Patent Publication Number: US-2016220926-A1

Title: Injector Inlet Fuel Screen

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to ring filters and, more particularly, to injector inlet fuel screens configured to ensure that flow paths being filtered by the screens are not obstructed by the screens. 
     BACKGROUND 
     In internal combustion engines, various fluids flow through the engine during operation for different purposes. For example, fuel flows from a fuel source through a fuel injector for discharge into a combustion chamber, and oil flows from an oil source through a control valve and into an area of the engine where the oil provides lubrication between moving parts. Often, the fuel injectors or control valves have hollow cylindrical bodies with radially extending circumferentially spaced fluid inlet ports allowing fluid from the source to enter the interior of the cylindrical body. In many cases, the cylindrical bodies have four circumferentially spaced fluid inlet ports. 
     In these types of fluid systems, and particularly in fuel injection systems, problems may arise with debris ingestion from the fluid intake side of the system. Debris may come from many sources. Particulate matter may enter the fluid when other components of the system fail, such as fuel pumps or oil pumps. Contamination of the fluid may also occur when components of the system are serviced or replaced. Contaminants may also be present in the fluid due to the machine working environment or fluid storage issues. In some implementations, debris from the fluid may account for a significant portion of total warranty repairs and replacements in a fuel injector family. The primary failures are a consequence of fluid intake side debris plugging the tips of the injectors, and result in reduced power, combustion misfiring and rough idling. 
     Band or ring type filters for filtering fluid flow through fluid inlet ports in fluid conducting bodies such as fuel injectors and control valves are known in the art. Such a filter is mounted, for example, on the hollow cylindrical member such as the control valve body or the fuel injector body for capturing extraneous materials in the fluid to prevent the inclusion of the extraneous materials into the cylindrical member. One example of such a ring filter for a fuel injector is disclosed in U.S. Pat. No. 5,807,483 to Cassidy et al. that teaches a filter ring including first and second semi-annular, band-shaped filter portions, an integrally formed hinge means for pivotally interconnecting the filter portions, and a snap latch mechanism for detachably connecting the opposite ends of the filter portions. The snap latch mechanism allows the filter ring to be removed without damage, whereupon it may be cleaned and reused many times before requiring replacement. Four semi-annular frames define four filter apertures with strips of filter mesh that correspond to the inlet ports of the fuel injector. 
     Ring filters of this type include components such as the hinge and the snap latch mechanism that may be prone to failure during the normal use and life of the ring filters, thereby necessitating premature replacement. Moreover, alignment of the ring filter is critical so that the frames do not overlay the inlet ports and obstruct the flow of fluid into the cylindrical body where the number of frames matches the number of inlet ports. Alignment must be assured during installation of the ring filter, which requires additional assembly time, or alignment mechanisms are provided on the cylindrical body and/or the ring filter, which increases the cost of the parts. In view of this, opportunities exist for improved ring filters that are less prone to failure and do not require excessive installation time and effort or additional alignment features to ensure the desired fluid flow through the ring filter. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, an injector inlet fuel screen is disclosed. The injector inlet fuel screen may include a first annular ring, a second annular ring, and a plurality of support ribs extending axially between and connecting the first annular ring and the second annular ring. The plurality of support ribs may be circumferentially spaced about the first annular ring and the second annular ring, and each adjacent pair of the plurality of support ribs and corresponding portions of the first annular ring and the second annular ring may define a filter window. At least one of the plurality of support ribs may have a generally rectangular cross-section and at least one of the plurality of support ribs may have a generally parallelogram-shaped cross-section with no right angles. The injector inlet fuel screen may further include a plurality of wire mesh panels, with each wire mesh panel overlaying a corresponding one of the filter windows. 
