Patent Publication Number: US-11391028-B2

Title: Flush valve assembly

Description:
The present invention relates to a flush valve assembly fora toilet or urinal. 
     BACKGROUND 
     Flushometer valves (flush valves, diaphragm valves) for use with urinals and/or commercial toilets, involve integrally formed central seating body parts. Central seating body parts accommodate a valve, such as a diaphragm valve for flushing the toilet and/or urinal. To form the central seating body part integrally with the flush valve body, two sand cores are used to form the shape of the flush valve body and the shape of the central seating body part. The two sand core casting process may result in a high number and frequency of defects in the production of flush valve bodies. The defects may result in many scrapped or wasted parts. That is, the defects may produce concavities or changes in the surfaces of flush valve bodies due to porosity of the sand cores. There is a need for a reduction in scrap and waste flush valve parts due to defects. There is a need for a central seating body part that may be formed separately from the flush valve body and secured thereto after the casting process for the flush valve body. 
     SUMMARY 
     Accordingly, disclosed is a flush valve assembly, comprising a flush valve body comprising an inlet, an outlet and an opening for receiving a flush valve lever assembly; and a central seating body part configured to permanently couple within the flush valve body. 
     Also disclosed is a bonnet nut for a flush valve lever assembly, the bonnet nut comprising a substantially tubular body having a first end and a second end; a first threaded surface at the second end for coupling to a flush valve body; and a second threaded surface at the second end for coupling to an actuator pin guide. 
     According to an embodiment, a flush valve assembly may include a flush valve body; and a central seating body part configured to permanently couple within the flush valve body. The flush valve body may include an inner threaded surface for mating engagement with an outer threaded surface of the central seating body part. The central seating body part may include splines for engaging a mounting key. 
     According to an embodiment, the flush valve body may include an extension having an inner threaded surface, wherein the extension protrudes longitudinally toward an outlet of the flush valve body. The extension may protrude substantially perpendicularly to an opening of the flush valve body. The opening may be configured to receive a flush valve lever assembly. The flush valve lever assembly may include an actuator pin guide and a bonnet nut. The bonnet nut may be configured to threadingly engage the opening of the flush valve body and the actuator pin guide. The bonnet nut may include an interior threaded surface and an exterior threaded surface. The actuator pin guide may include an exterior threaded surface for engaging an interior threaded surface of the bonnet nut. The opening of the flush valve body may comprise an interior threaded surface for engaging an exterior threaded surface of the bonnet nut. The flush valve lever assembly may include a seal between the actuator pin guide and the opening of the flush valve body. The extension may be substantially cylindrical. 
     According to an embodiment, the central seating body part may include a smooth portion configured to receive an O-ring. 
     According to an embodiment, the central seating body part may be configured to be threaded into the flush valve body, and wherein an adhesive or glue may be provided on the central seating body part such that a connection between the central seating body part and the flush valve body is permanently connected. The connection may be a threaded connection between an outer surface of the central seating body part and an inner surface of the flush valve body. 
     According to an embodiment, the flush valve body may include a shoulder, and wherein the central seating body part has a flange adjacent the shoulder. A body part flange may be configured to rest on and/or mate with a flush valve body shoulder. The flush valve may include an O-ring between the flush valve body and the flange. 
     According to an embodiment, the flush valve body may comprise brass and the central seating body part may comprise plastic. A plastic may be a thermoplastic, for instance a polyamide, a styrenic polymer, polyester, polyolefin, polycarbonate, mixtures thereof, copolymers thereof, and the like. 
     According to an embodiment, a bonnet nut for a flush valve lever assembly may include a substantially tubular body having a first end and a second end; a first threaded surface at the second end for coupling to a flush valve body; and a second threaded surface at the second end for coupling to an actuator pin guide. The first threaded surface may be an outer threaded surface and the second threaded surface may be an inner threaded surface. The bonnet nut may include a plurality of flat portions configured to receive a tool. The bonnet nut may include a flange, the flange having a surface configured to engage a surface of a flush valve body. The substantially tubular body may be configured to receive a flush valve lever assembly. The first end may include a rounded portion configured to receive a radial bearing. The first end may include a surface configured to engage a surface of the actuator pin guide. 
