Patent Publication Number: US-2012037557-A1

Title: Filter

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application claims the benefit of U.S. Provisional Patent Application No. 61/373,136, filed Aug. 12, 2010, which is incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Filters may be used to separate contaminants from a fluid. The contaminants may be particulate matter and/or other undesirable fluids. Filters may be used for many different applications. One application may be used for filtering fluids in vehicles, such as, trucks and automobiles. Examples of fluids which may be filtered may include fuel, oil, coolant, and other fluids. Examples of fuels may include diesel, bio-diesel, and gasoline. One potential use for a filter may be to separate water from a fuel, such as, separating water from bio-diesel. 
     The filter may be mounted onto a filter head. In some situations, the filter head may include a valve which may prevent the flow of fluid when the filter is not mounted to the filter head. The filter may include a projection which may engage the valve and allow the fluid to flow through the filter. 
     BRIEF SUMMARY OF THE INVENTION 
     The filter may include a first end cap, a second end cap, and a filter media. The filter media may be located between the first end cap and the second end cap. The filter media and the end caps may be located in a shell. An insert including a projection may be connected to the shell. The projection may engage a valve in the filter head when the filter is mounted onto a filter head. The projection may include a curved portion. The curved portion may engage a ball in the valve. 
     The filter media may be a coalescing media which may assist in separating water from a fuel and water mixture. The fuel and water mixture may enter the filter through an inlet opening. The fuel and water mixture may travel through the filter media. The filter media may aid in separating the water from the fuel. The water may sink to the bottom of the filter and the fuel may flow upward and through the outlet in the filter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a filter. 
         FIG. 2  is an exploded perspective view of the filter in  FIG. 1 . 
         FIG. 3  is a top view of the filter in  FIG. 1 . 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  in  FIG. 3 . 
         FIG. 5  is a side view of a second end cap. 
         FIG. 6  is a cross-sectional view taken along line  6 - 6  of  FIG. 5 . 
         FIG. 7  is a perspective view an insert. 
         FIG. 8  is a top view of the insert in  FIG. 7 . 
         FIG. 9  is a cross-sectional schematic representation of the fluid flow of the filter with a water sensor attached to the filter. 
         FIG. 10  is a cut away view of the filter attached to a filter head and a water sensor attached to the filter. 
         FIG. 11  is a cut away view of another embodiment. 
         FIG. 12  is a cut away view of another embodiment. 
         FIG. 13  is a cut away view of another embodiment. 
         FIG. 14  is a cut away view of another embodiment. 
         FIG. 15  is a perspective view of the insert and shield in  FIG. 14 . 
         FIG. 16  is a top view of the insert and shield in  FIG. 15 . 
         FIG. 17  is a cut away view of another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , the filter  100  may include a filter assembly  102 , an external grommet  104 , and an o-ring  105 . As shown in  FIG. 2 , the filter assembly  102  may include an internal grommet  106 , a lid  108 , an element assembly  110 , and a shell assembly  112 . The shell assembly  112  may include a shell  114  and an insert  116 . The insert  116  may include a projection  118 . 
     Referring to  FIGS. 2 and 4 , the element assembly  110  may include a first end cap  120 , a second end cap  122 , and a filter media  124 . The second end cap  122  may include an o-ring  126 . Referring to  FIG. 4 , the first end cap  120  may be attached to the filter media  124  with an adhesive  128  and the second end cap  122  may be attached to the filter media  124  with an adhesive  130 . The adhesive may be plastisol. In other embodiments, the adhesive may be epoxy, polyurethane, or hot melt. In other embodiments, the end caps may be attached to the filter media by other techniques, such as, ultrasonic welding, embedding, overmolding, or insert molding. The first end cap  120  may include an outer skirt  132  and an inner skirt  134 . The outer and inner skirts may be used to retain the adhesive when the media is positioned in the first end cap. In other embodiments, the first end cap may have an outer skirt but not an inner skirt, an inner skirt but not an outer skirt, or may not have an outer skirt nor an inner skirt. 
