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Title:
OVERFLOW SYSTEM
Document Type and Number:
WIPO Patent Application WO/2006/109007
Kind Code:
A1
Abstract:
An overflow management device for use in a liquid flow system, the device comprising : a first chamber for connection in a liquid inlet supply of a system and having an inlet and an outlet between which liquid can flow; a second chamber for receiving liquid from an overflow source of the system; a device trigger disposed in the second chamber and activatable by received liquid; and a closure means arranged to, in response to the device trigger being activated, move in the first chamber thereby substantially preventing liquid flowing from the inlet to the outlet. There is also provided a liquid flow system comprising an overflow management device.

Inventors:
Mason, David (21 Revels Road, Hertford, Hertfordshire SG14 3JU, GB)
Whitehead, Stephen (7 Comroston, Brocket Road Hoddesdon, Hertfordshire EN11 8PQ, GB)
Application Number:
PCT/GB2005/001457
Publication Date:
October 19, 2006
Filing Date:
April 15, 2005
Export Citation:
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Assignee:
THE HI-LO VALVE CO. LTD (5 Jupiter House, Calleva Park Reading, Berkshire RG7 8NN, GB)
Mason, David (21 Revels Road, Hertford, Hertfordshire SG14 3JU, GB)
Whitehead, Stephen (7 Comroston, Brocket Road Hoddesdon, Hertfordshire EN11 8PQ, GB)
International Classes:
E03C1/242; F16K31/30; F16K31/56
Attorney, Agent or Firm:
Kelda, Camilla Karen Style (Page White & Farrer, 54 Doughty Street, London WC1N 2LS, GB)
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Claims:
CLAIMS
1. An overflow management device for use in a liquid flow system, the device comprising : a first chamber for connection in a liquid inlet supply of a system and having an inlet and an outlet between which liquid can flow; a second chamber for receiving liquid from an overflow source of the system; a device trigger disposed in the second chamber and activatable by received liquid; and a closure means arranged to, in response to the device trigger being activated, move in the first chamber thereby substantially preventing liquid flowing from the inlet to the outlet.
2. An overflow management device according to claim 1 , wherein the second chamber is adjacent the first chamber and the closure means is disposed in the second chamber and is arranged to move into the first chamber.
3. An overflow management device according to claim 1 or claim 2, wherein the device trigger is arranged to be activated when received liquid reaches a predetermined level in the second chamber.
4. An overflow management device according to any preceding claim, wherein the device trigger comprises a float device which is moveable in response to liquid to thereby activate the device trigger.
5. An overflow management device according to any preceding claim, wherein the device trigger is arranged to, prior to activation, bias the closure means substantially entirely in the second chamber such that liquid can flow through the first chamber.
6. An overflow management device according to claim 5, wherein the device trigger comprises a portion arranged to extend between the closure means and the first chamber prior to activation, thereby holding the closure means biased.
7. An overflow management device according to any preceding claim, wherein the closure means comprises a plate.
8. An overflow management device according to any preceding claim, wherein the closure means is slideable between the second chamber and the first chamber.
9. An overflow management device according to any preceding claim, wherein the first chamber comprises means for receiving the closure means such that when in the first chamber, the closure means is held in a substantially liquidsealed manner.
10. An overflow management device according to any preceding claim, wherein the device trigger comprises reset means for resetting the device following movement of the closure means in the first chamber.
11. An overflow management device according to any preceding claim, wherein the second chamber comprises an inlet for receiving liquid from an overflow source of the liquid flow system, and an outlet for liquid, mutually sized and disposed such that if liquid is received at a flow rate below a predetermined flow rate, the liquid can flow out of the outlet without activating the device trigger, but if liquid is received at a flow rate above the predetermined flow rate, the second chamber fills with liquid such that the device trigger can be activated.
12. An overflow management device according to claim 11 , further comprising means for preventing movement of the closure device if liquid is received at a flow rate below the said predetermined flow rate, so that liquid can flow out of the outlet even if the device trigger is activated.
13. An overflow management device according to claim 12, wherein the means for preventing movement of the closure device is a stop device disposed in the first chamber.
14. An overflow management device according to claim 12 or claim 13, wherein the means for preventing movement of the closure device is arranged to function when liquid is flowing between the inlet and the outlet of the first chamber but is arranged to be nonfunctioning when liquid is substantially stationary between the inlet and the outlet of the first chamber.
15. An overflow management device according to any of claims 11 to 14, wherein the said outlet is connectable to an overflow drain of the system.
16. An overflow management device according to any of claims 11 to 15, wherein the second chamber comprises a further outlet for liquid, disposed to allow liquid which has reached a level in the second chamber above a level at which the device trigger is activated to flow out of the further outlet.
17. An overflow management device according to claim 16, wherein the further outlet is connectable to an overflow drain of the system.
18. An overflow management device substantially as herein described with reference to the accompanying drawings.
19. A liquid flow system comprising : a liquid inflow portion; a use portion arranged to receive liquid from the liquid inflow portion; an overflow from the use portion; and an overflow management device comprising : a first chamber connected in the said liquid inflow portion, the first chamber having an inlet and an outlet between which liquid can flow; a second chamber for receiving liquid from the said overflow; a device trigger disposed in the second chamber and activatable by said received liquid; and a closure means arranged to, in response to the device trigger being activated, move in the first chamber thereby substantially preventing liquid flowing from the inlet to the outlet.
Description:
OVERFLOW SYSTEM

