FIELD OF THE INVENTION The invention relates to a tire tray for supporting uncured tires in or at a tire manufacturing facility. The tire tray may in addition also be used for cured tires, but is in particular of benefit when handling uncured tires.

BACKGROUND OF THE INVENTION

Most tire manufacturing systems may rely on a relatively high degree of more or less automated material handling equipment and automated tire processing steps. Each of these steps must be carried out in a cost efficient manner, while assuring an optimum quality of the manufactured tire.

In some tire manufacturing systems, the tires are transported by conveyor equipment during some or all of their way through the system. In order to assure an optimum quality of the manufactured tire at an optimised cost, it is of outmost importance that a position of the tire at various stations in the system is relatively easy to determine, and more or less predetermined, preferably without having to reposition the tire.

Further, a tire manufacturing step of curing green tires may carry one of the main costs in tire manufacturing, such as due to erroneous loading of green tires to the curing press. This constitutes a risk of wasting both energy, raw materials as well as a risk of damaging the curing press itself and/or a risk of lower product quality.

Thus, in order to solve issues relating to such or other product costs and/or product quality problems, it has been appreciated, that an improved tire tray for supporting uncured tires, and an improved method of supporting and conveying uncured tires at a tire production facility in a tire tray is of benefit, and in consequence, the present invention has been devised. SUMMARY OF THE INVENTION

It may be seen as an object of the present invention to provide an improved tire tray for supporting uncured tires, and an improved method of supporting and conveying uncured tires at a tire production facility in a tire tray. Preferably, the invention alleviates, mitigates or eliminates one or more of the above or other disadvantages singly or in any combination.

In particular, it may be seen as an object of the invention to provide a tire tray for supporting uncured tires, and an improved method of supporting and conveying uncured tires at a tire production facility in the tire tray, which tray and/or method enables the tire to have a stable and predetermined position in the tray, while also enabling that the tire is essentially prevented from sticking to the tray. In particular, it may be seen as an object to provide a solution where the stable and predetermined position can be maintained, or substantially maintained, during conveyance of the tire in a conveying system while a sticking force of the tire to the tray is of sufficiently small magnitude that it still allows unloading the tire from the tray without damaging the tire and/or the tray. Further, it may be seen as an object to unload the tire from the tray with as low as possible use of force applied to the tire and/or the tray.

Accordingly there is provided, in a first aspect of the invention, a tire tray for supporting uncured tires, where

- the tray is adapted for supporting at least one of said tires,

- the tray is adapted for being conveyed in a conveyor system with said at least one tire supported in the tray,

- the tray comprises a tapered geometrical form narrowing gradually towards a centre, where the centre is adapted to coincide, or substantially coincide, with a centre of said at least one tire, and wherein

- the tapered form is dimensioned and includes one or more anti-stick elements so as to support said at least one tire, and wherein said one or more anti-stick elements are provided in a material different from the tire tray, and wherein at least one of said one or more anti-stick elements are provided for making contact with said tire and for supporting said tire in said tire tray. Thus, an improved tire tray is provided. It may be seen that the improvement at least lies in providing the tire tray with the tapered form and the one or more anti-stick elements as disclosed herein. It is understood, that the tapered geometrical form is a tapered support surface comprised in the tire tray and for supporting the tire. The surface forms an opening with a gradually decreasing bore or diameter, when seen from a top-view, hence the wording tapered form. A slope or angle of the gradually decreased diameter may be constant as illustrated herein, or it may alternatively or additionally comprise a slope changing along the surface.

The tire tray is in particular of benefit when handling uncured tires, also called green tires. But, the tire tray may also, or even alternatively, be used for cured tires, i.e. for supporting and conveying tires that have been cured in the curing press, but which are usually less sticky than uncured tires. Hereby, two types of trays in a conveying system can be prevented, such as rendering the necessity of multiple types of trays superfluous, which may be seen of benefit.

It is also a general insight disclosed hereby, that in addition to any other unwanted side effects which a too high sticking force may have, any non- intentional and possibly randomly placed marks on the tire resulting from the tire being stuck to any part of the conveying system, and/or stuck to any part of the tire production system, are highly unwanted.

