Patent Publication Number: US-9425539-B2

Title: Conical retention ring

Description:
BACKGROUND OF THE INVENTION 
     The subject matter herein relates generally to retention hardware for connector assemblies. 
     Threaded fasteners are used during mating of electrical connector assemblies. For example, in communication systems, such as network systems, servers, data centers, and the like, large printed circuit boards, known as backplanes, are used to interconnect midplanes, daughtercards, line cards and/or switch cards. The communication systems use high speed differential connectors mounted to the backplane and high speed differential connectors mounted to the line cards and switch cards to transmit signals therebetween. The threaded fasteners are used to secure or hold the mating interfaces of the connector assemblies against one another. 
     However, with some systems, the threaded fasteners may become unscrewed or loosen causing the mating interfaces to unseat or otherwise disrupt the transmission of signals. For example, vibration, mechanical motion, and/or temperature changes may cause the threaded fastener to loosen. Retention hardware, such as washers, may be used to prevent the threaded fastener from unscrewing. However, washers are generally placed on the threaded fastener during manufacturing, and may be difficult for an end user to add during installation. Snap rings may be added to the threaded fastener during installation for purposes of retaining the fastener or other hardware, however, snap rings do not provide a tensile force on the threaded fastener to prevent the threaded fastener from unscrewing. 
     A need remains for retention hardware that can be installed onto a threaded fastener to prevent the threaded fastener from becoming unscrewed. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, a conical retention ring is provided that includes an annular disc having a central axis, first and second major surfaces facing in substantially opposite directions along the central axis, a radially inner peripheral surface defining a central bore, a radially outer peripheral surface which is axially offset from the radially inner peripheral surface, and a spreading channel which is open from the radially outer peripheral surface to the central bore. The spreading channel allows the annular disc to spread apart to allow the central axis to receive a threaded fastener. 
     In another embodiment, a connector system is provided that includes a panel having a plurality of mating windows therethrough. The panel has mounting holes located proximate to the mating windows. The connector system also includes a connector assembly. The connector assembly has a support frame that defines a cavity configured to receive a connector therein. The connector assembly has a threaded fastener held by the support frame. The threaded fastener is threadably coupled to one of the mounting holes to couple the connector assembly to the panel. The connector system also includes a conical retention ring coupled to the threaded fastener and positioned between the support frame and the mounting hole. The conical retention ring has an annular disc having a central axis, first and second major surfaces facing in substantially opposite directions along the central axis, a radially inner peripheral surface defining a central bore, a radially outer peripheral surface which is axially offset from the radially inner peripheral surface, and a spreading channel which is open from the radially outer peripheral surface to the central bore and configured to receive a threaded fastener therethrough. The conical retention ring is loaded onto the threaded fastener when the channel is widened such that the threaded fastener passes through the central bore. The conical retention ring is compressed when the threaded fastener is threadably coupled to the mounting hole. 
     In another embodiment, a connector system is provided that includes a threaded fastener coupled to a support frame of a connector assembly. The threaded fastener is threadably coupled to a mounting hole of a panel. The connector system also includes a conical retention ring coupled to the threaded fastener and positioned between the support frame and the mounting hole. The conical retention ring has a central bore and a spreading channel open to the central bore. The conical retention ring is loaded onto the threaded fastener when the channel is widened such that the threaded fastener passes through the central bore. The conical retention ring has an inclined surface configured to deform to become substantially planar when the threaded fastener is threadably coupled to the mounting hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a connector system formed in accordance with an exemplary embodiment. 
         FIG. 2  illustrates cable connectors of the connector system formed in accordance with an exemplary embodiment. 
         FIG. 3  is a front perspective view of a rack assembly poised for mating to a panel formed in accordance with an exemplary embodiment. 
         FIG. 4  is a front perspective view of a portion of a cable connector assembly formed in accordance with an exemplary embodiment. 
         FIG. 5  is a perspective view of a conical retention ring formed in accordance with an exemplary embodiment. 
         FIG. 6  is a side perspective view of a conical retention ring in a compressed state formed in accordance with an embodiment. 
         FIG. 7  is a side perspective view of a conical retention ring in a normal state formed in accordance with an embodiment. 
