Patent Publication Number: US-2023152078-A1

Title: Method for the detection of cable spacing in green tire

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a method for the detection of cable spacing in green tires. More particularly, the present application involves a method that includes a probe that utilizes a hall effect sensor and an angular arrangement relative to a direction of cables in tissue used in the construction of the tire to sense whether cables are too far apart form one another. 
     BACKGROUND 
     The construction of tires involves the assembly of a tire carcass onto a drum. This includes wrapping various tissue, some being metallic tissue, around the cylindrical drum to build the assembly up to a green tire. During this build process the partially constructed tire could be uninflated or partially inflated. Other elements such as metallic beads are incorporated into the partially constructed tire. Once the green tire is constructed it is placed into a mold for curing in which it is subjected to sufficient heat and pressure for a time long enough to vulcanize the green tire into a final cured tire. Subsequent processing steps may be employed to take the now cured tire to a final product. In the green tire building stage, certain tissue having metallic cables, sometime referred to as chords, are wrapped around the products or drum and abutted to itself. The metal cables run in the axial direction of the drum during the build process. These metallic cables make up what are known as the radial cables of the tire. These radial cables can be hand checked to make sure the abutment is proper and to ensure that excessive spacing is not present between the cables at this location or at any other location within the metallic tissue. The checking process may be executed by an operator with a steel ruler to measure spacing between the metal cables to ensure that excessive spacing between these metal cables is not present. However, this hand validation takes place after additional tissue is placed onto the metallic tissue including the radial cables, and the radial cables may not be clearly seen and thus not clearly measured by the inspector. After curing, X-ray evaluation of the tire is conducted and if an open joint were missed by the evaluation the now cured tire will be thrown out thus wasting time, money and product. 
     Additional means of evaluating metallic cables in tires are known. Some of these systems use X ray devices that employ high-resolution magnetic field sensors that view the inside of the rubber. However, such systems evaluate the belt package of the tire and cannot measure the radial cables of the tire that extend generally from bead to bead along the axial length of the tire. Other systems utilize a sensor and software package that scans green tires to provide a topography of the tire at different stages of the production process. Although capable of telling an operator what the tire looks like, such systems are not able to use magnetic flux evaluation to determine spacing issues with radial cables of uncured tires before the curing stage. As such, there remains room for variation and improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, which makes reference to the appended Figs. in which: 
         FIG.  1    is a perspective view of a tire with portions cut away so that interior features of the tire can be seen. 
         FIG.  2    is a plan view of a portion of the tire that shows excessive spacing between successive radial cables. 
         FIG.  3    is a plan view of a portion of the tire that shows touching radial cables, broken radial cables, damaged radial cables, and crossed radial cables. 
         FIG.  4    is a side view of a partially constructed tire on a drum with a probe positioned next to the tire. 
         FIG.  5    is a top view of the probe and the partially constructed tire on the drum of claim  4 . 
         FIG.  6    is a top view of the probe positioned next to the partially constructed tire showing magnetic flux lines in response to cables that are not excessively spaced. 
         FIG.  7    is a tip view of the probe positioned next to the partially constructed tire showing magnetic flux lines in response to cables that are excessively spaced from one another. 
         FIG.  8    is a side view of the probe positioned next to the partially constructed tire in which the probe includes both a spacing hall effect sensor and a damaged wire hall effect sensor. 
         FIG.  9    is a top view of the probe of  FIG.  8    positioned next to a partially constructed tire that has cables with excessive spacing, and a cable that is broken. 
     
    
    
     Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the invention. 
     DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS 
     Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations. 