It is an insight of the present disclosure, that when supporting the tires in a tapered form with one or more anti-stick elements as described, the tray can be used for conveying and supporting several different sizes of tires in a stable manner, while a sticking force of the tire to the tray is of sufficiently small magnitude that it still allows unloading the tire from the tray without damaging the tire.

According to a particularly advantageous embodiment, the tapered form is having dimensions and the one or more anti-stick elements are provided so as to support said at least one tire on a shoulder portion of said at least one tire. In dependence of the form and/or shape of the tire tray and/or form and/or shape of the tire, the tire may alternatively or additionally be supported on its lowermost edge or lowermost surface in the tire tray 102. This edge or surface is a portion of the tire where later a bead portion of the tire will be provided in its final form.

According to embodiments of the invention, the anti-stick elements are provided to enable a tire to be unloaded from the tire tray with a force which is less than the force would have been if the tire was solely supported by material of the tray. In other words, a sticking force between the at least one tire and the material of anti-stick elements, is less than the sticking force between the tire and the material of the tray.

According to embodiments of the invention, the one or more anti-stick elements are protruding from a surface of the tapered form.

The anti-stick elements may have any geometrical form suited for their purpose. According to embodiments of the invention, at least one of said one or more anti- stick elements are provided as strips with one end towards an outer circumference of the tapered form and another end towards an inner circumference of the tapered form. The anti-stick elements may alternatively be provided as a mesh or net attached to at least a portion of the tire tray. However, in comparison with other embodiments, such provision of anti-stick elements may be more vulnerable to damage and/or more difficult to securely attach to the tapered form, and/or more difficult to replace, and/or increase a risk of leaving unintentional marks on the tires. Further, and according to other embodiments of the invention, at least one of said one or more anti-stick elements comprise a circular ring-formed shape.

In particular, it has been found that when the one or more anti-stick elements are provided by a single, preferably cylindrical and tapered formed, circular ring- formed shape attached on the tapered form, and possibly arranged for being the sole contact surface to the tire, a particular advantageous embodiment is provided. In such embodiment, as well as in other embodiments herein, a support surface, or at least a part of the support surface, of the anti-stick element is corresponding to the tapered form. Such embodiment may be particularly useful for several tire sizes, particularly robust, and, e.g., particular good for not leaving any visible marks, and/or particularly easy to attach and/or exchange.

A reason for such embodiment being particularly good for not leaving any marks itself is, particularly when provided as a single protruding element, that one unbroken surface is only in contact with the tire. Whereas, when using multiple protruding elements, each single elements supporting the tire will have one or more borders, which borders may be vulnerable to damage and/or may leave marks.

In this respect, and according to particular embodiments, the one or more of the anti-stick elements are provided by one or more cut-outs. The one or more cutouts are preferable provided from one or more sheets of material, of e.g. silicone and with a material thickness of e.g. 0.1 mm to 5 mm, such as 0.25 mm, 0.5 mm or 1, 2, 3 or 4 mm. Such one or more cut-outs, and preferably a single cut-out, is provided in a size and form so as to follow the tapered geometrical form when attached to the tapered geometrical form. The size of the one or more cut-outs is preferably provided so that the cut-out(s) cover the entire tapered form or substantially cover the entire tapered form. At least, it is preferred that, in particular in the areas where e.g. a shoulder of a supported tire will be positioned on the one or more cut-outs, there is an unbroken surface or substantially unbroken surface of anti-stick element provided by the one or more cut-outs. Thus, the one or more cut-outs preferably forms a circular ring-formed shape, e.g. a single circular ring, when attached to the tire tray and when seen in a top view.

