Patent Publication Number: US-8985016-B2

Title: Printing plate sleeve loading and unloading apparatus and method

Description:
RELATED APPLICATIONS 
     The present application claims priority of U.S. Provisional Patent Application No. 61/417,248 filed 25 Nov. 2010 to inventor Schwipps, titled PRINTING PLATE SLEEVE LOADING AND UNLOADING APPARATUS AND METHOD, the contents of which are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure is generally related to printing devices, and more specifically to the handling of printing sleeves and plates. 
     BACKGROUND 
     Flexographic printing plates may be formed from a flexographic material having a photosensitive layer. In a computer-to-plate operation, an image to be printed exposes an ablatable masking material on a photopolymer plate to form a mask. The resulting mask is then uniformly exposed to ultraviolet (UV) radiation, and processed to form raised portions for use in printing. Thus, for certain flexographic materials, processing includes curing an exposed material with UV radiation in a UV exposure unit. 
     It is common to use cylindrical sleeves of flexographic plate material to form printing plates. After exposure to imaging data, the sleeves are transferred from the imager to a UV exposure unit and other processing machines. In order to match diameters the sleeve diameter to the size of specific machines, it is also common to place the sleeves on the outer surface of sturdy cylindrical sleeve adapters for imaging and and/or UV exposure. 
     For purposes of this description, the sleeve or sleeve adapter is a hollow cylinder. One technique for holding cylindrical sleeves and/or adapters is by using conical end pieces (chucks) and the apex of such conical chucks into each hollow end of the cylinder, and supporting the base of each conical end. The cylinder is held by friction. In a UV exposure unit, for example, one or both end pieces are then rotated while the sleeve is exposed to UV radiation from lamps. The lamps may either extend the length of the sleeve or are shorter than the length of the sleeve and move longitudinally as the sleeve is rotated. 
     There may be several problems with using such prior art UV exposure units with such conical chucks that are related to the alignment of the sleeve, access to the sleeve, and ability to expose different sized sleeves. 
     For accurate rotation, the axis of the cylinder should coincide with the two apexes of the chucks, i.e., with the axis of rotation. If each conical end piece easily slides into the respective end of the sleeve or sleeve adapter, then the sleeve will be aligned with the rotation axis. However, the pieces and sleeve or adapter do not always slide easily in practice, resulting in the axis of the cylindrical sleeve not being co-linear with the conical end pieces. As a result, the sleeve may not rotate properly about the sleeve axis. 
     Other problems with some prior art mechanisms relate to the fact that the diameters of different sleeves may vary. 
     Furthermore, access to the entire length of the sleeve may also be important, e.g., in order to UV expose all the way to the end of the sleeve. Since the ends are supported by conical end pieces having a base larger in diameter than the sleeve, for relatively small diameters it may not be possible to place a lamp near the sleeve ends. This can be overcome my having many conical chucks of different diameter to accommodate many different sleeve diameters. However, such an approach may not be desirable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a side view image of an embodiment of a support device for a cylindrical printing sleeve or printing sleeve adapter; 
         FIG. 1B  shows a end view  1 B- 1 B of  FIG. 1A ; 
         FIGS. 2 to 4  show side view images of the device of  FIG. 1  in different configurations, where  FIG. 2  shows the device in a slightly closed configuration and where  FIGS. 3 and 4  shows the device in a more closed configuration; 
         FIG. 5A  shows a top perspective image showing the device of  FIG. 1  in a closed configuration as clamping a sleeve; 
         FIG. 5B  shows a end view showing the device of  FIG. 1  in a closed configuration; 
         FIG. 6  shows side perspective images of an embodiment of a flexographic UV exposure machine having a first and a second support device for supporting a cylindrical printing sleeve or printing sleeve adapter; 
         FIGS. 7 to 15  show images of the flexographic UV exposure machine of  FIG. 6  illustrating the placement of a sleeve within the machine, where  FIGS. 7 and 8  illustrate sequential steps of a user placing one end of a sleeve into a first chuck,  FIGS. 9 ,  10 ,  11 , and  12  illustrate sequential steps of a user placing and securing a second end of a sleeve into a second chuck,  FIGS. 13 and 14  illustrate sequential steps of a user securing the sleeve into the first chuck; and  FIG. 15  is a image of a sleeve mounted into the flexographic processing machine utilizing the first and second sleeve handling devices; 
         FIG. 16  shows a simplified sectional view  16 - 16  of  FIG. 1B ; and 
         FIG. 17  shows a simplified sectional view  17 - 17  of  FIG. 5B . 