     The present invention provides for a method of detecting excessive spacing  78  of radial cables  14  in a partially constructed tire  10 . The cables  14  are in a tissue  12  used to construct the tire  10 , and the spacing is detected when the partially constructed tire  10  is uncured as opposed to being cured. The method includes placing a probe  20  that has magnets  22 ,  24 , a magnetic bridge  26 , and a spacing hall effect sensor  28  proximate to the partially constructed tire  10 . The probe  10  is oriented relative to the cables  14  so that a probe first length direction 30 is not parallel to a first cable direction  16 . This orientation causes the probe  10  to be angled relative to the cables  14  so that an orientation angle  40  is established between these two elements. This orientation angle  40  enables the spacing hall effect sensor  28  to better detect a magnetic flux signature produced by excessive spacing  78  between successive cables  14  of the tissue  12 . In this regard, the probe  20  can detect the excessive spacing  78  between the successive cable  14  and the tire  10  can be repaired before the tire  10  is cured. Additional embodiments include the incorporation of a damaged wire hall effect sensor  44  into the probe  20  so that the probe  20  can execute additional measurements on the tissue  12  such as the detection of broken cables  46  and damaged cables  48 . 
     The production of a tire  10  involves assembling different types/sizes of rubber products, known as tissues  12 , with other components made of different chemical and metal materials. Some of these tissues  12  include cables  14  that can be made of nylon or metal. The various products are wrapped around one another on a drum  80  ultimately resulting in the formation of a green tire  10 . This green tire  10  is then placed into a mold where heat and pressure are applied to the green tire  10  in order cure it to form a cured tire  10 . This cured tire  10  can then be subsequently processed to form the final completed tire  10 .  FIG.  1    shows a finished, cured tire  10  with portions cut away to illustrate interior features of the tire  10 . The tire  10  includes a carcass that has a sidewall onto which tread  76  is positioned. The tread  76  can be variously shaped and can include a series of grooves, blocks, sipes, and other architectural features. The tread  76  is disposed on the crown portion of the carcass and is adjacent the sidewall of the tire  10 . The crown portion of the tire  10  may be known as the summit and includes a belt package  38  with belts that could run in the circumferential direction  86  or at an angle to the circumferential direction  86 . Three layers of belts in the belt package  38  are shown, but it is to be understood that any number of layers may be present in other embodiments. Layers below the belt package  38  in the radial direction  84  include the radial cables  14  that extend between the beads in the tire  10 , and these radial cables  14  have a portion that run in the radial direction  84  and the axial direction  82 . The first cable direction  16  is the direction the cables  14  run from bead to bead. The radial cables  14  are spaced  36  from one another in the circumferential direction  86 , which is denoted in  FIG.  1    as the second cable direction  18 . The spacing  36  in the second cable direction  18  should all be the same for the successive cables  14 , and the cables  14  should not touch one another so that successive cables  14  are not touching. The probe  20  that is used to sense spacing is configured for sensing the spacing of the radial cables  14  of the tire  10 , and is not used for the sensing of the spacing of the cables of the belt package  38 . As such, the probe  20  relates to the radial cables  14  and not the belt package  38  cables. 
       FIG.  2    shows a portion of the tire  10  that includes the tissue  12  that has the radial cables  14 . The radial cables  14  in the tissue  12  are shown as extending in the axial direction  82 , and are spaced from one another in the circumferential direction  86 . The first cable direction  16  is the same as the axial direction  82  in the figure, and the second cable direction  18  is the same as the circumferential direction  86  in the figure. The spacing  36  is the distances in the second cable direction  18 , circumferential direction  86 , between successive cables  14  in the tissue  12 . The successive cables  14  should not touch one another but should instead be spaced from one another and not touching. For desired construction of the tire  10 , the spacing  36  should not be excessive between the successive cables  14 , but should fall within a desired tolerance range. The tissue  12  in  FIG.  2    has an excessive spacing  78  defect in that two of the cables  14  as illustrated are spaced from one another in the second cable direction  18  an amount greater than the desired tolerance range. This excessive spacing  78  is identified by the probe  20  so that the tire  10  can be repaired before it is cured and would potentially be scrapped. In some embodiments, the maximum spacing  36  is 2 millimeters if the design spacing is 1.5 millimeters so that any spacing 2 millimeters or over is excessive spacing  78 . In other embodiments, if the spacing is designed to be 2.2 millimeters then any spacing 4.5 millimeters or greater would be classified as excessive spacing  78 . In the embodiment shown in  FIG.  2   , the excessive spacing  78  is 3 millimeters, but it is to be understood that various amounts may be classified as excessive spacing  78  in accordance with different exemplary embodiments. 
