The invention relates to a method for securing a retaining member to a sheet of woven fabric. The invention also relates to an assembly including a retaining member and a sheet of woven fabric. More in particular the invention relates to a method for securing a retaining member to a sheet of woven fabric and an assembly including a retaining member and a sheet of woven fabric for use as a covering for a building opening. Multiple uses exist, and depend on the type of woven fabric used. For example, certain types of woven fabric are ideal for use as an insect screen, and other types are ideal for use as a sunscreen for a building opening.

Such screens are known in the art and various methods are available for securing the retaining member to the sheet of woven fabric. The retaining member generally is used to connect the sheet of woven fabric to a frame or a roller of an insect screen or a sunscreen. As the properties of the different woven fabrics vary, there is no simple versatile method for securing the retaining member to the sheet of woven fabric. Some types of woven fabrics are susceptible to breakage; others are difficult to weld, or do not react well to standard adhesives. Some woven fabrics even melt and deform around the welding temperature required to secure the retaining member to the woven fabric.

Accordingly, it is an object of the present invention to provide a solution to these problems. It is also an object of the present invention to eliminate or ameliorate at least one of the disadvantages of the state of the art. It is a further object of the present invention to provide a simple method for securing a retaining member to multiple types of woven fabrics. More in general it is an object of the present invention to provide an improved method for securing a retaining member to a sheet of woven fabric. Alternatively it is an object of the present invention to at least provide the public with a useful choice. To this end the present invention provides a method for securing a retaining member to a sheet of woven fabric comprising the steps of: providing a sheet of woven fabric defining relatively open interstices between weft and warp yarns; providing a retaining member including an attachment body and rod-like elements protruding from the attachment body; arranging the sheet of woven fabric and the retaining member such that free distal ends of the rodlike elements pass through the interstices of the sheet of woven fabric; and joining the distal ends of the rod-like elements to the yarns of the fabric and/or to each other.

This simple method results in a reliable connection of the retaining member to the sheet of woven fabric. The rod-like elements not only provide an easy way of securing the sheet of woven fabric, but are also structurally strong. It will be clear that the rod-like elements may be joined to the yarns of the fabric, or that the rod-like elements may be joined to each other, or that the rod-like elements may be joined to both the yarns of the fabric and to each other. It will be appreciated that the term yarn as used in connection with the present invention does not exclude the use of metal threads.

Naturally in order for the retaining member to be secured to the sheet of woven fabric, a sufficient number of rod-like elements must protrude from the attachment body. Similarly, a sufficient number of distal ends of the rod-like elements must pass through the interstices of the sheet of woven fabric. It is possible that more than one distal end will pass through a single interstice. Additionally, it is conceivable that some of the distal ends of the rod-like elements do not pass through the interstices of the sheet of woven fabric at all. This may be due to poorly angled or sized rod-like elements. Furthermore, some of the distal ends of the rod-like elements may contact a waft or warp yarn and be bent back towards the attachment body.

A sufficient number of distal ends of the rod-like elements are joined to the yarns of the fabric and/or to each other. The properties of the retaining member and the sheet of woven fabric determine the number of rod-like elements, the number of distal ends passing through the interstices of the sheet of woven fabric, the number of distal ends passing through a single interstice, and the number of distal ends that are joined. Naturally a heavier fabric, larger sheet, or a heavier retaining member will require a greater number of distal ends protruding from the attachment body, such that a greater number of distal ends pass through the interstices of the sheet of woven fabric, and such that a greater number of distal ends are joined to the yarns of the fabric and/or to each other.

Optionally, the yarns of the fabric are coated. For example the coating may improve the yarns resistance to UV radiation.

Optionally, the rod-like elements protrude substantially perpendicular from a surface of the attachment body. When the rod-like elements protrude substantially perpendicular from the attachment body of the retaining member, it is easier to arrange the sheet of woven fabric and the retaining member such that the distal ends of the rod-like elements pass through the interstices of the sheet of woven fabric. Movement between the sheet of woven fabric and the retaining member only needs to be substantially perpendicular to the rod-like elements. This simplifies the production process. Alternatively, if the rod-like elements protrude from that attachment body at an angle, the step of arranging the retaining member and the sheet of woven fabric becomes more complex. However, the rod-like elements have a default direction and a better joining may occur as the rod-like elements already overlap each other and the yarns of the sheet of woven fabric prior to joining the rod-like elements to the yarns of the fabric and/or to each other.

