FIELD OF THE INVENTION

[0001] The present invention relates to fabrics. More particularly, the present invention relates to a patterned fabric having hydrophihc thread and hydrophobic thread.

BACKGROUND OF THE INVENTION

[0002] The Jacquard process enables automated patterning of woven or knitted fabrics. For example, threads of when two or more colors of threads, or other different types of threads, may be woven or knitted together on an automated loom or knitting machine. A pattern that is to be formed by the threads of different types may be encoded mechanically (e.g., on cards) or electronically. The machine may be controlled in accordance with the encoded pattern such that one or another of the colors is visible on at least one side of the fabric (e.g., on a side that is intended to be visible). Fabric that is patterned by the Jacquard process may be incorporated into a garment, tablecloth, curtain, upholstery, or otherwise.

SUMMARY OF THE INVENTION

[0003] There is thus provided, in accordance with an embodiment of the present invention, a textile fabric including: hydrophobic thread made of a hydrophobic material; and hydrophihc thread combined by a Jacquard process with the hydrophobic thread to form a pattern of contiguous regions where hydrophihc thread overlies the hydrophobic thread, and contiguous regions where the hydrophobic thread overlies the hydrophilic thread on at least one side of the fabric, wherein upon exposure of the fabric to a staining liquid, the liquid is absorbed only by the hydrophihc thread so as to enhance visibility of the regions of overlying hydrophihc thread against the regions of overlying hydrophobic thread.

[0004] Furthermore, in accordance with an embodiment of the present invention, the hydrophobic material includes a plastic.

[0005] Furthermore, in accordance with an embodiment of the present invention, the hydrophobic material includes polytetrafluoroethylene. [0006] Furthermore, in accordance with an embodiment of the present invention, the hydrophilic thread is selected from a group of threads consisting of cotton, silk, wool, bamboo and linen.

[0007] Furthermore, in accordance with an embodiment of the present invention, the Jacquard process includes knitting or weaving.

[0008] There is further provided, in accordance with an embodiment of the present invention, a method for producing a patterned textile fabric, the method including: providing a machine configured to combine hydrophobic thread made of hydrophobic material with hydrophilic thread by a Jacquard process, the machine programmed to combine the hydrophilic thread with the hydrophobic thread to form a predetermined pattern of contiguous regions where hydrophilic thread overlies the hydrophobic thread, and contiguous regions where the hydrophobic thread overlies the hydrophilic thread; and; operating the machine to combine the hydrophilic thread with the hydrophobic thread by the Jacquard process to form the pattern on at least one side of the fabric, whereby if the outer side is exposed to a staining hquid, the hquid is absorbed by the hydrophilic thread to enhance visibility of the regions of overlying hydrophilic thread against the regions of overlying hydrophobic thread.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order for the present invention, to be better understood and for its practical applications to be appreciated, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals.

[0010] Fig. 1 schematically illustrates a patterned fabric of hydrophilic thread and hydrophobic thread, in accordance with an embodiment of the present invention.

[0011] Fig. 2 schematically illustrates a staining liquid on the fabric shown in Fig. 1.

[0012] Fig. 3 schematically illustrates staining by the staining hquid of the fabric shown in Fig. 2.

[0013] Fig. 4 is a photograph of a fabric of knitted hydrophilic thread and hydrophobic thread after exposure to a staining hquid. [0014] Fig. 5 is a flowchart depicting a method for producing a hydrophilic and hydrophobic patterned fabric, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0015] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the invention.

