. Electric boilers operate in a similar fashion to a domestic kettle having an element that can be immersed in water. Fire-tube boilers combust a fuel to generate hot gases that are passed through tubes immersed in water. Water-tube boilers pass water through tubes around which the hot gases from combustion of a fuel are passed 5 to flash the water in the tubes into steam. The generators of all three classes can be categorized by their power rating. Electric boilers can be classified as follows: 500W - 2kW domestic; 2kW - 7kW light commercial, 7kW - 28kW light industrial; there are some electric generators with power ratings over 28kW but these are not common. For power requirements above 28kW it is more usual to use flash steam 0 boilers that have power ratings of approximately 28kW up to approximately 150kW, with physical size being the limiting factor. These boilers generate steam by burning propane or paraffin for example. The gases produced by burning are passed around tubes through which water is supplied. The water evaporates on contact with the hot tubes to generate the steam that is supplied through a tube or tubes to one or more 5 dispensing heads for cleaning purposes. One example of use of steam from a 1 50kW steam generator is for removing discarded chewing gum *om pavements, where an extremely intense cleaning process is required together with a large volume of steam per unit time.

20 Most steam generators, of all types, can output steam at 1 70 C and at 800,000 Pa (8 bar) pressure and have flow rates in the range 0.1 litres per minute to 1.25 litres per minute, with 3.5 - S litres per minute being exceptional. A length of tubing (for example 0.01m in diameter) carries the steam from the generator to a dispensing head. A useful length of tubing is approximately 1 Om that allows a user considerable 25 flexibility of movement in cleaning before having to move the boiler to the next location. The applicant estimates that along such a 10m length of tubing, the steam will lose approximately 1 0 C and approximately 100,000 Pa ( I bar).

The steam emitted from steam generators can be either "dry" or "wet". Dry 30 steam is substantially pure steam in which there are no water particles remaining and can be superheated, when not in contact with the water that generated it, where the temperature of the steam is higher than the boiling point corresponding to its pressure. Wet steam is a steam in which very small water particles are suspended and is seen as a mist. Both types of steam have cleaning applications in which they are 35 most useful for example machinery tor dry steam and floors for wet steam.

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Àe À À À e e À e ee. ee e À À e À e bee Àe e see - 3 - Although the properties of both kinds of steam are excellent for cleaning and sterilising purposes there are a number of difficulties in delivering the steam in a manner that will achieve the best cleaning effect. Once the steam has left the s dispensing head the extra energy available for cleaning is lost very fast through cooling and condensing on the surface being cleaned. The applicant estimates that the useful range of distance from the outlet of the tube to the surface being cleaned is lmm to 10mm, depending on the type of surface being cleaned. It is apparent that an inexperienced user may not be able to maintain the steam outlet at the appropriate 0 distance from the surface being cleaned, and ultimately may become dissatisfied with the effectiveness of the cleaning that they are able to achieve with steam.

Furthermore some of the steam released by a dispensing head can obscure the user's view of the surface being cleaned, exacerbating this problem. The area over which the steam can clean effectively is small, at most approximately 80mm2 for a 10 mm 5 diameter outlet.

Various tools have been proposed to distribute the steam over a wider area.

For example one known device is a scrubbing head mounted on the end of a lance.

The scrubbing head comprises a large number of bristles arranged around the outlet 20 of the lance. Steam emerges through the outlet directed straight at the surface being cleaned. The user moves the scrubbing head over the surface and ends up cleaning the surface with the water that is generated by the steam, although a small amount of steam cleaning is achieved. This would be more effective with the addition of appropriate cleaning chemicals, almost defeating the object of using steam.

When cleaning properly with steam it is not necessary to use bristles at all; the power of the steam is sufficient on its own. Nevertheless the steam is effective only over a small area and this means that the cleaning process is slow, even under control of an experienced user.

Accordingly it would be desirable to provide a device for delivering steam that has an increased effective cleaning area but which does not substantially reduce the power of the steam.

35 A further problem with which the present invention is concerned is that some

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- 4 prototypes made by the applicant for distributing steam over a larger surface area have suffered from being relatively bulky and heavy. This is because large forces can be placed on the dispensing head by steam at pressures of the order of 800,000 Pa (8 bar). Bulky and heavy heads are not practical for many cleaning applications s including cleaning machinery, walls and ceilings for example.

Another problem with which the present invention is concerned is that the use of steam for cleaning purposes generates a quantity of water that must be removed from the surface either with a cloth or with a wet vacuum for example. As explained 0 above this water contains the detritus that has been removed from the surface.

Accordingly it has been necessary to have two stages to the cleaning process: steam clean followed by wet vacuum (or wiping). It would be advantageous if the water and detritus could be removed by the same dispensing apparatus just after the steam has condensed so as to shorten overall cleaning time and make the cleaning of walls, 5 ceilings and objects above the floor possible without fouling the floor with water from the process.

Another problem with which the present invention is concerned is the maintenance of railway tracks and points. Safety is of paramount concern on railways 20 and it is important to keep points as clean as possible to prevent sticking and failure.

One known method for cleaning points involves using a wire brush with various chemical cleaning agents. However the process is slow and the results that can be obtained are not satisfactory, even when carried out by an experienced user.

2s A yet further problem with which the present invention is concerned is that the terminals and casing of flooded lead acid batteries, as well as the electrical connections used on the terminals, can become heavily sulphated during use and contaminated with electrolyte when re-filling. These problems lead to degradation in performance of the battery and ultimately to early replacement.

US-A-5 248 092 (Rankin) discloses a water driven rotating head mounted on a spindle. A pulsating effect is obtained with a diffuser plate mounted in front of the working face of the rotating head from which water emerges. The diffuser plate has a number of openings through which water can pass from the working face to the 3s surface to be cleaned. The openings are divided by web portions that cause the

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À e. À Àe À À - 5 pulsating effect as the water outlets move behind. Such a rotating head is not suitable for use with steam. It is believed that dry steam will not provide a fluid film for lubricating the shaft and bore as required in this document. Furthennore, the diffuser plate would almost certainly absorb the useful cleaning power of the steam and 5 increases the distance of the steam outlet from the surface. Both of these effects are highly undesirable for steam cleaning. As mentioned above it is very important that the steam reaches the surface to be cleaned with available cleaning power, otherwise it simply condenses before performing any useful function. US-A-5 248 092, in the field of water pressure cleaning, does not contemplate the problems nor suggest

lo solutions as set out herein in the field of steam cleaning.

SUMMARY OF THE PRESENT INVENTION

The present invention is based on the insight by the applicant that steam Is delivery heads can be made smaller and lighter by designing them such that the vector sum of the forces acting on the head from pressure of steam exiting therefrom is zero or substantially zero, for example in a direction along the longitudinal axis of the member and in a direction substantially perpendicular thereto. Thus, there is little or no force due to steam pressure attempting to displace the head, although this 20 pressure may be used to provide a rotational force in some embodiments. The result is that the head can be made smaller and lighter since large components are not needed to bear a displacement force.

According to a first aspect of the present invention there is provided a method 25 of cleaning a surface with steam, which method comprises the steps of: (1) supplying steam from a steam source to a cleaning head comprising a steam delivery means and a member mounted thereon; (2) passing steam from the steam delivery means to the member, the member being mounted on the steam delivery means so as to inhibit displacement, on 30 receipt of said steam, of the member relative to the steam delivery means; (3) rotating said member; and (4) passing steam through an outlet in the member for cleaning a surface in the proximity of the outlet. Some advantages of this are that there is little or no axial force on the member meaning that it can be reduced in size and manufactured 35 easily from one or only a few components; in some embodiments ball bearings are

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- 6 not required. In one embodiment the steam delivery means is such that steam is emitted laterally therefrom, for example from holes in the side of the steam delivery means. In another embodiment a plurality of members are mounted on the device. In one embodiment the working face of the member has a diameter of 41mm, with a 5 range of 20mm to l OOmm being a preferable range. In one embodiment the height of the member is 27mm, with 20mm to 60mm being a preferable range. In one embodiment the top face of the member is 22mm, with 15mm to 25mm being a preferable range. The member may be any suitable shape, truncated cone, truncated sphere and cylinder being preferable examples.