Optionally, the rod-like elements are longer than a width of each of the interstices in the sheet of woven fabric, enabling the distal ends of the rod-like elements to pass through the interstices to a significant extent. Optionally, the length of the distal end of the rod-like elements passing through the sheet of woven fabric is longer than the width of each interstice in the sheet of woven fabric enabling the distal ends of the rod-like elements to pass sufficiently through the interstices. It is desirable that a sufficient amount of the distal ends of the rod-like elements pass through the interstices of the sheet of woven fabric. The size of the relatively open interstices of the sheet of woven fabric may vary depending on the application of the covering.

Optionally, the step of joining the distal ends of the rod-like elements includes at least one of deforming the distal ends of the rod-like elements, melting the distal ends of the rod-like elements, and bonding the distal ends of the rod like elements. Different methods can be used to join the distal ends of the rod-like elements to the yarns of the fabric and/or to each other. For example, a strip of adhesive tape could be applied to the distal ends of the rodlike elements

Optionally, the step of joining the distal ends of the rod-like elements includes melting the distal ends of the rod-like elements to the yarns of the fabric and/or to each other. Melting the distal ends of the rod-like elements is a simple and effective way of creating a secure connection between the retaining elements and the sheet of woven fabric.

Optionally, the step of joining the distal ends of the rod-like elements includes melting the distal ends of the rod-like element to the yarns of the fabric and/or to each others. Again a heating element is a simple and effective way of melting the rod-like elements.

Optionally, the step of melting the distal ends of the rod-like elements includes one of heating, thermal welding, contact welding, hot gas welding, ultrasonic welding, laser welding, high frequency welding, and induction welding. Heating can be effectuated by a heating element. Additionally, the step of joining the distal ends of the rod-like elements by melting has the advantage that while the rod-like elements are cooling the sheet of woven fabric is stretched, resulting in a taught sheet of woven fabric.

Optionally, during and after the step of joining the distal ends of the rod-like elements, the sheet of woven fabric remains substantially un deformed. If the sheet of woven fabric remains substantially undeformed, an aesthetically pleasing connection is achieved. The method chosen for joining the distal ends of the rod-like elements and the material properties of the rod-like elements and the sheet of woven fabric determine if the sheet of fabric remains undeformed.

Optionally, the melting point of the distal ends of the rod-like elements is lower than the melting point of the sheet of woven fabric. Therefore if the method chosen for joining the distal ends is melting, the sheet of woven fabric will remain substantially undeformed, resulting in a more aesthetically pleasing connection.

Optionally, the retaining member is a brush profile, and the rod-like elements are filaments made of one of mohair and nylon. Brush profiles are abundant in coverings for building openings. Typically, brush profiles are used to improve the seal between a building opening and the edge of the sheet of woven fabric and/or the retaining member. Although brush profiles are quite common, brush profiles have not previously been joined or melted for securing a retaining member to a sheet of woven fabric. Optionally, the attachment body is a strip-like element, such that commercially available brush profiles may economically be employed.

Optionally, the method further comprising the steps of: providing an insect screen frame for removably receiving the retaining member; and attaching the so obtained sheet of woven fabric to the insect screen frame. Alternative to a frame, the retaining member may also be removably received in a blind or shade roller, if so provided. The insect screen frame, or roller is designed to be engaged in a building opening. The so obtained sheet of woven fabric including the retaining member can be removably received in the insect screen frame. Therefore the so obtained sheet of woven fabric can be removed from the insect screen frame and cleaned, or stored for example during the winter months. Optionally, the insect screen frame has an undercut channel. An undercut channel provides an ideal channel for removably receiving a flat retaining member, such as a brush profile.

Optionally, the method further comprises the step of prior to the step of joining the distal ends of the rod-like elements, inserting the retaining member with its attachment body into the undercut channel of the insect screen frame. In this way, the insect screen frame holds the retaining member in an ideal position for joining the distal ends of the rod-like elements. Furthermore, the insect screen frame and the undercut channel may be designed such that the just the necessary length of the distal ends will pass through the sheet of woven fabric. This simplifies the step of joining the distal ends and the production process.

Optionally, the method further comprises the step of flattening the distal ends of the rod-like elements. The distal ends of the rod-like elements may be flattened by a roller, or long metal element. Flattening the distal ends may occur either before, after, or during the step of joining the distal ends. Flattening improves the securing of the retaining member to the sheet of woven fabric, and improves the strength of the connection, as the distal ends of the rod-like elements are joined over the top of the warp and weft yarns.

