Abstract:
The present invention is directed to a shock-proof electrical wiring system for use in an AC electrical power distribution circuit including a plurality of AC electric power transmitting wires disposed between an AC power distribution point and a device box, a portion of the plurality of AC electric power transmitting wires being routed into an interior portion of the device box. The system includes a connector device having a connector housing. A plurality of connector contacts are disposed substantially inaccessible to a user within the connector housing. The plurality of connector electrical contacts are connected to a termination arrangement. The termination arrangement is configured to be connected to the portion of the plurality of AC electric power transmitting wires. An electrical wiring device includes a housing assembly that has at least one set of user-accessible receptacle openings disposed in a front major surface thereof in operative alignment with at least one shutter assembly configured to move from a closed position to an open position only in response to engaging a set of plug blades. The at least one shutter assembly is secured within the housing assembly by a plurality of registration elements disposed along at least two orthogonal axes of the shutter assembly such that the at least one shutter assembly is substantially fixed along a first axis of the at least two axes, portions of the at least one shutter assembly being slidably movable between an open position and a closed position along the second axis of the at least two axes, the housing assembly including an AC circuit assembly coupled to at least one set of receptacle contacts disposed in substantial alignment with the at least one shutter assembly, the housing assembly further including a power input arrangement formed in a rear portion thereof, the power input arrangement including a set of power contacts configured to mate with the plurality of connector contacts within the connector housing to thereby establish electrically continuous paths between the plurality of AC electric power transmitting wires and the AC circuit assembly and the at least one set of receptacle contacts, the portion of the AC power transmitting wires being stowed within the interior portion of the device box when the electrical wiring device is mounted to the device box.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part application of U.S. patent application Ser. No. 11/691,116 filed on Mar. 26, 2007, which is a continuation of U.S. patent application Ser. No. 11/357,563 filed on Feb. 17, 2006, which is a continuation of U.S. patent application Ser. No. 11/032,420 filed on Jan. 10, 2005, which is a continuation-in-part of U.S. patent application Ser. No. 10/680,797 filed on Oct. 7, 2003; This application is also a continuation-in-part application of U.S. patent application Ser. No. 11/933,928 filed on Nov. 1, 2007, which is a continuation of U.S. patent application Ser. No. 11/609,793 filed on Dec. 12, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 10/900,778 filed on Jul. 28, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/729,685 filed on Dec. 5, 2003, the contents of which are relied upon and incorporated herein by reference in their entirety, and the benefit of priority under 35 U.S.C. §120 is hereby claimed. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to electrical circuit installation, and particularly to electrical devices that facilitate installation of electrical circuits in a building or some other structure. 
         [0004]    2. Technical Background 
         [0005]    Installing electrical circuits in buildings and/or other structures is typically labor intensive, time-consuming, and a process that requires electricians of various skill levels. As a result the installation process is expensive. The first phase of the installation is commonly referred to as the “rough-in” phase. In new construction, either conduit or armored cable is disposed throughout the structure in accordance with the building plans. Junction boxes are installed at appropriate locations, and brackets and wiring device boxes are installed throughout the structure where electrical service is desired. Junction boxes, of course, are employed to house the connection point, or junction, of several conductors. Wiring device boxes are used to accommodate electrical wiring devices. For example, the types of electrical wiring devices may include, but are not limited to, receptacles, switches, dimmers, GFCIs, AFCIs, transient voltage surge suppressors (TVSS), protective devices, timer devices, sensors of various types including occupancy sensors, thermostats, lighting fixtures, and/or combinations thereof. After the boxes are placed, the electrical power conductor wires are pulled through the conduits and all of the circuits are bonded. At this point, the leads from the electrical wires extend from the boxes and are visible and accessible for the next phase of the installation process. 
         [0006]    Before discussing the next phase of the process, it is noted that electrical cables may include two to five conductive wires. For example, in a structure that requires high power, the most common way of distributing that power is by employing the three-phase power system. As those of ordinary skill in the art recognize, five wires are employed. Three phase power includes three “hot” or “live” wires. Each of these wires transmits electrical power that is 120 degrees out of phase with the other two hot wires. The other two wires are the neutral conductor and the ground wire. Three phase power typically comes from the power utility via four wires: the three-phase wires, and the neutral. If the current flowing through each of the phases is equal, no current will flow through the neutral. The neutral wire is typically connected to the building ground at the structure&#39;s main distribution panel. The five wire cable is distributed from the central panel. Some of the circuits in the structure are designed to provide power to grounded equipment. These circuits may employ three wires, a line conductor (hot wire), a neutral conductor, and a ground. Some circuits may only employ two wires, the line conductor and the neutral conductor. 