The method of the present invention can be used with all manner of steam sources and types of steam. In one aspect the head is suitable for use with steam in a pressure range of approximately 200,000 Pa (2 bar) to approximately 2,000,000 Pa (20 bar), in a temperature range of approximately 134 C and 215 C and at a flow I S rate of approximately 0. 2 to 3 litres per minute.

Further features of the method are set out in claims 2 to 5 to which attention is hereby directed.

20 According to another aspect of the present invention there is provided an apparatus for use in the method as aforesaid, which apparatus comprises a steam source, a cleaning head and means for delivering steam from the steam source to the cleaning head, which cleaning head comprises a member mounted on a steam delivery means through which steam can be received by the member from a steam 2s source, the member having an outlet through which received steam can pass for cleaning a surface in the proximity of the outlet, the arrangement being such that, in use, steam emerging from the steam delivery means is inhibited from displacing the member relative to the steam delivery means.

30 Advantageously, the member is rotatably mounted on the steam delivery means. This is a considerable advantage in that the steam is spread over a much greater surface area, quickening the cleaning process. Furthermore the surface being cleaned receives a "sweeping" action as the outlet passes across it that helps to remove more stubborn fouling. In one embodiment the axis of the hole forms an 3s angle of 20 to vertical, with 15 to 25 being a preferable range.

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Preferably, the member has at least two outlets through which received steam can pass for cleaning a surface in the proximity of the outlet. Thus the cleaning effect is further enhanced. The outlets may be located on a lower face of the member for s cleaning substantially flat items or machinery, or they may be located on the side of the member so that the device becomes suitable for cleaning the interior of tubulars for example. A preferred range of the number of outlets is between one and ten. For use with a low power steam machine a single outlet is usually sufficient. For use with higher power machines between two and five outlets are preferable. For cleaning lo upholstery a large number of small jets are desirable to limit the depth of penetration of the steam and inhibit wetting of the material.

Advantageously, each outlet is positioned such that, in use, different paths are traced by steam on the surface being cleaned. This further increases the effective 5 cleaning area of the device without diminishing the cleaning power of the steam. To trace different paths the outlets may be located at different radial distances.

Alternatively, they may be located on the same circumference, and angled between approximately 5 and 20 to achieve this effect.

20 Preferably, said outlet(s) are arranged on a working face of the member, the arrangement being such that, in use, said working face can be brought into proximity of a surface to be cleaned such that steam emitted from said outlet impinges on the surface with available cleaning power. In one embodiment the working face is substantially flat. The substantially flat face helps to keep the steam close to the 2s surface being cleaned and inhibits the steam from being wasted. This is also particularly important when the member is used in a shroud with a vacuum. Detritus moves past the working face and might damage the member if it was not substantially flat. In another embodiment the working face comprises a low coefficient of friction material. This helps to inhibit the member damaging the 30 surface and vice versa. In another embodiment the arrangement is such that steam can impinge directly on the surface being cleaned. I his helps to ensure that the steam reaches the surface with available cleaning power.

Advantageously, first and second ends of the member are supported for said 3s rotation, at least the first end being supported on the steam delivery means. In one

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À.. ew À 8 - embodiment the steam delivery means does not have to pass completely through the member. It is possible that the member can be supported on two co-axial steam delivery means. In this way the steam does not have to be emitted laterally into the member. In another embodiment the steam delivery means passes substantially 5 through the member and said second end is mounted on the steam delivery means. In either embodiment two bearing surfaces are provided to inhibit instability of the member across the axis of the steam delivery means.

Preferably, the member further comprises a chamber into which steam is to received from the steam delivery means and from which steam passes through the outlet(s). In one embodiment the combination of the member and chamber is such that the force due to steam pressure in one direction substantially cancels the force due to steam in the opposite direction. In one embodiment, these two directions are substantially parallel to the longitudinal axis of the member.

Advantageously, said member further comprises a projection that, in use, can maintain the outlet(s) at substantially an optimum distance from the surface being cleaned. This enables a user to know when the device is at the correct distance without having to judge it by eye, particularly if the device is clouded by steam.

Preferably, the device further comprises a tube having a tube outlet through which, in use, steam can be passed to exit from the tube outlet, the tube being separate from the member for cleaning areas that the member might not be able to reach. A separate nozzle can deal with smaller areas than the member and also helps 25 to reach into corners.

Advantageously, the member is constructed from polyetheretherketone (PEEK) or polyetheretherketone admixed with strengthening and/or friction reducing additives as desired. For example, bearing grade PEEK has been found to be 30 particularly useful; this type of PEEK includes some glass fibre, some graphite and some polytetrafluoroethylene (PTFE). Using PEEK material means that separate bearings are not necessary, further simplifying the device and enabling it to be small and light. The member may be constructed from any material that is impervious to high temperature steam, for example, but not limited to' stainless steel, light alloy, 35 plastic, aluminium and bronze, provided that suitable bushes (e.g. PEEK) are

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ace À À. À Àe - 9 included to provide bearing surfaces.

In one embodiment the device is attached to a handgrip to enable the device to be manoeuvred by a user.

Preferably, the device comprises a shroud that partially encloses the member leaving said outlets exposed, said shroud inhibiting contact between said member and the surface being cleaned. In one embodiment the shroud has a shroud outlet through which steam that has been condensed on the surface being cleaned and the detritus lo removed therefrom can be withdrawn by suction means when connected to the shroud outlet. This arrangement helps to reduce the overall cleaning time and also leaves the surface only warm to the touch and slightly damp. In one embodiment the working face of the shroud has a diameter of 60mm, with a range of 25mm to 1 20mm being preferable.

Advantageously, the shroud has a collar that, in use, can be urged against the surface being cleaned so that the shroud and collar substantially enclose that area of the surface being cleaned. In one embodiment the collar is removable to enable the member to be used at its optimum distance from the surface being cleaned. A collar 20 of a different depth can be replaced onto the shroud. For example, when cleaning upholstery the member needs to be as close to the surface as possible (for example approximately 2mm), whereas when cleaning a floor or other flat surface, for example, the optimum distance is approximately Smm above the surface. Different depth exchangeable collars enable the device to be quickly adapted for a wide range 25 of applications.

Preferably, the shroud further comprises a plurality of recesses and/or holes that, in use, inhibit the device from sticking to the surface being cleaned when said condensed steam and said detritus are withdrawn through said shroud outlet.

Advantageously, said member further comprises a series of vanes the arrangement being such that, in use, when said shroud outlet is connected to said suction means, said member can be rotated via interaction between said vanes and air withdrawn by the suction means. In this manner the full power of the steam can be 35 directed at the surface whilst still obtaining the cleaning effect over a larger surface

e e e e À e e e e e e e À e e ee e e e À see seeee e e À ee e e e see e ee e see - 10 area. The vanes may be located at or near a lower part of the member when air is withdrawn from the side of the device, or they may be at or near the top of the member when air is withdrawn through the top of the device. Additionally this will enable the device fitted with such a member to be used with low power steam 5 cleaning machines providing insufficient steam force to cause the member to rotate.

In accordance with another aspect of the present invention there is provided a cleaning head having any of the cleaning head features as aforesaid.

lo The member of the cleaning head may be injection moulded in two parts.

PEEK can be obtained in granulated form and is used in an injection moulding process. Those parts of the member that can be manufactured by an injection moulding process are set out in claims 26 and 27 to which attention is hereby directed. The two parts can be readily held together by snap fit for example.

Two particular uses of the invention are set out in claims 28 and 29 to which attention is hereby directed. A method of cleaning a surface with steam is also provided as set out in claim 20. In one embodiment the method is carried out with steam at approximately 800,000 Pa and approximately 1 70 C (measured at the outlet 20 of the steam generator).

