Abstract:
An indication device is provided which has an electrically conductive fluid driven by an MHD pump. The fluid has an indicator surface driven adjacent indices of an indicator so as to indicate a quantity. A position of the indicator surface is sensed and controlled to ensure accurate indication of the quantity. Optionally, the quantity indicated is time.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application is a PCT application claiming priority to U.S. application No. 61/974,448, filed 3 Apr. 2014, entitled SYSTEMS AND METHODS FOR ABSORBTION/EXPANSION OF A LIQUID IN A TRANSPARENT CAVITY, to U.S. application Ser. No. 13/422,438, filed 16 Mar. 2012, entitled WRISTWATCH, to U.S. application Ser. No. 14/083,538, filed 19 Nov. 2013, entitled FLUID INDICATOR, to U.S. application No. 62/033,686, filed on 6 Aug. 2014, entitled TIME KEEPING DEVICES INCLUDING INDICATIONS BY MAGNETIC PARTICLES IN SUSPENSION IN LIQUID FILLED CHAMBERS, to U.S. application 61/985,492, filed 29 Apr. 2014, entitled STEERING AND VELOCITY CONTROL OF A MENISCUS SYSTEM AND METHOD, AND TIME PIECE SYSTEM INCORPORATING SAME, to U.S. application 62/143,904, filed 7 Apr. 2015, entitled WATCH WITH LIQUID INDICATION, and to PCT/2015/______, filed 7 Apr. 2015, entitled SYSTEMS AND METHODS FOR ABSORBTION/EXPANSION/CONTRACTION/MOVEMENT OF A LIQUID IN A TRANSPARENT CAVITY the contents of the entirety of which are explicitly incorporated herein by reference and relied upon to define features for which protection may be sought hereby as it is believed that the entirety thereof contributes to solving the technical problem underlying the invention, some features that may be mentioned hereunder being of particular importance. 
     
    
     COPYRIGHT &amp; LEGAL NOTICE 
       [0002]    A portion of the disclosure of this patent document contains material which is subject to copyright protection. The Applicant has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. Further, no references to third party patents or articles made herein are to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention relates to systems and methods for timepieces that include movement/absorption/expansion/contraction of a liquid in a transparent cavity, particularly in wristwatches. 
         [0004]    Luxury watches exist that indicate time using a meniscus of a liquid which is driven by a purely mechanical system. Such watches are complicated and, consequently, very expensive. A need therefore exists for a low cost, electronic watch that accurately indicates time using the meniscus of a liquid. 
       SUMMARY OF THE INVENTION 
       [0005]    The invention provides a system for a device. The system for a device includes a channel fillable with one or more liquids. The individual liquids are preferable immiscible with each other. Each individual liquid can be transparent or colored, have the same refractivity as the substrate, can optionally contain solid particles, can be electrical conductive or electrical non-conductive. In a variant, the indication is done with a moving gas bubble, such as a radioactive tritium gas. The channel is formed as a closed loop or in a variant formed with ends ending in a reservoir. An electrically conductive liquid can be moved with the channel by the means of one or more magnetohydrodynamic pumps (MHD pumps). If a further variant, a second liquid is electrical non-conductive or electrically conductive, this liquid is pushed or pulled by the electrically conductive liquid driven by the MHD pump(s). 
         [0006]    In a variant, the position of the electrically non-conductive or electrical conductive liquid, in a variant embodied as a gas bubble, within the channel is sensed along the channel by its deviating dielectricity between the two or more liquids. The sensing of the capacitance or the sensing of the change of the capacitance is preferably made by a number of capacitors spread along the channel. 
         [0007]    In another variant, the channel is used in a timepiece. The permanent magnets and/or electrodes required in MHD pumps, in order to be non-visible to a user, are incorporated into design/decoration elements or hidden by design/decoration elements. In another variant, the permanent magnets and/or electrodes are visible to the user. 
         [0008]    In another variant, the capacitors used to sense the dielectricity or the change of the dielectricity is accomplished with sputtering, preferable as ITO (Indium-tin oxine) or FTO (Fluorin-doped tin oxine). 
         [0009]    In another variant, the channel is formed as a micro capillary. 