       FIG.  3    shows a portion of the tire  10  that includes tissue  12  with radial cables  14  that again have a first cable direction  16  that extends in the axial direction  82 , and a second cable direction  18  that extends in the circumferential direction  86 . The partially constructed tire  10  includes multiple defects in the arrangement of the radial cables  14 . A broken cable  46  is shown in which the cable  14  is discontinuous in extension in the first cable direction  16 . A damaged cable  48  is also identified in which the cable  14  is compressed or otherwise distorted or damaged. The damaged cable  48  may be a corroded cable. The damaged cable  48  may be the same cable  14  as the broken cable  46  or could be a different one of the cables  14  of the plurality of radial cables  14 . Another defect shown in  FIG.  3    are touching cables  50  in which two or more successive cables  14  in the second cable direction  18  engage one another. A still further defect identified in  FIG.  3    is a crossing cable  52  in which one of the cables  14  crosses over another one or ones of the cables  14  resulting in a tissue  12  that is not properly constructed. The various defects  46 ,  48 ,  50 ,  52  may or may not be identified by the probe  20  in certain exemplary embodiments. In addition some but not all of the various defects  46 ,  48 ,  50 ,  52  may be identified by the probe  20  in some embodiments. The various deficiencies including the broken cable  46 , damaged cable  48 , touching cable  50 , and crossing cable  52  can be different defects than the excessive spacing  78  defect of  FIG.  2   , and in some embodiments it is to be understood that the probe  20  only detects the excessive spacing  78  defect and not any of the other defects  46 ,  48 ,  50 ,  52 . 
     An embodiment of the probe  20  is shown with reference to  FIG.  4   . The probe  20  has a first magnet  22  and a second magnet  24  that are separated from one another in a probe first length direction  30  of the probe  20 . The probe first length direction  30  is a straight line that extends through both the first magnet  22  and the second magnet  24 , and may in some configurations of the probe  20  be along the length of the probe  20  that is the longest side of the probe  20 . In other embodiments, the probe first length direction  30  is not the side of the probe  20  that is longest. The first magnet  22  and second magnet  24  are not touching one another in the embodiment shown. The first magnet  22  has a north pole  66  and a south pole  68  in which the north pole  66  is closer to the tissue  14  than the south pole  68 . The second magnet  24  also has a north pole  70  and south pole  72 , but the south pole  72  is closer to the tissue  14  than the north pole  70 . The magnets  22 ,  24  may be permanent magnets. A magnetic bridge  26  can extend between the magnets  22 ,  24  in the probe first length direction  30  and can engage both of the magnets  22 ,  24 . The magnetic bridge  26  may be located farther from the tissue  12  than the magnets  22 ,  24 . In this regard, the probe  20  has a probe second height direction  32  that is perpendicular to the probe first length direction  30  and represents the distance that is closer to or farther from the tissue  12 . The magnetic bridge  26  is thus farther from the tissue  12  in the probe second height direction  32  than the magnets  22 ,  24 . The magnetic bridge  26  may be made of steel and is magnetically conductive so as to help keep the magnetic lines of flux from the magnets  22 ,  24  closer to the tested tissue  12  for measurement. If not present, the magnetic flux lines may move further outward in the probe second height direction  32  to result in a much weaker magnet flux field for measurement. The magnetic bridge  26  can be made of steel. The magnetic bridge  26  thus introduces as near a saturation of magnetic flux as is possible in the inspection material between the poles of the magnetic bridge  26 . 
     Another element of the probe  20  is a spacing hall effect sensor  28  that is located between the magnets  22 ,  24  in the probe first length direction  30 . The spacing hall effect sensor  28  is positioned relative to the magnetic bridge  26  so that the spacing hall effect sensor  28  is closer to the tissue  12  in the probe second height direction  32  than the magnetic bridge  26 . The spacing hall effect sensor  28  is arranged in a vertical orientation  42  in the probe  20 . The spacing hall effect sensor  28  may have sides that have different amounts of surface area. One of the sides may have a greater surface area  58  and one of the sides may have a lesser surface area  60 . The lesser surface area  60  is positioned closer to and facing the tissue  12 , and the greater surface area  58  has a portion farther from the tissue  12  than the lesser surface area  60  in the probe second height direction  32 . If it’s the case that the spacing hall effect sensor  28  does not have rectangular sides, then the lesser surface area  60  may be one of the sides that is smaller in surface area than the greater surface area  58  even though these two sides  58 ,  60  need not have the smallest and greatest surface area respectively. 