According to another aspect of the present invention there is provided a method of cleaning the terminals and/or casing of a flooded lead acid battery, and/or the terminals of electrical connectors for use therewith, which method comprises the 25 steps of: ( I) supplying steam from a steam source to a cleaning head provided with an electrical insulating material; (2) passing steam through the cleaning head to an outlet; and (3) positioning said outlet in the proximity of said terminals and/or said 30 casing such that steam passing through the outlet can perform a cleaning function thereon. The cleaning head may have any of the features as aforesaid.

According to another aspect of the present invention there is provided a device for delivering steam for cleaning purposes, which device comprises a housing 35 in which a member is rotatably mounted, the housing having an inlet and the member

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À. À Àe e see having a ring-like shape with an outer external surface, an inner external surface and a plurality of channels connecting the outer and the inner external surfaces, the arrangement being such that, in use, steam can be supplied through the inlet of the housing to the outer external surface from where it passes to the inner external 5 surface through the plurality of channels, and wherein the member is rotated to enhance the cleaning effect of the steam emerging from the plurality of channels on an article passing through the member. This arrangement is particularly useful for cleaning all manner of tubular goods that can be readily passed length ways through the member.

Preferably, at least some channels of the plurality of channels are such that, in use, the member is rotated under action of steam leaving the channels. This mitigates the need for a separate driving means for rotating the member.

5 In one embodiment the member is constructed from polyetheretherketone (PEEK) and in another embodiment it is constructed from bearing grade polyetheretherketone, the advantages of which are mentioned herein.

Preferably, said external outer surface comprises a groove in fluid 20 communication with the plurality of channels for receiving steam from the inlet of the housing. this helps to ensure even distribution of the steam around the member so that it impinges evenly over the surface of the object being cleaned.

According to another aspect of the present invention there is a provided a set 25 of interchangeable collars for use with a shroud as defined herein, the interchangeable collars enabling the device to be used for different cleaning purposes where the optimum distance of the member above the surface being cleaned varies according to the purpose.

30 According to another aspect of the present invention there is a provided a device for delivering steam for cleaning purposes, which device comprises a member having an inlet for receiving steam from a steam source, an outlet for delivering received steam to a surface to be cleaned and a device outlet through which detritus and condensed steam can be withdrawn from the surface being cleaned, the 35 arrangement being such that, in use when sai<l shroud is positioned adjacent a surface

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to be cleaned said device outlet is substantially enclosed by the shroud and the surface so as to permit suction means to withdraw detritus and condensed steam from the surface being cleaned through said device outlet.

5 Advantageously, said member is rotatably mounted on said device such that, in use, steam is delivered over a larger area than the area covered by the outlet.

Preferably, said outlet is mounted on said device within the shroud.

10 BRIEF DESCRIPTION OF THE DRAWINGS

Fig. l is a side cross section through a prototype of a steam dispensing head; Fig. 2 is a perspective view of a first embodiment of a steam dispensing and 5 collecting head in accordance with the present invention with associated feed tube only part of which is shown; Fig. 3 is a side cross section through the steam dispensing head and feed tube of Fig. 2; Fig. 4 is a top plan view of the steam dispensing head and feed tube of Fig. 2, the cover of the steam dispensing head removed for clarity; Fig. 5 is bottom plan view of the steam dispensing head and feed tube of Fig. 25 2, the shroud of the head being shown in cross section to illustrate the holes therein; Fig. 6 is an end cross section through the feed tube of Fig. 2; Fig. 7 is a side cross section through a spindle used in the steam dispensing 30 head of Fig. 2; Fig. 8 is a side cross section through the member of the steam dispensing head of Fig. 2; 3s Fig. 9 is a bottom plan view of the member of Fig. 8;

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À. À. À e. .. . :-. À À À. Àe: - 13 Fig. 10 shows the member of Fig. 9and, in dashed line, the paths traced by steam emitted from the holes; 5 Fig. 11 is an alternative embodiment of the working face of the member; Fig. 12 is a side view of part of an alternative embodiment of the shroud used with the dispensing head of Fig. 2; lo Fig. 13 is a top view in cross section of an apparatus for delivering steam for cleaning purposes in accordance with the invention; Fig. 14 is a side view of the apparatus of Fig. 13; 5 Fig. 15 is a bottom plan view of an alternative embodiment of a member for use with the dispensing head of Fig. 2; Fig. 16 is a side view in cross section of the member of Fig. 15; 20 Fig. 17 is a side view of a vane used on the member in Figs. 15 and 16; Fig. 18 is a side view of a second embodiment of a steam dispensing and collecting head in accordance with the present invention; 25 Fig. 19 is a side cross section through a third embodiment of a steam dispensing and collecting head in accordance with the invention; Fig. 20 is a side cross section through a fourth embodiment of a steam dispensing and collecting head in accordance with the invention; Fig. 21 is a side cross section through a fifth embodiment of a steam dispensing and collecting head in accordance with the invention; Fig. 22 is a side cross section through a sixth embodiment of a steam 35 dispensing head in accordance with the invention; and

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- 14 Fig. 23 is a lateral cross section through the member of the steam dispensing head of Fig. 22.

5 Referring to Fig. I a prototype steam dispensing head generally identified by reference numeral I comprises an enclosure 2 constructed from plastics material in which a stainless steel body 3 is mounted. A stainless steel spindle 3a is mounted within the body 3, the upper end of which has an external thread for coupling to a tube (not shown) through which steam can be supplied to an inlet 3b of the spindle lo 3a. The lower end of the spindle 3a is wider than the upper end so as to be able to accommodate a stainless steel spigot 4. A PEEK (polyetheretherketone) bearing 4a and a PTFE (polytetrafluoroethylene) bearing 4b reside around that part of the spigot accommodated in the lower end of the spindle 3a, the PTFE bearing 4b residing uppermost and the PEEK bearing 4a lowermost. A ball race 5 lies between an outer 5 shoulder 3c of the spindle 4, the body 3 and a stainless steel top cap 5a. The top cap 5a is fixed to the body 3. A stainless steel mounting plate 6 is positioned between the top cap 5a and the enclosure 2 and is mounted on the enclosure 2 with fixing bolts (not shown) in boltholes 6a. The body 3 is mounted on the enclosure 2 by threading the upper end of the spindle 3a onto the mounting plate 6. The body 3 is also held in 20 place by the tube (not shown) that supplies steam to the spindle attached to that part of the thread which projects through the upper surface of the enclosure 2. A cylindrical stainless steel bottom member 7 has a bore 7a in fluid communication with the outlet of the spigot 4. Two hollow stainless steel arms 8 and 8a are brazed to the bottom member 7, one at either end of the bore 7a. Each arm 8 and 8a has a 25 respective hole 9 and 9a at its extremity. The holes 9 and 9a face outwardly of the enclosure 2 and have their axes displaced 20 to vertical. The bottom member 7 is retained on the body 3 via three bolts (not shown) passing through the top cap 5a and bottom member 7. These bolts pass through boltholes (not shown) in the top cap 5a and bottom member 7 in positions not visible in the cross section of Fig. 1.

In use, steam is fed through the spindle 3a from the tube (not shown) connected to a steam source (not shown). The steam passes through the spindle 3a, into the spigot 4 and into the bottom member 7 where it is divided so as to pass along the arms 8 and 8a, ultimately exiting through the holes 9 and 9a. Since the holes 9 35 and 9a have their axes displaced relative to the vertical as described above, the arms

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- 15 are caused to rotate under reaction from the force of the steam exiting the holes 9 and 9a. Thus the cleaning effect of the steam is distributed over a larger area than can be covered by a single jet of steam.

s However, the prototype of Fig. 1 suffers from a number of disadvantages, one of which is its relatively large size (0.25m diameter, 0.08m depth) and weight (2kg).

The head I is useful for cleaning flat, readily accessible surfaces e.g. floors.

However, steam can be used for such a wide variety of cleaning applications that a bulky head is not practical, particularly for cleaning machinery, walls and ceilings for 0 example. Clearly its size makes the cleaning of irregular surfaces difficult. One important factor in steam cleaning is that the steam is delivered very close to the surface to be cleaned and with sufficient power. Failure to do this severely reduces the effectiveness of the cleaning operation. A further problem is that use of the head generates a quantity of dirty water that must be removed in a separate cleaning 5 operation, effectively doubling the cleaning time.