[0016] Although embodiments of the invention are not limited in this regard, discussions utilizing terms such as, for example, "processing," "computing," "calculating," "determining," "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information non- transitory storage medium (e.g., a memory) that may store instructions to perform operations and/or processes. Although embodiments of the invention are not limited in this regard, the terms "plurality" and "a plurality" as used herein may include, for example, "multiple" or "two or more". The terms "plurality" or "a plurality" may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. Unless otherwise indicated, the conjunction "or" as used herein is to be understood as inclusive (any or all of the stated options). [0017] In accordance with an embodiment of the present invention, a textile fabric includes hydrophobic thread and hydrophilic thread that are automatically combined, e.g., woven, knitted, or otherwise combined together, to form a patterned textile fabric. For the sake of clarity and simplicity, any such process of combining two or more types of threads to form a patterned fabric (e.g., including weaving, crocheting, tapestry, or other process that may be automated so as to be automatically controllable to form a pattern) may be referred to the herein as "knitting", and the produced fabric as "knitted". Any reference herein to "knitting" or "knitted" should thus be understood as referring to any such automatable process of combining threads to produce a patterned fabric. Any reference herein to thread should be understood as including yarn or any spun, twisted, braided, extruded, or otherwise produced elongated flexible material that may be knitted (as defined above) to form a two-dimensional fabric.

[0018] Any reference herein to a pattern or background should be understood as referring to a contiguous region of the fabric in which one type of thread overlies one or more other types of threads with which it is knitted on at least one side of the fabric such that the overlying thread is visible in that region on at least that one side. In some cases (e.g., depending on the type of knitting process), the pattern that is visible on one side of the fabric may be the negative of the pattern on the other side (e.g., a type of thread that overlies another on one side is overlain by the other on the other side). In other cases, the same pattern may be visible on both sides of the fabric, or one side of the fabric may lack contiguous regions of an overlying type of thread.

[0019] As used herein, in order to simplify the discussion, a region in which hydrophilic thread overlies hydrophobic thread is referred to herein as a part of a pattern. A region in which hydrophobic thread overlies hydrophilic thread is referred to herein as a background. Thus, pattern regions need not refer to discrete or isolated elements, or to repeating elements or motifs. A pattern, as used herein, may, in some cases, refer to a region that is contiguous throughout the area of the fabric. Similarly, a background region need not refer to a single contiguous region, but may refer to one or more noncontiguous regions of overlying hydrophobic thread.

[0020] As used herein, a hydrophobic thread is composed entirely of a hydrophobic material, and not of a hydrophilic material that is coated or otherwise treated with a hydrophobic material. The hydrophobic thread may include a plastic thread or other thread of a material that does not attract or bond to water molecules, or to other liquids whose molecules are capable of hydrogen bonding or are at least partially polarized. For example, the thread may be made of polytetrafluoroethylene (PTFE, also known as Teflon™), or another material. A hydrophilic thread may include cotton, silk, wool, bamboo, linen, or another thread material that attracts or bonds to water or to other liquids whose molecules are capable of hydrogen bonding or are at least partially polarized.

[0021] In some cases, a patterned fabric may be intended for viewing from a preferred side. For example, the preferred side may be intended to face outward when the fabric is incorporated into a garment that is being worn. In other examples, the preferred side may face outward when incorporated into furniture as upholstery, may be intended to face outward and be visible when incorporated into and used as a tablecloth, bed linen, rug, curtain, or other article that has one side that is intended for display.

[0022] Typically, the hydrophilic thread and hydrophobic thread are automatically combined to form a patterned fabric of separate background and pattern regions. For example, such automatic combining may be controlled to form the pattern by application of a Jacquard process. In a Jacquard process, a pattern to be created both the combining of two types of thread (hydrophilic and hydrophobic in the present case, different colors or otherwise different types in other cases) is encoded in a mechanically readable medium (e.g., as punched holes or raised bosses on paper or cardboard sheets, cards, or another medium, or otherwise) or an electronically readable medium (e.g., on a computer data storage device or memory, on a computer-readable data storage medium, at a remote or otherwise).

[0023] A Jacquard knitting machine may be configured to read the encoded pattern. The knitting machine may then cause the hydrophilic thread to overlie the hydrophobic thread in pattern regions of the fabric, and to be overlain by the hydrophobic thread at points within the background. Thus, the pattern made of overlying hydrophilic thread may appear to be raised or may otherwise differ in appearance (in some cases subtly, e.g., with a difference in texture) against the regions of the fabric that form the background of overlying hydrophobic thread. In some cases, when an opposite side of the fabric is viewed, the regions of pattern and background may be identical, may be interchanged, or no patterning may be distiguishable.