The present invention also relates to an assembly comprising a sheet of woven fabric defining relatively open interstices between weft and warp yarns and a first retaining member, wherein the first retaining member includes an attachment body and rod-like elements, wherein the rod-like elements protrude from the attachment body and free distal ends of the rod-like elements being passed through the interstices of the sheet of woven fabric, and wherein the distal ends of the rod-like elements are joined to the yarns of the fabric and/or to each other. The retaining member is reliably secured to the sheet of woven fabric by the joined distal ends of the rod-like elements.

Optionally, the assembly further comprises an insect screen frame, and wherein the insect screen frame is arranged to removably receive the first retaining member by its attachment body. The insect screen frame is designed to be engaged in a building opening. The retaining member and the sheet of fabric thereto secured can be removably received in the insect screen frame by the retaining member's attachment body. Therefore the sheet of woven fabric including the retaining member can be removed from the insect screen frame and cleaned, or stored for example during the winter months.

Optionally, the insect screen frame includes an undercut channel arranged to slideably receive the first retaining member by its attachment body. As mentioned above, an undercut channel provides an ideal channel for removably receiving a flat attachment body of the retaining member.

Optionally, the insect screen frame includes an undercut channel arranged to receive the first retaining member via a disconnectable snap connection. Depending on the shape of the retaining member, different types of connections between the retaining member and the undercut channel can be realized. For example, the retaining member may be provided with outwardly elastic arms, which can elastically expand in the undercut channel, resulting in a snap connection.

Optionally, the assembly further comprises a second retaining member, wherein the second retaining member includes an attachment body and rod- like elements, wherein the rod-like elements of the second retaining member protrude from the attachment body of the second retaining member and free distal ends of the rod-like elements pass through the interstices of the sheet of woven fabric, and wherein the distal ends of the rod-like elements of the second retaining member are joined to the yarns of the fabric and /or to each other. Optionally, the first and second retaining members are positioned on the same side of the sheet of woven fabric. Optionally, the first retaining member retains a first longitudinal edge of the sheet of woven fabric, and the second retaining member retains a second longitudinal edge of the sheet of woven fabric, and wherein the first longitudinal edge is opposite and parallel to the second longitudinal edge. Although the sheet of woven fabric may be retained by a single retaining member, two retaining members offers better support to the sheet of woven fabric. Depending on the application or shape of the sheet of woven fabric, it may be necessary to secure more than two retaining members to the sheet of woven fabric. For example four retaining members provide maximum support to a rectangular sheet of woven fabric.

Optionally, the assembly comprises a second sheet of woven fabric defining relatively open interstices between weft and warp yarns and wherein the distal ends of the rod-like elements protruding from the attachment body pass through the interstices of the first sheet of woven fabric and the second sheet of woven fabric, and wherein the distal ends of the rod-like elements are joined to the yarns of the fabric of the first sheet of woven fabric, the yarns of the fabric of the second sheet of woven fabric, and/or to each other. In this way two sheets of woven fabric can be connected together. In addition to connecting the two sheets of woven fabric, the retaining member additionally provides support. It is conceivable that an application may require multiple standard sized sheets of woven fabric to be connected together and to be supported, for example, in order to cover a large building opening.

Optionally, the distal ends of the rod-like elements are at least one of deformed, melted, or bonded to the yarns of the fabric and/or to each other. As mentioned above different types of methods can be used to join the distal ends of the rod-like elements to the yarns of the fabric and/or to each other.

Optionally, the distal ends of the rod-like elements are melted to the yarns of the fabric and/or to each other. As mentioned earlier, melting the distal ends of the rod-like elements is a simple and effective way of creating a secure connection between the retaining elements and the sheet of woven fabric.

Optionally, the distal ends of the rod-like elements are melted by one of heating, thermal welding, contact welding, hot gas welding, ultrasonic welding, laser welding, high frequency welding, and induction welding. Optionally, the distal ends of the rod-like elements are melted by a heating element.

Optionally, the sheet of woven fabric is substantially undeformed. The technique chosen for joining the distal ends of the rod-like elements and the material properties of the rod-like elements and the sheet of woven fabric determine if the sheet of fabric is substantially undeformed.