It would be desirable to make the head I smaller and lighter so as to be useful for a wider variety of steam cleaning applications. The applicant believes that a smaller version of the head one could be made down to approximately 0. Im in width 20 since it needs to be constructed from stainless steel to inhibit rusting. The limiting factor is that steam at 800,000 Pa passing through the spindle 3a exerts a large axial force on the spigot 4 and consequently on the bottom member 7. This axial force must be borne by retaining bolts, ball race 5 and spindle 3a. Accordingly, reducing them in size becomes more difficult since they must still accommodate the same axial 25 force. The remaining embodiments are based on an insight by the applicant that it is possible to reduce or even minimise the axial force on the head with a very simple construction and therefore make it smaller, opening up a wide range of steam 30 cleaning applications to the improved spinning method of distributing the steam.

Referring to Figs. 2 and 3 a steam dispensing and collecting head generally identified by reference numeral 10 comprises a cylindrical stainless steel body 12 of 0.06m diameter and 0.06m length open at its upper and lower ends. The head weighs 35 0.3kg. An inlet 16 ofthe teed tube 14 is attached to an opening in the side ofthe body

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À 16 12, best seen in Fig. 2. The feed tube 14 carries electrical wires 18 and steam supply tubes 20 (see Fig. 6) into the head 10 and performs a further function as described in more detail below. The opposite end 22 of the feed tube 14 is attached in a fluid tight manner to a flexible corrugated hose 24 with a rubber seal 26. The flexible s corrugated hose 24 carries the electrical wires 18 and steam supply tubes 20 from a steam generator (not shown) to the feed tube 14. The flexible corrugated 24 hose is also connected to a vacuum source (not shown) by which fluid can be drawn from the head through the feed tube 14 and flexible corrugated tube 24 to a storage vessel (not shown) for subsequent disposal. The feed tube 14 is 0.3m in length providing a solid lo handgrip for a user and the flexible corrugated hose 24 is 13m in length enabling the head 10 to be easily manoeuvred. A top cover 28 constructed from plastics material is push-fitted onto the upper end of the body 12. Two electrical control switches 30 and 32 are mounted on the top cover 28 whose function will be described in greater detail below. One end of the electrical wires 18 are connected to the two electrical control 5 switches 30 and 32, and the other end of the electrical wires 18 is connected to a steam generator (not shown).

Reterring to Figs. 3 to 5 and 7 to 9 inclusive, a cross bar 34 constructed from stainless steel is mounted adjacent the upper end of the body 12. A first steam outlet 20 36 is mounted on the cross bar so as to project downwardly in the volume enclosed by the body 12 and top cover 28. The steam outlet 36 comprises a steam delivery means in the form of a spindle 38 of uniform cross section along its length constructed from stainless steel and on which a member 40 is rotatably mounted. The spindle 38 is mounted on the cross bar 34 with a screw 42 and the member 40 is 25 retained on the spindle 38 with a screw 44 and washer 45 (see Fig. 5). It will be noted that the spindle 38 passes through the entire length of the member 40. The spindle 38 has a central bore 46 through its length with a respective thread 48 at either to receive the screws 42 and 44. The spindle 38 has a wider upper end 50 to provide an abutment with the upper end of the member 40. A lateral bore 52 in the upper end 50 30 provides fluid communication between an inlet of the lateral bore 52 and the central bore 46. One of the steam supply tubes 20 feeds the lateral bore 52. The lower end 54 of the spindle 38 comprises three holes 56 spaced equally around the circumference of the spindle approximately half way along the length of the lower end 54 of the spindle 38. The three holes 56 are in fluid communication with the central bore 46.

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À - À Àe The member 40 is a truncated cone machined from a single piece of bearing grade PEEK 450G (polyetheretherketone) that contains carbon fibre reinforced with graphite and PTFE (polytetrefluoroethylene) lubricants. This PEEK material is very easy to machine and has excellent steam resistant and bearing properties, being able s to work continuously in temperatures of up to approximately 250 C without degradation (see www. boedeker.com/peek-p.htm for further properties), making it ideal for dispensing steam over a temperature range of 100 C to approximately 230 C. It is widely available and can be obtained in rod form from RS Components Ltd. Birchington Road, Corby, Northamptonshire, UK (rswww.com) for example.

0 The member 40 has a central bore 58 in fluid communication with a chamber 60 in the form of an annular truncated cone, the base of which is located adjacent the lower end or working face 62 of the member 40 and the apex of which joins the central bore 58. The working face 62 is substantially planar and is 41mm in diameter. The member has a height of 27mm and the upper surface is 22mm in diameter. Referring 5 particularly to Fig. 9, four holes 64, 66, 68 and 70 of 1.25mm diameter have been drilled through the member 40 on the annulus defined by the base of the chamber 60 (dashed line in Fig. 9) so that the chamber 60 is in fluid communication with the region outside the member 40. All of the holes 64, 66, 68 and 70 have been drilled so that their axes form an angle of 20 with the vertical. However, the holes 64 and 68 20 have been drilled with their axes tangential to the annulus defined by the base of the chamber 60, whilst axes of the holes 66 and 70 have been further rotated by an angle in the horizontal plane, the effect of which will be described below.

The lower end of the body 12 is provided with a shroud 72 that is a push fit 2s thereon and which is constructed from PTFE (polytetrafluoroethylene) plastics material. The shroud 72 has a plurality of holes 74 located around its circumference a approximately 0. 002m (2mm) above its base and each separated by 0.001m (Imm).

Also mounted in the body 12 is a second steam outlet 74 comprising a stainless steel tube that passes *om the upper rear portion (adjacent the inlet 16 of the feed tube 14) 30 to the lower *ont portion of the body 12, substantially following the contour of the inner surface thereof. One of the two steam supply tubes 20 feeds the inlet of the second outlet 74.

in use, steam is fed *om a steam generator (not shown) to the steam supply 35 tubes 20. The control switches 30 and 32 determine whether steam is fed to the first

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steam outlet 36 or to the second steam outlet 74. When directed to the first steam outlet, steam passes through the outlet of one of the steam supply tubes 20 into the lateral bore 52 in spindle 38, into the central bore 46 and out laterally out of the spindle 38 through the holes 56 into the chamber 60. The steam passes through the 5 chamber 60 and out through the holes 64, 66, 68, 70 to the surface to be cleaned.

Since holes 64, 66, 68, 70 have an angle of 20 to the vertical, the member 40 is caused to spin about the spindle 38. The effect of this is twofold: firstly the holes pass over a much larger surface area than if they were to remain stationary, thereby reducing the time required to clean an area, and secondly the greater cleaning ability lo of a concentrated jet is obtained over this larger surface area, achieving a "sweeping" effect from the point of view of the surface being cleaned.

An important effect of passing the steam laterally out through the spindle 38 is that there is little or no axial force exerted on the member 40 by this steam. This 5 enables the structure to be made smaller and lighter as there is no need to accommodate an axial force. The applicant believes that this is due to the fact that the vector sum of the forces on the internal surface of the member due to steam pressure is zero. It is to be noted that arrangements can be devised where this benefit can be obtained without emitting steam laterally from the spindle. Furthermore, mounting 20 the member 40 on the spindle 38 permits bearing surfaces 76 and 78 to be part of the first steam outlet and the provision of separate bearings around the member 40 is mitigated. Accordingly, the overall size and weight of the head 10 is reduced, increasing the speed and length of time at which the head 10 can be used. This deals with an acute problem with the prototype shown in Fig. 1, namely that an operative 25 quickly becomes physically tired due to its size and weight, particularly when cleaning walls and ceilings for example. A further advantage of the two bearing surfaces 76 and 78 is that rotation across the longitudinal axis of the spindle is inhibited helping to stabilise the member 40 that rotates at high speed that the applicant estimates to be of the order of 15000 rpm. A small amount of steam escapes 30 from through the central bore 58 between the spindle 38 and the member 40 at its upper and lower ends. In a wet steam application this provides a further lubricating effect on bearing surfaces 76 and 78 in addition to that provided by the PEEK material. 35 Referring to Fig. 10 the paths traced on the surface being cleaned are shown

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À I r À. À. projected onto the working face 62 of the member 40 in dashed lines. As described above, the holes 64 and 68 have their axes tangential to the annulus defined by the base of the chamber 60. Accordingly steam emitted from these holes traces the path 80. The hole 66 has the 20 angle to provide a driving force on the member 40, but s has been further rotated in a horizontal plane such that steam emitted therefrom traces the path 82. The hole 70 also has the 20 angle to provide a driving force on the member 40, and has been further rotated in a horizontal plane such that steam emitted therefrom traces the path 84. In this manner the surface area covered by the jets of steam is increased. It will be apparent that the same effect can be achieved by drilling 0 the each hole 64, 66, 68 and 70 at a different radius on the working face 62 (see Fig. 11). It will be recalled that the working face 62 of the member 40 is planar. One advantage of this is that, in use, steam is trapped between the surface being cleaned 5 and this working face so that the cleaning power is extracted from as much of the steam as possible.