The present invention relates to an overflow management device and a liquid flow system comprising an overflow management device.

In a conventional liquid flow system, for example a water supply to a bathroom basin, in normal use, water comes into the interior of the basin through a liquid supply via taps, is used as required, and is then drained out of the basin. The liquid supply is often brought into the building from a mains water supply and the drain is arranged to lead eventually to a mains drainage. The water source is therefore essentially endless.

Provision is made in such a system for overflow water. For example, with respect to a basin, a user may fit a plug to the basin, turn on the taps and then become distracted, thus quickly filling the basin to close to its capacity. In order to deal with this eventuality, such a basin is often provided with an overflow outlet near the top of the interior, usually in the form of an overflow hole in the side of the basin. Thus when the water level nears the top of the basin, water can flow out of the hole rather than spilling out of the basin onto the floor. The hole is also arranged to lead eventually to a mains drainage.

There are some problems with the above-described system. Firstly, the flow rate of the taps may be greater than the maximum possible flow rate out of the overflow hole. Consequently, in time, excess water will start spilling out of the basin anyway, even if some still flows out of the overflow hole.

Secondly, even if the overflow hole is large enough to cope with the flow rate of water trying to flow out of the basin and thus prevent spillage, in such a situation, water continues to flow out of the taps and literally goes down the drain. Such wastage of water is unacceptable given the cost and energy at source required to bring drinking water to our taps, particularly in times of drought, and is costly at the user end for a building with a water meter fitted.

It would be desirable to provide a means of minimising liquid wastage in the event of an overflow situation in a liquid flow system.

According to a first aspect of the present invention, there is provided an overflow management device for use in a liquid flow system, the device comprising : a first chamber for connection in a liquid inlet supply of a system and having an inlet and an outlet between which liquid can flow; a second chamber for receiving liquid from an overflow source of the system; a device trigger disposed in the second chamber and activatable by received liquid; and a closure means arranged to, in response to the device trigger being activated, move in the first chamber thereby substantially preventing liquid flowing from the inlet to the outlet.

According to a second aspect of the invention, there is provided a liquid flow system comprising : a liquid inflow portion; a use portion arranged to receive liquid from the liquid inflow portion; an overflow from the use portion; and an overflow management device comprising : a first chamber connected in the said liquid inflow portion, the first chamber having an inlet and an outlet between which liquid can flow; a second chamber for receiving liquid from the said overflow; a device trigger disposed in the second chamber and activatable by said received liquid; and a closure means arranged to, in response to the device trigger being activated, move in the first chamber thereby substantially preventing liquid flowing from the inlet to the outlet.

The device trigger and the closure means could be provided as a single element.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which :

Figure 1 shows a front view of an overflow management device of the invention in an inactivated state, with water flowing past the device;

Figure 2 shows a front view of the overflow management device of figure 1 in an inactivated state, with no water flowing past the device;

Figure 3 shows the overflow management device of figure 1 in an activated state;

Figure 4 shows a top plan view of the overflow management device of figure 1 ; and

Figure 5 shows schematically the overflow management device of figure 1 connected in a liquid flow system.