     The first end cap  120  may include standoffs  136 ,  138 . The standoffs may assist in holding the end of the filter media  124  away from the adjacent surfaces of the end cap in order to improve the seal created by the adhesive. The standoffs  136 ,  138  may have a circular configuration around the first end cap  120 , as shown in  FIG. 2 . In other embodiments, the standoffs may have other configurations, such as, a radial configuration, or a wavy line in a circular configuration. The standoffs may be continuous. In other embodiments, the standoffs may be discontinuous. In other embodiments, the first end cap may have a different number of stand offs, such as one, three, four, or more stand offs. Referring to  FIGS. 2 and 4 , the first end cap  120  may include an upper rib  140 . The upper rib  140  may provide stiffness or rigidity to the first end cap  120 . The upper rib  140  may have a circular configuration around the end cap, as shown in  FIG. 2 . In other embodiments, the upper rib may have other configurations, such as, a radial configuration, or a wavy line in a circular configuration. The upper rib may be continuous. In other embodiments, the upper rib may be discontinuous. In other embodiments, the first end cap may have two, three, four or more upper ribs. 
     Referring to  FIG. 2 , the first end cap  120  may include an opening  142 . The opening may engage the internal grommet  106 , as shown in  FIG. 4 . The first end cap  120  may be made of metal and may be formed to the particular shape. In other embodiments, the first end cap may be made of other materials, such as, plastic. 
     Referring to  FIG. 4 , the second end cap  122  may include an outer skirt  144  and an inner skirt  146 . The outer and inner skirts may be used to retain the adhesive when the media is positioned in the second end cap. In other embodiments, the second end cap may have an outer skirt but not an inner skirt, an inner skirt but not an outer skirt, or may not have an outer skirt nor an inner skirt. 
     Referring to  FIG. 4 , the second end cap  122  may include a standoff  148 . The standoff may assist in holding the end of the filter media  124  away from the adjacent surfaces of the second end cap in order to improve the seal created by the adhesive. The standoff  148  may have a circular configuration around the second end cap  122 , as shown in  FIG. 2 . In other embodiments, the standoff may have another configuration, such as, a radial configuration, or a wavy line in a circular configuration. The standoff may be continuous. In other embodiments, the standoff may be discontinuous. In other embodiments, the second end cap may have a different number of stand offs, such as two, three, four, or more stand offs. 
     Referring to  FIG. 4 , the second end cap  122  may have an opening  149 . The opening  149  may permit the insert  116  to pass through the second end cap  122 . In one embodiment, the insert  116  does not engage the second end cap  122 . In addition, the opening  149  may allow contaminants to travel to the bottom of the filter. 
     The second end cap  122  may have a seal to engage the shell  114 . Referring to  FIGS. 2 and 4 , the seal may be an o-ring  126 . The second end cap may have a groove  150 . The groove  150  may receive the o-ring  126 . The o-ring  126  may engage the shell  114 . The seal may be resilient and may deform or deflect to create a seal with the shell  114 . 
     In another embodiment, the seal may be a flange on the second end cap. Referring to  FIG. 11 , the filter  300  may be similar to the filter  100  except as noted below. The second end cap  322  may have a flange  326 . The flange  326  may engage the shell  314 . The flange  326  may be resilient and may deform or deflect to create a seal with the shell  314 . In one embodiment, the flange  326  may be molded as one piece with the second end cap  322 . In other embodiments, the flange and the second end cap may be overmolded or insert molded. 
     In another embodiment, the seal may be an axial seal on the second end cap. Referring to  FIG. 12 , the filter  400  may be similar to the filter  100  except as noted below. The second end cap  422  may have a seal  426 . The seal  426  may be located in a groove  450 . The seal  426  may be resilient and may deform or deflect to create a seal with the shell  414 . The seal  426  may engage a ledge  415  on the shell. In one embodiment, the seal  426  may have a rectangular cross-section. In other embodiments, the seal may have other cross-sections, such as, circular, beveled, or trapezoid. The filter may be designed to prevent movement of the element assembly  410  in the axial direction so that the seal  426  remains in contact with the shell  414 . 