Very quickly after steam is emitted from the holes 64, 66, 68 and 70 it condenses on the surface being cleaned. This water helps to remove detritus that has 20 been loosened by the steam. Once the water has moved out from under the working face 62 of the head 10 it resides in the region between the extremity of the member 40 and the body 12. Under influence of the vacuum source (not shown) associated with the steam generator (not shown) the water and detritus is sucked up into the feed tube 14 through the flexible corrugated hose 24 and into a storage vessel (not shown) 2s in the steam generator for subsequent disposal. A suitable power range for the vacuum source is 1 to 5kW. This leaves the surface being cleaned only slightly damp. With many prior steam cleaners it was necessary to wet vacuum the area after the steam cleaning process which is undesirable since it takes longer to carry out two processes and a relatively large volume of water might reside on the surface being 30 cleaned or adjacent surfaces for some time before it is removed. Some surfaces are easily damaged or spoilt when saturated.

The holes 74 around the shroud 72 perform two functions. Firstly, the applicant has found that without the holes the partial vacuum in the head 10 created a 3s considerable sticking effect. Steam condensing out on the surface being cleaned

À c 4 À À À c 4 c .- c. t r c c c c. r.' ace - 20 found its way between this surface and the shroud creating a seal. The partial vacuum then caused the head 10 to stick to the surface making movement of the tool difficult.

The holes 74 ensure that this sticking effect does not occur by providing a continuous air source for the vacuum so that movement of the head 10 is easy. Another problem s encountered was a quantity of steam continually escaping from the head 10 making visibility of the surface being cleaned difficult; it is important to be able to see whether the surface has been cleaned properly otherwise time may be spent cleaning an area unnecessarily. The second function of the holes 74 is to recover steam that has escaped from the periphery of the head 10 via the vacuum source.

During use the shroud 72 wears down and will eventually need replacement.

Accordingly the shroud 72 is of the push-fit variety so as to enable easy replacement.

This feature has a further advantage in that the shroud 72 can readily be exchanged for a different shroud according to the function that the head 10 is used for. For 5 example, when cleaning upholstery the outlets of steam should be as close as possible (approximately 2mm) to the upholstery to achieve the maximum cleaning effect.

However, when cleaning floors, walls or ceilings for example, the outlets of steam should be approximately 5mm from the surface for maximum cleaning effect.

Different styles of shroud can be designed and interchanged accordingly.

Referring to Fig. 11 an alternative embodiment of the working trace 62 of the member 40 is shown referenced a 62' and 40' respectively. Instead of providing steam exit holes on a common circumference, holes 86' of 1.25mm diameter are provided on a common radius of the working face 62'. As with the earlier as embodiment each hole 86' has an axis 20 to the vertical so that the steam provides a driving effect when passing therethrough.

Referring to Fig. 12 an alternative embodiment of the shroud 72 on the body 12 is shown referenced as 72' and 12' respectively. Instead of providing complete 30 holes the lower portion of the shroud 72 is formed with recesses 74' to perform the same function.

Referring to Figs. 13 and 14 a second embodiment of a cleaning head generally identified by reference numeral 100 comprises a stainless steel housing 102 3s in which a member 104 is mounted. The outside diameter of the housing 102 is 0.1 m

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8 r 8 À À 8 c 18 Be 8 8' À 8 8 8 8 8 Be - 21 (a useful range is approximately 0.06 to 0.2m). The member 104 comprises a ring of bearing grade PEEK having a continuous groove 106 around the circumference of its outer surface and a plurality of holes 108 of 1.25mm diameter spaced equidistantly around the circumference of its inner surface. The holes 108 provide a fluid path 5 between the groove 106 and the space enclosed by the member 104. The axis of each hole 108 forms an angle of 20 to the radial line between that hole and the centre of the member 104, this angle lying in the plane defined by the holes 108. Feed tubes I 10 are arranged to provide fluid input to the inside of the housing 102.

lo in use, steam is fed through the feed tubes 110 from a steam generator (not shown) to the inside of the housing 102. The steam passes into the groove 106 and emerges from the holes 108 in the form of jets into the space defined by the member 104. Some steam moves into the regions between the housing 102 and the member 104 so as to lubricate the bearing surfaces formed therebetween. The PEEK from 5 which the member 104 is constructed mitigates the need for separate bearings. By virtue of the angle of each hole as defined above, a driving force is exerted on the member 104 to rotate it in the housing 102. The cleaning head 100 can be used to clean tubular goods, for example tubulars formed in an injection moulding process.

Such tubulars emerge from the process covered in lubricants that need to be removed.

20 By passing the tubulars through the cleaning head 100, these lubricants can readily be removed. By rotating the member 104, the intense cleaning action of the steam jets is applied to the entire surface of the tubular. As described above steam jets have an excellent cleaning ability. However, this cleaning effect works over a very small area only close to the point at which the steam exits. The cleaning head 100 enables this 25 effect to be obtained over a much greater surface area in a shorter period of time. The cleaning head 100 can also be used to clean goods on a conveyor belt that passes through the member 104.

In an alternative embodiment, the cleaning head 100 is also provided with a 30 shroud having an outlet connectable to suction means for removing condensed steam from the head.

Referring to Figs. 15 and 16 an alternative embodiment of a member for use in the cleaning head 10 is generally identified by reference numeral 200 that is 35 generally similar to the member 40 described in connection with Fig. 8, like numerals

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- 22 indicating like parts. However, the member 200 is provided with a series of vanes 202 around the circumference of the lower part of the member 200. The working face 204 of the member 200 has a diameter of 48mm. Each vane 202 (see Fig. 17) has a curved outer portion 206, a flat upper portion 208, a flat lower portion 210 and flat s sides 212. The length of the curved outer portion is I Omm, the height of the vane 202 is I Omm and its depth is 4mm. The side 212 forms an angle of 45 with the flat lower portion 210.

In use, when the water and detritus is extracted through the outlet 16 under lo influence of the vacuum source (not shown) air passing the vanes 202 causes the member 202 to rotate on the spindle (not shown). Thus it is not necessary for the steam outlet holes to have their axes at an angle to drive the member in rotation. This means that all of the downward force of steam leaving the holes 264 can be used for cleaning purposes. If the outlet 16 is positioned in the top of the head 10, the vanes 5 202 can be positioned around the upper part of the member 240 to rotate it in the saline way. This manner of rotating the member is particularly useful in low power machines where there is not enough steam pressure to drive the member.

Referring to Fig. 18 an alternative embodiment of a member is generally 20 identified by reference numeral 300 that is similar to the member 40. However, the member 300 comprises a projection 302 projecting from its working face 304. The projection 302 is constructed from PEEK that has been fashioned into a dome shape and the centre of which has a hole (not shown). The hole receives the screw 306 that retains the member on the spindle (not shown). In use, the head 300 can be mounted 2s on a lance (not shown) and offered up to surface to be cleaned. The projection 302 enables the user to ascertain the optimum cleaning distance by feel rather than by eye. This is particularly advantageous when a shroud is not used with the member 300 as steam emerging therefrom can obscure a user's view of that part of the surface being cleaned.