     In another aspect of the present disclosure, an injector inlet fuel screen for a cylindrical fluid conducting body having four radially extending fluid inlet ports circumferentially spaced about the fluid conducting body is disclosed. The injector inlet fuel screen may include a first annular ring, a second annular ring, and first, second, third, fourth, fifth and sixth support ribs extending axially between and connecting the first annular ring and the second annular ring. The first, second, third, fourth, fifth and sixth support ribs may be approximately circumferentially spaced about first annular ring and the second annular ring, with the second support rib disposed between the first support rib and the third support rib, the third support rib disposed between the second support rib and the fourth support rib, the fourth support rib disposed between the third support rib and the fifth support rib, the fifth support rib disposed between the fourth support rib and the sixth support rib, the sixth support rib disposed between the first support rib and the fifth support rib. Each adjacent pair of the first, second, third, fourth, fifth and sixth support ribs and corresponding portions of the first annular ring and the second annular ring may define a filter window. The injector inlet fuel screen may further include a plurality of wire mesh panels, with each wire mesh panel overlaying a corresponding one of the filter windows and being retained by the adjacent pair of the first, second, third, fourth, fifth and sixth support ribs and corresponding portions of the first annular ring and the second annular ring defining the filter window. 
     Additional aspects are defined by the claims of this patent. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an injector inlet fuel screen in accordance with the present disclosure; 
         FIG. 2  is a top view of the injector inlet fuel screen of  FIG. 1 ; 
         FIG. 3  is a front view of the injector inlet fuel screen of  FIG. 1 ; 
         FIG. 4  is a side view of the injector inlet fuel screen of  FIG. 1 ; 
         FIG. 5  is a cross-sectional view of the injector inlet fuel screen of  FIG. 1  taken through line  5 - 5  of  FIG. 4 ; 
         FIG. 6  is a perspective view of the injector inlet fuel screen of  FIG. 1  installed on an exemplary fuel injector body; 
         FIG. 7  is a cross-sectional view of the injector inlet fuel screen and fuel injector body taken through line  7 - 7  of  FIG. 6  with the injector inlet fuel screen in a first position relative to the fuel injector body; 
         FIG. 8  is the cross-sectional view of the injector inlet fuel screen and fuel injector body of  FIG. 7  with the injector inlet fuel screen rotated to a second position relative to the fuel injector body; 
         FIG. 9  is the cross-sectional view of the injector inlet fuel screen and fuel injector body of  FIG. 7  with the injector inlet fuel screen rotated to a third position relative to the fuel injector body; and 
         FIG. 10  is the cross-sectional view of the injector inlet fuel screen and fuel injector body of  FIG. 7  with the injector inlet fuel screen rotated to a fourth position relative to the fuel injector body. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows one embodiment of an injector inlet fuel screen  10  in accordance with the present disclosure. The injector inlet fuel screen  10  may be configured to fit over fuel inlet ports of a fuel injector body (not shown) to prevent debris in the fuel from entering the fuel inlet ports as will be described further below. However, application of the fuel screen  10  may not be limited to fuel injectors, and the fuel screen  10  may be configure for use on other types of fluid conducting bodies having cylindrical shapes and fluid inlet ports. The injector inlet fuel screen  10  may have a generally cylindrical form and include a first or upper annular band or ring  12 , a second or lower annular band or ring  14  and a plurality of axially-extending support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  connecting the first ring  12  to the second ring  14 . The annular rings  12 ,  14  may be fabricated from an appropriate resilient material such as nylon with 13% fiberglass reinforcement, or other appropriate materials such as polyurethane, polyethylene, polypropylene that are known in the art. It should be noted that the terms “first,” “second,” “upper,” and “lower” are used for reference and clarity of description of the components of the fuel screen  10  and are not intended to be limiting in the following description. 
     The annular rings  12 ,  14  have similar configurations and are centered on a common longitudinal axis A. The first annular ring  12  has cylindrical inner surface  12   a , a cylindrical outer surface  12   b , an annular outward surface  12   c , an annular inward surface  12   d  and a chamfered or beveled edge  12   e  between the outer surface  12   b  and the outward surface  12   c . Similarly, the second annular ring  14  has an inner surface  14   a , an outer surface  14   b , an outward surface  14   c , and inward surface  14   d  and a beveled edge  14   e . Referring to the top view of  FIG. 2 , the inner surfaces  12   a ,  14   a  have a constant and equal inner diameter, and the outer surfaces  12   b ,  14   b  have a constant and equal outer diameter. With the annular rings  12 ,  14  axially aligned and configured as shown, the fuel screen  10  is symmetrical about a plane perpendicular to the longitudinal axis A and positioned midway between the annular rings  12 ,  14 . 