         FIG. 8  is a perspective view of a conical retention ring being helically wound formed in accordance with an embodiment. 
         FIG. 9  is a perspective view of a conical retention ring having a wave pattern formed in accordance with an embodiment. 
         FIG. 10  is a perspective view of a conical retention ring having teeth along a central portion formed in accordance with an embodiment. 
         FIG. 11  is a perspective view of a conical retention ring having teeth along an outer portion formed in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a front perspective view of a connector system  100  formed in accordance with an exemplary embodiment. The connector system  100  may be used in a data communication application, such as a network switch. The connector system  100  may be used as part of a backplane system, such as a cable backplane system, and thus may be referred to hereinafter as a backplane system  100  or a cable backplane system  100 . The connector system  100  may be electrically connected to a mating connector assembly  102 , such as a line card, a switch card, another type of mating connector mounted to a circuit board or another type of mating connector assembly. 
     The connector system  100  includes one or more connector assemblies  104 , also referred to as connector bricks  104  that are mounted to a panel  106 . In an exemplary embodiment, the connector assemblies  104  are cable connector assemblies having a plurality of electrical cables  108  (shown in  FIG. 2 ) associated therewith, and thus may be referred to hereinafter as cable connector assemblies  104 . In alternative embodiments, rather than being cable connector assemblies, the connector assemblies may be terminated to circuit boards, such as a backplane. 
     The panel  106  includes a plurality of mating windows  110 . A portion of each of the cable connector assemblies  104  is exposed through a respective mating window  110 . The mating window  110  permits one of the cable connector assemblies  104  to be presented for engaging one of the corresponding mating connector assemblies  102 . The panel  106  may receive a portion of the mating connector assembly  102  through the mating window  110 . 
     The panel  106  supports the components of the connector assembly  104 . The panel  106  may include a chassis, a rack, a cabinet, or other suitable structures for holding the connector assembly  104  and for mating with the mating connector assembly  102 . The panel  106  includes mounting holes  112  positioned proximate to each of the mating windows  110 . The mounting holes  112  are configured to receive a threaded fastener  114  (shown in  FIG. 4 ) coupled to the connector assembly  104 . The mounting holes  112  are threaded. Optionally, the mounting holes  112  may be part of a mounting block coupled to the panel  106 . When driven to an engaged position, the threaded fastener  114  holds the connector assembly  104  against the panel  106  to allow the mating connector assembly  102  to mate with the connector assembly  104 . In an exemplary embodiment, a conical retention ring  116  (shown in  FIG. 4 ) is coupled to the threaded fastener  114 . The conical retention ring  116  is configured to apply a preload force on the threaded fastener  114  to prevent the threaded fastener  114  from disengaging or becoming unscrewed. Accordingly, the conical retention ring  116  may prevent the connector assembly  104  from becoming unseated or disconnected from the mating connector assembly  102 . The conical retention ring  116  is configured to be loaded onto the threaded fastener  114  when the conical retention ring is spread open, as discussed below. The panel  106  may include structures for guiding, supporting and/or securing the mating connector assembly  102  to the connector assembly  104 . 
     Each connector assembly  104  includes one or more connectors  118 , which may be interconnected by the cables  108  (shown in  FIG. 2 ) or by a circuit board (not shown), within the connector system  100 . When embodied as cable connectors  118 , the cable connector assemblies  104  eliminate interconnections via traces of a circuit board, such as a backplane circuit board, and instead interconnect various cable connectors  118  with the cables  108 . The cable connector assemblies  104  may improve signal performance along the signal paths between various connectors of the cable backplane system  100  as compared to conventional backplanes. For example, the cable connector assemblies  104  support higher speeds, longer signal path lengths and lower cost per channel as compared to conventional backplanes. The connector assemblies  104  may provide shielding of signal lines for improved signal performance. The connector assemblies  104  may be packaged in a structure, such as the rack assembly  132  shown in  FIG. 3 , which allows accurate connector  118  location for mating with the corresponding mating connector assemblies  102 . The connector assemblies  104  include guide pins  120  that are used to locate the connectors  118  and the corresponding mating connector assemblies  102  during mating. 