[0024] In some cases, the hydrophilic thread may have an appearance that is similar to that of the hydrophobic thread. For example, the hydrophilic thread and hydrophobic thread may have similar colors (e.g., typically white, gray, or colorless), similar shininess, or other visible characteristics. Thus, the pattern may not be readily visible against the background under at least some lighting conditions (e.g., may be visible only under close examination or as a subtle change in texture).

[0025] A staining liquid (e.g., including water, alcohol, or another Uquid that behaves like water with regard to the hydrophilic thread) may come into contact with the fabric. For example, a staining liquid may include a clear or almost clear Uquid, such as water, white wine, soda, clear soft drink, or another similar clear Uquid. As another example, the staining liquid may include a colored Uquid, such as coffee, tea, red wine, colored fruit juice, ink, or another colored Uquid.

[0026] When the staining Uquid comes into contact with the hydrophilic thread, the liquid may be absorbed by the hydrophilic thread. For example, contact with a colored liquid may cause the hydrophilic thread to absorb the coloring of the Uquid. In the case of a clear or colorless liquid, the appearance of the hydrophilic thread may be altered permanently (e.g., by trace dissolved colorants), or temporarily (e.g., until the fabric is fuUy dried) by interaction of the clear Uquid with the hydrophilic thread.

[0027] On the other hand, the staining Uquid that comes into contact with the hydrophobic thread of the background is not absorbed. For example, the staining liquid may remain on the surface of the hydrophobic thread until removed (e.g., by being wiped off or wipe dry by use of an absorbent cloth). As another example, the staining liquid on the background of hydrophobic thread, or may migrate from the hydrophobic thread background to the hydrophilic thread of the pattern, e.g., assisted by gravity, air currents, capillary action, or otherwise.

[0028] Thus, exposure of the fabric to the staining liquid may enhance the visibility of the pattern of hydrophilic thread against the background of hydrophobic thread. The appearance of the hydrophilic thread of the pattern may be permanently altered by the staining Uquid, or may be temporarily altered (e.g., until evaporation, cleaning, or other removal of remains of the liquid). On the other hand, the background of hydrophobic thread retains its original appearance. Thus, the visibility of the pattern against the background may be enhanced by contact with the staining liquid.

[0029] Incorporation into an article of such a fabric with a pattern of hydrophilic thread on a background of hydrophobic thread may be advantageous over use of another type of fabric in the article. For example, a fabric that is made entirely of hydrophilic thread when exposed to a staining liquid could form an amorphous stain over the fabric. Such an amorphous stain would likely be recognized as a stain by even a casual observer. Thus, an owner of an article whose hydrophilic fabric is so stained may be reluctant or embarrassed to continue to use or display the article. Removal of such a stain to enable future use or display may be difficult or impossible, e.g., depending on one or more of the type of fabric, the structure of the article that incorporates the fabric, the nature of the staining liquid, the period of time before the stain is cleaned, or on other factors. For example, effective cleaning of a stain from some types of articles may risk damaging the fabric or the article. On the other hand, use of a fabric that is produced from hydrophobic thread alone could often not be suitable or desirable for use for many purposes. For example, an article of entirely hydrophobic fabric may, depending on the particular type of article or its intended use, may have an undesirable appearance, may be uncomfortable to the touch, may be stiff or otherwise unwieldy in handling, or may be otherwise unsuitable or undesirable. A hydrophobic layer that is applied to (e.g., sprayed onto, printed onto, or otherwise applied to) a hydrophilic material may disintegrate or wear off with use or exposure to some environmental conditions (e.g., sunlight or other light, temperature extremes, laundry detergents or substances, folding, bending, friction, or other mechanical stress, or other conditions).