Optionally, the sheet of woven fabric is woven polypropylene yarn including a liquid crystalline polymer. The polypropylene yarn is made UV- resistant through the addition of the liquid crystalline polymer. Also

optionally, the sheet of woven fabric can be a PVC encased woven glass fibre screen fabric.

Optionally, the rod-like elements are made of plastic. Optionally, the rod-like elements are nylon fibers. Optionally, the rod-like elements are made of mohair. Plastics, nylon fibers, and mohair are well suited as rod-like elements and have the necessary properties for melting the distal ends and securing the sheet of woven fabric to retaining member. Moreover, in practice the sheet of woven fabric is chosen such that the melting point of the material of the rod-like elements, is less than that of the sheet of fabric. Therefore the sheet of fabric is not deformed or damaged yet it is well secured to the retaining member. It is conceivable that the rod-like elements are made up of multiple materials having different properties. For example, the distal end of the rod-like elements may be made from a material with a low melting point, and the remaining portion of the rod-like elements may be made from a strong material with a higher melting point.

Optionally, the retaining member is a brush profile. As mentioned above, brush profiles are abundant in coverings for building openings.

Typically, brush profiles are used to improve the seal between a building opening and the edge of the sheet of woven fabric and/or the retaining member. Although brush profiles are quite, brush profiles have not previously been used to secure a retaining member to a sheet of woven fabric. The present invention also relates to a kit of parts for constructing an insect screen including: a sheet of woven fabric having a first and a second longitudinal edge; a first retaining member including an attachment body and rod-like elements, wherein the rod-like elements protrude from the attachment body; and a second retaining member including an attachment body and rodlike elements, wherein the rod-like elements protrude from the attachment body for practising the method according to the invention and for obtaining the assembly according to the invention. Optionally, the kit of parts further includes a heating element. Optionally, the kit of parts further includes additional retaining members. Thus homeowners can purchase the kit of parts and construct their own coverings for building openings.

Presently, the invention will be further elucidated on the basis of a number of exemplary embodiments as shown in the accompanying drawings, in which:

Figure 1 is a schematic representation of a sheet of woven fabric; Figure 2 is a perspective view of a retaining member including rodlike elements;

Figure 3 is a schematic side view of a sheet of woven material and a retaining member arranged such that the distal ends of the rod-like elements pass through the interstices of the sheet of woven fabric;

Figure 4 is a cross sectional view of an insect screen frame;

Figure 5 A-D is a cross sectional view of a method for securing a retaining member to a sheet of woven fabric according to an embodiment of the invention;

Figure 6 is a schematic representation of an assembly according to an embodiment of the invention;

Figure 7 is a cross sectional view of an embodiment according to the invention including an insect screen frame arranged to receive the retaining member via a disconnectable snap connection; and Figure 8 is a schematic cross sectional view of an assembly according to an embodiment of the invention comprising a first sheet of woven fabric and a second sheet of woven fabric

In a first embodiment, the method for securing a retaining member to a sheet of woven fabric will be discussed. First a sheet of woven fabric is provided. Figure 1 shows a schematic representation of the sheet of woven fabric 2. The sheet of woven fabric 2 is depicted here as a rectangle. In practice the sheet of woven fabric may take on any shape desired. Examples of a warp yarn 3 and a weft yarn 5 are given in Figure 1. The relatively open interstice 4 is formed by boarding warp and weft yarns. For the present invention, it is not necessary that the warp 3 and weft 5 yarns are straight or evenly spaced.

Additionally, it is not required that the interstice is rectangular. Other shapes such as hexagons or triangles are also possible. In this example, interstices 4 are small enough to prevent a large variety of insects from passing through the fabric, yet large enough for one or more rod-like elements 8 to pass through.

Figure 2 is a perspective view of a retaining member 6 including an attachment body 10 and rod-like elements 8. The rod-like elements 8 protrude from the attachment body 10 of the retaining element 6. In this example the retaining member 6 is a commercially available brush profile common to the building opening covering industry. Due to the inexpensive nature of the brush profile, the rod-like elements are not all the same length and are, in this example, nylon fibers. The nylon fibers have a lower melting point than the sheet of woven fabric 2 Examples of materials that can be connected using the technique of the invention are virtually unlimited. Provided that the rod-like elements of the brush profile are thermoplastic artificial fibers the sheet of woven fabric may also be of natural fibers. It is also not necessary that the rodlike elements and the fibers of the sheet of fabric are connected by melting. In a situation where only the free ends of the rod-like elements are melted to one another, the fibers of the sheet of fabric can also be locked in, without being melted or otherwise connected to the brush profile. Though not required by the present invention, in the example according to Figure 2 rod-like elements 8 protrude substantially perpendicular from the attachment body 10 of retaining member 6.