Referring to Fig. 19 a steam dispensing and collecting head generally identified by reference numeral 310 comprises a stainless steel cylindrical body 311 open at its lower end and closed at its upper end by a stainless steel plate 312 welded thereto. The body 311 is 0.115m in diameter and 0.07m in depth (Martin I couldn't 3s get this from the scale in your pictures). The head 310 weighs 0.4 kg. This particular

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head 310 is designe<l for cleaning floors having a substantially smooth surface over which the head can move. An inlet 313 of a feed tube 314 is attached to an opening in the side of the body 311. The feed tube 14 carries a steam supply tube 315 into the head 310. The opposite end (not shown) of the feed tube 314 is attached in a fluid s tight manner to a flexible corrugated hose (not shown) with a rubber seal (not shown) in a manner similar to that described in connection with Fig. 3. The flexible corrugated hose carries the steam supply tube 315 from a steam generator (not shown) to the feed tube 314. The flexible corrugated 24 hose is also connected to a vacuum source (not shown) by which fluid can be drawn from the head 310 through lo the feed tube 314 and flexible corrugated tube to a storage vessel (not shown) for subsequent disposal. The feed tube 314 is 0.3m in length providing a solid handgrip for a user and the flexible corrugated hose is 13m in length enabling the head 310 to be easily manocuvred.

5 A steam outlet 316 is bolted to the centre of the stainless steel plate 312 so as to project downwardly in the volume enclosed by the body 311 and the stainless steel plate 312. The steam outlet comprises a steam delivery means in the form of a spindle 317 of uniform cross section affixed to a steam receiving member 318 that comprises a stainless steel hollow cylindrical body and tube 319. A free end of the tube is 20 connected to the steam supply tube 315 and the other end is affixed to the cylindrical body. The cylindrical body is open at its lower end to provide a path for steam from the steam delivery tune 315 to the spindle 317. The spindle 317 has a pair of holes positioned half way along its length and oriented 180 apart from one another.

2s A member 320 is rotatably mounted on the steam outlet 316 that comprises a stainless steel disc 321 to which a stainless steel tubular upright 322 has been brazed.

An annular polytetrafluoroethylene (PTFE) disc 325 is affixed to the lower working surface of the disc 321 with three nuts and screws (not visible in this cross section) spaced at 120 intervals therearound. Two tubes 323 and 324 pass from half way up 30 the height of the upright 322 to points on the extremity of the disc 321, and are oriented to be 180 apart when view in plan. The tubes 323 and 324 pass though the disc 321 and PTFE disc 325 and define respective outlets 326 and 327 that are flush with the lower face of the PTFE disc 325 and each have 5mm diameter. The outlets 326 and 327 are angled at 20 to the vertical. Two PEEK sleeves 328 and 329 are 35 held in respective upper and lower positions with grub screws (not visible in this

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- 24 cross section) between the spindle 317 and the upright 322. The member 320 is retained on the spindle 317 with a screw 330 and metal washer 331. A PEEK washer 331 is positioned between the metal washer and the disc 321 to inhibit friction therebetween. The lower end of the body 311 is provided with a shroud 332 that is a push fit thereon. The shroud is identical to and performs the same function as the shroud 72 describedabove in connection with Figs. 3 to 5 and 7 to 9, except in dimensions. The inner edge of the shroud 332 and the outer edge of the disc 321 and PTFE disc 325 0 form an annular space around the member 320 that is 8mm in width.

In use, steam is fed from a steam generator (not shown) through the steam supply tube 315. Steam passes into the steam receiving member 318 and into the spindle 317 and out laterally through the holes therein into the tubes 323 and 324.

5 The steam passes through these tubes to the outlets 326 and 327 and on to the surface to be cleaned. Since holes 326 and 327 have an angle of 20 to the vertical, the member 320 is caused to spin about the spindle 38. The effect of this is twofold: firstly the holes pass over a much larger surface area than if they were to remain stationary, thereby reducing the time required to clean an area, and secondly the 20 greater cleaning ability of a concentrated jet is obtained over this larger surface area, achieving a "sweeping" effect *om the point of view of the surface being cleaned.

The PTFE disc 325 ensures that the head glides smoothly over any raised portions of the surface being cleaned and helps to reduce the chance of scuffing the surface or damaging the head 310. This arrangement overcomes a further problem with the 2s prototype of Fig. I in that sizeable debris on the surface being cleaned (of the order of 10-40mm) may become entangled with the arms of that embodiment and damage the head. By making the working face substantially flat this problem is inhibited.

Very quickly after steam is emitted from the holes 325 and 326 it condenses 30 on the surface being cleaned. This water helps to remove detritus that has been loosened by the steam, although it is to be noted that it is the steam that performs the actual "cleaning" i.e. loosening of dirt on the surface since the steam is heated so as to have energy above the latent heat required to turn the water into steam. Once the water has moved out from under the working face of the head 310 it resides in the 35 annular space between the inner surface of the shroud 332 and the outer surfaces of

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À. À e. À Àe - 25 the disc 321 and PTFE disc 325. Under influence of the vacuum source (not shown) associated with the steam generator (not shown) the water and detritus is sucked up into the feed tube 314 through the flexible corrugated hose and into a storage vessel (not shown) in the steam generator for subsequent disposal. The power rating of the s vacuum source used with this head is 3kW. If the head is made any larger the surface is not left substantially dry with this power of vacuum. Larger vacuums could be used although this increases the size and weight of machine that must be moved by the operator. A 3kW vacuum leaves the surface being cleaned only slightly damp.

lo Referring to Fig. 20 another embodiment of a steam cleaning head generally identified by reference numeral 400 comprises a brass sleeve 401 having an upper external thread 402 to enable connection with a steam cleaning lance (not shown) via external spanner flats (not shown). The sleeve 401 has in internal bore 403 for fluid communication with the lance. A thread 404 extends over a lower part of the bore IS 403 by which a steam delivery means in the form of a spindle 405 is connected. The spindle 405 is constructed from stainless steel and has and internal bore 406 in fluid communication with the bore 403. Two holes 407 and 408 are located approximately half way along the length of the spindle. A member 409 is rotatably mounted on the spindle 405 and is retained thereon with a screw 410 that co-operates with an internal 20 thread at the lower end of the spindle. The screw 410 also retains a washer 411. The member 409 is constructed in the same manner and from the same grade of PEEK material as described above in connection with Fig. 8. The washer is constructed from PTFE plastic material and is fashioned so that its outer edge projects downwardly beyond the head of the screw 410. The function of the washer will be 2s described in greater detail below.

The member 409 has a central bore 412 in fluid communication with a chamber 413 in the form of an annular truncated cone, the base of which is located adjacent the lower end or working face 414 of the member 409 and the apex of which 30 joins the central bore 412. The working face 414 is substantially planar and is 50mm in diameter. The member 409 has a height of 0.028m and the upper surface is 0.022m in diameter. Three holes (only one of which can be seen in Fig. 20) of 4mm diameter have been drilled through the member 40 on the annulus defined by the base of the chamber 413 so that the chamber 413 is in fluid communication with the region 3s outside the member 40. All of the holes have been drilled so that their axes form an

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À À À..DTD: - 26 angle of 20 with the vertical. However, one hole has been drilled with its axis tangential to the annulus defined by the base of the chamber 413, whilst axes of the other two holes have been further rotated by an angle in the horizontal plane.

5 A shroud 415 constructed from polyester plastics material is pushfitted over the sleeve 401. The edge 416 of the shroud is rounded off and resides forward of member 409 but rearward of the face of the washer 411.