     According to an embodiment, a method for assembling a flush valve may include providing a flush valve body, the flush valve body having a connection member; permanently coupling a central seating body part to the connection member; and coupling a flush valve lever assembly to an opening of the flush valve body. The method may include inserting a diaphragm valve into the central seating body part; and securing a flush valve cap to the flush valve body. The connection member may be an extension comprising a threaded surface. Coupling the central seating body part to the connection member may include threading the central seating body part to the connection member. The method may include engaging splines on a mounting key with splines on the central seating body part; and rotating the mounting key to rotate the central seating body part. The method may include applying adhesive to a threaded surface of the central seating body part; and rotating the mounting key to engage the threaded surface of the central seating body part with a threaded surface of the flush valve body. The method may include permanently coupling the central seating body part to the flush valve body with adhesive. The method may include installing a seal on the central body seating part prior to coupling the central seating body part to the connection member. Coupling the flush valve lever assembly to the opening of the flush valve body may include threading a bonnet nut to an actuator pin guide; and subsequently threading the bonnet nut to the opening of the flush valve body. The method may include installing a seal on the actuator pin guide prior to threading the bonnet nut to the opening of the flush valve body. 
     Additional features, advantages, and embodiments of the invention are set forth or apparent from consideration of the following detailed description, drawings and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure described herein is illustrated by way of example and not by way of limitation in the accompanying figures. For simplicity and clarity of illustration, features illustrated in the figures are not necessarily drawn to scale. For example, the dimensions of some features may be exaggerated relative to other features for clarity. Further, where considered appropriate, reference labels have been repeated among the figures to indicate corresponding or analogous elements. The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. 
         FIG. 1  is a cross-section view of a flush valve assembly, according to an embodiment. 
         FIG. 2 a    shows a perspective view of a flush valve body, according to an embodiment. 
         FIG. 2 b    shows a side view of a flush valve body, according to an embodiment. 
         FIG. 2 c    shows side view of a flush valve body, rotated about 90 degrees from  FIG. 2 b   , according to an embodiment. 
         FIG. 2 d    shows side view of a flush valve body, rotated about 180 degrees from  FIG. 2 c   , according to an embodiment. 
         FIG. 2 e    shows a top view of a flush valve body, according to an embodiment. 
         FIG. 2 f    shows a bottom view of a flush valve body, according to an embodiment. 
         FIG. 2 g    shows a cross-section view of a flush valve body, according to an embodiment. 
         FIG. 3 a    shows a side view of a central seating body part for a flush valve assembly, according to an embodiment. 
         FIG. 3 b    shows a cross-section view of a central seating body part, according to an embodiment. 
         FIG. 3 c    shows a perspective view of a central seating body part, according to an embodiment. 
         FIG. 4 a    is a cross-section view of a flush valve assembly comprising a flush valve body having a central seating body part in an interior thereof, according to an embodiment. 
         FIG. 4 b    shows an enlarged view of a connection between the flush valve body and central seating body part of  FIG. 4 a   , according to an embodiment. 
         FIG. 4 c    is a perspective view of a mounting key for a central seating body part, according to an embodiment. 
         FIG. 5 a    shows a perspective view of a flush valve assembly comprising a flush valve body with a central seating body part disposed therein, according to an embodiment. 
         FIG. 5 b    shows a side view of a flush valve assembly, according to an embodiment. 
         FIG. 5 c    shows a side view of a flush valve assembly, rotated about 90 degrees from  FIG. 5 b   , according to an embodiment. 
         FIG. 5 d    shows a side view of a flush valve assembly, rotated about 180 degrees from  FIG. 5 c   , according to an embodiment. 
         FIG. 5 e    shows a top view of a flush valve assembly, according to an embodiment. 
         FIG. 5 f    shows a bottom view of a flush valve assembly, according to an embodiment. 
         FIG. 5 g    shows a cross-section view of a flush valve assembly comprising a flush valve body having a central seating body part disposed therein, according to an embodiment. 
         FIG. 6 a    depicts a partial cross-section view of a flush valve lever assembly coupled to a flush valve body, according to an embodiment. 
         FIG. 6 b    shows a partial cross-section view of a flush valve lever assembly coupled to a flush valve body, according to an embodiment. 
         FIG. 7 a    shows a cross-section view of a flush valve assembly, according to an embodiment. 