     
    
    
     Reference symbols are used in the drawings to indicate certain components, aspects or features shown therein, with reference symbols common to more than one drawing indicating like components, aspects or features shown therein. 
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Brief Overview 
     It may be advantageous to have an apparatus for handling sleeves or sleeve adapters that can align a sleeve or sleeve adapter relative to a rotation axis. It may also be advantageous to have a mechanism for handling sleeves or sleeve adapters that can expose the entire surface of the sleeve. It may also be advantageous to have a mechanism for handling sleeves or sleeve adapters that is usable with a variety of sleeve and/or sleeve adapter diameters. It may also be advantageous to have a mechanism for handling sleeves or sleeve adapters that is compatible with current flexographic sleeve processing machines. It may also be advantageous to have a mechanism for handling sleeves or sleeve adapters that is relatively easy to use. Some embodiments of the present invention may have one or more of these properties, although the inventor is not insisting that any of these advantages is or are provided by any embodiment of the invention. Rather, the invention is as described by the claims and their legal equivalents. 
     Embodiments of the present invention include a pair of chucks for holding the ends of a cylindrical sleeve or sleeve adapter from the interior surface of the hollow ends of the cylinder. 
     In one embodiment, an apparatus for mounting a hollow cylindrical printing sleeve or printing sleeve adapter along the axis in a housing is provided, where the cylindrical printing sleeve or printing sleeve adapter has a first hollow end and a second hollow end. The apparatus includes a first device and a second device. The first device includes a first chuck attached to the housing, where the first chuck has a first plurality of jaws each having a grip end, and where the grip ends of the first plurality of jaws can move radially towards or away from the axis. The second device includes a second chuck attached to the housing, where the second chuck has a second plurality of jaws each having a grip end, and where the grip ends of the second plurality of jaws can move radially towards or away from the axis. The first plurality of jaws and the second plurality of jaws are spaced along the axis to accept the first hollow end and the second hollow end, respectively. While the first plurality of jaws and the second plurality of jaws are in the first and second hollow ends, the grip ends of the first plurality of jaws and the grip ends of the second plurality can be caused to extend radially away from the axis to grip, by friction, the first and the second hollow ends to mount the object within the housing. 
     In another embodiment, an apparatus for mounting a hollow cylindrical printing sleeve or printing sleeve adapter having a hollow cylindrical end in a housing is provided. The apparatus includes a chuck including a chuck body and a plurality of jaws each having a grip end and hinge end. The chuck body is attached to a shaft that is rotatably attached to the housing about an axis, and the each of the plurality of jaws is hinged at or near the hinge end to the chuck body to cause the grip ends to move radially in a plane perpendicular to said axis to accommodate different diameter hollow cylindrical printing sleeves or printing sleeve adapters. The apparatus also includes a first actuator operably connected to the plurality of jaws. The actuator includes a threaded rod that can move a cam that is in contact with the plurality of jaws, the thread coupled to one or more matching threaded portions in the shaft such that when the threaded rod is rotated relative to the shaft, the rod moves within the shaft to cause the cam to move the grip ends towards or away from the axis. The grip end may thus be caused to extend radially away from the axis to grip, by friction, the hollow end to mount the printing sleeve or printing sleeve adapter within the housing. 
     In yet another embodiment, a method of handling a flexographic sleeve, or sleeve on an adapter, having an axis and a length within a flexographic processing machine, is provided. The method includes restraining the sleeve by: placing a first end of the sleeve, or the adapter supporting the sleeve, over a first internal chuck; expanding the first internal chuck to restrain the sleeve, or the adapter supporting the sleeve; placing a second end of the sleeve, or the adapter supporting the sleeve, over a second internal chuck; and expanding the second internal chuck to restrain the second end of the sleeve, or the adapter supporting the sleeve. Each of the first and second internal chucks includes a plurality of fingers each having a grip end. Expanding each of the first and second internal chucks is by moving the grip ends radially out away from the axis. 