     Referring back to  FIG. 1 , the six support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  are circumferentially spaced about the annular rings  12 ,  14 . The support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  are not necessarily evenly spaced about the annular rings  12 ,  14 . Consequently, the adjacent pairs of the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  may be circumferentially spaced apart by approximately 60°, or by angles of greater than or less than 60°. Each adjacent pair of the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  along with corresponding portions of the inward surfaces  12   d ,  14   d  of the annular rings  12 ,  14 , respectively, define a filter window  28 ,  30 ,  32 ,  34 ,  36 ,  38  that will allow fluid to flow radially through the fuel screen  10 . As the spacing between the supports ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  may vary depending on the exact positioning of the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26 , the widths of the filter windows  28 ,  30 ,  32 ,  34 ,  36 ,  38  may not necessarily be equal as may be seen in  FIGS. 3 and 4  where the width of the filter windows  30  may be greater than the widths of the filter windows  32 ,  34 . 
     Wire mesh panels  40 ,  42 ,  44 ,  46 ,  48 ,  50  may overlay corresponding filter windows  28 ,  30 ,  32 ,  34 ,  36 ,  38  to capture debris in the fluid and prevent the debris from entering the fluid conducting body on which the fuel screen  10  is disposed through the filter windows  28 ,  30 ,  32 ,  34 ,  36 ,  38 . The wire mesh panels  40 ,  42 ,  44 ,  46 ,  48 ,  50  may be portions of a continuous wire mesh band that may be embedded within the annular rings  12 ,  14  and the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26 , or may be individual wire mesh panels installed within the filter windows  28 ,  30 ,  32 ,  34 ,  36 ,  38 . These alternatives, as well as alternative fabrication methods for the fuel screen  10  are discussed further below. The wire mesh panels  40 ,  42 ,  44 ,  46 ,  48 ,  50  may be fabricated from an appropriate material with appropriately sized openings to capture large debris while allowing the fluid and debris of sufficiently small size as to not pose a significant risk to the performance of the fluid conducting body to flow through the wire mesh. In one implementation, the wire mesh panels  40 ,  42 ,  44 ,  46 ,  48 ,  50  may be fabricated from stainless steel wire cloth having mesh openings of approximately 65 microns. Of course, other materials and other mesh openings sizes may be used as dictated by the operating requirements for the fuel screen  10 . 
     The support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  are configured to reduce the risk and amount of obstruction of the inlet ports of the flow conducting body, and to more effectively direct the flow of fluid to and through the filter windows  28 ,  30 ,  32 ,  34 ,  36 ,  38 . The cross-sections of the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  are shown in greater detail in  FIG. 5 . The support ribs  16 ,  22  are positioned diametrically opposite each other and have generally rectangular cross-sections. Inner surface  16   a ,  22   a  are flush with the inner surfaces  12   a ,  14   a  of the annular rings  12 ,  14 , respectively, and have a slight concave curvature matching the curvature of the inner surfaces  12   a ,  14   a . Outer surfaces  16   b ,  22   b  of the support ribs  16 ,  22  are flush with the outer surfaces  12   b ,  14   b  of the annular rings  12 ,  14 , respectively, and have a slight convex curvature matching the curvature of the outer surfaces  12   b ,  14   b . In alternative embodiments, the outer surfaces  16   b ,  22   b , maybe be positioned inwardly or outwardly from the outer surfaces  12   b ,  14   b , and may be generally planar and not match the curvature of the outer surfaces  12   b ,  14   b.    