In the figures, like reference numerals indicate like parts.

Referring firstly to figure 1 , an overflow control device labelled generally with reference numeral 1 is shown. The front of the device is omitted in the figure so that internal components are visible. The device 1 comprises a flow chamber 2 and a float chamber 4. The flow chamber 2 has an approximately square cross-section and is elongate. It is designed to receive an inflow of water at its lower end as shown by the arrow marked IN, and for water to flow out of its top end, as shown by the arrow marked OUT. The ends of the flow chamber 2 are threaded for connection into a water supply for a flow system such as a bathroom basin, and are therefore generally circular in cross-section.

The float chamber 4 is located adjacent the flow chamber 2 but is hermetically sealed from it. The float chamber 4 is rectangular in cross-section, being wider across the figure than into the page, and of a similar length to the flow chamber 2. The float chamber 4 has a water inlet 6 at the bottom of the chamber, shown on the right hand side of the float chamber 4 in the figure, and two water outlets. The first outlet 8 is at the bottom of the chamber 4 and is shown on the left hand side of the float chamber 4 in the figure. The second outlet 10 is located near the top of the float chamber 4, in a region away from the flow chamber 2. It is shown as a rightwards exit. The inlet 6 is designed to be connected to a source overflow from a flow system, and the outlets 8, 10 are designed for connection to an existing drain

overflow of the flow system. Thus the inlet 6 and outlets 8, 10 are generally circular in cross-section.

Approximately three-quarters of the way up the float chamber 4 from the bottom, is shown a float arm 12 attached to the wall of the float chamber 4 in the region adjacent the flow chamber 2 at a pivot point 14. This arm has a small cross-section relative to its length and a horizontal portion 12b extends lengthwise across the float chamber 4 away from the flow chamber 2. Just less than half-way along from the flow chamber 2, the float arm 12 has a downwardly extending portion 12a. In the inactive position of figure 1 , the main portion of the float arm 12b extends substantially horizontally and thus the downwardly extending portion 12a extends substantially vertically. A cross-bar 13 extends from the pivot 14 to the bottom of the portion 12a for use in resetting the device, as will be explained below.

The portion 12a thus prevents leftward movement of a plate 16 (shown hatched to distinguish it from other components). The plate 16 has an upwardly extending portion 16a which "catches" to the right of the portion 12a, hence holding the plate 16 in the position of figure 1 , and a substantially horizontal portion 16b which extends from the portion 16a leftwards in the figure towards the flow chamber 2. The portion 16b extends into a first seal 18. Attached to the frame 16 at the end that is in the first seal 18 is a bar 20, which runs across the width of the flow chamber 2 in a sealed frame 22. The frame 22 has an upper portion 22a and a lower portion 22b, each of which runs around the inside surface of the flow chamber 2 in an approximately horizontal plane. Since the bar 20 has a relatively small depth (into the page in figure 1) water can flow through the frame 22 and past the bar 20 relatively unobstructed.

At the other end of the bar 20 is a second seal 24, the other side of which is a coil spring 26 attached to the bar 20. In figure 2 the spring 26 has been compressed by the action of a reset button 28 which has been pushed rightwards in the figure, and is held compressed by virtue of the plate 16 being held by the portion 12a of the float arm.

The plate 16, the arm 20, the spring 26 and the reset button 28 are effectively one continuous portion although they could be manufactured from separate pieces and joined together.

Attached to the portion 12b of the float arm 12 is a float 30. The float 30 is attached to the float arm 12 towards the end of the portion 12b distal from the flow chamber 2 and is disposed beneath the float arm 12. The float 30 is shaped to be relatively large in comparison to the float arm 12 i.e. it has a relatively large height in figure 1 but it is cut-out to form a general L-shape so that it can fit around the portion 12a of the float arm 12 and the portion 16a of the plate 16 without touching. The float 30 extends across much of the depth of the float chamber 4 (into the page in figure 1).