[0030] In the other hand, the appearance of a fabric with a knitted pattern of hydrophilic thread on a background of hydrophobic thread may be enhanced after exposure to a staining liquid. Elements of the pattern of hydrophilic thread may be designed to have an esthetically pleasing effect when stained by the staining liquid. Therefore, an article that incorporates the fabric may continue to be usable, and its appearance may, in some cases, be rendered more pleasing, after staining. [0031] Fig. 1 schematically illustrates a patterned fabric of hydrophilic thread and hydrophobic thread, in accordance with an embodiment of the present invention.

[0032] Hydrophilic and hydrophobic patterned fabric 10 is shown in Fig. 1 as viewed from an outer side. In hydrophobic fabric background 12, hydrophobic thread overlies the hydrophilic thread such that only the hydrophobic thread is visible.

[0033] Hydrophilic and hydrophobic patterned fabric 10 is patterned with hydrophilic pattern 11 of a plurality of solid pattern forms 14 and outlined pattern forms 16. In the example shown, hydrophilic pattern 11 includes both solid pattern forms 14 and outlined pattern forms 16. In the example shown, solid pattern forms 14 and outlined pattern forms 16 are triangular.

[0034] Each solid pattern form 14 includes a contiguous region of visible hydrophilic thread. For example, a solid pattern form 14 of hydrophilic thread may be produced by knitting in which, in the region of solid pattern form 14, hydrophilic thread overlies the hydrophobic thread with which it is knitted.

[0035] Each outlined pattern form 16 includes a contiguous border region that fully (e.g., forming a closed border) or partially (e.g., forming a border with one or more gaps) surrounds a surrounded pattern background region 18. The border region of outlined pattern form 16 includes a contiguous region (e.g., each segment of which has a width that is visibly smaller than its length, or otherwise) of visible hydrophilic thread. For example, a border region of outlined pattern form 16 of hydrophilic thread may be produced by knitting in which, in the border region of outlined pattern form 16, hydrophilic thread overlies the hydrophobic thread with which it is knitted. Each surrounded pattern background region 18 includes a contiguous region of visible hydrophobic thread. For example, a solid surrounded pattern background region 18 of hydrophobic thread may be produced by knitting in which, in the region of surrounded pattern background region 18, hydrophobic thread overhes the hydrophilic thread with which it is knitted. (In accordance with the above explanations regarding usage herein of the terms "pattern" and "background", interchanging the visibility of hydrophilic and hydrophobic threads would cause regions 11, 14, and 16 to function as background regions, and regions 12 and 18 to function as pattern regions.) [0036] When an opposite side of hydrophiUc and hydrophobic patterned fabric 10 is viewed, the same pattern may be visible, no pattern may be visible, or the composition of the fabric background and of pattern forms, such as solid pattern forms 14, outlined pattern forms 16, and surrounded pattern background regions 18, may be reversed. For example, on the opposite side of hydrophilic and hydrophobic patterned fabric 10, the fabric background and surrounded pattern background regions 18 may include contiguous regions of visible hydrophilic thread (functioning as pattern regions). On the other hand, solid pattern forms 14 and the border regions of outlined pattern forms 16 may include contiguous regions of visible hydrophobic thread (functioning as background regions).

[0037] A hydrophilic and hydrophobic patterned fabric 10 may be exposed to a staining liquid.

[0038] Fig. 2 schematically illustrates a staining liquid on the fabric shown in Fig. 1.

[0039] In the example shown, a stain region 20 of hydrophilic and hydrophobic patterned fabric 10 has been exposed to a staining Uquid. Typically, the staining liquid to which stain region 20 has been exposed has been spilled onto hydrophilic and hydrophobic patterned fabric 10, or may have otherwise unintentionally or haphazardly been brought into contact with hydrophilic and hydrophobic patterned fabric 10 (e.g., by deliberate or unintentional spraying, throwing, or splashing of the staining liquid). For example, hydrophilic and hydrophobic patterned fabric 10 may have been incorporated into a chair, sofa, or other piece of furniture onto which a colored or colorless liquid (e.g., a beverage) was spilled. As another example, hydrophiUc and hydrophobic patterned fabric 10 may have been incorporated into a garment that was being worn when the staining Uquid was spilled or otherwise brought into contact with hydrophiUc and hydrophobic patterned fabric 10.