     The mating connector assembly  102  includes a circuit board  122  and a plurality of mating connectors  123  mounted thereto. When the mating connector assembly  102  is mated with the connector assembly  104 , the connector  118  is electrically and mechanically connected to one of the mating connectors  123 . The mating connector assembly  102  may also include mounting blocks  124 . The mounting blocks  124  have openings that receive the guide pins  120  therein. The guide pins  120  guide mating of the mating connector assembly  102  and the connector assemblies  104 . Alternatively, the mounting blocks  124  may receive the threaded fastener  114  to secure the mating connector assembly  102  to the connector assembly  104 . 
       FIG. 2  illustrates a portion of the cable connector assembly  104  formed in accordance with an exemplary embodiment. The cable connector assembly  104  includes the cable connectors  118 , which may be referred to hereinafter as first and second cable connectors  118   a ,  118   b , respectively, and a cable bundle  128  between the cable connectors  118 . The cable connectors  118  are provided at ends of the cable bundle  128 . The cable bundle  128  includes the plurality of cables  108 . Optionally, the cable connectors  118  may be identical to one another. The cable connectors  118  may define header connectors. In an exemplary embodiment, the cable connector  118  is a high speed differential pair cable connector that includes a plurality of differential pairs of conductors, such as signal contacts  130 , mated at a common mating interface. The differential conductors are shielded along the signal paths thereof to reduce noise, crosstalk and other interference along the signal paths of the differential pairs. 
       FIG. 3  is a front perspective view of a rack assembly  132  poised for mounting to the panel  106 . The rack assembly  132  includes a plurality of the connector assemblies  104  that are held together by a common chassis  134 . 
     The panel  106  includes a variety of openings that permit elements of the connector assemblies  104  to pass therethrough. For example, the panel  106  includes the mating windows  110 , guide holes  136 , and the mounting holes  112 . The mating windows  110  are configured to receive portions of the cable connectors  118  therethrough. The guide holes  136  are configured to receive the guide pins  120  therethrough. 
     Each of the mounting holes  112  is configured to receive one of the threaded fasteners  114  therein. The mounting holes  112  may have complementary threads that mate with a threaded portion  152  (shown in  FIG. 4 ) of the threaded fastener  114  such that the threaded fastener  114  and the mounting holes  112  create a threaded connection therebetween. For example, the threaded fastener  114  may be configured as a jackscrew to draw the connector assembly  104  closer to the panel  106  as the threaded fastener  114  is tightened to secure the connector assembly  104  to the panel  106 . 
     In the illustrated embodiment, the conical retention ring  116  is coupled to the threaded fastener  114 . The conical retention ring  116  is positioned between the panel  106  and the connector assembly  104  as is discussed below. When the connector assembly  104  is secured to the panel  106 , the threaded fastener  114  is tightened or driven to cause the connector assembly  104  to approach the panel  106  as indicated by the arrow A. As described below, the conical retention ring  116  deforms to apply a preload force on the threaded fastener  114  in a direction B that is opposite of A. The preload force causes the threaded fastener  114  to resist further rotation, movement, and/or disengagement. 
       FIG. 4  is a front perspective view of a portion of the cable connector assembly  104 . The connector assembly  104  includes a support frame  140  defining a cavity  142 . The cable connectors  118  are positioned in the cavity  142 . Any number of cable connectors  118  may be held in the cavity  142 . 
     The support frame  140  includes side walls  144  and spacers  146  between the side walls  144 . As illustrated, one first end of the connector assembly  104  is shown. An opposite end may include similar components as described in relation to the first end. For example, the opposite end may include a second spacer  146  between the side walls  144 . Each spacer  146  has an outer surface  178  that faces the panel  106  (shown in  FIG. 3 ) when the cable connector assembly  104  is poised for mating. The cavity  142  is defined between the side walls  144  and between the spacers  146 . In an exemplary embodiment, the side walls  144  include slots  148  that receive lugs (not shown) extending from the housings of the cable connectors  118 . The slots  148  may be oversized to allow a limited amount of floating movement of the cable connectors  118  relative to the support frame  140 , such as to allow the cable connectors  118  a range of movement for aligning with the mating connectors of the mating connector assembly  102  (shown in  FIG. 1 ) during mating. 