Any of the anti-stick elements disclosed herein may be provided with a surface roughness, which is adjusted so as to optimize the anti-stick function relative to other characteristics of the one or more anti-stick elements, such as durability and/or likeliness of leaving permanent marks in the tires. This may as an example be provided by scattering separate knobs or similar, protruding from a surface of the anti-stick element(s). Such knobs may e.g. be provided 1-10 mm apart, and with a height of e.g. 1-2 mm and a diameter of e.g. 1-5 mm. By utilising such knobs or similar, it is possible to optimize a surface area that supports the tire, so as hereby alternatively or additionally to control a sticking force of the tire to the anti-stick surface. Alternatively or additionally, the adjusted surface roughness may be provided by electrical discharge machining of the tools or dies providing the anti-stick elements, corona treatment of the anti-stick elements or similar. According to particular embodiments of the invention, the tire tray has one or more through-going holes in the tapered form, which are used for at least partly attachment of and/or for at least partly maintaining the one or more anti-stick elements in place. In addition to the holes, other means, such as glue, may be used for attachment of the one or more anti-stick elements. In a particular embodiment, the anti-stick elements are provided with a form so as to interact with the holes to secure them to the tapered surface after initially being introduced in the holes. Alternatively or additionally, a part of a sticking element may be secured to an upper side or lower side of the tapered form by pressing an additional fastening element, such as a plate held by screws or similar, or simply by screws, towards it. If such additional fastening element is provided from the upper surface of the tapered form, it must of course be provided below a level of the one or more protruding anti-stick elements, in order for such additional fastening element not to be in contact with the tire, which is seen as unwanted.

A compromise between the amount of material for the one or more anti-stick elements may possibly be neccessary in view of e.g. factors such as, leaving unwanted visible marks, and/or in view vulnerability of the one or more anti-stick elements.

According to embodiments of the invention, one or more or all of said one or more anti-stick elements are exchangeable. This may be of benefit if or when the anti- stick element(s) is/are worn to a certain extend after extensive use, and/or if production methods and/or production environments, and/or tire rubber composition change. Whereas the sticking force can be lowered to some extend by only at least partly supporting the tire with one or more anti-stick elements, and this may be of benefit, a particularly low sticking force is given between the tire tray and the tire when only the one or more anti-stick elements are in contact with said tire. According to embodiments of the invention the tire tray comprises an injection- mouldable, rotation-mouldable, vacuum-formable or otherwise thermo-formable plastic material or compound, such as PP, PE, ABS or PVC. The tray may alternatively comprise metal, or comprise a steel or metal insert. The insert may or may not form the tapered form.

According to embodiments of the invention at least one of, or all of, the anti-stick elements comprise a material with a lower adhesion to the tire than the material of the tire tray, such as silicone.

According to embodiments of the invention, the tire tray forms a closed hollow space or substantially closed hollow space inside it. Hereby, the tapered form may, along with the sides of the tray form the only support structure between an upper and a lower surface of the tray. Alternatively, the tire tray may be provided with an open-bottomed structure, or where a bottom part can be easily removed, whereby replacing the one or more anti-stick elements may be easier. Such open or closed formed trays may additionally or alternatively be provided with further strengthening and/or support structures, such as ribs or the like. The tire tray is for use in a tire production facility for supporting a tire.

According to a second aspect of the invention there is provided a method of supporting and conveying uncured tires at a tire production facility in a tire tray, where

- the tray is adapted for supporting at least one of said tires,

- the tray is adapted for being conveyed in a conveyor system with said at least one tire supported in the tray,

- the tray comprises a tapered geometrical form narrowing gradually towards a centre, where the centre is adapted to coincide, or substantially coincide, with a centre of said at least one tire, and wherein

- the tapered form is dimensioned and includes one or more anti-stick elements so as to support said at least one tire, and wherein said one or more anti-stick elements are provided in a material different from the tire tray, and wherein at least one of said one or more anti-stick elements are provided for making contact with said tire and for supporting said tire in said tire tray, where the method comprises

- loading said at least one tire into the tire tray, so that the tire is in contact with and at least partly supported by at least one of said one or more anti-stick elements,

- conveying said tire tray with said at least one tire in a conveying system at the tire production facility, and

- unloading the tire from the tire tray by lifting the tire from the tire tray and/or by tilting the tire tray. Thus, an improved method of supporting and conveying uncured tires at a tire production facility in a tire tray is provided. An improvement may be seen to lie therein that when supporting the tire in the tray as disclosed herein, an optimum can unexpectedly easily be found, where tires with several sizes and weights can be stably supported in the tray while conveyed, but can also easily be unloaded from the tray.