         [0010]    In another variant, the channel is formed by two or more glass wafers, preferably connected to each other by a suitable bonding process. 
         [0011]    In another variant, the channel is formed by two or more polymer wafers, preferably connected to each other by a suitable bonding process. 
         [0012]    In another variant, a membrane is embedded between wafers. 
         [0013]    In another variant, the channel system has one or more open access holes to allow an initial filling of the system with liquid(s), implicating an automated filling of the system during the production process. Through one access hole, a liquid is inserted, while another access hole provides access to ambient pressure. After initial filling, the access hole(s) are closed in a fluid and/or gas tight manner. Optional, the access hole(s) can be opened and closed again, e.g. for maintenance reasons. 
         [0014]    In another variant, as well for a closed loop system, as for a variant with ends ending in a reservoir, is equipped with a system to compensate thermal expansion/contraction of the liquid(s). This is accomplished by a thin and therefore flexible wafer, or a separate gas chamber, or a flexible soft material part, or a membrane. The flexible soft material part can be placed in the channel or in a separate chamber, which is in fluid communication with the channel. The compensation system is non-visible to a user, and in another variant visible to the user. The non-visible system is disposed underneath the visible system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a schematic top view of the invention. 
           [0016]      FIG. 2  is a schematic top view of the invention in another variant. 
           [0017]      FIG. 3  is a detail view of an indicator liquid arrangement of the invention. 
           [0018]      FIG. 4  is a schematic perspective view of an MHD motor used in the invention. 
           [0019]      FIG. 5  is a schematic top view of the invention in another variant. 
           [0020]      FIG. 6  is a cross sectional detail view of the liquid reservoir of the invention. 
           [0021]      FIG. 7  is a cross sectional detail view of a variant of the liquid reservoir of the invention. 
           [0022]      FIG. 8  is a cross sectional detail view of another variant of the liquid reservoir of the invention. 
           [0023]      FIG. 9  is a cross sectional view of a detail view of an element of  FIG. 8 . 
           [0024]      FIG. 10  is a cross sectional detail view of still another variant of the liquid reservoir of the invention. 
           [0025]      FIG. 11  is a schematic top view of the invention in another variant. 
           [0026]      FIG. 12  is a schematic perspective view of the invention in still another variant. 
           [0027]      FIG. 13  is a schematic top view of the invention in a further variant. 
       
    
    
       [0028]    Those skilled in the art will appreciate that elements in the Figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, dimensions may be exaggerated relative to other elements to help improve understanding of the invention and its embodiments. Furthermore, when the terms ‘first’, ‘second’, and the like are used herein, their use is intended for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. Moreover, relative terms like ‘front’, ‘back’, ‘top’ and ‘bottom’, and the like in the Description and/or in the claims are not necessarily used for describing exclusive relative position. Those skilled in the art will therefore understand that such terms may be interchangeable with other terms, and that the embodiments described herein are capable of operating in other orientations than those explicitly illustrated or otherwise described. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    The following description is not intended to limit the scope of the invention in any way as it is exemplary in nature, serving to describe the best mode of the invention known to the inventors as of the filing date hereof. Consequently, changes may be made in the arrangement and/or function of any of the elements described in the exemplary embodiments disclosed herein without departing from the spirit and scope of the invention. 
         [0030]      FIG. 1  is a top view of a system  100  including a capillary channel  116 , at its both ends having a reservoir  102  attached. It is appreciated that the capillary channel  116  can take on a variety of geometric cross-sectional two dimensional or three dimensional cross-sectional and overall shapes or configurations, e.g. a cylindrical tube, a square, a rectangle, a circle, an oval, an oval shape, a triangular shape, a pentagonal shape, a hexagonal shape, an octagonal shape, a cubic shape, a spherical shape, an egg shape, a cone shape, a dome shape, a rectangular prism shape, and a pyramidal shape, by way of further example. In this variant the capillary channel  116  is filled with a first essentially electrically conductive, optionally colored liquid  106 , implicating for example a Sodium chloride solution and a second electrically conductive or electrically non-conductive, optionally colored liquid  114 , implicating for example a silicone oil or a liquid sapphire (as used herein, any liquid having the same refractivity as the substrate), in a variant accomplished using a gas bubble. Of course, the system can contain more or less liquids and another combination of different liquids. Further, this variant is equipped with one or more magnetohydrodynamic pumps (MHD pumps)  112 . The channel  116  has optionally one or more open access holes  120  to allow an initial filling of the system with liquid(s), implicating an automated filling of the system during the production process. The system is further equipped with capacitors  302 . The system does compensate thermal expansions and compressions of a liquid  106  located in the channel  202 , as proposed in  FIGS. 7 to 11 . 