         [0007]    Referring back to the installation process, after the “rough-in” phase has been completed, the electrical wiring devices are terminated, i.e., they are electrically connected to the wire leads. This part of the installation process is the most costly and time consuming. A journeyman electrician must perform, or supervise, the connection of each wiring device in the structure. In this process, each electrical wire must be stripped and terminated to the device. 
         [0008]    Once the electrical wiring device is terminated and power is applied, it begins its operational life span. Because safety is paramount, there are several safety issues that must be considered. One safety issue that must be considered relates to child-safely and is concerned with preventing the child from inserting foreign objects into the face receptacles. Another issue relates to safely disabling or tripping the device once an end-of-life condition has been reached. Yet another issue relates to safely replacing the wiring device once end-of-life has been reached. 
         [0009]    What is needed, therefore, is an efficient, labor-saving, and cost effective means for terminating the electrical wires and coupling them to the individual devices. The electrical wiring device should be shock-proof, i.e., that it addresses the issues presented in the paragraph immediately preceding this one. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention addresses the needs described above by providing an efficient, labor-saving, and cost effective means for terminating the electrical wires and coupling them to the individual devices. The system and method is cost-effective because it eliminates many of the labor intensive practices that are currently in use. The system of the present invention is also shock-proof, in that it prevents children from inserting foreign objects into the face receptacles, trips the device once an end-of-life condition has been reached, and may be safely and easily replaced without the possibility of shock. 
         [0011]    One aspect of the present invention is directed to an electrical wiring system that includes a shock-proof electrical wiring system for use in an AC electrical power distribution circuit including a plurality of AC electric power transmitting wires disposed between an AC power distribution point and a device box, a portion of the plurality of AC electric power transmitting wires being routed into an interior portion of the device box. The system includes a connector device having a connector housing. A plurality of connector contacts are disposed substantially inaccessible to a user within the connector housing. The plurality of connector electrical contacts are connected to a termination arrangement. The termination arrangement is configured to be connected to the portion of the plurality of AC electric power transmitting wires. An electrical wiring device includes a housing assembly that has at least one set of user-accessible receptacle openings disposed in a front major surface thereof in operative alignment with at least one shutter assembly configured to move from a closed position to an open position only in response to engaging a set of plug blades. The at least one shutter assembly is secured within the housing assembly by a plurality of registration elements disposed along at least two orthogonal axes of the shutter assembly such that the at least one shutter assembly is substantially fixed along a first axis of the at least two axes, portions of the at least one shutter assembly being slidably movable between an open position and a closed position along the second axis of the at least two axes, the housing assembly including an AC circuit assembly coupled to at least one set of receptacle contacts disposed in substantial alignment with the at least one shutter assembly, the housing assembly further including a power input arrangement formed in a rear portion thereof, the power input arrangement including a set of power contacts configured to mate with the plurality of connector contacts within the connector housing to thereby establish electrically continuous paths between the plurality of AC electric power transmitting wires and the AC circuit assembly and the at least one set of receptacle contacts, the portion of the AC power transmitting wires being stowed within the interior portion of the device box when the electrical wiring device is mounted to the device box. 
         [0012]    In another aspect, the present invention is directed to a shock-proof electrical wiring system for use in an AC electrical power distribution circuit including a plurality of AC electric power transmitting wires disposed between an AC power distribution point and a device box. A portion of the plurality of AC electric power transmitting wires are routed into an interior portion of the device box. The system includes a connector device including a connector housing and a plurality of female electrical contacts disposed substantially inaccessible to a user within the connector housing. The plurality of female electrical contacts are internally connected within the housing to a plurality of wire segments. The plurality of wire segments are configured to be connected to the portion of the plurality of AC electric power transmitting wires. An electrical wiring device includes a cover assembly having at least one set of user-accessible receptacle openings disposed in a major cover surface thereof in operative alignment with at least one shutter assembly. The at least one shutter assembly is configured to move from a closed position to an open position in response to engaging at least one set of plug blades and otherwise preventing an external object from making contact with the at least one set of face receptacle contacts. The device also includes a body member having an AC circuit assembly coupled to the at least one set of face-receptacle contacts disposed in substantial alignment with the at least one shutter assembly. The body member further includes a power input arrangement formed in a rear portion thereof. The power input arrangement includes a set of male power contacts configured to mate with the plurality of female connector contacts within the connector housing when the connector device is mated with the power input arrangement to thereby establish an electrically continuous path between the AC circuit assembly and the plurality of AC electric power transmitting wires such that the connector device is safely removable from the electrical wiring device when the electrical wiring system is energized. 