Finally there is shown in the flow chamber 2 a stop 32. The stop 32 is attached to the bar 20 and is located on the right hand side of the flow chamber 2 in the figure. It is disposed to one side of the bar 20 (into the page) and it is designed to interact with a stop arm 34. The stop arm 34 is attached to the left hand side of the flow chamber 2 in the figure in a pivotable manner such that it can pivot downwards so that its end distal from the attachment point falls infront (i.e. to the left in the figure) of the stop 32. In figure 1 the stop arm 34 is shown in a substantially horizontal position in which it is not in contact with the stop 32. The stop arm 34 is of a narrow depth (into the page) so that it does not interrupt the flow of water when in the horizontal position.

For a better understanding of the relative sizes and positions of the above- described components, please refer to figure 4 which shows a top view of the device 1 of figure 1 , with the tops of the flow chamber 2 and the float chamber 4 omitted so as to show the components beneath. The stop 32 and stop arm 34 can be seen to be located to one side of the bar 20. The exact design and location of these two components can be varied and they are shown in the figures as a schematic illustration of their principle of use which will be explained below.

Figure 1 shows the situation when water is flowing through the flow chamber 2 as required by a user. For example, a tap to which the flow chamber 2 is connected may have been switched on. Thus there is no unwanted overflow of water, and the components are maintained in their position as follows. One end of the horizontal portion 16b of the plate 16 is held in place by the first seal 18 so it is not just floating freely. However, the plate 16 is prevented from moving leftwards into the frame 22 because its upwardly extending portion 16a is retained by the downwardly extending portion 12a of the float arm 12.

Furthermore, the flowing water maintains the stop arm 34 in a substantially horizontal position so that should a problem occur, as will be explained with reference to figure 3 below, the stop arm 34 and the stop 32 will not prevent activation of the device 1.

Figure 2 shows the situation when a user is no longer using new water. In other words, the flow of water through the flow chamber 2 has been stopped by the user turning off a tap, for example. This causes a change in the flow pattern of the water, as shown by arrows in the figure, and causes a return pressure to act on the stop arm 34. This pressure, together with the absence of any moving flow of water from the bottom of the flow chamber, is enough to swing the stop arm 34 downwards such that its distal end contacts the stop 32. The effect of this is that even if a small amount of overflow water comes into the inlet 6, and moves the float 30, the device 1 will not be triggered because the plate 16 can not move into the flow chamber 2 since it is prevented from doing so by the stop 32. Triggering of the device 1 will be explained with reference to figure 3 below, This is advantageous because it allows small quantities of water to splash into the overflow of the system without the water supply being shut off and thereby inconveniencing a user.

Turning now to figure 3, this shows the situation in which a significant amount of overflow water comes into the inlet 6, for example if a user has turned on a tap and left it, allowing a basin, for example, to overflow. Assisted by the outlet 8 being narrower in cross-section than the inlet 6, water builds up in the float chamber 4.

When the water reaches the level of the float 30, the float 30 begins to rise with the water level. However, since the float 30 is attached to the float arm 12, which is in turn attached at the pivot 14, the entire float arm 12 and float 30 assembly pivots anticlockwise about the pivot 14. The attachment position of the float 30 to the float arm 12 at a point away from the pivot 14 provides good leverage. Eventually, the pivot arm 12 has rotated to a sufficient degree that the downwardly extending portion 12a clears the portion 16a of the plate 16. Thus there is no longer any means of maintaining compression in the spring 26 and therefore the spring force is released, letting the reset button 28 leftwards. Consequently, leftward movement of the arm 20 pulls the plate 16 into the frame 22 within the flow chamber 2, such that it reaches the position shown in figure 3. In this position the plate 16 has slid between the upper and lower portions 22a, 22b of the plate 22. The plate 16 does not move any further because the portion 16a catches on the dividing material separating the flow chamber 2 and the float chamber 4, and the plate 16 can not fit through the seal 24.

The portion 16b of the plate 16 is sized heightwise to be able to move into the frame 22 but to be only slightly smaller in area than the frame 22 such that water can not flow between the edge of the plate 16 and the inner edge of the frame 22. In the position of figure 2, the upflowing water in the flow chamber 2 pushes the plate 16 against the upper portion 22a of the frame 22 so that after only a short delay, the plate 16 prevents any water flowing upwards and out of the flow chamber 2. Thus, although a supply of water is. available at the bottom of the flow chamber 2, this water has nowhere to flow and consequently no further water is lost from the system.