     Referring to  FIGS. 2 and 5 , the second end cap  122  may include ribs  152  above the groove  150 . The ribs may assist in the assembly process. The ribs  152  may provide an indication to the assembly personnel that the o-ring  126  is not located in the groove  150 . For example, if the o-ring  126  was assembled on the second end cap  122  but positioned in the area of the ribs  152 , then the assembly personnel may notice that the o-ring  126  is not located in the groove  150 . If the ribs  152  were not present, then the improper location of the o-ring  126  in this area may be less noticeable to the assembly personnel. In addition, if the o-ring  126  was positioned in the area of the ribs  152 , then the second end cap  122  may not fit properly in the shell  114 . For example, referring to  FIG. 4 , if the o-ring  126  was positioned in the area of the ribs  152 , then the o-ring  126  may not move into the second portion  153  of the shell because the size of the mis-positioned o-ring  126  may be greater than the size of the second portion  153 . If the ribs  152  were not present, then the improper location of the o-ring  126  in this area may permit the mis-positioned o-ring  126  to move into the second portion  153  of the shell. In one embodiment, the second portion  153  of the shell may be smaller in size than the first portion  151  of the shell. Referring to  FIG. 6 , the ribs  152  may be oriented in a manner which facilitates removal from a two part mold. The second end cap  122  may be made from plastic. 
     The end cap, such as, the second end cap  122 , and the seal, such as, the o-ring  126 , may be different colors. The end cap may be a first color and the seal may be a second color. For example, the end cap may be a light color and the seal may be a dark color. For example, the end cap may be a white, a cream, or a tan color and the seal may be a black color. The different colors may provide an indication to the assembly personnel that the seal is not located in the groove  150 . Also, if a machine vision inspection system is used in the assembly process, the inspection system may be able to detect the improper assembly of the seal on the end cap. In another example, the end cap may have a grey color (such as a recycled plastic) and the seal may have a dark color, such as, a black color. In other embodiments, the end cap may have a dark color and the seal may have a light color. For example, the end cap may be a black color and the seal may be a green, a red, or a yellow color. 
     Referring to  FIG. 4 , the second end cap  122  may include a first portion  154  and a second portion  156 . The second portion may extend radially inwardly from the outside surface  158  of the first portion to form a ledge  160 . 
     Referring to  FIG. 2 , the filter media  124  may be a pleated material. In one embodiment, the pleated material may have approximately 65 to 71 pleats with a pleat width of approximately 3.36 inches and a pleat height of approximately 0.709 inches. In other embodiments, the pleated material may have a different number of pleats, pleat width, and/or pleat height. Furthermore, in other embodiments the filter media may be configured as wrapped media, string wound media, or corrugated media. In one embodiment, the pleated material may be from Ahlstrom Corporation, P.O. Box 329, Salmisaarenaukio 1, F1-00101 Helsinki, Finland as part number 98PCFFL-1. In one embodiment, the media may have layers of material. For example, the layers may be, starting from the inside layer to the outside layer: the first layer may be a cellulose blended base sheet; the second layer may be a microglass layer; the third layer may be a spunbonded layer; and the fourth layer may be a spunbonded layer. In other embodiments, the filter media may be made of chemically treated cellulose, melt blown synthetic, spun bonded synthetic, a microglass, or combinations thereof. One example of a filter media is described in U.S. Patent Publication 2009/0178970A1 to Stanfel et al and assigned to Ahlstrom Corporation, which is incorporated herein in its entirety. The filter media may filter particulate matter from the fluid. The filter media may be a coalescing media which may assist in separating water from another liquid, such as, fuel. The fuel may be diesel fuel, or biodiesel fuel. 
     Referring to  FIG. 2 , the insert  116  may include a projection  118 , a leg portion  162 , and a lower portion  164 . Referring to  FIG. 4 , the projection  118  may include a curved portion  166 . The curved portion  166  may assist in engaging a ball  168  in a valve  170  as shown in  FIG. 10 . In other embodiments, the projection may not have a curved portion. For example, the end of the projection may be substantially flat, or the end of the projection may have a pointed surface. Referring to  FIG. 7 , the projection  118  may also include fins  172 . In one embodiment, the projection may include five fins. In addition, the spaces  174  between the fins may permit more fluid to flow into the valve than if the spaces did not exist and were occupied with material. In other embodiments, the projection may include one, two, three, four, six or more fins. In other embodiments, the projection may not include fins. For example, the projection may be solid and have a width which is smaller, equal to, or greater than the width of the projection with the fins. 