         [0031]      FIG. 2  is a top view of a system  200  including a capillary channel  202  formed as a closed loop. It is appreciated that the capillary channel  202  can take on a variety of geometric cross-sectional two dimensional or three dimensional cross-sectional and overall shapes or configurations as mentioned above. In this variant the capillary channel  202  is filled with a first essentially electrically conductive, optionally colored liquid  106 , implicating for example a Sodium chloride solution and a second electrically conductive or electrically non-conductive, optionally colored liquid  114 , implicating for example a silicone oil or liquid sapphire, in a variant accomplished using a gas bubble. Of course, the system can contain more or less liquids and another combination of different liquids. Further, this variant is equipped with one or more magnetohydrodynamic pumps (MHD pumps)  112 . The channel  202  has optionally one or more open access holes  120  to allow an initial filling of the system with liquid(s), implicating an automated filling of the system during the production process. The system is further equipped with capacitors  302 . The system does compensate thermal expansions and compressions of a liquid  106  located in the channel  202 , as proposed in  FIGS. 7 to 11 . 
         [0032]      FIG. 3  is a sectional view A-A of  FIG. 1  including a capillary channel  116 . In this variant the capillary channel  116  is filled with a first essentially electrically conductive, optionally colored liquid  106 , implicating for example a Sodium chloride solution and a second electrically conductive or electrically non-conductive, optionally colored liquid  114 , implicating for example a silicone oil or liquid sapphire, and in a variant accomplished using a gas bubble. Of course, the system can contain more or less liquids and another combination of different liquids. Further, this variant is equipped with one or more magnetohydrodynamic pumps (MHD pumps)  112  to drive an electrically conductive or a non-conductive, optionally colored liquid  114 , implicating for example a silicone oil or liquid sapphire, in a variant accomplished using a gas bubble, surrounded by an optionally colored, transparent conductive liquid  110 . The system is further equipped with capacitors  302  used to sense the dielectricity or the change of the dielectricity essentially at areas  304  near the capacitor or the pair of capacitor or the triple of capacitors. The capacitors are made by sputtering, preferable as ITO (Indium-tin oxine) or FTO (Fluorin-doped tin oxine). Several capacitors are placed along the channel  116 . The dielectricity and/or the change of dielectricity can be sensed by dedicating one, a pair or a triple of capacitors to an area  304 . 
         [0033]      FIG. 4  is a perspective view of a magnetohydrodynamic pumps (MHD pumps)  112 . The MHD pump  112  includes a permanent magnet with its polarization North  502  directed towards a channel  504 , a permanent magnet with its polarization South  506  directed towards a channel  504  and essentially opposite to permanent magnet with its polarization North  502 . The channel contains liquids  514 , implicating for example a silicone oil, liquid sapphire or a Sodium chloride solution, in a variant accomplished using a gas bubble. The system is further equipped with a pair of electrodes  510 ,  512 , reframing the channel  504  and essentially 90° to the permanent magnets  502 ,  506 . To the electrodes  510 ,  512  a direct current (DC), positive or negative polarized, can be applied. The swap of polarization will reverse the flow of the liquids  514 . The permanent magnets  502 ,  506  may either be in contact with the liquids  514  or not be in contact with the liquids  514  and/or gas. The electrodes  510 ,  512  are in contact with the liquids  514  and/or gas. 
         [0034]    Considering the circular capillary sub-systems  100  or  200 , and its various dimensions, a time of 60 seconds is used to completely fill the circular capillary sub-system  100  or  200 . An exemplary specification for a robust, efficient, fit for purpose MHD pump  112  is as follows: 
         [0000]                                    1. Capillary sub-system 100 or 200 cross-sectional area:   A = 0.5 mm 2         2. MHD flow mean velocity:   V MHD =             1.895 mm/s       3. MHD flow rate:   Q MHD =             57.165 μL/min                    
Of course, the stronger the MHD pump  112  is the more fluid is moved into cavity  116  or  202  at a faster rate. Slower rates of filling are accomplished by weaker MHD pumps  112  depending on their overall specifications and pumping strength.