     The building of the tire  10  includes wrapping various pieces around the drum  80  and building them on one another until a green tire  10  is constructed for subsequent curing. The partially build tire  10  can be non-inflated, partially inflated, or fully inflated during different portions of its construction on the drum  80 . The tissue  12 , that may include rubber, can be wrapped around the drum  80  or components all ready on the drum  80  and its ends may be abutted. This tissue  12  includes the radial cables  14 , and the radial cables  14  are arranged in a parallel direction to the axis about which the drum  80  rotates. The probe  20  is positioned next to the tissue  12  that has the cables  14 , and is distanced a space  74  from the tissues  12 /cables  14  in the probe second height direction  32 . The space  74  can be 3 millimeters in one embodiment, but it is to be understood that the space  74  can be other distances than 3 millimeters in other embodiments. The space  74  may be measured as the closest approach of the probe  20  to the tissue  12  in the probe second height direction  32 . This closest point may be the first magnet  22 , the second magnet  24 , the spacing hall effect sensor  28 , or any combination of these components. The probe  20  can be spaced from the tissue  12 /cables  14  so that it does not engage the tissues  12 /cables  14  during the measuring process. The probe  20  may thus directly face the tissue  12  during measurement. In other embodiments, there can be one or more tissues or products placed upon the tissue  12  that has the cables  14  so that the probe does not directly face the tissue  12  with the cables  14 . The probe  20  may in these manners still measure the cables  14  but will do so with other tissues or products between it and the cables  14  in the probe second height direction  32 . 
     The probe  20  can measure the partially built tire  10  when the partially built tire  10  is in a confirmation stage of building. Here, the partially built tire  10  may somewhat take the shape of the final form of the tire  10 , and may or may not have some degree of inflation imparted thereon during the measurement. The measurement may take place before the summit package which includes the belt package  38  is placed onto the tissues of the carcass. However, the present measurement with the probe  20  could in fact be done downstream from this point and thus the excessive spacing  78  and/or cable properties  46 ,  48 ,  50  and/or  52  could be identified with the belt package  38  or other tissues on and over the tissue  12  so long as the partially constructed tire  10  has not yet been cured. 
     The probe  20  and drum  80  of  FIG.  4    are shown in top view in  FIG.  5   . The probe  20  has a probe third width direction  34  that is parallel to both the probe first length direction  30  and the probe second height direction  32 . The probe  20  is shortest in the probe third width direction  34  as compared to the other two directions  30  and  32 . The probe  20  is arranged at an angle relative to the cables  14 . In this regard, the first cable direction  16  extends in the same direction as the axial direction  82  of the partially constructed tire  10  which is also in the same direction as the axis about which the drum  80  rotates. The first cable direction  16  is the desired direction of the cables  14  such that cables  14  are designed to run in this direction. The probe  20  has the probe first length direction  30  as discussed which is the direction extending through both the magnets  22 ,  24  and in this case also the spacing hall effect sensor  28 . The probe first length direction  30  also represents the longest side of the probe  20  in this embodiment but it need not in other embodiments. The probe first length direction  30  is not parallel to the first cable direction  16 . Instead, an orientation angle  40  is established between the probe first length direction  30  and the first cable direction  16  (and here also the axial direction  82  and the direction of the axis of the drum  80 ). The orientation angle  40  can be from 10-55°, from 10-45°, from 10-35°, from 10-25°, from 20-30°, from 30-45°, from 2-10°, from 5-65°, or from 15-25°. In a preferred embodiment, the orientation angle  40  is 20°. It is therefore the case that the probe  20  is arranged at an angle to the cables  14  and the probe  20  is not set up so as to be parallel to the extension direction of the cables  14  in the tissue  12 . 