     Particular embodiments may provide all, some, or none of these aspects, features, or advantages. Particular embodiments may provide one or more other aspects, features, or advantages, one or more of which may be readily apparent to a person skilled in the art from the figures, descriptions, and claims herein. 
     Some Example Embodiments 
       FIG. 1A  shows side view image of an embodiment of a cylindrical printing sleeve or printing sleeve adapter support device  100 . Device  100  includes a base body  107  supporting a chuck  110  comprising a chuck body  118  attached to a shaft  104 , the chuck body  119  having a jaw alignment portion  112 , a plurality of jaws  113  each having a grip end  109  and a hinge end, one or more of springs  114  attached to the jaws, and an actuator  120  having a knob  121 , a rod  123 , and an interlock  126  to restrain motion of the chuck. The chuck body  118  and shaft  104  are rotatably attached to the housing so that they rotate about axis  104 . When the interlock  126  is used, the rod  123  and shaft  104  rotate together about the housing. As shown in  FIG. 1A , chuck  110  and actuator  120  are generally aligned along an axis  105 , which is also the axis of the shaft  104 . As described subsequently, when rod  123  is moved along its length along axis  105  relative to the shaft  104 , jaws  113  rotate about respective jaw axes of rotation near their respective hinge ends so that their respective grip ends  109  move radially towards or away from the axis. In certain embodiments, the movement of jaws  113  permit chuck  110  to be used as an internal chuck that may be used to grip and therefore support the inner cylindrical surface of a flexographic sleeve or sleeve adapter during exposure to UV radiation and for other purposes. 
       FIG. 1B  illustrates one embodiment of device  100  that includes five jaws  113  symmetrically distributed about axis  105 . Chuck  110  as shown in  FIGS. 1A and 1B  is in an open configuration, with each grip end  109  of the plurality of jaws  113  in a position near axis  105  and arranged to fit within a circle C, formed by an outer surface of chuck body  118 , having a radius R 1  about axis  105 . Different embodiments can have a different number of jaws. 
       FIGS. 2 to 4  show side view images of device  100  with chuck  110  in different configurations.  FIG. 2  shows the chuck in a slightly closed configuration, and  FIGS. 3 and 4  shows the chuck in a more open configurations, i.e., with the grip ends  109  of the plurality of jaws  113  more expanded outwards in the radial direction than in  FIG. 2 . Specifically, in  FIG. 2  the grip ends  109  of the plurality of jaws  113  are radially expanded outwards from axis  105  to a radial distance of R 2 , R 2 &gt;R 1 , and in  FIG. 3  the grip ends  109  of the plurality of jaws  113  are radially expanded outwards from axis  105  to a radial distance of R 3 , R 3 &gt;R 2 . 
       FIG. 5A  shows a top perspective image and  FIG. 5B  shows an end view showing chuck  110  of  FIG. 1  in a closed configuration as having the grip ends  109  applying force, and thus restraining by friction the inner surface of a specific sleeve or sleeve adapter  10  having has an inner radius of R, which is greater than R 1 . Actuator  120  has been moved to expand the grip ends  109  applying of jaws  113  outwards such that grip ends  109  are in contact with the inner surface of the sleeve or sleeve adapter. 
     Device  100  is able to accommodate sleeves or sleeve adapters  10  having a large range of radii, each radius greater than R 1 . 
     In different embodiments, rod  123  may be connected to jaws  113  using linkages, springs, cams, rods, and/or threaded components (not shown in  FIG. 1A ) and which may be manipulated to cause the grip ends  109  of the jaws to move away from and towards axis  105 . In one embodiment, the rod  123  is threaded at least in parts, and is inserted into part of shaft  104  via threaded portions. The shaft can move a cam. Rotating the rod relative to the shaft  104  causes the rod to move longitudinally relative to the shaft  104 , which in turn causes the cam to move and such motion causes the grip ends of the jaws to open and close. 