         FIG. 7 b    depicts an enlarged view of a connection of a flush valve body and a flush valve lever assembly of  FIG. 7 a   , according to an embodiment. 
         FIG. 8  shows an exploded view of components of a flush valve lever assembly. 
         FIG. 9 a    and  FIG. 9 b    show perspective views of an actuator pin guide, according to an embodiment. 
         FIG. 9 c    shows a top view of an actuator pin guide, according to an embodiment. 
         FIG. 9 d    shows a bottom view of an actuator pin guide, according to an embodiment. 
         FIG. 9 e    and  FIG. 9 f    show side views of an actuator pin guide, at about 180 degree rotation intervals, according to an embodiment. 
         FIG. 9 g    and  FIG. 9 h    show cross-section views of an actuator pin guide, according to an embodiment. 
         FIG. 10 a    and  FIG. 10 b    show a perspective views of a bonnet nut, according to an embodiment. 
         FIG. 10 c   ,  FIG. 10 d   , and  FIG. 10 e    show side views of a bonnet nut, at about 90 degree rotation intervals, according to an embodiment. 
         FIG. 10 f    shows a top view of a bonnet nut, according to an embodiment. 
         FIG. 10 g    shows a bottom view of a bonnet nut, according to an embodiment. 
         FIG. 10 h    is a cross-section view of a bonnet nut, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In an embodiment, disclosed is a flush valve body having a central seating body part formed separate from the casting of a flush valve body. The central seating body part may be coupled to the flush valve body after the flush valve body has been cast. The central seating body part may have a threaded surface which interacts with a threaded surface on a flush valve body. A central seating body part may be permanently coupled or secured to a flush valve body during assembly. In an embodiment, also disclosed is a flush valve lever assembly for a flush valve. A flush valve lever assembly may include a bonnet nut and actuator pin guide for securing to a flush valve body. A flush valve lever assembly may eliminate the need for a separate mounting nut or mounting feature and may result in an enhanced seal between a flush valve lever assembly and a flush valve body. 
       FIG. 1  is a cross-section view of flush valve assembly  100 , according to an embodiment. Flush valve assembly  100  may include a flush valve body  101 , a central seating body part  102 , a valve  103 , and a flush valve cap  104 . Central seating body part  102  may be secured within flush valve body  101  as will be described in more detail to follow. Central seating body part  102  may be a valve seat for the valve  103 . Valve  103  may be a diaphragm valve. Valve  103  may be seated within central seating body part  102  for actuation with a flush valve lever assembly. A flush valve lever assembly may be coupled to an opening  105  in flush valve body  101 . Flush valve cap  104  may be secured to flush valve body  101 . Flush valve  100  includes a flush valve inlet  106  and a flush valve outlet  107 . 
       FIGS. 2 a -2 g    show views of flush valve body  101 . Flush valve body  101  contains a central open space or bore  201 . Flush valve body  101  includes opening  105 , flush valve inlet  106 , and flush valve outlet  107 . Opening  105  may have a threaded surface  202  for receiving a housing, such as a bonnet nut (not depicted), for a flush valve lever assembly. Threaded surface  202  may be an outer threaded surface. Flush valve inlet  106  may have a threaded surface  203  for coupling to a pipe or pipe connection for coupling flush valve body  101  to a main water supply. Threaded surface  203  may be an inner threaded surface. Flush valve outlet  107  may have a threaded surface  204  for coupling directly to a toilet or urinal or for coupling to a connection (e.g. a pipe) to a toilet or urinal. Threaded surface  204  may be an outer threaded surface. Flush valve body  101  may include an upper opening  205 . Upper opening  205  may allow for installation or insertion of a valve. Upper opening  205  may have a threaded surface  206  for coupling to a flush valve cap. Threaded surface  206  may be an outer threaded surface. Although threaded surface  203  is depicted and described as an inner threaded surface, an outer threaded surface may be provided. Similarly, although threaded surfaces  202 ,  204 , and  206  are depicted and described as outer threaded surfaces, an inner threaded surface may be provided. 