     The cables  14  are not properly constructed and excessive spacing  78  is shown in  FIG.  5    in which the excessive spacing  78  is greater than other spacing  36  of the cables  14  in the second cable direction  18  and is greater than an approved tolerance for maximum spacing of the cables  14  in the second cable direction  18 . The probe  20  is shown as being above the excessive spacing  78 , and the orientation of the probe  20  causes portions of the probe  20  to be on opposite sides of the excessive spacing  78  in the second cable direction  18 . The drum  80  can be rotated 360°, thus rotated in the circumferential direction  86 /second cable direction  18 , so that all of the cables  14  are run past the probe  20  to measure all the spacing  36 . In other embodiments, the probe  20  may instead move around the cables  14  and drum  80  360° and while the cables  14  and drum  80  remain stationary. 
       FIG.  6    shows a top view of the probe  20  positioned next to the cables  14  of the tissue  12  as the partially constructed tire  10  is built upon the drum  80 . The probe  20  is again angled relative to the cables  14  and drum  80 . The magnets  22 ,  24  create flux lines  88  that go through the cables  14  and the magnetic bridge  26  as they are contained by the magnetic bridge  26 . The cables  14  are all properly aligned in  FIG.  6    with respect to spacing  36  so that no excessive spacing  78  exists. The flux lines  88  generated by the magnets  22 ,  24  are sized and spaced in a certain way via the aligned cables  14  and the magnetic bridge  26 . The spacing hall effect sensor  28  will sense the flux lines  88  and generate an electrical signal indicative of these particular flux lines  88 . The signal from the spacing hall effect sensor  28  will be sent to a processor where it will be processed to inform the system or operator that the cables  14  are appropriately spaced  36  in the second cable direction  18 . The processor may include or be part of an appropriate electronic circuit capable of receiving output from the sensors  28 ,  44  of the probe  20  and converting this to output indicative of the sensed conditions. 
       FIG.  7    is an embodiment set up the same way as in  FIG.  6   , but in which two of the cables  14  are not properly spaced from one another resulting in an excessive spacing  78  between these two cables  14 . The probe  20  will detect this excessive spacing  78  by detecting flux leakage in the flux lines  88  caused by the excessive spacing  78 . As shown, the flux lines  88  generated by the magnets  22 ,  24 , and contained by the magnetic bridge  26 , and effected by the cables  14  in a different way because of the excessive spacing  78 . There will be a flux leakage of the flux lines  88  into this excessive spacing  78  so that the flux lines  88  as measured by the spacing hall effect sensor  28  will be different than that as measured in the  FIG.  6    arrangement. The excessive spacing  78  distorts the flux lines  88 , and this distortion is measured by the spacing hall effect sensor and an electrical signal is sent to the processing equipment to provide notification that excessive spacing  78  of the cables  14  is present. The excessive spacing  78  causes a flux plumage and thus causes the flux lines  88  to be deflected away from the spacing hall effect sensor  28 . The tire  10  may then be repaired before it is cured and would otherwise need to be scrapped. The orientation angle  40 , preferably at 20°, allows for the detection of the excessive spacing  78  as at an orientation angle  40  the flux leakage into the excessive spacing  78  can be detected by the spacing hall effect sensor  28  as opposed to other arrangements in which this excessive spacing  78  cannot be so detected because the corresponding flux leakage into the excessive spacing  78  cannot be created. 