 
         [0035]    Now looking at other MHD pump variants in the comparison provided below, and summarized in Table 1 below, it is appreciated that the example highlighted in red approximates the required specifications. Other MHD pumps can be used, depending upon the requirements of fluid movement, either continuous or intermittent, or those that require faster or slower fluid movement in the cavity  116  or  202 . It is appreciated that an MHD pump  112 , and circular capillary sub-system  100  or  200  featuring cavity  116  or  202  is provided in another variant. Other variants of dimensions (area, volume, geometric shape) of components of sub-system  100  or  200  are also provided in combination with other MHD pumps that have other engineered properties and modes of operation, some being fit for purpose and some not, but preferably, the specifications of MHD pump  112  highlighted in red in Table 1 are preferable for optimal fluid movement in cavity  116  or  202 . 

 
         [0036]    The following list of references with respect to MHD pumps are incorporated into this patent application by reference in their entirety, showing the variety of MHD pumps in the market:
       1. Design, Microfabrication, and Characterization of MHD Pumps and their Applications in NMR Environments, Thesis by Alexandra Homsy, 2006, the content of which is incorporated herein by reference thereto.   2. Bislug Flow in Circular and Noncircular Channels and the Role of Interface Stretching on Energy Dissipation, Thesis by Joseph E. Hernandez, August 2008, the content of which is incorporated herein by reference thereto.       
 
         [0039]    In yet a further aspect, the invention also provides for a grouping of sub-systems that include a circular (or other geometric configuration) capillary sub-system(s) with one or more MHD pumps  112 . The groups include one or more MHD pumps  112  and tube/cavity combinations or groups of inter-related sub-systems. The one or more than one MHD pump  112  manages displacement of one or more fluids within individual circular capillary sub-systems or by way of manifold into more than one capillary sub-systems, in series or in parallel, alone or in combination with other MHD pumps providing for multiple indicator functionality within a single device, e.g. a wristwatch. 
         [0040]      FIG. 5  is a perspective view of a timepiece  600  equipped with system  200 . The system  200  includes a capillary channel  202  formed as a closed loop. In this variant the capillary channel  202  is filled with a first essentially electrically conductive liquid  106 , implicating for example a Sodium chloride solution and a second electrically conductive or electrically non-conductive, optionally colored liquid  114 , implicating for example silicone oil or liquid sapphire, in a variant accomplished using a gas bubble. Of course, the system can contain more or less liquids and another combination of different liquids. Further, this variant is equipped with four magnetohydrodynamic pumps (MHD pumps)  112 . The magnetohydrodynamic pumps (MHD pumps) are incorporated into design/decoration elements or hidden by design/decoration elements  602 ,  604 ,  606 ,  610 , in order to be non-visible to a user. 
         [0041]      FIG. 6  is a cross sectional view of variant of system  100  or system  200 . The channel  702  is formed by two wafers  704 ,  706 , implicating wafers made out of glass and/or polymer. The wafers  704 ,  706  are fixed to each other preferably by a suitable bonding process. The channel  702  contains one or more liquids and/or gas  710 , implicating for example a silicone oil, liquid sapphire or a Sodium chloride solution. Wafer  706  is particularly thin in the region of the channel  702  and is therefore enough flexible in that region to compensate thermal expansions and compressions of a liquid  710  located in the channel  702 . The channel  702  has optionally one or more open access holes  712  to allow an initial filling of the system with liquid(s)  710 , implicating an automated filling of the system during the production process. 
         [0042]      FIG. 7  is a cross sectional view of variant of system  100  or system  200 . The channel  702  is formed by three or more wafers  802 ,  804 ,  806 , implicating wafers made out of glass and/or polymer. The wafers  802 ,  804 ,  806  are fixed to each other preferably by a suitable bonding process. The channel  702  contains one or more liquids and/or gas  710 , implicating for example a silicone oil, liquid sapphire or a Sodium chloride solution. Wafer  806  is particularly thin in the region of the channel  702  and is therefore enough flexible in that region to compensate thermal expansions and compressions of a liquid  710  located in the channel  702 . The channel  702  has optionally one or more open access holes  712  to allow an initial filling of the system with liquid(s)  710 , implicating an automated filling of the system during the production process. 