     The threaded fastener  114  is coupled to the spacer  146  and extends through the spacer  146 . The threaded fastener  114  extends through an opening  149  extending through the spacer  146 . In an exemplary embodiment, the threaded fastener  114  is allowed to rotate freely relative to the spacer  146 , such as within a bore  150  through the spacer  146 . The threaded fastener  114  may be any threaded fastener configured to secure the cable connector assembly  104  to the panel  106  (shown in  FIG. 1 ). 
     The threaded fastener  114  includes the threaded portion  152 , a shaft  154 , and a drive portion  156  opposite the threaded portion  152 . The threaded portion  152  has threads  153  that extend from the shaft  154 , such as at or near an end  155  of the fastener  114 . In the illustrated embodiment, the threaded portion  152  terminates to a tip  158  having a chamfered or beveled edged  160 . The edge  160  may be beveled to encourage alignment of the threaded fastener  114  with the bore  150  and with the mounting hole  112  (shown in  FIG. 3 ). The threaded portion  152  has a thread diameter D 1  that extends through the threads  153 . 
     The shaft  154  extends between the threaded portion  152  and the drive portion  156 . The shaft  154  may have a smooth surface and a shaft diameter D 2  that extends along the shaft  154 . The shaft diameter D 2  is less than the diameter D 1  of the threaded portion. As such, the shaft  154  is narrower than the threaded portion  152 . When the threaded fastener  114  is coupled to the spacer  146 , the shaft  154  extends to and through the bore  150 . The shaft  154  terminates to the drive portion  156 . The drive portion  156  is configured to turn the threaded fastener  114  along a body axis  162 . For example, the drive portion  156  may include a knurled portion (not shown) and/or a head configured to be driven by a drive tool (not shown). 
     In an exemplary embodiment, the conical retention ring  116  is loaded onto the shaft  154  of the threaded fastener  114 , as will be discussed below. The retention ring  116  may be loaded onto the threaded fastener  114  after the threaded fastener  114  has been coupled to the spacer  146 . As such, the retention ring  116  may be coupled to the threaded fastener  114  without removing the threaded fastener  114  from the spacer  146 . The retention ring  116  is positioned between the threaded portion  152  and the spacer  146 . Alternatively, the retention ring  116  may be positioned between the drive portion  156  and the spacer  146 . 
       FIG. 5  is a perspective view of the conical retention ring  116 . The retention ring  116  includes an annular disk  163 , which may be generally C-shaped, having a central bore  164  (also shown in  FIG. 4 ) partially circumferentially surrounded by an inclined surface  166 . The bore  164  passes through, and is aligned with, a central axis  168 . The central axis  168  is generally parallel with the body axis  162  (shown in  FIG. 4 ) when the retention ring  116  is mounted on the threaded fastener  114 . The bore  164  has a bore diameter D 3  defined by an inside face defining a radially inner peripheral surface  170  of the inclined surface  166 . The radially inner peripheral surface  170  extends around an inner perimeter  171  of the inclined surface  166 . The bore diameter D 3  is greater than the shaft diameter D 2  (shown in  FIG. 4 ), but is narrower than the thread diameter D 1  (shown in  FIG. 4 ), and as such, the retention ring  116  cannot be removed in an axial direction from the threaded fastener  114  because the threaded portion  152  will stop removal. The conical retention ring  116  has a radially outer peripheral surface  173  that is axially offset from the radially inner peripheral surface  170  at the outer edge. 