     The probe  20  may be provided so that it can detect not only excessive spacing  78 , but also the other damage conditions  46 ,  48 ,  50 ,  52  as previously discussed.  FIG.  8    shows an exemplary embodiment of the probe  20  arranged in a similar manner to those previously discussed, but also including a damaged wire hall effect sensor  44 . The damaged wire hall effect sensor  44  is oriented in a different manner than the spacing hall effect sensor  28 . In this regard, the two sensors  28 ,  44  are arranged at an angle  56  to one another. This angle  56  may be 90° in some exemplary embodiments. The damaged wire hall effect sensor  44  is arranged in a horizontal orientation  54 . The damaged wire hall effect sensor  44  has surfaces that have a greater surface area  62  and a lesser surface area  64 . The greater surface area  62  has a greater surface area than the lesser surface area  64 . The greater surface area  62  surface is closer to the tissue  12  and cables  14  being measured than the lesser surface area  64 . In this regard, some portion of the lesser surface area  64  is farther from the tissue  12  and cables  14  than all of the greater surface area  62  in the probe second height direction  32 . If the damaged wire hall effect sensor  44  does not have all rectangular surfaces, the surface area of the surface directly facing the tissue  12 /cables  14  is a greater surface area  62  than the lesser surface area  64  surface not directly facing and having portions farther from in the probe second height direction  32 . The two sensors  28 ,  44  are arranged relative to one another so that one is in the vertical orientation  42  and the other in the horizontal orientation  54  such that a larger surface of one faces the tissue  12  and a smaller surface of the other faces the tissue  12 . The damaged wire hall effect sensor  44  is located between the magnets  22 ,  24  in the probe first length direction  30 , and is closer to the tissue  12  in the probe second height direction  32  than the magnetic bridge  26 . The damaged wire hall effect sensor  44  can be the portion of the probe  20  that is closest to the tissue  12  in the probe second height direction  32 , or may be farther from or the same distance from the tissue  12  in this direction  32  as other parts of the probe  20  such as the magnets  22 ,  24  and the spacing hall effect sensor  28 . 
     The angle  56  can be the angle from the greater surface area  58  of the spacing hall effect sensor  28  to the greater surface area  62  of the damaged wire hall effect sensor  44 . The angle of  56  being 90° is the optimal angle for detection. Although shown as being 90°, this angle  56  can be any other angle in accordance with other embodiments. In some embodiments, the angle  56  is 10°, from 10-25°, from 25-35°, from 35-55°, from 55-90°, from 90-120°, or up to 170. As such, although other angles are possible, an angle  56  of 90° is preferred. 
       FIG.  9    is a top view of the probe  20  of  FIG.  8    as positioned over cable  14  for evaluation. The probe  20  is again angled relative to the tissue  12  so that an orientation angle  40  is present that could be 20° in some embodiments. The magnets  22 ,  24  will generate flux lines  88  as previously discussed and the flux leakage into the excessive spacing  78  can be detected by the spacing hall effect sensor  28  and reported by the probe  20  so that the excessive pacing  78  can be identified. The cables  14  also feature a broken cable  46  and touching cable  50 . The broken cable  46  will create a variation in the flux lines  88  at this location. Similarly, the touching cable  50  will create a variation in the flux lines  88  at the location of touching. The variations in the flux lines  88  will be sensed by the damaged wire hall effect sensor  44  and electrical signals indicative of the broken cable  46  and touching cable  50  will be transmitted by the damaged wire hall effect sensor  44  from the probe  20  to processing equipment that will interpret the signals and inform the system that this broken cable  46  and touching cable  50  are present. The probe  20  may thus be used to identify the excessive spacing  78  in addition to none or any combination of cable anomalies  46 ,  48 ,  50 ,  52 . If these anomalies  46 ,  48 ,  50 ,  52  are detected the pre-cured tire  10  could be repaired or scrapped as desired. 
     Although shown and described as employing only a single spacing hall effect sensor  28  and a single damaged wire hall effect sensor  44 , it is to be understood that other embodiments are possible in which a plurality of sensors  28  and/or  44  are present in the probe  20  for detection of the damage conditions  78 ,  46 ,  48 ,  50 , and/or  52 . Further, although described as cables or radial cables  14 , it is also known in the industry to call these elements radial cords, and it is to be understood that the term cables also includes cords. The static magnetic field created by the magnets  22 ,  24  is evaluated by different angle of attack placements of the hall effect sensors  28 ,  44  due to the orientation angle  40 . The disclosed arrangement allows the probe  20  to detect differences between the flux field densities  88  of normal cable  14  spacing  36  and abnormal excessive spacing  78 . This process set up allows the cables  14  to be evaluated by the system. The tire  10  that is partially constructed is a brand new tire  10 , and not a used carcass or tire that is being subjected to a retread process. Further, the tire  10  that is ultimately build and is thus evaluated by the present process can be a heavy duty truck tire. Although any portion of the partially constructed tire  10  can be evaluated for excessive spacing  78 , the portion onto which the belt package  38  is placed may be the part of the partially constructed tire  10  that is evaluated by the present method. 
     While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.