     Flush valve body  101  may include an extension  207 . Extension  207  may be a connection member for coupling flush valve body  101  to the central seating body part. Extension  207  may protrude longitudinally within flush valve body  101 . Extension  207  may protrude longitudinally toward a flush valve outlet  107 . As can be seen in  FIG. 2 a    and  FIG. 2 e   , extension  207  may be substantially cylindrical. Extension  207  may have an upper surface  208 . Upper surface  208  may form a ledge or shoulder within flush valve body  101 . Extension  207  may have an inner threaded surface  209 . Inner threaded surface  209  may be configured to couple to a central seating body part. 
       FIG. 3 a   ,  FIG. 3 b   , and  FIG. 3 c    show view of a central seating body part  300 . Central seating body part  300  may be substantially cylindrical. Central seating body part  300  includes a bore  301  extending from an upper surface  302  to a lower surface  303 . Bore  301  may accommodate a valve, such as valve  103  of  FIG. 1 . Central seating body part  300  may include one or more splines  304  in an outer surface thereof. One or more splines  304  may be a plurality of splines. One or more splines  304  may extend longitudinally downward from upper surface  302 . One or more splines  304  may be a series of protrusions and recesses or ridges and grooves. One or more splines  304  may be configured to mate or correspond to one or more splines on a mounting key ( FIG. 4 c   ). 
     Central seating body part  300  may have a flange  305 . Central seating body part  300  may include a threaded surface  306 . Threaded surface  306  may be an outer threaded surface. Threaded surface  306  may extend longitudinally below the flange  305 . Threaded surface  306  may couple to or engage with an inner threaded surface  209  of flush valve body  101 . A smooth portion  307  may be provided between flange  305  and a top of threaded surface  306 . Smooth portion  307  may be configured to accommodate an O-ring. 
       FIG. 4 c    shows mounting key  401 , which may be provided to install a central seating body part within a flush valve body. Mounting key  401  may be a cap. Mounting key  401  may include one or more flat portions  402  to receive a wrench (not depicted) or other tool. Mounting key  401  may have a bore  403  to receive at least a portion of a central seating body part during installation. Mounting key  401  may have one or more splines  404 . One or more splines  404  may mate with or correspond to one or more splines on a central seating body part ( FIG. 3 a   ,  FIG. 3 c   ). In this manner, when mounting key  401  is rotated, the corresponding mated splines will cause rotation of a central seating body part. 
       FIG. 4 a    shows a flush valve assembly  400  comprising a flush valve body having a central seating body part in an interior thereof, according to an embodiment.  FIG. 4 b    is an enlarged view of the circled portion of  FIG. 4 a   . Flush valve assembly  400  contains central seating body part  300  disposed within flush valve body  101 . Upon assembly, an O-ring  405  may be placed on a smooth portion  307  of central seating body part  300 . O-ring  405  may be any sealing member, such as a gasket or metal seal. Central seating body part  300  may be lowered into the flush valve body  101  with threaded surface  306  entering the bore  201  first. Central seating body part  300  may be threaded into flush valve body  101 . Threading may occur by coupling threaded surface  306  of central seating body part  300  with inner threaded surface  209  of flush valve body  101 . To achieve threading, mounting key  401  may be installed on a top of central seating body part  300 . One or more splines  404  may be aligned with one or more splines  304  on central seating body part  300 . Although splines are depicted and described, any mating surface that permits a mounting key to transfer rotational movement to a central seating body part may be provided. Mounting key  401  may be rotated (e.g. such as with a wrench on the flat portions  402 ). Rotation of mounting key  401  may translate to rotation of central seating body part  300 . As mounting key  401  and central seating body part  300  rotate, threaded surface  306  may engage inner threaded surface  209 . Mounting key  401  and central seating body part  300  may be rotated until flange  305  of central seating body part  300  contacts extension  207  of flush valve body  101 . When installed, O-ring  405  may be located within a space between an inner wall of flush valve body  101  and smooth portion  307 , and above threaded portion  406 . O-ring  405  may provide a seal within flush valve body  101 . 