The plate 16 is constructed to withstand the pressure that it is being subjected to. For a given regular flow pressure of water in the flow chamber 2, the actual pressure to which the plate 16 is subjected in the flow chamber 2 is likely to be higher.

Since prior to activation of the device and moving of the plate 16 into the flow chamber 2, water has been flowing through the flow chamber 2, the stop arm 34 is maintained in a horizontal position as described with reference to figure 1. Consequently the stop 32 is not held in its rightward position by the stop arm 34 and is therefore not prevented from moving. Thus it does not obstruct the movement of the plate as described above with respect to figure 2. Instead, the stop 32 moves across the flow chamber by virtue of its being attached to the arm 20. There is just enough room for it at the left hand side of the flow chamber 2 such that the plate 16 can properly engage in the frame 22 and prevent water flow through the flow chamber 2. In other embodiments, the stop 32 could be designed differently to fulfil its various functions in the situations of figures 1-3, and it should be appreciated that the relative lengths of the plate 16 and the arm 20 and hence the position of the stop 32 are not shown accurately in the figures.

When the volume of overflow water eases off, the plate 16 remains in position in the flow chamber 2 until it is manually reset. Thus no more water will be allowed to flow into the liquid flow system until the cause of the overflow has been removed and the user of the liquid flow system decides to allow water to be available to the system once again.

In order to reset the system the reset button 28 is pushed in towards the flow chamber 2, thus re-compressing the spring and pushing the plate 16 back into the float chamber 4. This can only be done when the water level in the float chamber has returned to a low level. The cross-bar 13 assists in this process since as the portion 16a of the arm 16 is pushed underneath it, the float arm 12 is pushed upwards such that the portion 16a can slide underneath the portion 12a of the float arm. The float arm 12 then drops back downwards under gravity, thus once more holding the portion 16a behind the portion 12a.

Any excess water which fills the float chamber 4 beyond that required to rotate the float arm 12 and float 30 assembly can flow out of the outlet 10 of the float chamber 4, from where it joins a drain overflow together with any water from the outlet 8.

The outlet 10 also acts as a precautionary water outlet in the event that the plate system does not work for any reason.

Referring now to figure 5, the device of figures 1 , 2 and 3 is shown connected to a liquid flow system. In the example of figure 5, the liquid flow system is for supplying water to a basin 40. The flow chamber 2 connects the device 1 to the system by being located between two suitable connection points in a water inlet, for example two tap-offs, such that it forms part of the water inlet to the basin 40. Figure 5 is not shown to scale and it should be remembered that in practice the pipes and components of the system may have different relative locations from those shown.

Water flows into the system from a mains supply along a pipe 42 connected in-line to the flow chamber 2 (marked IN). The device 1 is shown in its inactivated state as in figure 1 , and hence water flows from the pipe 42 into the flow chamber 2, up past the bar 20 and the frame 22 and into another pipe 44 which leads to the basin 40. The basin 40 is provided with a tap 46 which enables a user to turn the flow of water either on so as to use the water in the basin 40 or off when the basin 40 is not in use. Whilst water is flowing the stop arm 34 is in the horizontal position as shown in figure 5, but when the tap 46 is turned off, the stop arm 34 will engage with the stop 32 as described with reference to figure 2. The basin 40 has an overflow outlet 48 which is connected into a valve 50 which has two outlets. A first outlet 52 is connected to a source overflow pipe 54 which is routed to the inlet 6 of the device 1. The outlet 8 of the device 1 is routed into a drain overflow pipe 56 and the outlet 10 of the device 1 is routed into a drain overflow pipe 58. Both the pipes 56, 58 are routed to a common drain overflow 60 which leads eventually to a mains drain.

Thus it can be understood that in normal operation of the system, water from the mains supply flows into the pipe 42, through the flow chamber 2 and to the basin 40. If the tap 46 is open, water flows into the basin 40 for use. If a small quantity of water flows out of the overflow 48 of the basin, this is routed along the pipe 54 and into the inlet 6 of the float chamber 4, from where it can drain directly out of the

outlet 8. If the float 30 is moved upwards in this situation, the device 1 will nevertheless not activate because of the action of the stop arm 34 on the stop 32, as described with reference to figure 2.