         [0013]    In yet another aspect, the present invention is directed to a shock-proof electrical wiring system for use in an AC electrical power distribution circuit including a plurality of AC electric power transmitting wires disposed between an AC power distribution point and a device box. A portion of the plurality of AC electric power transmitting wires are routed into an interior portion of the device box. The system includes an insertable connector assembly having a plurality of connector contacts inaccessibly disposed in a connector housing characterized by a predetermined form factor, the connector assembly including a termination arrangement electrically coupled to the plurality of connector contacts and configured to terminate the portion of the plurality of AC electric power transmitting wires. An electrical wiring device includes a cover assembly having at least one set of user-accessible receptacle openings disposed in a major surface thereof and at least one frameless shutter assembly disposed in the cover assembly in substantial alignment with the at least one set of user-accessible receptacle openings. The at least one shutter assembly is configured to move from a closed position to an open position only in response to engaging a set of plug blades. The device includes a body member having a power input receptacle substantially conforming to the predetermined form factor and formed in a rear portion thereof. The power input receptacle includes a set of power contacts configured to mate with the plurality of connector contacts when the connector assembly is inserted in the power input receptacle preventing a foreign object from accessing an interior portion of the power input receptacle. At least one set of face receptacle contacts is coupled to the set of power contacts by a corresponding set of conductive paths and disposed in substantial alignment with the at least one shutter assembly. A fault protection mechanism is configured to interrupt at least one of the conductive paths in response to detecting a fault condition. 
         [0014]    In yet another aspect, the present invention is directed to a shock-proof electrical wiring system for use in an AC electrical power distribution circuit including a plurality of AC electric power transmitting wires disposed between an AC power distribution point and a device box. A portion of the plurality of AC electric power transmitting wires are routed into an interior portion of the device box. The system includes a connector device having a housing and a plurality of female electrical contacts disposed substantially inaccessible to a user within the housing. The plurality of female electrical contacts are connected to a termination arrangement. The termination arrangement is configured to be connected to the portion of the plurality of AC electric power transmitting wires. An electrical wiring device includes a cover assembly having a power output arrangement disposed in a major surface of the cover assembly. The power output arrangement includes at least one set of user-accessible receptacle openings disposed in the major cover surface in operative alignment with at least one shutter assembly. The at least one shutter assembly is configured to move from a closed position to an open position in response to engaging at least one plug blade having a predetermined plug blade geometry and preventing an external object not having the predetermined plug blade geometry from making contact with the at least one set of face receptacle contacts. The electrical wiring device further includes a body member having an AC circuit assembly coupled to at least one set of face-receptacle contacts disposed in substantial alignment with the at least one shutter assembly. The body member further includes a power input arrangement formed in a rear portion thereof. The power input arrangement includes a set of male power contacts configured to mate with the plurality of female connector contacts within the connector housing when the connector device is mated with the power input arrangement to thereby establish an electrically continuous path between the AC circuit assembly and the plurality of AC electric power transmitting wires and preventing a foreign object from making contact with the set of male contacts. The connector device is safely removable from the electrical wiring device when the electrical wiring system is energized. 