[0040] If a staining Uquid were to come into contact with a region of similar to stain region 20 of a fabric that was completely formed from hydrophiUc thread, the result could be an amorphous stain, e.g., having the shape of stain region 20. In the case of a colored staining Uquid, the result could be a colored blotch or stain. Similarly, a stain of a generaUy colorless Uquid on such a hydrophilic fabric could cause a similarly shaped discontinuity in appearance of the fabric. In either case, such a colored region or discontinuous region could be readily recognizable as an unintentional stain or discoloration. In many cases, such a colored region or discontinuous region could be widely deemed as esthetically unappealing and in need of removal or other cleaning.

[0041] When a stain region 20 of hydrophilic and hydrophobic patterned fabric 10 is exposed to a staining liquid, the staining liquid may be absorbed selectively by the hydrophilic thread of hydrophilic pattern 11. On the other hand, the staining liquid may be repelled by (e.g., may not be absorbed by such that the liquid may flow off of) the hydrophobic thread of hydrophobic fabric background 12. Thus, the staining liquid may migrate from the hydrophobic thread of hydrophobic fabric background 12 and surrounded pattern background region 18 to the hydrophilic thread of solid pattern forms 14 and outlined pattern forms 16 of hydrophilic pattern 11. The migration may include spontaneous migration (e.g., due to surface tension or capillary forces that attract the staining liquid from the hydrophobic thread to the hydrophilic thread as the staining hquid is absorbed by the hydrophilic thread), or may be assisted by other factors (e.g., gravity on a sloped surface or on a surface that is temporarily sloped by bending or distortion of the surface, by vibration, air movement, by wiping, or by other factors).

[0042] As a result of the exposure to the staining liquid, parts of hydrophilic pattern 11, e.g., within or near stain region 20 of hydrophilic and hydrophobic patterned fabric 10, may absorb the staining hquid, thus changing their appearance. On the other hand, the appearance of hydrophobic fabric background 12 and the hydrophobic thread of surrounded pattern background region 18 may remain unaffected by the staining liquid.

[0043] Fig. 3 schematically illustrates staining by the staining hquid of the fabric shown in Fig. 2.

[0044] In stained fabric 30, the hydrophilic thread in parts of hydrophilic pattern 11 that are within stain region 20 have absorbed the staining hquid to form stained pattern 31. For simplicity, the boundaries of stained pattern 31 are shown as sharply defined and as coinciding with the boundaries of stain region 20. In an actual fabric, where the staining liquid may diffuse within the hydrophilic thread of hydrophilic pattern 11, or may otherwise cause the boundaries of stained pattern 31 to not be sharply defined. Rather, in the case of an actual fabric, hydrophilic thread within the interior of stained pattern 31 may be deeply stained (e.g., the color of the hydrophilic thread within the interior stained pattern 31 having a maximum saturation or a greatest change in appearance). The degree of staining (e.g., as quantifiable as a change in color saturation, or otherwise as a change in appearance), e.g., along a line segment that extends from the interior of stained pattern 31 to a point outside of stained pattern 31 may gradually change from deepest staining to weakest staining (e.g., no change in color or appearance, lowest saturation of coloring, or other smallest change in appearance).

[0045] Within stained pattern 31, the hydrophilic thread in solid pattern forms 14 has been stained to form stained solid pattern forms 32. Similarly, the hydrophilic thread in outlined pattern forms 16 has been stained to form stained outlined pattern forms 34.

[0046] On the other hand, the appearance of the hydrophobic thread in hydrophobic fabric background 12 and in surrounded pattern background regions 18 within stained pattern 31remains the same as outside of stained pattern 31.

[0047] Thus, instead of the staining liquid producing an amorphous stain, a colored or otherwise visible pattern may become visible. Hydrophilic pattern 11 may be designed such that in the event of exposure of hydrophilic and hydrophobic patterned fabric 10 to a staining liquid, stained pattern 31 may become visible.