     The conical retention ring  116  has a first end  172  and a second end  174  spaced apart by a gap  176  therebetween. The first and second ends  172 ,  174 , respectively, oppose each other at a spreading channel  180 . The spreading channel  180  extends between the radially inner peripheral surface  170  and the radially outer peripheral surface  173 . The gap  176  defines the spreading channel  180  and when the spreading channel  180  is spread open, the gap is widened and the bore  164  is widened, which allows the conical retention ring to pass onto the threaded fastener  114  (shown in  FIG. 4 ). In an exemplary embodiment, the bore  164  is widened enough that the conical retention ring  116  is able to pass over the threaded portion  152  of the threaded fastener  114 . Alternatively, the conical retention ring  116  may be side-loaded over the side of the threaded fastener  114  rather than being loaded over the end of the threaded fastener  114  when the spreading channel  180  is spread apart. When the retention ring  116  is being loaded onto the threaded fastener  114 , the ends  172 ,  174  are pulled apart from one another to increase a channel or gap width between the ends  172 ,  174  to a gap width that corresponds to a bore width greater than the thread diameter Dl to load the threaded fastener  114  through the bore  164 . The gap  176  has a resting gap width W 1  that represents a natural gap width when the ends  172 ,  174  are not pulled apart. The resting gap width W 1  is less than the shaft diameter D 2  (shown in  FIG. 4 ), and as such, the spreading channel  180  is narrower than the shaft  154  (shown in  FIG. 4 ). Thus, the retention ring  116  cannot be inadvertently removed in a radial direction from the threaded fastener  114 . 
     When the conical retention ring  116  is loaded onto the threaded fastener  114 , the conical retention ring  116  is elastically deformed to allow the threaded fastener  114  to pass through the bore  164  in an axial direction. As such, the first end  172  and the second end  174  are spread apart a width W 2  (shown in phantom) that that corresponds to a bore diameter that is greater than the thread diameter D 1 . In other words, the gap width is increased to a gap width W 2  to widen the bore  164  and allow the threaded fastener  114  to pass through the bore  164 . When the threaded fastener  114  is received in the bore  164 , the ends  172 ,  174  are released and return to the resting gap width W 1 . The conical retention ring  116  may be sufficiently resilient to allow the conical retention ring  116  to deform. The conical retention ring  116  may be made of any sufficiently elastic material. For example, the conical retention ring  116  may be made of a metal material, a plastic material, and/or the like. After the conical retention ring  116  is loaded onto the threaded fastener  114 , the conical retention ring  116  is free to linearly and rotationally move about the shaft  154  (shown in  FIG. 4 ), but is bound between the threaded portion  152  (shown in  FIG. 4 ) and an outer surface  178  (shown in  FIG. 4 ) of the spacer  146  (shown in  FIG. 4 ). 
     In the illustrated embodiment, the conical retention ring  116  includes engagement holes  182  and  184 . The engagement hole  182  is situated proximate to the first end  172 . The engagement hole  184  is situated proximate to the second end  174 . The engagement holes  182 ,  184  may extend through the inclined surface  166 . The engagement holes  182 ,  184  are configured to receive a head  186  of an engagement tool  188 . For example, the head  186  may include a first prong  190  sized and shaped to be received in the first engagement hole  182 , and a second prong  192  sized and shaped to be received in the second engagement hole  184 . The engagement tool  188  is configured to enable a user to spread the first and second ends  172 ,  174  apart to widen the spreading channel  180  to allow the threaded fastener  114  to pass therethrough. In other embodiments, other arrangements are possible. For example, the ends  172 ,  174  may include flanges (not shown) configured to receive the head  186  of the engagement tool  188 . 
     The conical retention ring  116  is generally cone like having a frusto-conical shape. The general shape of the retention ring  116  may be similar to a cone-disc spring, also generally known as a Belleville washer. The inclined surface  166  extends between a central portion  194  and an outer portion  196 . The central portion  194  includes the inside face  170 . The inclined surface  166  includes a first side defining a first major surface  198  and a second side defining a second major surface  200 , both extending from the central portion  194  to the outer portion  196  along opposite sides of the retention ring  116 . The first and second sides  189 ,  200  generally face in opposite directions along the central axis  168 . 