     Referring to  FIGS. 7 and 8 , the leg portion  162  may include vertical support ribs  176 . The support ribs  176  may improve the strength of the leg portion without the additional material across the entire leg portion. The leg portion  162  may have three vertical support ribs  176 . In other embodiments, the leg portion may have one, two, four, or more support ribs. The leg portion may also include a horizontal support rib  178 . The horizontal rib  178  may facilitate the flow of material during the molding process. The horizontal rib  178  may also provide rigidity to the leg portion  162 . In other embodiments, the leg portion may have two, three, four or more horizontal support ribs. 
     Referring to  FIG. 7 , the lower portion  164  may include threads  180 . The threads may receive a water sensor  182  as shown in  FIG. 10 . Referring to  FIG. 7 , the lower portion  164  may include one or more outer ribs  184 . Referring to  FIG. 8 , the lower portion  164  may include eight ribs  184 . In other embodiments, the lower portion may include one, two, three, four, five, six, seven, nine, or more ribs. The ribs  184  may increase the strength of the lower portion  164 . Referring to  FIGS. 4 and 10 , the ribs  184  may also be used to engage the retention portions  186  of the shell in order to reduce rotation of the lower portion  164  relative to the shell  114 . The retention portions may be created by deforming the shell, such as, by staking. In one embodiment, the shell  114  may have four retention portions  186 . In other embodiments, the shell may have one, two, three, five, or more retention portions. 
     Referring to  FIG. 7 , the lower portion  164  may include a rib  185 . The rib  185  may extend around the outer surface of the lower portion  164 . Referring to  FIG. 4 , when the insert  116  is positioned in the shell  114 , the insert  116  may engage a lip  187  on the shell. The retention portion  186  may engage the insert  116 , such as, the upper surface of the rib  185 . The engagement with the retention portion may assist in retaining the insert  116  to the shell  114  and may assist in preventing upward movement of the insert  116  with respect to the shell  114 . The engagement may also assist in reducing rocking movement, and/or side to side movement of the insert  116  with respect to shell  114  so that the projection  118  can maintain the proper alignment with the outlet opening  196  as shown in  FIG. 4 . In another embodiment, the insert  116  may be attached to the shell  114  by other techniques, such as, by using an adhesive. The insert  116  may be made of plastic, such as, glass filled nylon. In other embodiments, the insert may be made of other plastics, such as, nylon, high density polyethylene (HDPE), or polyethylene terephthalate (PET), or combinations thereof. In other embodiments, the insert may be made of metal, such as, die cast aluminum. In other embodiments, the insert may be made of combinations of plastic and metal. 
     Referring to  FIG. 4 , in one embodiment, the projection  118  is not part of the first end cap  120  or the second end cap  122 . In addition, in one embodiment, the projection  118  is not connected to or attached to the first end cap  120  or the second end cap  122 . Furthermore, in one embodiment, the projection  118  does not engage the first end cap  120  or the second end cap  122 . 
     Referring to  FIGS. 2 and 3 , the lid  108  may include one or more inlet openings  188 . In one embodiment, the lid may include eight inlet openings. In other embodiments, the lid may include a different number of inlet openings. The lid  108  may also include threads  190 . The threads  190  may be used to engage threads on the filter head  246  as shown in  FIG. 10 . Referring to  FIG. 2 , the lid  108  may include one or more outer ribs  192 . The outer ribs  192  may be used to engage detents  194  in the shell  114 . The engagement of the ribs  192  with the detents  194  may prevent rotation between the lid  108  and the shell  114 . In one embodiment, the lid may include eight ribs. In other embodiments, the lid may include a different number of ribs, such as, one, two, three, four, five, six, seven, nine, or more ribs. 