     Thus, for example, the movement of jaws  113  described with reference to  FIGS. 1 to 5B  by rotating or pushing the actuator, depending on the particular mechanism within base body  107  in the particular embodiment. In certain embodiments, the action of spring  114  is not required to return the grip ends  109  of the jaws  113  towards axis  105 , and the spring may be an optional component. The movement of actuator  120  may be performed manually or, alternatively, automated by being driven by a motor. In certain embodiments, chuck  110  is free to rotate, or may be driven to rotate, about axis  105 . In certain other embodiments, chuck  110  does not rotate about axis  105 . 
     In the embodiment in rod  123  has an external thread, an interlock  126  is used to lock the rod relative to the shaft. In one embodiment, the interlock  126  has a thread that matched the thread on rod  123 . To lock, the interlock  126  is screwed against the shaft ( 104 ) such that the rod  123  and the shaft  104  are connected and rotating the rod  123  also causes the shaft  104  to rotate. This also fixes the actuator, and thus plurality of jaws  113 , relative to chuck body  118 . In one embodiment, the external thread in rod  123  on which the interlock  126  operates is the same external thread that is matched with threads in shaft  104 . In some such embodiments, the thread in the portion of rod  123  on which the interlock  126  operates is different that then thread that is matched with threads in shaft  104 . 
     In different embodiments, interlock  126  may include, for example, and without limitation, a ferrule (not shown) that crimps down on rod  123  when the interlock is rotated, fixing the actuator, and thus plurality of jaws  113 , relative to chuck body  118 . 
     As illustrated in  FIGS. 1 to 5B , actuator  120  may be moved by a user to cause the grip ends  109  of jaws  113  to move radially towards or away from central axis  105 . Thus, for example and described subsequently, a user may place an inner surface a cylindrical sleeve or sleeve adapter, the inner surface being cylindrical having a radius of R (where R&gt;R 1 ) along axis  105  and over the plurality of jaws  113 , and then may manipulate actuator  120 , causing the grip ends  109  of jaws  113  to expand radially outwards from axis  105  towards radius R. As shown in  FIG. 4 , the ends of jaws  113 , in one embodiment, have grip ends  109  that each includes a rubber tip for contact with the inner surface of a cylindrical tube. 
     Other embodiments may have a fewer number or greater number of jaws  113 . Thus, for example, and without limitation, alternative embodiments of device  100  may have 3, 4, 6, 7, or 8 jaws. 
     In an alternative embodiment, chuck  110  is rotatably mounted in base body  107  such that the chuck can rotate about axis  105 . In another alternative embodiment, a rotatably mounted chuck  110  is operably connected to a motor that rotates the chuck. 
     The internal structure and operation of device  100  is illustrated by example in  FIGS. 16 and 17 .  FIG. 16  is a simplified sectional view  16 - 16  of  FIG. 1B , showing the device in an open configuration, and  FIG. 17  is a simplified sectional view  17 - 17  of  FIG. 5B  showing the device in a closed configuration. These figures are not drawn to scale, and some aspects, such as threads, are shown exaggerated. Furthermore, rod  123  is shown in  FIGS. 16 and 17  as being threaded throughout the length of rod  123 , which in other embodiments, only portions of rod  123  are threaded. Device  100  of  FIGS. 16 and 17  is generally the same as device  100  of  FIGS. 1-5 , except where explicitly stated. For illustrative purposes only, and without limitation,  FIGS. 16 and 17  include dimensions, in millimeters, of one embodiment of device  100 . 
     As shown in the embodiment illustrated in  FIGS. 16 and 17 , device  100  includes hinges  1601 , a shaft  104  part of which is shown as  1603 , and having: an interior  1621 ; bearing rest surface  1615  and faceplate  1604 ; a tapered cam block  1605  having a curved cam surface  1625 ; bearings  1607 ,  1609 , and  1611 ; a lock nut  1613 ; and a belt  1619 . Interlock  126  includes a set of inner threads  124 , shaft  104  (shaft part  1603 ) includes a set of inner threads  125 , and rod  123  includes threads  122  that match threads  124  and  125 . Device  100  also includes an optional stop  127  including a hinge to rotate about axis  128 , and an optional pulley  1617  that may be used to rotate the shaft of the device. 