Particularly, with the tire tray and method disclosed herein, a force for

maintaining the tire tray supported by the conveyor system upon unloading the tire from the tire tray can be provided alone from forces due to the weight of the tire tray. Preferably, the tire is lifted from the tray vertically in a direction of gravity, or substantially in a direction of gravity. Preferably, the tray does not need to be actively gripped, or otherwise held down, during such removal of the tire from the tray, and still without the tray hereby being lifted from the conveyor. In order to assure that the tray does not move upon e.g. gripping and/or unloading the tire from the tray, a force for maintaining the tire tray supported by the conveyor system upon unloading the tire from the tire tray is alternatively or additionally provided by gripping the tire tray. It is to be understood that the tire tray as disclosed herein can be used for the method as disclosed herein.

By referring to an advantage herein, it must be understood that this advantage may be seen as a possible advantage provided by the invention, but it may also be understood that the invention is particularly, but not exclusively, advantageous for obtaining the described advantage.

In general the various aspects and advantages of the invention may be combined and coupled in any way possible within the scope of the invention.

These and other aspects, features and/or advantages of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 is a simplified top-view of a tire tray,

FIG. 2 is a more detailed perspective top-view of the tire tray in figure 1,

FIG. 3 is an end or side view of the tire tray in figure 2,

FIGS. 4a-4c illustrate a first embodiment of the tire tray shown in figures 1-3, with four anti-stick elements formed as strips,

FIGS. 5a-5c illustrate a second embodiment of the tire tray shown in figures 1-3, with eight anti-stick elements formed as dots,

FIGS. 6a-6c illustrate a third embodiment of the tire tray shown in figures 1-3, with a single anti-stick element formed as a circular ring,

FIGS. 7a-7c illustrate a fourth embodiment of the tire tray shown in figures 1-3, with the single anti-stick element formed as a circular ring and attached using holes in the tire tray,

FIGS. 8a-8c illustrate a fifth embodiment of the tire tray shown in figures 1-3. with 12 separately protruding, but possibly connected anti-stick elements, FIGS. 9a and 9b illustrate the angle of the tapered form,

FIGS. 10a -10c illustrate a tapered form with another angle, and alternative forms of the tapered form, and

FIGS. 11a and lib where the tire is supported in the tapered form due to different form of the tapered form and/or different form of the tire,

FIGS. 12a -12d illustrate an anti-stick element provided by a single cut-out, FIGS. 13a -13d illustrate the one or more anti-stick elements when the one or more anti-stick elements are provided as two cut-outs, and

FIG. 14 illustrates one anti-stick element when the one or more anti-stick elements are provided as four cut-outs.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a simplified top-view of a tire tray 102. The tire tray is for use in a conveying system, not shown, and being a part of a tire production facility. The tire tray is to be used for supporting an uncured and/or cured tire on an upper surface of the tray, and the tray is to be moved by a conveyor, not shown, by friction applied to a lower surface of the tray 102. It is illustrated that the tire tray is generally rectangular with an opening substantially in the middle. The opening is adapted for supporting a tire in, on or by the tray.

FIG. 2 is a more detailed and perspective top-view of the tire tray 102 in figure 1. It follows that the tray 102 has protrusions 202 and indentations 204 enabling stacking the trays on each other and/or gripping and/or otherwise handling the trays. The tray is provided with a tapered form 208 forming an opening, or hole as shown, with a gradually decreasing diameter as illustrated in the tire tray. In the shown embodiment, the tapered form 208 ends in a through-going hole 206, but may just be formed as an opening, i.e. not ending in a through-going hole. In the shown embodiment, the hole 206 is circular and substantially centred in the tire tray 102.

FIG. 3 is an end or side view of the tire tray 102 of figure 2 in the direction and along the line A-A indicated in figure 2. There is pointed at an upper surface 302, and a lower surface 304 of the tire tray 102. As illustrated in figures 4c, 5c, 6c, 7c and 8c, the tapered form 208 is provided for receiving a tire into the tire tray from above the tire tray and onto the tapered form. The tapered form provides the circular opening in the upper surface 302 of the tire tray. The tapered form is provided with a form and/or slope of its surface so as to enable the tire tray to be used as a tray for several different tire sizes. FIGS. 4a-4c illustrate a first embodiment of the tire tray shown in figures 1-3, with four anti-stick elements 402 formed as elongated members, which may be referred to as strips. The elongated members are as illustrated provided with one end towards an outer circumference towards a maximum diameter of the tapered form, and another end towards an inner circumference and towards a minimum diameter of the tapered form 208 with the centre 404. As best seen in figure 4b or 4c, the anti-stick elements protrude from the surface of the tapered form. In the illustrated embodiment, the elements extend substantially from the maximum diameter of the tapered form 208 to the minimum diameter of the tapered form.