         [0015]    Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
         [0016]    It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operation of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a top perspective view of an electrical wiring system in accordance with a first embodiment of the present invention; 
           [0018]      FIG. 2  is a bottom perspective view of the electrical wiring system shown in  FIG. 1 ; 
           [0019]      FIG. 3  is a bottom perspective view of the electrical wiring device shown in  FIG. 1 ; 
           [0020]      FIG. 4  is an exploded view of the electrical wiring device depicted in  FIG. 1 ; 
           [0021]      FIG. 5  is a detail side view of the electromechanical assembly of the electrical wiring device shown in  FIG. 1 ; 
           [0022]      FIG. 6  is an exploded view of a shutter assembly depicted in  FIG. 4 ; 
           [0023]      FIG. 7  is a perspective view of the shutter assembly employed in the front cover of the electrical wiring device shown in  FIG. 4 ; 
           [0024]      FIG. 8  is a perspective view of the inside portion of the front cover of the electrical wiring device shown in  FIG. 1 ; 
           [0025]      FIG. 9  is a lateral cross sectional view of the electrical wiring device shown in  FIG. 1  through the cover, the shutter assembly and the separator; 
           [0026]      FIG. 10  is a schematic view of a GFCI circuit in accordance with an embodiment of the present invention; 
           [0027]      FIG. 11  is a bottom perspective view of an electrical wiring device in accordance with a second embodiment of the present invention; 
           [0028]      FIG. 12  is a bottom perspective view of an electrical wiring device in accordance with a third embodiment of the present invention; 
           [0029]      FIG. 13  is a perspective view of a GFCI/Light combination device in accordance with a fourth embodiment of the present invention; and 
           [0030]      FIG. 14  is an exploded view of the electrical wiring device depicted in  FIG. 13 . 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. An exemplary embodiment of the system of the present invention is shown in  FIG. 1 , and is designated generally throughout by reference numeral  10 . 
         [0032]    As embodied herein, and depicted in  FIG. 1 , a perspective view of an electrical wiring system  10  in accordance with a first embodiment of the present invention is disclosed. System  10  includes a plug connector  20  that mates with electrical wiring device  30 . Electrical power conductor wires ( 12 , 14 , 16 ) are terminated by plug contacts disposed within plug housing  200 . When plug  20  is installed in device  30 , electrical continuity is established between the plurality of wires ( 12 , 14 , 16 ) and the wiring device  30 . One feature of the present invention is that it includes no external terminal connections. Power is provided to device  30  via plug connector  20 . Service, depending on the nature of the device, is provided to the user via the front face. The present invention may be configured to accommodate 2 wire systems and three-phase (5 wire) systems, as well as the 3-wire system shown. Further, system  10  of the present invention may be adapted to a wiring system that employs more than 5 wires. 
         [0033]    The exterior portion of wiring device  30  includes a cover  300 , a separator portion  304 , and a body member  306 . A mounting strap  302  is disposed between the cover  300  and the separator  304 . Body  306 , separator  304  and cover  300  are injection molded components fabricated using materials such as polymers, polycarbonate, or nylon materials. 
         [0034]    The cover member  300  includes a raised portion  350  disposed at either end. Each raised portion  350  is configured to accommodate a shutter assembly  100  (not shown in this view). Each raised portion  350  includes a set of receptacle openings including hot blade opening  352 , neutral blade opening  354 , and ground prong opening  353 . The central portion of the cover member  300  includes a test button  311  a reset button  310  and a lens formed at the end of light pipe (trip indicator)  314  disposed in alignment with the reset button  310 . When the indicator  314  is illuminated, the user is guided to the reset button  310 . If the device has not reached an end-of-life condition, it will be reset when the reset button  310  is depressed by the user, and the light emanating from the trip indicator light  314  will be extinguished. 
         [0035]    The mounting strap  302  may be fabricated using polymer, polycarbonate or nylon materials, a copper alloy or plated steel. When an electrically conductive material is used, strap  302  serves to ground an electrically conductive outlet box or mounting surface to the wiring device. When an electrically non-conductive material is used, the strap may be integral to body  306 , separator  304 , or cover  300 . 
         [0036]    Referring to  FIG. 2 , a bottom perspective view of the electrical wiring system shown in  FIG. 1  is disclosed. In this view, the plug connector  20  is shown in an inserted position within a receptacle  308  formed in the rear portion of electrical wiring device  30 . The plug connector  20  shown in this embodiment features a novel  900  design such that the electrical power conductors ( 12 , 14 , 16 ) enter the plug connector at an angle of approximately 90° relative to the orientation of the contacts. This feature reduces the width dimension of the plug connector, allowing installation of the device in a greater variety of wiring boxes. By way of example, an elongated wiring box, commonly referred to as “raceway” restricts the width dimension of the device (depth behind the strap to the rearward surface of the plug connector) to less than about 1.70 inches. In one embodiment of the present invention, the width dimension (depth behind the strap to the rearward surface of the plug connector) is 1.52 inches. The conductor wires ( 12 , 14 , 16 ) closely parallel the back surface of body member  306  in this embodiment. Plug  20  includes a housing  200  and connector contacts (which are disposed within body  200  and therefore not shown in the Figure). In the embodiment shown, connector contacts  202  are female contacts designed to accept male contacts disposed within wiring device  30 . However, those of ordinary skill in the art will understand that system  10  may be designed the other way around, i.e., with male plug contacts and female device contacts. 