     The support ribs  16 ,  22  further include oppositely disposed lateral surfaces  16   c ,  16   d ,  22   c ,  22   d  extending between the inner surfaces  16   a ,  22   a  and the outer surfaces  16   b ,  22   b . The lateral surfaces  16   c ,  16   d ,  22   c ,  22   d  may be planar as shown, with the lateral surfaces  16   c ,  16   d  of the support rib  16  being parallel to each other and the lateral surfaces  22   c ,  22   d  of the support rib  22  being parallel to each other. The lateral surfaces  16   c ,  16   d ,  22   c ,  22   d  may also be parallel to a diametral line  52  bisecting the support ribs  16 ,  22  such that the lateral surfaces  16   c ,  22   d  are approximately coplanar and the lateral surfaces  16   d ,  22   c  are approximately coplanar as indicated by the dashed lines  54 ,  56 , respectively. In alternative embodiments, the support ribs  16 ,  22  may have cross-sections more closely approximating trapezoids, with the lateral surfaces  16   c ,  16   d ,  22   c ,  22   d  tapering inwardly or outwardly as they extend from the outer surfaces  16   b ,  22   b  toward the inner surfaces  16   a ,  22   a.    
     The support ribs  18 ,  20 ,  24 ,  26  are distributed on the annular rings  12 ,  14  with the support ribs  18 ,  20  disposed on one side of the support ribs  16 ,  22  and the support ribs  24 ,  26  disposed on the opposite side of the support ribs  16 ,  22 . The cross-sections of the support ribs  18 ,  20 ,  24 ,  26  are different than the cross-sections of the support ribs  16 ,  22 , and more closely approximate a parallelogram that does not have right angles. As with the support ribs  16 ,  22 , the support ribs  18 ,  20 ,  24 ,  26  have inner surfaces  18   a ,  20   a ,  24   a ,  26   a  that are flush with the inner surfaces  12   a ,  14   a  of the annular rings  12 ,  14  and slightly concave to match the curvature of the inner surfaces  12   a ,  14   a . Outer surfaces  18   b ,  20   b ,  24   b ,  26   b  are flush with the outer surfaces  12   b ,  14   b  of the annular rings  12 ,  14  and slightly convex to match the curvature of the outer surfaces  12   b ,  14   b . In alternative embodiments, the outer surfaces  18   b ,  20   b ,  24   b ,  26   b  maybe be positioned inwardly or outwardly from the outer surfaces  12   b ,  14   b , and may be generally planar and not match the curvature of the outer surfaces  12   b ,  14   b.    
     The support ribs  18 ,  20 ,  24 ,  26  further include oppositely disposed lateral surfaces  18   c ,  18   d ,  20   c ,  20   d ,  24   c ,  24   d ,  26   c ,  26   d  extending between the inner surfaces  18   a ,  20   a ,  24   a ,  26   a  and the outer surfaces  18   b ,  20   b ,  24   b ,  26   b . Similar to the lateral surfaces  16   c ,  16   d ,  22   c ,  22   d , the lateral surfaces  18   c ,  18   d ,  20   c ,  20   d ,  24   c ,  24   d ,  26   c ,  26   d  may be planar as shown, with the lateral surfaces  18   c ,  18   d ,  20   c ,  20   d ,  24   c ,  24   d ,  26   c ,  26   d  of each of the support ribs  18 ,  20 ,  24 ,  26  being parallel to each other. However, because the support ribs  18 ,  20 ,  24 ,  26  approximate parallelograms, the lateral surfaces  18   c ,  18   d ,  20   c ,  20   d ,  24   c ,  24   d ,  26   c ,  26   d  are not parallel to diametral lines of the annular rings  12 ,  14 . Instead, the lateral surfaces  18   c ,  18   d ,  20   c ,  20   d ,  24   c ,  24   d ,  26   c ,  26   d  of each of the support ribs  18 ,  20 ,  24 ,  26  are angled away from the adjacent support rib  16 ,  22  and toward the adjacent support rib  18 ,  20 ,  24 ,  26  as the support ribs  18 ,  20 ,  24 ,  26  extend inwardly from the outer surfaces  12   b ,  14   b  toward the inner surfaces  12   a ,  14   a . For example, the lateral surfaces  18   c ,  18   d  of the support rib  18  are angled away from one adjacent support rib  16  and toward the other adjacent support rib  20 . In the illustrated embodiment, the lateral surfaces  18   c ,  18   d ,  20   c ,  20   d ,  24   c ,  24   d ,  26   c ,  26   d  are angled to an extent where the support ribs  18 ,  20  are aligned with the lateral surfaces  18   c ,  18   d  being approximately coplanar with the lateral surfaces  20   d ,  20   c , respectively, as indicated by dashed lines  58 ,  60 , and the support ribs  24 ,  26  are aligned with the lateral surfaces  24   c ,  24   d  being approximately coplanar with the lateral surfaces  26   d ,  26   c , respectively, as indicated by dashed lines  62 ,  64 . 