     Shaft  104  (including shaft part  1603 ) extends from interlock  126  to faceplate  1604  that is attached to chuck body  118  with screws (not shown). Bearings  1607 ,  1609 , and  1611  are in housings (not shown) that are attached to base body  107  and to shaft  104  to permit the shaft to rotate about axis  105  within the base body. Adjacent bearings  1609  and  1611  restrict axial motion of shaft  104  by being restrained between lock nut  1613 , which is threaded into the shaft part  1603  and the change in diameter forming bearing rest surface  1615 . 
     Rod  123  extends from knob  121 , is threaded through interlock  126  and through shaft interior  1621 . Rod  123  terminates at a conical end  1602  that rests against tapered block  1605 . When knob  121  is rotated, rod  123  moves along axis  105 , which may also allow tapered block  1605  to move along axis  105 . 
     Each jaw  113  is hinged to chuck body  118  with one of hinges  1601 . Each jaw may thus rotate to cause the grip end away from or towards axis  105 , with spring  114  providing a restorative force, urging jaw towards axis  105 . Cam surface  1625  of tapered block  1605  is in contact with curved back surface  1623  of jaw  113  and rotates the jaws when actuated. 
     Optional pulley  1617  is attached to shaft  1603 , permitting a belt  1619  attached to a motor  1618  to rotate chuck  110  and actuator  120  about axis  105 . Pulley  1617  may be, for example and without limitation, be a poly-V pulley for a poly-V belt. 
       FIGS. 16 and 17  illustrate the effect of rotating knob  121  from one extreme position to another. From the open position of  FIG. 16 , as knob  121  is rotated, rod  123  rotates and is pushed against tapered block  1605 , as forced by springs  114 . Surfaces  1623  and  1625  are curved to transfer the force applied from rod  123  to force each of jaws  113  to rotate to cause the respective jaw end of the jaws away from axis  105  and thus close chuck  11 . Stop  127  may be rotated between the positions shown in  FIGS. 16 and 17 , and provide a stand-off distance A for positioning a sleeve on device  100 . 
     Interlock  126  is also threaded into the shaft. When interlock  126  is rotated about rod  123  and against shaft  1603 , tension on threads  122 ,  124 , and  125  prevents rod  123  from moving, and thus prevents jaws  113  from returning towards axis  105 , restraining the motion of the rod along axis  105 . 
     When knob  121  is rotated to move chuck  110  back from the closed position of  FIG. 17  to the open position of  FIG. 16 , rod  123  rotates and tapered block  1605  moves way from jaws  113 . Spring  114  provides a restorative force to move the grip ends of jaws  113  towards the axis, with surface  1623  contacting surface  1625 . 
     Note that the method of interlocking using interlock  126  is only one way of locking the position of rod  121 , and other methods of interlocking would be clear to one of ordinary skill in the art, and within the scope of the present invention. 
     The use of device  100  is described, for illustrative purposes, in the side perspective image of  FIG. 6  as an embodiment of a machine  600  for flexographic sleeves. The machine has a first cylindrical printing sleeve or sleeve adapter support device  100   a  and a second cylindrical printing sleeve or sleeve adapter support device  100   b . In one embodiment, the shaft of one of devices  100   a  and  100   b  includes pulley  1617  for rotating the shaft of the device. At least one of devices  100   a  and  100   b  is slidably mounted on a rail  601 , and are otherwise generally similar to device  100 , except as explicitly stated. In one embodiment, one device is fixed, and the second device is slidable mounted on a rail  601 . When the chucks of each of the two devices hold a sleeve or sleeve adapter, and the shaft of one of the devices includes a pulley with a belt drive to a motor, and the motor used to rotate the pulley, the sleeve/sleeve adapter and both shafts of the devices rotate. 