From figure 4c, it can be seen that an uncured tire 406 is in contact with and supported by the anti-stick elements 402 at a shoulder portion 408 of the tire.

The anti-stick elements in figures 4-6 may be attached to the tapered form by gluing, welding, heating or attached to the tapered form in other suitable ways e.g. by a two-component moulding technique. In a two-component moulding technique the tray itself is provided in a first material, and the anti-stick elements are provided and moulded in a second material, and moulded into, and hereby attached to the first material. Alternatively, the elements may be attached to the tire tray using holes in the tray, such as disclosed in figures 7 and 8.

FIGS. 5a-5c illustrate a second embodiment of the tire tray shown in figures 1-3, with eight anti-stick elements 502 formed as separate dots or patches. The anti- stick elements protrude from the surface of the tapered form 208.

FIGS. 6a-6c illustrate a third embodiment of the tire tray shown in figures 1-3, with a single anti-stick element formed as a single circular ring 602. It can be seen that the form, shape and size follow the tapered form 208 and that the circular ring has substantially the same minimum and maximum diameter as the tapered form.

For illustration purposes, the ring 602, as well as the ring 702 of figure 7c, do not completely fill the tapered form, but to completely fill the whole of the tapered form may be preferred in order to use the complete tapered form for as many different sized tires 406 as possible. FIGS. 7a-7c illustrate a fourth embodiment of the tire tray shown in figures 1-3, with the single anti-stick element formed as a circular ring and attached using holes 704 in the tire tray. The tire tray is illustrated having 12 holes, but may alternatively only have two, three, four, five, six, seven or any other number of holes for attachment of the anti-stick element. It is to be understood that the element 702 is foreseen to be provided around the whole surface of the opening of the tapered form, as shown for the element 602 in figure 6. In the shown embodiment, it can be seen that at least two of the through-going holes 704 in the tapered form are at least partly used for attachment of and/or for maintaining the one or more anti-stick elements in place. It is preferred to use more than two of the holes, and possibly all of the 12 or more holes for at least partly

attachment of the anti-stick element 702. Using the through-going holes, possibly along with a particular form of the part of the anti-stick element which enters the holes, may assure a particular stable attachment and/or a manner and means for attachment that enable easy renewal or change of the one or more anti-stick elements. FIGS. 8a-8c illustrate a fifth embodiment of the tire tray shown in figures 1-3, with 12 separately protruding, but possibly connected anti-stick elements. The tire tray 102 is illustrated having 12 holes 704, but may alternatively only have two, three, four, five, six, seven or any other number of holes for attachment of the anti-stick element(s). The separately protruding elements 802 may only be protruding separately, and may be formed as a single member, though not seen in the figure. This single member is then, as an example, and e.g. when not provided using two-component moulding, attached, and possibly also fastened, from below and with the separate protruding members extending through each of the holes 704 in a direction towards, and protruding from, the upper surface of the tire tray 102.

Alternatively, several separate anti-stick elements can be provided, such as 12. Alternatively, three separate anti-stick elements can be provided with each four protruding members adapted to make contact with the tire. In all the illustrated embodiments herein, only the one or more anti-stick elements are in contact with the tire. However, embodiments where, e.g., only half of the tire is supported by anti-stick elements may be provided. In such case, removal of the tire from the tray may be started at a part of the tire where the tire is supported by one or more anti-stick elements, and the tire may be easily removed utilising a kind of peel effect.

FIGS. 9a and 9b illustrate the angle 902 of the tapered form 208. In the embodiment in figure 9a, the angle 902 is approximately 35 degrees and is from the embodiment of figure 7. In the embodiment in figure 9b, the angle 904 is approximately 50 degrees and is from the embodiments of figure 4-6. The angles are just examples for the various embodiments and these or other angles may be chosen for any of the embodiments herein. FIG. 10a illustrates a tapered form 208 with an angle 1002 in the interval 15-25 degrees, more particularly in the interval 15-20 degrees, more particularly about 15 degrees.

FIG. 10b illustrates a tapered form 208 where the decrease in diameter is provided in two or more steps in diameter as illustrated.