       FIG. 6  is a side perspective view of the conical retention ring  116  in the compressed state.  FIG. 7  is a side perspective view of the conical retention ring  116  in a normal state. The retention ring  116  has a flatter shape in the compressed state than in the normal state. In the normal state, the first and second sides  198 ,  200  are angled such that the first and second sides  192 ,  200  are oblique relative to the central axis  168 . Thus, the inclined surface  116  is inclined forming the conic section described above. The conical retention ring  116  is compressed as the threaded fastener  114  (shown in  FIG. 4 ) is driven into the mounting hole  112  (shown in  FIG. 3 ). For example, the retention ring  116  may compress as the first side  198  abuts the panel  106  (shown in  FIG. 3 ), and the second side  200  abuts the outer surface  178  (shown in  FIG. 4 ) of the spacer  146  (shown in  FIG. 4 ). When the threaded fastener  114  is approximately fully engaged with the mounting hole  112 , the retention ring  116  may enter a fully compressed state such as shown in  FIG. 6 . In the fully compressed state, the inclined surface  166  deforms to become substantially planar such that the first and second sides become generally perpendicular to the central axis  168 . 
     As the retention ring  116  is compressed, the retention ring  116  exerts a preload force on the threaded fastener  114  (shown in  FIG. 4 ), indicated by arrow B (also shown in  FIG. 4 ). When compressed, the inclined surface  116  deforms acting as a linear spring. The retention ring  116  applies the preload force on the surface of the spacer  146  (shown in  FIG. 4 ) and on the panel  106  (shown in  FIG. 1 ), which in turn applies a force to the fastener  114  which is engaged in the mounting hole  112 . The retention ring applies equal and opposite forces. The preload force applies tension on the threaded fastener  114  to prevent the threaded fastener  114  from disengaging from, or rotating relative to the mounting hole  112  (shown in  FIG. 3 ). Additionally, the preload force may compensate for any loosening of the threaded fastener  114 . Optionally, a plurality of retention rings  116  may be loaded onto the threaded fastener  114  to achieve a desired preload force. 
       FIG. 8  is a perspective view of an embodiment of a conical retention ring  202  that is helically wound. The retention ring  202  is similar to the retention ring  116  and like components are identified with like reference numerals. The retention ring  202  is helically wound such that the first and second ends  172 ,  174 , respectively, are offset axially along the central axis  168 . For example, the first end  172  may be translated forward in the direction of the central axis  168  relative to the second end  174 . The retention ring  202  may be helically wound to provide a greater compression distance and/or a greater spring constant thereby increasing the amount of preload force applied as the retention ring  202  is compressed. 
       FIG. 9  is a perspective view of an embodiment of a conical retention ring  210  having a wave pattern. The retention ring  210  is similar to the retention ring  116  and like components are identified with like reference numerals. As illustrated, the inclined surface  166  has a wave pattern such that the inclined surface  166  is sinusoidally translated around a circumference of the inclined surface  166 . The wave pattern may provide a greater spring constant thereby increasing the amount of preload force applied as the retention ring  210  is compressed. 
       FIG. 10  is a perspective view of an embodiment of a conical retention ring  220  having an array of teeth  222  extending along the central portion  194 . The teeth  222  extend around the inner perimeter  171  of the retention ring  220 .  FIG. 11  is a perspective view of an embodiment of a conical retention ring  230  having an array of teeth  222  extending along the outer portion  196 . The teeth  222  extend around an outer perimeter  232  of the retention ring  230 . The retaining rings  220 ,  230  are both similar to the retention ring  116  and like components are identified with like reference numerals. The teeth  222  provide increased friction between the conical retention rings  220 ,  230  and contact surfaces. For example the teeth  222  of the conical retention ring  220  provides increased friction between the panel  106  (shown in  FIG. 1 ) and the first side  198  of the retention ring  220 . The teeth  222  of the conical retention ring  230  may also provide increased friction between the outer surface  178  (shown in  FIG. 4 ) of the spacer  146  (shown in  FIG. 4 ) and the second side  200  of the retention ring  230 . In certain embodiments, both the central portion  194  and the outer portion  196  may include teeth  222 . In the illustrated embodiment, the teeth  222  protrude along both sides  198 , 200  of the inclined surface  166 , but in other embodiments, the teeth  222  may protrude from only one of the sides  198  or  200 . The increased friction may prevent the threaded fastener  114  from becoming unscrewed or loosed once tightened. For example, the teeth  222  may dig into a portion of the outer surface  178  of the spacer  146  and the panel  106 . 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.