Figure 3 shows the step of arranging the sheet of woven fabric 2 and the retaining member 6 such that the distal ends of the rod-like elements pass through the interstices 4 of the sheet of woven fabric. For the working of the present invention, it is not necessary that the distal ends of all rod-like elements 8 of the retaining member 6 pass through the interstices 4 of the sheet of woven fabric 2. A rod-like element may not pass through the

interstices of the sheet of woven fabric for different reasons. One reason could be that due to the inexpensive nature of the retaining element, not all rod-like elements 8 are of equal length, rod-like element 16 in Figure 3. Another reason could be that the rod-like element is deflected by either a warp 3 or weft 5 yarns, rod-like element 14 in Figure 3. It is also possible that not every interstice 4 in an area of the sheet of woven fabric defined by the contour of the retaining member 6 has a distal end of a rod-like element passing through it, interstice 18 Figure 3.

The number of distal ends of the rod-like elements 8 and the length I of the rod-like element passing through the sheet of woven fabric 2 necessary to support the sheet of woven fabric depends on the specific application and material properties of the retaining member 6 and sheet of woven fabric. Some woven fabrics are heavier than others and may require that more distal ends of the rod-like elements pass through the sheet of fabric. Likewise certain material choices for the rod-like elements 8 and retaining member 6, will secure the retaining member 6 better to the sheet of woven fabric 2.

Next, the distal ends of the rod-like elements 8 are joined to the yarns of the fabric and/or to each other. In this example the distal ends of the rod-like elements 8 are joined to both the yarns of fabric and to each other through hot gas welding. Hot gas, in this example air, is blown on the distal ends of the rod-like elements 8. The distal ends begin to melt, and the rod-like elements 8, in this case, nylon fibers melt to the sheet of woven fabric 2 and to each other. After a substantial amount of the fibers are melted, the nylon fibers and screen are allowed to cool. The melted fibers secure the retaining member 6 to the sheet of woven fabric 2.

A second embodiment including an insect screen frame will now be discussed. The insect screen frame comprises two frame sections 20. A cross section of an individual frame section 20 is shown in Figure 4. Each frame section 20 has an undercut channel 22 for removably receiving retaining member 6. A method for securing retaining members 6 A and 6B to the sheet of woven fabric 2 according to the second embodiment is depicted in Figures 5A- 5D.

A sheet of woven fabric 2 is provided in Figure 5A. Additionally, an insect frame comprising two frame sections 20A and 20B is provided. Note frame sections 20A and 20B originate from individual frame section 20. Frame section 20A is rotated 180 with respect to Frame section 20B. An additional frame brace 42 and 44, not pictured in Figures 5A-5D for clarity when describing the method, but shown with assembly 40 in Figure 6, may be added to the ends of frame sections 20A and 20B to maintain the distance between frame sections 20A and 20B. Next retaining members 6A and 6B are inserted into the respective undercut channels 20A and 20B. Retaining member 6A and 6B have the same properties as retaining member 6, discussed in the first embodiment. Typically retaining member 6A and 6B are cut to match the length of frame sections 20A and 20B. The shape of retaining member 6A and 6B allows the retaining member 6A and 6B to be easily inserted into undercut channels 22A and 22B, yet are securely held in place by the undercut channels 22A and 22B.

Next the sheet of woven fabric 2 is positioned above the insect screen frame 20A, 20B and is lowered in the direction of arrows 24, substantially perpendicular to rod-like elements 8A and 8B, until the sheet of woven fabric 2 comes to rest on the insect screen frame. If the rod-like elements 8A and 8B did not protrude substantially perpendicular to the attachment body of the retaining member, then it might have been necessary to lower the sheet of woven fabric 2 at an angle such that the distal ends of the rod-like elements 8A and 8B can pass through the sheet of woven fabric.

The undercut channels 22A and 22B are designed such that a desired length of the rod-like element extends past the sheet of woven fabric 2. In other words the depth of undercut channels 22A and 22B and the length of rod-like elements 8A and 8B determines the amount of rod-like element making up the distal ends to be joined.