     INDUSTRIAL APPLICABILITY 
     With the configuration illustrated and described herein, the fuel screen  10  does not require precise orientation and alignment to ensure sufficient fluid flow into the inlet ports of a fluid conducting on which the fuel screen  10  is installed. For example,  FIG. 6  illustrates the fuel screen  10  installed on a fluid conducting body in the form of a fuel injector nozzle  100  over an injector nozzle case  101 . As shown, the fuel screen  10  was installed on the injector nozzle case  101  starting by inserting a tip  102  through the annular ring  12  and sliding the fuel screen  10  all the way up to the portion of the injector nozzle case  101  having the fuel inlet ports (not shown). The fuel inlet ports may extend through an outer surface of the injector nozzle case  101  within an annular groove cavity. As the fuel screen  10  slides up the injector nozzle case  101 , the annular rings  12 ,  14  may pass a section of greater outer diameter than the inner diameter of the fuel screen  10  before reaching the groove cavity and being engaged thereby to prevent substantial axial movement of the fuel screen  10  on the injector nozzle case  101 . Depending on the outer diameter of the injector nozzle case  101  within the groove cavity, the fuel screen  10  may fit snuggly in the groove cavity to prevent rotation of the fuel screen  10 , or the fuel screen  10  may be able to rotate around the groove cavity when the fuel injector nozzle  100  is operating. 
     After installation of the fuel screen  10  on the nozzle  100 , assembly of the fuel injector may be completed by inserting the injector nozzle case  101  into a fuel injector bore (not shown) of an engine header (not shown). During insertion, the beveled edge  14   e  of the annular ring  14  may assist in aligning the injector nozzle case  101  within the injector bore. Due to the symmetry of the fuel screen  10 , the fuel screen  10  is reversible so that the fuel screen  10  may be flipped and the tip  102  may first be inserted through the annular ring  14  without affecting the functioning of the fuel screen  10  to filter debris from fluids. 
     In previously known fuel screens and filter rings, the number of the support ribs ( 4 ) of the filter ring typically matches the number of fluid inlet ports ( 4 ) of the fluid conducting body on which the filter ring is installed. This condition allows for the possibility that each of the support ribs can align with a corresponding one of the fluid inlet ports and thereby significantly reduce the amount of fluid flow into the inlet ports and the fluid conducting body. In some implementations of filter rings, a further alignment mechanism is designed into the filter ring and/or the fluid conducting body to ensure proper alignment of the filter ring without obstructing the inlet ports. In contrast as shown in  FIGS. 7-10 , the fuel screen  10  in accordance with the present disclosure and including six support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  minimizes obstruction of the flow paths into the injector nozzle case  101  without the necessity of an additional alignment mechanism. 
     Referring to the cross-sectional view of  FIG. 7 , the injector nozzle case  101  may have a generally cylindrical housing  104  having four radially extending fuel inlet ports  106 ,  108 ,  110 ,  112  evenly circumferentially spaced about the housing  104  at the location where the fuel screen  10  is installed. In the orientation of the fuel screen  10  shown in  FIG. 7 , the diametrically opposite support ribs  16 ,  22  are aligned with the fuel inlet ports  106 ,  110  and partially obstruct fuel flow there through. However, at the same time, the filter windows  30 ,  36  are aligned with the remaining fuel inlet ports  108 ,  112  and allow fuel to flow into the fuel inlet ports  108 ,  112  without obstruction. 