If, on the other hand, something goes wrong, for example, a user turns on the tap 46, puts the plug in the basin and then becomes distracted and water continues to flow even though the basin is becoming full, much greater quantities of water will flow out of the overflow 48, into the valve 50, out of the outlet 52 and down the pipe 54 and into the float chamber 4 through the inlet 6. The water level will build up and operate the device 1 as described with reference to figure 3, such that water is prevented from flowing past the plate 16 in the flow chamber 2. Thus even though the mains supply coming into the pipe 42 is still active, no more water reaches the basin 40.

It is likely that the basin 40 will have both hot and cold taps. Therefore, if, say, the system shown in figure 5 is for the cold water inlet, the second outlet 51 of the valve

50 can be connected to another similar system such that the flow chamber 2 is inline the hot water inlet. Water will flow approximately at the same rate into outlets

51 and 52, thereby allowing both hot and cold taps to be shut off. More outlets could of course be provided should this be required.

It will be appreciated that the particular shapes and dimensions shown in the figures are not essential to operation of the invention. For example, the relative dimensions of the inlet 6 and the outlet 8 of the float chamber 4 can be varied in dependence on the likely overflow rate out of the system to which the device 1 is connected. Thus the device 1 can be calibrated to fill at a particular rate as desired by variation of the sizes of the outlets and the size of the float chamber 4, together with the position at which the float arm 12 is attached. The described shapes and relative dimensions of the various components could also be varied within the scope of the invention. In one preferred embodiment, means can be provided at either or both of the inlet 6 and outlet 8 for varying the dimensions thereof and hence the rate of flow of water into and/or out of the float chamber. Such means

could for example be a conical screw fitting which is rotatable to either increase or decrease the diameter of the inlet/outlet depending on the direction of rotation. In this way, the configuration of the device can be tuned on-site according to the user's preferences and/or the particulars of the water system in which the device is installed.

An important feature of the device 1 is that it is easily connectable and useable with Standard system fittings. The threaded ends of the flow chamber 2 can be made as standard plumbing connections, for example HEP2o, BSP or copper connections. Furthermore, the valve 50 can be made to fit standard overflow systems. It is suitably made of plastics material. The pipes 44, 54, 58 and 60 can be standard water pipes of metal or plastics material and are connectable to the device 1 and the valve 50 with standard connections. Suitable materials for the plate 16 include metals, plastics or nylon. Provided the material is strong enough, the plate 16 can have a thickness of only around 2mm and the portions 22a, 22b of the frame 22 are suitably spaced apart to receive the plate.

It can be understood that the flow chamber 2 must be built to withstand the pressure of the incoming water supply and particularly the shock when the water supply is shut off as in the situation of figure 3. The float chamber 4 can be lighter in construction since it does not have to withstand such high pressures. The flow chamber 2 and the float chamber 4 can be manufactured as a single unit in, for example, stainless steel or tough plastics material.

The inlet water into the flow chamber 2 does not need to come from a mains water supply but could be from any source of flowing water e.g. from a pumped supply or a gravity fed system. The device 1 would work with liquids other than water. The device 1 can be supplied either as a stand-alone unit or with the valve and pipes as shown in figure 5. The connections to the device 1 at the top and bottom of the flow chamber 2 and into and out of the float chamber 4 can be integrally moulded into the flow and float chamber or could be provided at least partially as separate parts.

The exact mechanism described in the embodiment whereby the flow chamber is shut off could be modified within the scope of the invention.

Embodiments of the present invention use the float sensor to judge the condition of the water supply and a second chamber with a mechanical device to shut off the supply water if needed, leaving the overflow water to continue to overflow. Embodiments of the present invention have a preset tension spring to combat the higher water pressure flow. By having two separate chambers (a flow chamber for the high pressure and a float chamber for sensing water flow condition), embodiments of the present invention are able to evaluate the water conditions and activate in a single movement.

Furthermore, embodiments of the present invention have the advantage that the mechanical shut off mechanism, that is the spring, is situated outside the valve and is thus located outside the water supply. Because the shut off mechanism is located outside the water supply, disadvantages associated with water contamination and build up of lime scale preventing movement of the shut off mechanism over time are avoided.

The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.