At this point, heating element 30 is preheated to the melting point of the rod-like elements, in this embodiment the rod-like elements 8A and 8B are made from mohair. Additionally, in this embodiment the melting point of the rod-like elements is lower than the melting point of the sheet of woven fabric 2. Next heating element 30 is lowered in the direction of arrows 26. Heating element 30 causes the rod-like elements 8A and 8B to melt and to join to the yarns of fabric and to each other. Ideally, all distal ends of rod-like elements 8 A and 8B are melted simultaneously by heating element 30. However, it is conceivable that the heating element is smaller than the length of the retaining element and that the heating element must be moved along the distal ends of the rod-like elements. Or, that first the rod-like elements 8A of retaining member 6A are melted followed by the melting of rod-like element 8B of retaining member 6B.

Once substantially all of the rod-like elements have been melted, heating element 30 is lifted away, in the direction of arrows 28, from newly assembled assembly 40. The joined rod-like elements 8A form connection 32A and the joined rod-like elements 8B form connection 32B. The cooling of connections 32A and 32B results in a natural tightening up of the sheet of woven fabric 2. Therefore assembly 40 has a taught sheet of woven fabric 2.

Due to the difference in melting points between the rod-like elements 8A and 8B and the sheet of woven fabric 2, the sheet of woven fabric remains substantially undeformed. The heating element 30 does not melt or deform the sheet of woven fabric.

In the case of an insect screen frame, four frame sections and four retaining members may be used in order to provide the best building covering possible. Similarly in the assembly 40, frame braces 42 and 44 may be provided with brush profiles, not intended to be joined, but to better seal off the insect screen frame.

Figure 7 is a cross sectional view of an embodiment according to the invention. In this embodiment an insect screen frame is arranged to receive the retaining member via a disconnectable snap connection. It is noted that insect screen frame section 50 differs slightly from frame section 20 in the previous embodiments. Frame section 50 also includes an undercut channel

52. In this embodiment retaining member 56 has rod-like elements 58 made of thermoplastic resin. Retaining member 56 is also provided with outwardly elastic arms 58A and 58B. As shown in Figure 7, the outwardly elastic arms elastically expand in the undercut channel 52, resulting in a disconnectable snap connection.

Figure 8, is a schematic cross sectional view of an assembly according to an embodiment of the invention comprising a first sheet of woven fabric 2 A and a second sheet of woven fabric 2B. This first and second sheet of woven fabric 2A, 2B are connected together and supported by retaining member 6 and rod-like elements 8. In this embodiment rod-like elements 8 have been melted by a heating element causing the rod-like elements to join to the yarns of the first sheet of woven fabric 2A, to the yarns of the second sheet of second sheet of fabric, and to each other. The resulting connection 32 connects two standard sized sheets of woven fabric, for example in order to cover a large building opening.

Accordingly a method is disclosed for securing a retaining member to a sheet of woven fabric. This method comprising the steps of: providing a sheet of woven fabric 2 defining relatively open interstices between weft and warp yarns; providing a retaining member 6 including an attachment body 10 and rod-like elements 8 protruding from the attachment body 10; arranging the sheet of woven fabric 2 and the retaining member 6 such that free distal ends of the rod-like elements 8 pass through the interstices 4 of the sheet of woven fabric 2; and joining the distal ends of the rod-like elements 8 to the yarns 3, 5 of the fabric and/or to each other.

It is thus believed that the method and assembly of the present invention will be apparent from the foregoing description and drawings appended thereto. It will be clear to the skilled person that the invention is not limited to any embodiment herein described and that modifications are possible which should be considered within the scope of the appended claims. In the claims, any reference signs shall not be construed as limiting the claim. The term 'comprising' and 'including' when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Thus the expression 'comprising' as used herein does not exclude the presence of other elements or steps in addition to those listed in any claim. Furthermore, the words 'a' and 'an' shall not be construed as limited to 'only one', but instead are used to mean 'at least one', and do not exclude a plurality. Features that are not specifically or explicitly described or claimed may be additionally included in the structure of the invention within its scope. Expressions such as: "means for ..." should be read as: "component configured for ..." or "member constructed to ..." and should be construed to include equivalents for the structures disclosed. The use of expressions like: "critical", "preferred", "especially preferred" etc. is not intended to limit the invention. Additions, deletions, and modifications within the purview of the skilled person may generally be made without departing from the spirit and scope of the invention, as is determined by the claims.