     A flush valve body of the present disclosure may achieve an easier casting process due to removal of a central seating body part from the casting process. In an embodiment, casting of flush valve body  101  no longer includes casting of a central seating body part  300 . This may reduce the number of defects in a single flush valve body and may reduce the frequency of defects in a production line of flush valve bodies. Reduction in defects may reduce the reduction in waste due to discarding of flush valve bodies that are unusable due to the number, size, shape, etc. of defects. This saves cost due to a reduction in waste or scrapped parts and a reduction in tooling. A single sand core may be used to form a flush valve body. Where a central seating body part is integral to a flush valve body as in  FIG. 6 b   , two sand cores are required. A reduction in tooling (e.g. due to the reduction in sand cores) may reduce the cost of materials, tooling, and cost associated with increased production time. 
     A central seating body part may be formed of a hard, stable material capable of withstanding the high pressures experienced during a flush cycle. In an embodiment, the material may be at least about 50 percent glass filled silica. A central seating body part may be formed via injection molding. A central seating body part may have a hardened surface after molding. A central seating body part may be permanently installed in a flush valve body during the production phase of a flush valve assembly. A central seating body part may be assembled with adhesive on a threaded surface  306 . An adhesive may permanently secure a central seating body part within an extension  207  of a flush valve body  101 . A central seating body part may be permanently coupled to a flush valve body on the production line such that the relationship between a valve  103  and a central seating body part is consistent between all flush valves  100  produced on the assembly line. 
     In an embodiment,  FIGS. 5 a -5 g    depict a flush valve assembly  500  comprising a flush valve body  501  and central seating body part  300 . Opening  502  contains an inner threaded surface for coupling to a flush valve lever assembly. Also shown are inlet  503  and outlet  504 . 
       FIG. 6 a    and  FIG. 6 b    show partial side cross-section views of a flush valve lever assembly  600  and  600   x , respectively. Flush valve lever assembly  600  provides a view of a flush valve lever assembly coupled to flush valve assembly  500  of  FIGS. 5 a -5 g   . Alternatively, flush valve lever assembly  600   x  provides a view of a flush valve lever assembly coupled to a central seated body part  601   x  integrally formed with a flush valve body  602   x . A flush valve lever assembly may include a nozzle  601 , an actuator pin guide  602 , a seal  603 , a bonnet nut  604 , a radial bearing  605 , an axial bearing  606 , an actuator pin  607 , a biasing member  608 , and a lever  609 . Biasing member  608  may be a spring, such as, for example, a coil spring. Seal  603  may be an O-ring. Seal  603  may be ethylene propylene diene monomer rubber (EPDM) or other rubber or rubber-like material. 
       FIG. 7 a    shows a cross-section view of flush valve assembly  700 , according to an embodiment. Flush valve body  501  contains central seating body part  300  disposed therein. Flush valve body  501  is coupled to flush valve lever assembly  600 . Visible are actuator pin  607 , lever  609 , actuator pin guide  602 , and bonnet nut  604 . Bonnet nut  604  secures actuator pin guide  602  via threaded connections. Bonnet nut  604  may receive radial bearing  605  and lever  609 .  FIG. 7 b    provides an enlarged view of the connection circled in  FIG. 7   a.    
       FIG. 8  provides an exploded view of a portion of flush valve body  501 , opening  502 , actuator pin guide  602 , and bonnet nut  604 , according to an embodiment. Opening  502  contains an inner threaded surface. An opening  502  inner threaded surface may mate with an outer threaded surface  801  on bonnet nut  604 . Bonnet nut  604  may contain an inner threaded surface  802 . 
       FIGS. 9 a -9 h    provide views of actuator pin guide  602 , according to an embodiment. Pin guide  602  may have an outer threaded surface  901 . Threaded surface  901  may be configured to mate with threaded surface  802  of bonnet nut  604 . Pin guide  602  comprises bore  902 . The bore  902  may receive biasing member  608  ( FIG. 6 a   ). Actuator pin guide  602  may include an extension  903 . Extension  903  may include a bore  904  configured to receive actuator pin  607 . Pin guide  602  may include a flange  905  including a groove as shown. A flange groove may receive an O-ring  603  as shown in  FIG. 6 a   . Actuator pin guide  602  may be secured between a surface of a bonnet nut and a surface of an opening of a flush valve body. Seal  603  may provide a seal between an outside of a flush valve body and an inside of a flush valve body. An actuator pin guide may be formed of a thermoplastic. In some embodiments, an actuator pin guide may be formed via injection molding. 