     Referring to  FIG. 4 , the lid  108  may include an outlet opening  196 . The outlet opening  196  may have an inner surface  198  and an outer surface  200 . The inner surface  198  may engage the external grommet  104 . In order to retain the external grommet  104  to the lid  108 , the inner surface may include a ledge  202  which may engage a ledge  204  on the grommet  104 . In other embodiments, different techniques may be used to retain the external grommet to the lid. The external grommet  104  may engage the nipple  206  on the filter head as shown in  FIG. 10 . Referring to  FIG. 4 , the external grommet  104  may include one or more ribs  208 . The ribs  208  may assist in providing a seal with respect to the nipple  206  on the filter head as shown in  FIG. 10 . In one embodiment, the grommet may include two ribs. In other embodiments, the grommet may include one, three, four, or more ribs. 
     Referring to  FIG. 4 , the outer surface  200  of the outlet opening  196  may engage the internal grommet  106 . The internal grommet  106  may include a ledge  210 . The ledge  210  may engage the first end cap  120  in order to assist in retaining the internal grommet  106  with respect to the first end cap  120 . The internal grommet  106  may include a rib  212  on the interior surface. The rib  212  may be used to assist in providing a seal with the outer surface  200  of the outlet opening  196 . In other embodiments, the internal grommet may include two, three, or more internal ribs. 
     Referring to  FIG. 2 , the shell  114  may include one or more detents  194 . The detents  194  may be used to engage the outer ribs  192  on the lid  108 . The ribs and detents may assist in preventing rotation between the lid  108  and the shell  114 . In one embodiment, the shell may include eight detents. In other embodiments, the shell may include a different number of detents, such as, one, two, three, four, five, six, seven, nine, or more detents. In one embodiment, the shell may be made of metal, such as, tin plated steel, aluminum, or stainless steel. The metal may have a coating, such as, an epoxy coating if appropriate. In other embodiments, the shell may be made of plastic, such as, nylon, high density polyethylene (HDPE), polyethylene terephthalate (PET), or combinations thereof. In one embodiment, the shell and the insert may be molded from plastic. The shell and insert may be molded as one piece, may be overmolded, or may be insert molded. For example, referring to  FIG. 13 , the filter  500  may be similar to filter  100  except that the shell  514  and the insert  516  may be molded as one piece. 
     Referring to  FIG. 4 , the shell may include a ledge  214 . The element assembly  110  may move in the longitudinal direction with respect to the shell  114 . The ledge  214  may act as a stop for the second end cap  122  to assist in preventing downward movement of the element assembly  110 . The bottom of the lid  108  may act as a stop to assist in preventing the upward movement of the element assembly  110  when the internal grommet  106  engages the lid  108 . The o-ring  126  may assist in providing a seal between the second end cap  122  and the side wall of the shell  114 . 
     The filter assembly  100  may be assembled in the following manner. Referring to  FIGS. 2 and 4 , the insert  116  may be positioned into the shell  114 . The shell  114  may be deformed at the retention portions  186 , such as, by staking. The element assembly  110  may be inserted into the shell  114 . The o-ring  126  may engage the sidewall of the shell  114 . The internal grommet  106  may be assembled to the opening  142  on the first end cap  120 . The lid  108  may be inserted into the shell  114 . The top  216  of the shell  114  may be deformed over the lid  108  to hold the lid onto the shell. The external grommet  104  may be positioned in the outlet opening  196  on the lid  108 . 
     In another assembly method, some of the steps may be different. After the insert  116  is attached to the shell  114 , the internal grommet  106  may be assembled to the opening  142  on the first end cap  120  of the element assembly  110 . The lid  108  may be inserted into the internal grommet  106  on the element assembly  110 . The combination of the internal grommet  106 , the lid  108  and the element assembly  110  may be inserted into the shell. The top  216  of the shell  114  may be deformed over the lid  108 . 
     Referring to  FIG. 9 , the filter  100  may operate in the following manner. The fuel and water mixture  218  may enter the filter  100  through the openings  188  in the lid  108 . The fuel and water mixture  218  may travel through the filter media  124 . The filter media  124  may facilitate the separation of the water  220  from the fuel  222 . The water  220  may sink to the bottom of the filter and may remain at the bottom of the filter until the water  220  is drained through a drain valve  224 . The fuel  222  may flow upward and through the outlet opening  196  in the filter. 