[0048] An article that incorporates hydrophilic and hydrophobic patterned fabric 10 may be continue to be used in an exposed manner, and need not be removed or covered, under circumstances where there is increased possibility of spilling or other exposure to staining liquids (such as dinners or parties, visits by children, or other circumstances). Hydrophilic and hydrophobic patterned fabric 10 may be designed with a hydrophilic pattern 11 that is selected or designed to be esthetically pleasing (e.g., to a designer, to a user, or to a viewer of stained fabric 30) when hydrophilic pattern 11 is exposed to a staining liquid to form a visible stained pattern 31. An article that incorporates such an esthetically pleasing stained fabric 30 after exposure to a staining liquid may continue to be used and displayed without embarrassment.

[0049] Fig. 4 is a photograph of a fabric of knitted hydrophilic thread and hydrophobic thread after exposure to a staining liquid.

[0050] Stained fabric 40 may be formed by knitting of hydrophilic thread and hydrophobic thread using a Jacquard process. Part of stained fabric 40 has been exposed to a staining liquid. Regions of stained fabric 40 that were not exposed to the staining liquid are patterned with unstained pattern 41. Regions of stained fabric 40 that had been exposed to the staining liquid are patterned with stained pattern 51.

[0051] In the example shown, viewing an outer side of stained fabric 40, hydrophobic background threads 42 are visible throughout the background regions of stained fabric 40 and in regions surrounded by unstained outlined pattern forms 44 and by stained outlined pattern forms 54. Unstained hydrophilic thread is visible within unstained solid pattern forms 44 and in unstained outlined pattern forms 44 of unstained pattern 41. Stained hydrophilic thread is visible in stained solid pattern forms 52 and in stained outlined pattern forms 54 of stained pattern 51.

[0052] In transition regions of stained fabric 40 at the boundary of stained pattern 51, partially stained solid pattern forms 56 and partially stained outlined pattern forms 58 may, in some cases, exhibit a gradual transition from fully stained hydrophilic thread to unstained hydrophilic thread.

[0053] Fig. 5 is a flowchart depicting a method for producing a hydrophilic and hydrophobic patterned fabric, in accordance with an embodiment of the present invention..

[0054] It should be understood with respect to any flowchart referenced herein that the division of the illustrated method into discrete operations represented by blocks of the flowchart has been selected for convenience and clarity only. Alternative division of the illustrated method into discrete operations is possible with equivalent results. Such alternative division of the illustrated method into discrete operations should be understood as representing other embodiments of the illustrated method.

[0055] Similarly, it should be understood that, unless indicated otherwise, the illustrated order of execution of the operations represented by blocks of any flowchart referenced herein has been selected for convenience and clarity only. Operations of the illustrated method may be executed in an alternative order, or concurrently, with equivalent results. Such reordering of operations of the illustrated method should be understood as representing other embodiments of the illustrated method. [0056] Fabric production method 100 may be executed by a knitting machine (or loom or other fabric production machine) that is programmable to operate to combine thread to form a patterned fabric in accordance with a Jacquard process.

[0057] A Jacquard process machine that is programed and configured to combine the hydrophobic thread and the hydrophilic thread to form a pattern of hydrophilic thread on a background of hydrophobic thread may be provided (block 110). For example, the pattern may be programmed mechanically (e.g., on punched cards or sheets), electronically (e.g., on a computer storage device or memory, on a computer readable medium, or otherwise). The pattern may be designed to be acceptable to and end user of the produced fabric, or of an article into which the produced fabric is incorporated, after staining with a staining liquid. Appropriate hydrophobic thread and hydrophilic thread may be loaded onto appropriate spools or other thread holders of the machine.

[0058] The Jacquard process machine may be operated in accordance with the programming to form a pattern of hydrophilic thread against a background of hydrophobic thread, at least on an outer side of the fabric (block 120). The completed fabric may be incorporated into an article that may be used, and possibly exposed to a staining liquid or other staining agent, by an end user.

[0059] Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[0060] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.