In use, steam is supplied from a steam generator (not shown) to the lance (not lo shown) into the bore 403 in sleeve 401, through the holes 407 and 408, into the chamber 413 from where it passes through the three holes to the surface to be cleaned. Due to the angles of these holes the member is driven in rotation by the steam so as to clean a larger surface area than would be cleaned were the member 409 stationary. The holes also trace three different paths in a manner similar to that 5 described in connection with Fig. 10. Due to opaque nature of the steam emerging from the head 400, it is difficult for a user to position the head correctly t'or optimum cleaning. It is particularly important that the outlets on the member are the correct distance from the surface if the maximum cleaning power is to be extracted from the steam. As described above, the outer edge of the washer 411 projects forward of the 20 head 400 to perform a spacing function. In use when the head is brought near a surface the user can determine the optimum position by feel when the washer 411 contacts the surface. The outer edge of the washer 411 has a rounded profile 417 to prevent snagging on any uneven surfaces. The shroud 415 also ensures that the dynamic balance of the member 409 is not disturbed through contact with parts of 25 machinery for example during the cleaning process. The rounded edge 416 also reduces the likelihood of snagging. The head 400 is useful particularly, but not exclusively, for cleaning machinery where large flat surfaces are not present.

Referring to Fig. 21 another embodiment of a cleaning head generally 30 identified by reference numeral 500 is similar to the head 400 with like numerals indicating like parts. The main dit'ference is that the head 500 has a diameter of 35mm and accordingly the member 509 is of smaller diameter. In this embodiment there is not room on the working face 514 of the head to accommodate a washer that that has the t'orwardly projecting portion as in Fig. 20. Accordingly in use the shroud 35 515 performs a spacing function that permits the user to position the head the correct

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- 27 distance from the surface being cleaned to obtain maximum cleaning effect from the steam, without danger of the member 509, which spins at high speed, from contacting the surface. The head 500 is useful particularly, but not exclusively, for cleaning in small and difficult to reach areas on machinery for example.

Referring to Fig. 22 a further embodiment of a cleaning head generally identified by reference numeral 600 comprises a steam delivery means in the form of a stainless steel spindle 601 that can be connected at its upper end to a steam cleaning lance (not shown). The spindle 601 has an internal bore 602 that is in fluid lo communication with two outlets 603 and 604 located approximately half way along its length. A member 605 is rotatably mounted on the spindle 601 between an upper disc 606 and a lower disc 607, all of which are constructed from PEEK plastic. The upper disc 606, member 605 and lower disc 607 are retained on the spindle 601 by a washer (not shown) that bears on the lower disc 607 fixed by a bolt (not shown) 5 screwed into the end of the spindle 601. It will be noted that the upper disc 606 and lower disc 607 have a larger diameter than the member 605; the discs extend lOmm beyond the outer surface of the member 605 (they can have diameter of between Imm and lOmm greater than the member for optimum performance). The member 605 is of solid annular form with a chamber 608 midway along its length and around 20 its internal circumference that is in fluid communication with the outlets 603 and 604. Referring to Fig. 23, four passages 608, 609, 610 and 611 connect the bore 608 with the extremity of the member 605, two of which can be seen in Fig. 22. Each axis of the passages 608, 609, 610 and 611 forms an angle with a line on the radius of the member 605 so that in Fig. 22 the section through the two passages is elliptical.

In use, steam is fed from a steam generator (not shown) to the cleaning head 600 where it passes through the bore 602 and through the outlets 603 and 604 into the chamber 608. From there steam passes through the four passages 608, 609, 610 and 611 to emerge from the member 605. Since the passages are inclined with respect to 30 lines on the radius of the member 605, the steam generates a driving force that rotates the member 605 about the spindle 601 to obtain the same advantages as described above in connection with the other embodiments. Since steam emerges from the side of the member 605 the head 600 is useful for cleaning the internal surface of pipes, ducting and the side walls of crevices in machinery for example. The larger diameter 35 upper and lower discs 606 and 607 inhibit the member 605 from contacting and

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- 28 damaging the inner surface of a pipe.

One particular application in which the applicant has found steam to be of benefit is for cleaning flooded lead acid batteries. Such batteries and their electrical 5 connectors can become heavily sulphated and corroded during use. Furthermore the electrolyte must be kept topped up in these batteries with inevitable spillage onto the casing, terminals and connectors. The electrolyte can damage these parts of the battery. The sulphation, corrosion and contamination can lead to decreased performance and shorter battery life. At present many such batteries are simply 10 discarded when performance drops too low since the cleaning process is too difficult and slow to be economically worthwhile. By application of steam with a small nozzle of 7mm diameter (4mm to 8mm is a preferable range) at the aforementioned pressures and temperatures from a steam source, these parts of the battery are effectively and efficiently cleaned. Furthermore the nozzle is provided with or 5 comprises an electrically insulating material so as to protect the user from electric shock. The nozzle allows the application of steam close to the battery and can reach into the crevices and around the awkward parts thereon. The insulating material allows the user to touch the terminals of the battery with the nozzle without fear of shock, thereby permitting thorough cleaning. Once cleaned with steam the battery 20 does not usually require replacement and the performance is usually returned to a level nearer that when new. The head described in connection with Fig. 21 may also be used for this purpose.

Another application in which the application of steam using heads described 25 herein has been found to be useful is for cleaning railway points. It is vital that the smooth and reliable operation of points is maintained for obvious safety reasons. At present in the UK such points are cleaned with a wire brush with the assistance of various chemical cleaning agents. The process is slow (a skilled worker may be able to cover an area of approximately Im2 in one hour) and the results achievable, even 30 by experienced workmen, is not satisfactory. After cleaning the points are lubricated, but with points that have not been cleaned properly in the first place, such lubrication is of limited value. The cleaning heads of the present invention have been found to offer improved cleaning times (approximately 5m2 per hour) and improved results.

Once cleaned with steam, the points can be properly lubricated.

À À. À À e À e À À .. À Àe À À - 29 As used in the appended claims, the term "cleaning" is intended to cover all known uses of steam cleaning (including sterilising), together with those specifically mentioned herein.

Claims (10)

À À À e e e e e e e e e À e be. ea À e e e e e a.e bee - 30 CLAIMS

1. A method of cleaning a surface with steam, which method comprises the steps of: s (1) supplying steam from a steam source to a cleaning head comprising a steam delivery means and a member mounted thereon; (2) passing steam *om the steam delivery means to the member, the member being mounted on the steam delivery means so as to inhibit displacement, on receipt of said steam, of the member relative to the steam delivery means; lo (3) rotating said member; and (4) passing steam through an outlet in the member for cleaning a surface in the proximity of the outlet.

2. A method as claimed in claim 1, further comprising the step of causing the 15 member to rotate about the steam delivery means under action of steam passing through the outlet.

3. A method as claimed in claim 2, further comprising the step of passing steam through at least two outlets.

4. A method as claimed in claim 3, further comprising the step of tracing different paths on the surface being cleaned with said at least two outlets.

5. A method as claimed in any preceding claim, further comprising the step of 25 removing condensed steam and detritus *om the surface being cleaned through said cleaning head with a suction means, the removal taking place substantially continuously during application of steam to the surface so as to leave the surface substantially dry.

30

6. An apparatus for use in a method as claimed in any of claims I to 5, which apparatus comprises a steam source, a cleaning head and means for delivering steam *om the steam source to the cleaning head, which cleaning head comprises a member mounted on a steam delivery means through which steam can be received by the member *om a steam source, the member having an outlet through which received 35 steam can pass for cleaning a surface in the proximity of the outlet, the arrangement

À À À

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- 31 being such that, in use, steam emerging from the steam delivery means is inhibited from displacing the member relative to the steam delivery means.

7. An apparatus as claimed in claim 6, wherein the member is rotatably mounted s on the steam delivery means.

8. An apparatus as claimed in claim 6 or 7, further comprising least two outlets.

9. An apparatus as claimed in claim 8, wherein each outlet is positioned such to that, in use, different paths are traced by steam on the surface being cleaned.

10. motor vehicle having a regeneration system as claimed in Claim 10.

10. An apparatus as claimed in claim 6, 7, 8 or 9, wherein, in use, said steam delivery means passes steam laterally into said member.

11. An apparatus as claimed in any of claims 6 to 10, wherein said the or each outlet is positioned on a working face of the member, the arrangement being such that, in use, said working face can be brought into proximity of a surface to be cleaned such that steam emitted from said outlet impinges on the surface with available cleaning power.