       FIG. 10  shows the filter  100  installed on a filter head  226 , the projection  118  may open the valve  170  in the filter head. More specifically, the curved portion  166  of the projection may engage the curved surface of the ball  168  in the valve  170 . The ball  168  may move upward against the spring and the ball  168  may unseat from the seating surface on the valve. Fuel may flow around the projection  118  and between the fins  172  of the projection  118  into the valve. The external grommet  104  may create a seal with the nipple  206  on the filter head. In addition, the o-ring  126  may create a seal on the filter head. A water sensor  182  may be installed onto the filter  100 . Referring to  FIG. 9 , the water sensor  182  may include a seal  228 , such as, an o-ring, to create a seal between the water sensor  182  and the filter  100 . 
     Referring to  FIG. 14 , another embodiment of a filter is shown. The filter  600  may be similar to filter  100  except as noted below. The filter  600  may include a shield  619 . The shield  619  may prevent the water which has collected at the bottom of the filter from moving upward. In one embodiment, the shield  619  may have a domed shape. In other embodiments, the shield may have other shapes, such as, a conical shape, a flat shape, or a pyramid shape. The shield  619  may be spaced away from the second end cap  622  and the filter media  624  to create a gap  625 . The gap  625  may permit the water which coalesces on the filter media to travel downward through the gap  625 . The water may then collect at the bottom of the filter  600 . However, the size of the gap is small enough to assist in preventing a significant portion of the water at the bottom of the filter from moving upward. The shield  619  may be connected to the insert  616 . The shield  619  may be attached to the insert  616  by a friction fit, adhesive, ultrasonic welding, or mechanical attachment, such as, a rib on the insert, or a hook on the shield which engages a portion of the insert. The insert  616  may have a cylindrical portion  627  which may facilitate with the attachment. In other embodiments, the shield may be in other locations. In other embodiments the shield may be connected to other parts. For example, the shield may be attached to the second end cap or the filter media. In other embodiments, the shield may or may not be attached to the insert. 
     Referring to  FIGS. 15 and 16 , the shield  619  may extend around the insert. The shield  619  may engage the sides of the leg portion  662  on the insert. The shield may extend approximately 301 degrees around the insert. The leg portion  662  of the insert may act as a shield in the remaining 59 degrees. In other embodiments, the angles of the shield and insert may be different combinations of angles. In other embodiments, the shield may extend 360 degrees around the insert. The shield may be made of plastic, metal, or another material, such as, a hydrophobic material. 
     Referring to  FIG. 17 , another embodiment of a filter is shown. The filter  700  may be similar to filter  100  except as noted below. The filter  700  may include a first element assembly  710  and a second element assembly  711 . The first element assembly  710  may include a first end cap  720 , a second end cap  722 , and a first filter media  724 . The second element assembly  711  may include a third end cap  721 , a fourth end cap  723 , and a second filter media  725 . The third end cap  721  may be connected to the first end cap  720 . The third end cap  721  may be attached to the first end cap  720  with the adhesive  730 . In other embodiments, the third end cap  721  may be attached to the first end cap  720  with a mechanical attachment. In other embodiments, the third end cap  721  and the first end cap  720  may be molded as one piece, may be overmolded, or may be insert molded. The third end cap  721 , the fourth end cap  723 , and the second filter media  725  may be connected in the manners described herein with respect to the first element assembly  110 . 
     The fourth end cap  723  may include a seal  729 . The seal  729  may engage the insert  716 . In one embodiment, the seal  729  may engage the cylindrical portion  727  of the insert  716 . The seal  729  may have a groove which may engage an edge of the fourth end cap  723 . In other embodiments, the seal and the fourth end cap may be overmolded or insert molded. In other embodiments, the seal may be a flange which may be molded as one piece with the fourth end cap. In other embodiments, the seal may be attached to the fourth end cap with a press fit, an adhesive, or ultrasonic welding. 
     The filter media  725  may provide additional filtration of contaminants, such as, particulate matter and undesirable fluids. The filter media  725  may have a construction similar to the filter medias described herein with respect to filter media  124 . The filter media  725  may also have an outer layer which prevents the entry of water droplets. For example, the outer layer may be a hydrophobic layer, such as, a silicone treated media, or a silicone coated nylon screen. The outer layer may assist in preventing the water which has collected at the bottom of the filter from moving upward into the outlet opening  796 . 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.