         [0043]      FIG. 8  is a cross sectional view of variant of system  100  or system  200 . The channel  702  is formed by four wafers  902 ,  904 ,  906 ,  910 , implicating wafers made out of glass and/or polymer. The system can also be formed by less or more wafers. The wafers  902 ,  904 ,  906 ,  910  are fixed to each other preferably by a suitable bonding process. The channel  702  contains one or more liquids  710 , implicating for example a silicone oil, liquid sapphire or a Sodium chloride solution. Wafers  906 ,  910  form a gas chamber  912  containing essentially gas  920 . Gas chamber  912  and channel  702  are connected to each other through a thin transit passage  914 . The thin transit passage has a certain length  916 , typically 0.5-2 mm. The intersection  918  between gas  920  and liquid  710  is essentially within the length  916 . The compressibility of gas  920  in combination with this system allows to compensate thermal expansions and compressions of a liquid  710  located in the channel  702 . The channel  702  and/or the gas chamber  912  has optionally one or more open access holes  712  to allow an initial filling of the system with liquid(s)  710  and/or gas  920 , implicating an automated filling of the system during the production process. 
         [0044]      FIG. 9  is the detail view B of  FIG. 8 . The thin transit passage  914  is shown in detail. To optimize the trapping of a liquids  710 , the angle  1004  between wafers  906 ,  910  at the entrance of the thin transit passage can be positive, zero or negative. The forming of the thin transit passage  914  can further be freely chosen in order to optimize a proper separation of gas  920  and liquid  710 . To prevent mixing or migration of gas  920  from gas chamber  912  to the channel  702 , the dimensions and shape of the thin transit passage  914  has to be adapted according to the viscosities of the liquids  710 . 
         [0045]      FIG. 10  is a cross sectional view of variant of system  100  or system  200 . The channel  702  is formed by four wafers  1102 ,  1104 ,  1106 ,  1110 , implicating wafers made out of glass and/or polymer. The system can also be formed by less or more wafers. The wafers  1102 ,  1104 ,  1106 ,  1110  are fixed to each other preferably by a suitable bonding process. The channel  702  contains one or more liquids  710 , implicating for example a silicone oil, liquid sapphire or a Sodium chloride solution, in a variant accomplished using a gas bubble. A soft material  1112  is located at a specific place to be in contact with the liquid and/or gas  710 . The soft material  1112  has the property to compensate thermal expansions and compressions of a liquid  710  located in the channel  702 . The channel  702  has optionally one or more open access holes  712  to allow an initial filling of the system with liquid(s) and or gas  710 , implicating an automated filling of the system during the production process. 
         [0046]      FIG. 11  is a top view of a system  1200  including a capillary channel  1202  formed as a closed loop. It is appreciated that the capillary channel  1202  can take on a variety of geometric cross-sectional two dimensional or three dimensional cross-sectional and overall shapes or configurations. In this variant the capillary channel  1202  is filled with a first essentially electrically conductive, optionally colored liquid  1206 , implicating for example a Sodium chloride solution and a second electrically conductive or electrically non-conductive, optionally colored liquid  1214 , implicating for example a silicone oil or liquid sapphire, in a variant accomplished using a gas bubble. Of course, the system can contain more or less liquids and another combination of different liquids. Further, this variant is equipped with one or more magnetohydrodynamic pumps (MHD pumps)  112 . A reservoir  1220  is located at a specific place in fluid communication with the channel  1202 . The housing  1222  of the reservoir  1220  has the ability to compensate thermal expansions and compressions of a liquid  1206  located in the channel  1202 . Such compensation, however, may also be obtained such as described in  FIG. 3  of PCT/2015/______, filed 7 Apr. 2015, entitled SYSTEMS AND METHODS FOR ABSORBTION/EXPANSION/CONTRACTION/MOVEMENT OF A LIQUID IN A TRANSPARENT CAVITY. The channel  1202  and/or the housing  1222  of the reservoir  1220  has optionally one or more open access holes  712  to allow an initial filling of the system with liquid(s) or gas  1206 ,  1214 , implicating an automated filling of the system during the production process. 