       FIGS. 10 a -10 h    provide various views of bonnet nut  604 . A bonnet nut may be substantially cylindrical. Bonnet nut  604  comprises a first end  803  configured to receive radial bearing  605 . First end  803  may comprise flat portions  804  configured for interacting with a tool, such as a wrench. A second end  805  comprises an inner threaded surface  802  and an outer threaded surface  801 . Outer threaded surface  801  is configured for mating with an inner threaded surface of a flush valve body opening. 
     Bonnet nut  604  comprises a bore  806  configured to receive components of a flush valve lever assembly. Bore  806  may receive an actuator pin guide, an actuator pin, a biasing member, a radial bearing, an axial bearing, and a lever. Bore  806  includes inner threaded surface  802 , configured to mate with a threaded surface of actuator pin guide  602 . Bonnet nut  604  may include a flange  807 . Flange  807  may be configured for engaging or nearing a surface of a flush valve body. A bonnet nut may be formed of brass and may be chrome plated. A bonnet nut may be machined, such as, for example, on a lathe. 
     During assembly, components of a flush valve lever assembly may be aligned within a flush valve body opening and a bonnet nut may be turned (e.g. with a tool on the flat portions thereof) to secure the flush valve lever assembly to the flush valve body. A bonnet nut may be rotated until a surface, for instance a flange, is adjacent, touches, or is near to a surface of the flush valve body. A bonnet nut may include an inner threaded surface configured to mate with an outer threaded surface on an actuator pin guide. During assembly, a bonnet nut may be secured to an actuator pin guide via a threaded connection of a bonnet nut inner threaded surface and a pin guide outer threaded surface. A bonnet nut may be threaded to an actuator pin guide prior to securing an outer threaded surface of the bonnet nut to an inner threaded surface of a flush valve opening. 
     In some embodiments, a flush valve lever assembly of the present disclosure may eliminate the use of a mounting nut when coupling a flush valve lever assembly to a flush valve body. A flush valve lever assembly may be secured to a flush valve body with a single nut, the bonnet nut. Elimination of a mounting feature allows for a universal mount nut. This may save materials and cost. This may achieve enhanced sealing between the flush valve body and the flush valve lever assembly (e.g. due to the inclusion of a seal in the actuator pin guide). 
     The term “coupled” means that an element is “attached to” or “associated with” another element. Coupled may mean directly coupled or coupled through one or more other elements. An element may be coupled to an element through two or more other elements in a sequential manner or a non-sequential manner. The term “via” in reference to “via an element” may mean “through” or “by” an element. Coupled or “associated with” may also mean elements not directly or indirectly attached, but that they “go together” in that one may function together with the other. 
     The term “flow communication” means for example configured for liquid or gas flow there through. The terms “upstream” and “downstream” indicate a direction of gas or fluid flow, that is, gas or fluid will flow from upstream to downstream. 
     The term “towards” in reference to a of point of attachment, may mean at exactly that location or point or, alternatively, may mean closer to that point than to another distinct point, for example “towards a center” means closer to a center than to an edge. 
     The term “like” means similar and not necessarily exactly like. For instance “ring-like” means generally shaped like a ring, but not necessarily perfectly circular. 
     The articles “a” and “an” herein refer to one or to more than one (e.g. at least one) of the grammatical object. Any ranges cited herein are inclusive. The term “about” used throughout is used to describe and account for small fluctuations. For instance, “about” may mean the numeric value may be modified by ±0.05%, ±0.1%, ±0.2%, ±0.3%, ±0.4%, ±0.5%, ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, ±10% or more. All numeric values are modified by the term “about” whether or not explicitly indicated. Numeric values modified by the term “about” include the specific identified value. For example “about 5.0” includes 5.0. 
     The term “substantially” is similar to “about” in that the defined term may vary from for example by ±0.05%, ±0.1%, ±0.2%, ±0.3%, ±0.4%, ±0.5%, ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, ±10% or more of the definition; for example the term “substantially perpendicular” may mean the 90° perpendicular angle may mean “about 90°”. The term “generally” may be equivalent to “substantially”. 
     All U.S. patent applications, published patent applications and patents referred to herein are hereby incorporated by reference. 
     Although the foregoing description is directed to certain embodiments of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the invention. Moreover, features described in connection with one embodiment of the invention may be used in conjunction with other embodiments, even if not explicitly stated above.