FIG. 10c illustrates a tapered form 208 where the tapered form and the decrease in diameter is provided by two conical forms inclined downwards towards the lower surface of the tire tray. The conical forms are shown with the same slope, angle or inclination, but may be different from each other. More than two conical forms may also be provided.

In FIGS. 11a and lib the tire 406 and 406b is supported on its lowermost edge 1102 in the tire tray 102. This edge is a portion of the tire where later a bead portion of the tire will be provided in its final form. Support of the tire at this portion of the tire can be provided when the angle of tapered form is relatively low, such as the angle of about 15 degrees shown, and/or when the tire has a relatively low profile, such as the tire 406b when compares with the tire 406. FIGS. 12a -12d illustrate an anti-stick element provided by a single cut-out 1202. As shown in figure 12a, the cut-out has an inner radius 1204 and an outer radius 1206, and an angle 1208 between ends of the cut-out 1202. The cut-out in the shown embodiment is provided from a sheet of anti-stick material, such as silicone or a mixture containing silicone, with a material thickness 1212, such as 2 mm, as illustrated in figure 12c in the cross-section A-A as indicated in the top view of figure 12d.

In figure 12b there is pointed to and illustrated a line 1210, where the two ends of the single cut-out 1202 are joined together when the cut-out is ready to be mounted to the tire tray, or when the cut-out has already been mounted on the tire tray. Figure 12b is a perspective top-view of the anti-stick element 1202, when the anti-stick element is provided by the described features and in the described manner. It is seen that the shape and form resembles that of the tapered geometrical form of the supporting surface of the tire tray. Thus, the anti- stick element can be attached to the tapered form so as to follow the tapered form as described elsewhere herein.

FIGS. 13a -13d illustrate that the one or more of the anti-stick elements can be provided by two cut-outs 1302a and 1302b as illustrated in figure 13a. From figure 13b it follows that from these two anti-stick elements, a circular anti-stick element 1304 can be formed by joining the ends of the anti-stick elements 1302a and 1302b along the lines as pointed to with the lines 1310. One of the joining lines is not immediately apparent in the figure. As seen from figures 13c and 13d, the final shape of the anti-stick element resembles that of figure 12c and 12d.

FIG. 14 illustrates one anti-stick element 1402, when the one or more anti-stick elements are provided as four cut-outs. The four cut-outs are then joined, e.g. when attached on the tire-tray, so as to give a final shape and anti-stick function as illustrated and described elsewhere herein, and particularly as described and shown in figures 12 and 13. It is understood that due to tolerances in the tapered geometrical form of the tire tray and/or of a size of the cut-out(s), a minor gap or a minor overlay may be given at the joining lines for any of the embodiments of figure 12-14. In short, there is herein disclosed a tire tray for supporting uncured tires and a method of supporting and conveying uncured tires at a tire production facility. The solution provides a stable and predetermined position of the tire which can be maintained, during conveyance of the tire in the tray, while a sticking force of the tire to the tray still enables unloading the tire from the tray while maintaining the quality of the tire and/or the tray. The tray includes a tapered geometrical form 208 having one or more anti-stick elements 402, 502, 602, 702, 802 to support the tire in the tapered form. The one or more anti-stick elements are provided in a material different from the tire tray 102, and at least one of the one or more anti- tack elements are provided for making contact with the tire 406 and for supporting the tire in the tire tray.

Although the present invention has been described in connection with preferred embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the present invention is limited only by the accompanying claims.

In this section, certain specific details of the disclosed embodiment are set forth for purposes of explanation rather than limitation, so as to provide a clear and thorough understanding of the present invention. However, it should be

understood readily by those skilled in this art, that the present invention may be practised in other embodiments which do not conform exactly to the details set forth herein, without departing significantly from the spirit and scope of this disclosure. Further, in this context, and for the purposes of brevity and clarity, detailed descriptions of well-known apparatus, circuits and methodology have been omitted so as to avoid unnecessary detail and possible confusion.

In the claims, the term "comprising" does not exclude the presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. Thus, references to "a", "an", "first", "second" etc. do not preclude a plurality. Reference signs are included in the claims however the inclusion of the reference signs is only for clarity reasons and should not be construed as limiting the scope of the claims.