     In  FIG. 8 , the fuel screen  10  is rotated approximately 22.5° relative to the housing  104  of the injector nozzle case  101 . In this position, the support ribs  16 ,  22  are rotated out of alignment with the fuel inlet ports  106 ,  110 , and fuel inlet ports  106 ,  110  are now aligned with the filter windows  28 ,  34 . At the same time, the support ribs  20 ,  26  partially overlay the fuel inlet ports  108 ,  112 . Due to the parallelogram cross-sections of the support ribs  20 ,  26 , the angled lateral surfaces  20   d ,  26   d  will assist in directing fuel flow into the fuel inlet ports  108 ,  112  as fuel engages the lateral surfaces  20   d ,  26   d  and is guided toward the fuel inlet ports  108 ,  112 . 
     The fuel screen  10  is rotated an additional approximately 22.5° in the same direction in  FIG. 9 . In this position, each of the fuel inlet ports  106 ,  108 ,  110 ,  112  is slightly overlaid and obstructed by one of the parallelogram-shaped support ribs  18 ,  20 ,  24 ,  26 , respectively. Despite the slight obstruction, the angle of the lateral surfaces  18   d ,  20   c ,  24   d ,  26   c  may assist in directing fuel flow into the fuel inlet ports  106 ,  108 ,  110 ,  112  so that sufficient fuel reaches the interior of the injector nozzle case  101 . An additional rotation of approximately 22.5° is shown in  FIG. 10 . In this position, the fuel inlet ports  108 ,  112  are unobstructed and aligned with the filter windows  32 ,  38 , respectively, and the fuel inlet ports  106 ,  110  are partially obstructed by the support ribs  18 ,  24  in a similar manner as the fuel inlet ports  108 ,  112  were partially obstructed by the support ribs  20 ,  26  in FIG.  8 . As can be seen through the series of rotations, the obstruction of the fuel inlet ports  106 ,  108 ,  110 ,  112  is minimized at any position of the fuel screen  10  through the use of a different number of support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  than fuel inlet ports  106 ,  108 ,  110 ,  112  provided in the fluid conducting body, and by configuring the cross-sections of the support ribs  18 ,  20 ,  24 ,  26  in a manner that promotes fluid flow into the fuel inlet ports  106 ,  108 ,  110 ,  112  when partial obstruction does occur. 
     The fuel screen  10  may be fabricated using any appropriate manufacturing method. In one alternative fabrication method, the wire mesh panels  40 ,  42 ,  44 ,  46 ,  48 ,  50  may be provided by a single continuous wire mesh band embedded within the annular rings  12 ,  14  and the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26 . After the wire mesh band is formed, the annular rings  12 ,  14  and the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  may be over-molded thereon as a single integral unitary component using a molding process such as injection molding. In an alternative fabrication method, the wire mesh panels  40 ,  42 ,  44 ,  46 ,  48 ,  50  may be provided as individual panels configured to cover the filter windows  28 ,  30 ,  32 ,  34 ,  36 ,  38 , and the annular rings  12 ,  14  and the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  may also be provided as individual components that are assembled with the wire mesh panels  40 ,  42 ,  44 ,  46 ,  48 ,  50  engaged thereby and retained within the filter windows  28 ,  30 ,  32 ,  34 ,  36 ,  38 . Still further, it is also contemplated that three dimensional ( 3 D) printing may develop to the point where the wire mesh band may be provided and the  3 D printer will be capable of maneuvering the printing head to deposit the material for the annular rings  12 ,  14  and the support ribs  16 ,  18 ,  20 ,  22 ,  24 ,  26  onto the wire mesh band. Additional fabrication methods will be appreciate by those skilled in the art and are contemplated by the inventor as having use in fabricating fuel screens  10  in accordance with the present disclosure. 
     While the preceding text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of protection is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the scope of protection. 
     It should also be understood that, unless a term was expressly defined herein, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to herein in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term be limited, by implication or otherwise, to that single meaning.