         [0047]      FIG. 12  is a variant of a system as e.g. described in  FIG. 2 ,  FIG. 5  or  FIG. 11 , including a closed loop  1302 . The channel  1306  is formed by fixing two or more wafers  1310 ,  1312 ,  1314  together, implicating wafers made out of glass and/or polymer. The channel  1306  may be filled with fluid, gas, solid particles or a combination thereof. In this variant, the channel is filled with two different types of fluids  1316 ,  1320 , implicating for example a silicone oil, liquid sapphire or a Sodium chloride solution. At least one of the filled liquids is essentially electrically conductive. An MHD pump  112  is integrated having its permanent magnets  502 ,  506  placed along the inner diameter and along the outer diameter between two wafers  1310 ,  1314 . Further, wafer  1310  and wafer  1314  are electrically conductive and function as electrodes. The electrical conductivity on wafers  1310 ,  1314  are preferable achieved by sputtering, preferable as ITO (Indium-tin oxine) or FTO (Fluorin-doped tin oxine). The essentially electrically conductive liquid  1316  will be driven forward or backwards by a Lorenz force, created by the magnetic field  1322  generated by the permanent magnets  502 ,  506  in combination with the electrical field  1324  generated between the two wafers  1310 ,  1314  connected to a direct current (DC) voltage source. The swap of polarization will reverse the flow of the liquids  1316 ,  1320 . Of course, this variant contains mechanism to compensate thermal expansion and/or contractions of the fluid, as described before. And of course, this variant contains capacitors to measure the dielectricity and/or the change of dielectricity as described in  FIG. 3 . 
         [0048]    The instant provisional patent application incorporates by reference in its entirety, as if fully set forth herein, U.S. patent application Ser. No. 61/787,727, filed on 15 Mar. 2013, and International patent application no. PCT/IB2014/000373, filed on 17 Mar. 2014, both entitled “TEMPERATURE DRIVEN WINDING SYSTEM”. 
         [0049]    As used herein, the terms “comprises”, “comprising”, or variations thereof, are intended to refer to a non-exclusive listing of elements, such that any apparatus, process, method, article, or composition of the invention that comprises a list of elements, that does not include only those elements recited, but may also include other elements described in the instant specification. Unless otherwise explicitly stated, the use of the term “consisting” or “consisting of” or “consisting essentially of” is not intended to limit the scope of the invention to the enumerated elements named thereafter, unless otherwise indicated. Other combinations and/or modifications of the above-described elements, materials or structures used in the practice of the present invention may be varied or adapted by the skilled artisan to other designs without departing from the general principles of the invention. The patents and articles mentioned above are hereby incorporated by reference herein, unless otherwise noted, to the extent that the same are not inconsistent with this disclosure. 
         [0050]    Other characteristics and modes of execution of the invention are described in the appended claims. Further, the invention should be considered as comprising all possible combinations of every feature described in the instant specification, appended claims, and/or drawing figures which may be considered new, inventive and industrially applicable. 
         [0051]    Copyright may be owned by the Applicant(s) or their assignee and, with respect to express Licensees to third parties of the rights defined in one or more claims herein, no implied license is granted herein to use the invention as defined in the remaining claims. Further, vis-à-vis the public or third parties, no express or implied license is granted to prepare derivative works based on this patent specification, inclusive of the appendix hereto. 
         [0052]    Additional features and functionality of the invention are described in the claims appended hereto. Such claims are hereby incorporated in their entirety by reference thereto in this specification and should be considered as part of the application as filed. 
         [0053]    Multiple variations and modifications are possible in the embodiments of the invention described here. Although certain illustrative embodiments of the invention have been shown and described here, a wide range of changes, modifications, and substitutions is contemplated in the foregoing disclosure. While the above description contains many specific details, these should not be construed as limitations on the scope of the invention, but rather exemplify one or another preferred embodiment thereof. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the foregoing description be construed broadly and understood as being illustrative only, the spirit and scope of the invention being limited only by the claims which ultimately issue in this application.