     Machine  600  may be, for example and without limitation, a UV exposure unit used in flexographic processing. Thus, for example, a flexographic sleeve is exposed in an exposure unit. The flexographic sleeve, or the flexographic sleeve supported internally by a sleeve adapter, are then transferred into machine  600 . 
       FIGS. 7 to 15  show images of the flexographic processing machine  600  illustrating steps in the placement of a sleeve (or sleeve adapter)  10  having ends  11  and  13 .  FIGS. 7 and 8  illustrates sequential steps of a user placing sleeve or sleeve adapter  10  into the first device  100   a ,  FIGS. 9 ,  10 ,  11 , and  12  illustrate sequential steps of a user placing and securing a sleeve into the second device  100   b ,  FIGS. 13 and 14  illustrate sequential steps of a user securing the sleeve into the first device  100   a;  and  FIG. 15  is a image of a sleeve mounted into the flexographic processing machine utilizing the first and second devices. Sleeve (or sleeve adapter)  10  may be removed from machine  600  by reversing the steps of  FIGS. 7 to 15 . 
       FIG. 7  illustrates device  100   a  in an open configuration, such as in  FIG. 1 , and a user placing a sleeve or sleeve adapter between devices  100   a  and  100   b.    
       FIG. 8  illustrates the user moving end  11  towards, and then over device  100   a.    
       FIG. 9  illustrates the user sliding device  100   b  along rail  601  such that the device moves into end  13 . 
       FIG. 10  illustrates the user tightening a knob  603  of device  100   b  that fixes the position of device  100   b  on the rail. 
       FIG. 11  illustrates the user moving actuator  120  to expand the jaws and tighten the chuck  110  of device  100   b  against an inside surface and end  13 . 
       FIG. 12  illustrates interlock  126  of device  100   b  adjusted to fix the position of the grip ends  109  of jaws  113  of device  100   b  as, for example, in  FIGS. 5A and 5B . 
       FIG. 13  illustrates actuator  120  of device  100   a  adjusted to move the grip ends  109  of jaws  113  against the inside surface of end  11 , as, for example, in  FIGS. 5A and 5B . 
       FIG. 14  illustrates interlock  126  of device  100   a  adjusted to fix the position of the grip ends  109  of jaws  113  of device  100   a.    
       FIG. 15  shows the sleeve (or sleeve adapter)  10  mounted on devices  100   a  and  100   b  in machine  600 . With the sleeve (or sleeve adapter)  10  so mounted, one of device  100   a  or  100   b  may be driven by pulley  1617  to rotate both devices and the sleeve (or sleeve adapter). 
     In certain embodiments, devices  100   a  and  100   b  are sized to hold sleeve (or sleeve adapter)  10  having a range of lengths. In one embodiment, the range of lengths is any length denoted L of between 1 m to 2 m. In another embodiment, the range of lengths is 1.5 to 2.5 m. Other embodiments may hold a wider range of lengths, while others may hold a narrower range of lengths. Thus for example, and without limitation, for one example sleeve, L may be approximately 2.0 m. In certain other embodiments, devices  100   a  and  100   b  are sized to hold a sleeve or an adapter having an inside diameter of from 89 mm to 300 mm. Other embodiments may hold a wider range of diameters, while others may hold a narrower range of diameters. 
     Reference throughout this specification to “one embodiment,” “an embodiment,” and “certain embodiments” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” or “in certain embodiments” in various places throughout this specification is not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. 
     Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Description of Example Embodiments, with each claim standing on its own as a separate embodiment of this invention. 
     Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. 
     As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. 
     Any discussion of prior art in this specification should in no way be considered an admission that such prior art is widely known, is publicly known, or forms part of the general knowledge in the field. 
     In the claims below and the description herein, any one of the terms comprising, comprised of or which comprises is an open term that means including at least the elements/features that follow, but not excluding others. Thus, the term comprising, when used in the claims, should not be interpreted as being limitative to the means or elements or steps listed thereafter. For example, the scope of the expression a device comprising A and B should not be limited to devices consisting only of elements A and B. Any one of the terms including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising. 
     Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. For example, the devices or mechanisms presented are merely representative of devices or mechanisms that may be used. Steps may be added or deleted to methods described within the scope of the present invention.