         [0037]    Referring to  FIG. 3 , a bottom perspective view of the electrical wiring device  30  shown in  FIG. 1  is disclosed. Receptacle opening  308  is disposed in one end of body member  306 . Receptacle opening  308  consists of a molded plastic material that is shaped to accommodate the plug connector  20 . The receptacle opening  308  may included a perimetric wall  3080  that is designed to abut the plug connector  20  when it is fully inserted therein. The perimetric wall  3080  may include a receptacle latch portion  3082  that is configured to coupled with a corresponding latch mechanism disposed on plug connector  20 . The interior portion of the receptacle opening  308  includes receptacle hot contact blade  460 , receptacle neutral contact blade  480 , and the receptacle ground blade  440  disposed in a predetermined geometric relationship that facilitates mating with plug connector  20 . 
         [0038]    Referring to  FIG. 4 , an exploded view of the electrical wiring device  30  depicted in  FIG. 1  is disclosed. The electrical wiring device  30 , of course, includes a full duplex style cover member  300  having two raised portions  350  that are configured to accommodate the shutter assemblies  100  as shown. Cover member  300  also includes lateral skirt portions  355  which are configured to cover the lateral portions of the face receptacle terminal structures ( 201 ,  210 ). In the exploded view, the reset button and pin  310  are clearly shown. The reset button is accessible via the front cover and the attached reset pin is inserted into spring member  312  and a corresponding aperture  3042  within separator  304 . The reset pin, of course, is ultimately disposed within the latch block  412  and is configured to move between a reset position and a tripped position. 
         [0039]    The test button  311  is also accessible via the front cover and is employed by a user to move the test blade  316  in a downward direction. A lead from a test resistor R 1  (not shown in this Figure) extends from tower  3044 . When the test blade  316  is pressed by the user in a downward direction such that it contacts the lead of resistor R 1 , a current path is established between the line neutral and the load hot to simulate a fault condition. See also  FIG. 10 . 
         [0040]    The separator member  304  accommodates the hot receptacle terminal structure  201  and the neutral receptacle terminal structure  210 . The hot receptacle terminal structure  201  includes a hot fixed contact  203  disposed at an intermediate portion thereof and hot receptacle contact structures  204  formed at either end. The neutral receptacle terminal structure  210  includes a neutral fixed contact  212  disposed at an intermediate portion thereof and neutral receptacle contact structures  214  formed at either end. Therefore, both ends of device  30  include a shutter assembly disposed between a raised portion  350  and a set of hot and neutral receptacle contacts ( 204 ,  214 ). Note also that the separator  304  includes a shutter support structure  3040  disposed at either end. The mounting strap  302  is also disposed within the separator member  304  between the hot receptacle terminal structure  201  and the neutral receptacle terminal structure  210 . 
         [0041]    The electromechanical assembly  500  is disposed within back body member  306 . The various components of the electromechanical assembly  500  are discussed in greater detail below. However, the hot terminal structure  400  is coupled to the electromechanical assembly  500  at one end and at another end to receptacle hot contact blade  460  by way of a black wire  420 . In similar fashion, the neutral terminal structure  410  is coupled to the electromechanical assembly  500  at one end and at another end to receptacle neutral contact blade  480  by way of a white wire  430 . Although it is not clearly shown in the Figure, the white wire  430  and the black wire  420  cross each other underneath the electromechanical assembly  500 . The receptacle ground blade  440  is coupled to the ground strap  302 . The contacts ( 460 ,  480 ,  440 ) are fabricated using copper alloy materials They may be plated with an electrically conductive material such as a tin alloy. 
         [0042]    Referring to  FIG. 5 , a detail side view of the electromechanical assembly of the electrical wiring device shown in  FIG. 1  is disclosed. In this view, the back body  306 , separator  304 , and cover member  300  are omitted for clarity of illustration. In the previous discussion, it was noted that strap  302  is disposed in the separator and therefore disposed a predetermined distance over the other components disposed on printed circuit board (PCB)  550 . Various components such as latch block  412 , LED  528 , SCR  510 , solenoid  516 , and test resistor R 1  are disposed on PCB  550 . 