12. An apparatus as claimed in claim 8, wherein said working trace is substantially flat. 13. An apparatus as claimed in claim 11 or 12, wherein said working face 25 comprises a low coefficient of friction material.

14. An apparatus as claimed in any of claims 6 to 13, wherein said member has first and second ends supported for said rotation, at least the first end being supported on the steam delivery means.

15. An apparatus as claimed in claim 14, wherein the steam delivery means passes substantially through the member and said second end is mounted on the steam delivery means.

35 16. An apparatus as claimed in any of claims 6 to 15, wherein the member further

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À 6 6., À 6

I - 32

comprises a chamber into which steam is received from the steam delivery means and from which steam passes to the outlet(s).

17. An apparatus as claimed in any of claims 6 to 16, wherein said member 5 further comprises a projection that, in use, can maintain the outlet(s) at substantially an optimum distance from the surface being cleaned.

18. An apparatus as claimed in any of claims 6 to 17, further comprising a tube having a tube outlet through which tube, in use, steam can be passed to exit from the lo tube outlet, the tube being separate from the member for cleaning areas that the member might not be able to reach.

19. An apparatus as claimed in any of claims 6 to 18, wherein the member is constructed from polyetheretherketone (PEEK).

20. An apparatus as claimed in any of claims 6 to 19, the cleaning head further comprising a shroud that partially encloses the member leaving said outlet(s) exposed, said shroud inhibiting contact between said member and the surface being cleaned. 21. An apparatus as claimed in claim 20, wherein the shroud has a shroud outlet through which steam that has been condensed on the surface being cleaned and the detritus removed therefrom can be withdrawn by suction means when connected to the shroud outlet.

22. An apparatus as claimed in claim 20 or 21, wherein the shroud has a collar that, in use, can be urged against the surface being cleaned so that the shroud and collar substantially enclose that area of the surface being cleaned.

30 23. An apparatus as claimed in claim 20, 21 or 22, wherein the shroud further comprises a plurality of recesses and/or holes that, in use, inhibit the device from sticking to the surface being cleaned when said condensed steam and said detritus are withdrawn through said shroud outlet.

35 24. An apparatus as claimed in any of claims 20 to 23, wherein said member

t b b À. -e À e b À t 4. At. B - further comprises a series of vanes the arrangement being such that, in use, when said shroud outlet is connected to said suction means, said member can be rotated via interaction between said vanes and air withdrawn by the suction means.

s 25. For use with an apparatus as claimed in any of claims 6 to 24, a cleaning head having any of the cleaning head features of those claims.

26. A method of manufacturing part of member for use in a cleaning head as claimed in claim 25, which method comprises the step of injection moulding from lo polyetheretherketone the member or an upper part of the member that comprises the inlet for the steam delivery means.

27. A method of manufacturing part of a member for use in a cleaning head as claimed in claim 25, which method comprises the step of injection moulding from 5 polyetheretherketone a lower part of the member comprising a cap for closing an upper part as deemed in claim 26.

28. Use of an apparatus as claimed in any of claims 6 to 24 for cleaning points on a railway track.

29. Use of an apparatus as claimed in any of claims 6 to 24, when using steam at an appropriate temperature, for substantially sterilising walls, floors and ceilings.

30. A method of cleaning the terminals and/or casing of a flooded lead acid 2s battery, and/or the terminals of electrical connectors for use therewith, which method comprises the steps of ( 1) supplying steam from a steam source to a cleaning head provided with an electrical insulating material; (2) passing steam through the cleaning head to an outlet; and 30 (3) positioning said outlet in the proximity of said terminals and/or said casing such that steam passing through the outlet can perform a cleaning function thereon. 31. A method as claimed in claim 30, wherein said cleaning head is as set out in 3s any of claims 6 to 24.

c c c c 8 C C C C

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egg C C81 e 8 e C C 8 À 8 e t CC CC 48 8 CC - 34 32. An apparatus for delivering steam for cleaning purposes, which apparatus comprises a housing in which a member is rotatably mounted, the housing having an inlet and the member having a ring-like shape with an outer external surface, an inner 5 external surface and a plurality of channels connecting the outer and the inner external surfaces, the arrangement being such that, in use, steam can be supplied through the inlet of the housing to the outer external surface from where it passes to the inner external surface through the plurality of channels, and wherein the member is rotated to enhance the cleaning effect of the steam emerging from the plurality of lo channels on an article passing through the member.

33. An apparatus as claimed in claim 32, wherein at least some channels of the plurality of channels are such that, in use, the member is caused to be rotated under action of steam leaving the channels.

34. An apparatus as claimed in claim 32 or 33, wherein the member is constructed from polyetheretherketone (PEEK) or bearing grade polyetheretherketone.

35. An apparatus as claimed in any of claims 32, 33 or 34, wherein said external 20 outer surface comprises a groove in fluid communication with the plurality of channels for receiving steam from the inlet of the housing.

36. A device for delivering steam for cleaning purposes, which device comprises a member having an inlet for receiving steam from a steam source, an outlet for 25 delivering received steam to a surface to be cleaned and a device outlet through which detritus and condensed steam can be withdrawn from the surface being cleaned, the arrangement being such that, in use when said shroud is positioned adjacent a surface to be cleaned said device outlet is substantially enclosed by the shroud and the surface so as to permit suction means to withdraw detritus and 30 condensed steam from the surface being cleaned through said device outlet.

37. A device as claimed in claim 36, wherein said member is rotatably mounted on said device such that, in use, steam is delivered over a larger area than the area covered by the outlet.

3s

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.......CLME: À 35 38. A device as claimed in claimed 36 or 37, wherein said outlet is mounted on shill device within the shroud.

Amendments to the claims have been filed as follows -b Claims

1. A method of regenerating an internal combustion engine exhaust aftertreatment device of a vehicle in which method the vehicle is provided with a navigational system having stored information relating to vehicle routes and which is connected to a regeneration controller, wherein an intended journey is programmed into the navigational system, the navigation system gathers information relating to the intended journey, the controller receives and stores information from the navigation system and the gathered information is compared with pre-

programmed route information to predict short term future vehicle operating conditions so that the controller can initiate the future regeneration of the device within a predicted future period of suitable vehicle operating conditions, characterised in that the controller may interact with the navigational system to suggest alternative routes to facilitate the regeneration of the dcvicc.

2. A method as claimed in Claim 1, wYcrcin the method provides that navigational information is provided by a GPS based navigational system.

3. A method as claimed in Claim 1 or Claim 2, wherein the method provides that navigation information is provided by a traffic management system which distributes information in relation to traffic conditions along a proposed route.

4. A method as claimed in any one of Claims 1 to 3, wherein the controller is programmed to recognise a repeat journey and thereby predict a suitable period of vehicle operating conditions for optimum regeneration based on previously stored information.

-1 5. A method as claimed in any one of Claims to 4, wherein the controller is programmed to store information relating to the vehicle operating conditions for a plurality of journeys and utilise the information to predict said suitable period.

6. A method as claimed in any one of Claims 1 to 5, wherein said method is utilised for regeneration of exhaust aftertreatment devices utilised with diesel engines.

7. A control system for the operation of a regeneration process for an internal combustion engine exhaust aftertreatment device of a vehicle, said control system including a navigational system pre-programmed with information relating to vehicle routes and into which an intended journey is programmable, the navigation system being capable of gathering information relating to said intended route, and a controller which receives and stores information from the navigation system, the controller being pre-programmed to process the information relating to the intended vehicle route to predict short term future vehicle operating conditions for controlling the initiation oi the regeneration of the device to occur within a predicted inlure period of suitable vehicle operating conditions, characterized in that the controller may interact with the navigational system to suggest alternative routes to i:acilitate the regeneration process.

8. A system as clairneu in Clairr 7, wherein the ccui-olle- is an integral pal-. o1 a -logoilei-atio supervisor. 9. A regeneration system for a vehicle engine exhaust aftertreatment device and which includes a control system as claimed in Claim 7 or Claim 8.