         [0043]    At one end of PCB  550 , the toroid assembly  502  is disposed between hot line terminal structure  400  and neutral line terminal  410 . At the far end of PCB  550 , plug connector  20  is mated with the blade contacts ( 440 ,  460 ,  480 ) disposed in rear receptacle  308 . Black and white conductors  420  and  430 , respectively, extend underneath PCB  550 , between their respective terminal connections and their respective receptacle blade connections. In the example provided in  FIG. 5 , hot rear receptacle blade  460  is connected to AC power wire  12  via plug connector  20 . Black hot wire  420  is connected to hot receptacle blade  460  and extends under the PCB  550  where it is ultimately terminated at hot terminal structure  400 . Similarly, the neutral receptacle blade  480  is connected to white wire  430  which terminates at neutral terminal structure  410 . In the view provided by  FIG. 5 , the neutral cantilever interrupting structure  411  is seen to extend from neutral terminal structure  410 . A neutral contact  413  is disposed at the end of the cantilever  411 , the neutral contact  413  is, of course, in alignment with fixed contact  212 . 
         [0044]    Those of ordinary skill in the art will understand that the aforementioned components disposed on PCB  550  implement a GFCI circuit. However, the present invention may be implemented using any suitable type of device including a transient voltage surge suppressor (TVSS), an arc fault circuit interrupter (AFCI), a timer mechanism, an occupancy sensor or other type of sensor, a thermostat, a night light, or a device that includes a combination of the above. Clearly, the form factor of cover member  300  will change accordingly. 
         [0045]    As embodied herein and depicted in  FIG. 6 , an exploded view of a shutter assembly depicted in  FIG. 4  is disclosed. The protective shutter assembly  100  is a frameless mechanism that includes a lower shutter member  120  and an upper shutter member  140 . A spring member  130  is disposed between lower shutter  120  and upper shutter  140 . 
         [0046]    The lower shutter  120  includes side rails  122  and a base member  123  disposed therebetween. Base  123  has a first hot contact aperture  126  and a neutral contact aperture  124  formed therein. A transverse hot blade contact structure  128  is disposed between rails  122  and spans a portion of the first hot contact aperture  126 . 
         [0047]    Transverse contact structure  128  includes a spring retainer pocket  1280 , upper rail guides  1282  and blade contact ramp  1284 . As the name suggests, upper rail guides  1282  allows the rails  142  of the upper shutter to slide therebetween, allowing shutter  100  to move between the open position and the closed position. Rail guides  1282  also have a rail stop function. Upper shutter rail stop members  1420  abut rail guides  1282  to prevent upper shutter  140  from disengaging lower shutter  120  due to the force exerted by spring  130  in the closed position. 
         [0048]    Transverse contact structure  128  includes a blade detection geometry implemented by hot blade contact ramp  1284  and ramp base  1286 . The hot blade contact ramp  1284  is disposed in a central portion of structure  128 . Ramp  1284  has a predetermined width and includes contoured surfaces that recede into the face of structure  128 . Those of ordinary skill in the art will recognize that the contoured surfaces will cause foreign objects having a width that is less than the predetermined width of ramp  1284 , such as paper clips and the like, to slide off the ramp and strike the base  1286 . As a result, a perpendicular force relative to the longitudinal axis of base  123  will be applied by the person wielding the object and the object will be blocked. The predetermined width of ramp  1284 , of course, is selected in accordance with the geometry of a proper plug blade. Those of ordinary skill in the art will understand that the contoured surface of ramp  1284  may be of any suitable shape, such as an arcuate shape, a pointed shape, etc. 
         [0049]    The upper shutter member  140  includes guide rails  142  having a base member  148  disposed therebetween. As noted above, the guide rails include a stop member  1420  that is configured to abut lower shutter rail guides  1282  to prevent the shutters ( 120 ,  140 ) from disengaging due to the force exerted by the spring  130 . An upper shutter hot contact aperture  144  is disposed in base member  148 . 
         [0050]    Upper shutter member  140  also includes a transverse neutral blade contact structure  146  disposed at one end thereof. Transverse neutral blade contact structure  146  includes a spring retainer pocket  1460 , guide rails  142  and, like the lower shutter transverse contact structure  128 , a blade detection geometry implemented by neutral blade contact ramp  1462  and ramp base  1465 . The neutral blade contact ramp  1462  is disposed at an end portion of shutter  140 . In the closed position, neutral blade contact ramp  1462  covers the lower shutter neutral aperture  124 . Ramp  1462  has a predetermined width and includes contoured surfaces that recede into the face of structure  146 . Again, those of ordinary skill in the art will recognize that the contoured surfaces will cause foreign objects having a width that is less than the predetermined width of ramp  1462 , such as paper clips and the like, to slide off the ramp and strike the base  1465 . As a result, a perpendicular force relative to the longitudinal axis of base  1465  will be applied by the person wielding the object and the object will be blocked. The predetermined width of ramp  1462  is selected in accordance with the geometry of a proper plug blade. Those of ordinary skill in the art will understand that the contoured surface of ramp  1462  may be of any suitable shape, such as an arcuate shape, a pointed shape, etc. 
         [0051]    The protective shutter assembly  100  includes registration members disposed on the frameless shutter sub-assembly. The registration members are configured to position and align the protective shutter assembly  100  within the cover assembly of an electrical wiring device. The lower shutter includes a lower shutter longitudinal registration members  1222  and the upper shutter includes an upper shutter longitudinal registration members  1464 . As their names suggest, the lower shutter longitudinal registration members  1222  and the upper shutter longitudinal registration members  1464  are configured to correctly align and position the protective shutter assembly  100  within the cover assembly at a position along a longitudinal axis of the protective shutter assembly. Protective shutter assembly  100  also includes snap-in registration members  1220 . The snap-in elements, of course, allows the shutter assembly  100  to be snapped, as a unit, into the cover assembly, provided that the lower shutter longitudinal registration member  1222  and the upper shutter longitudinal registration member  1464  are correctly registered with a corresponding registration structure within the cover assembly. 
         [0052]    Note that the protective shutter assembly  100  is characterized by a length (L) that is approximately equal to an inch. In a 15A embodiment, the length (L) is approximately equal to 0.860″. In a 20A device, the length (L) is approximately equal to 1.060″. 
         [0053]    As embodied herein and depicted in  FIG. 7 , a perspective view of a shutter assembly employed in the front cover of the electrical wiring device shown in  FIG. 6  is disclosed. When assembled, the upper shutter  140  is inserted into lower shutter  120  until stop members  1420  extend beyond rail guides  1282  and snap into place. This position represents the closed position, wherein upper transverse structure covers neutral aperture  124  and upper base  148  covers hot aperture  126 . The lower shutter member  120  and the upper shutter member  140  are movable relative to each other from the closed position to the open position in response to being simultaneously engaged by the hot plug blade and the neutral plug blade of an electrical plug. To facilitate this movement, shutter members ( 120 , 140 ) are made from a family of plastics having natural lubricity. These include nylon 6-6, Delrin, and Teflon. Shutter members ( 120 , 140 ) may be made from a substrate on which these materials are coated, the substrate having a differing flammability or flexural characteristic. 
         [0054]    If a foreign object having a width substantially the same as a hot plug blade is inserted into the hot receptacle opening, the shutter assembly remains closed. The foreign object causes ramp  1284 , and therefore, lower shutter  120 , to move. However, this foreign object insertion does not cause upper shutter  140  to move relative to shutter  120 . As a result, the foreign object inserted into the hot receptacle opening strikes lower base member  148  of the upper shutter. On the other hand, if a foreign object having a width substantially the same as a neutral plug blade is inserted into the neutral receptacle opening, transverse structure  146  will move upper shutter  140  but not move lower shutter  120 . Accordingly, the lower base member  123  does not move and the neutral aperture  124  (See  FIG. 1 ) is not exposed. Thus, the foreign object inserted into the neutral receptacle opening strikes lower base member  123 . 
         [0055]    Only when the hot plug blade and the neutral plug blade of an electrical plug simultaneously engage ramp  1284  and ramp  1462 , respectively, will the lower shutter member  120  and the upper shutter member  140  move relative to each other from the closed position to the open position. In the open position, the lower hot aperture  126  is aligned with the upper hot contact aperture  144  and, the inward edge of the lower neutral contact aperture  124  is substantially aligned with the outer edge of ramp  1462 . In this position, the lower shutter  120  and the upper shutter  140  allow the plug contact blades to pass through the protective shutter  100  and engage the contacts disposed in the interior of the electrical wiring device. 
         [0056]    In another embodiment, the predetermined electrical plug geometry that opens the shutters may include only some of the characteristics that have been described. The geometry may include just one or more of the following: two plug blades separated by a predetermined distance, plug blades contacting the two blade structures simultaneously, a neutral plug blade having a predetermined width, or a hot plug blade having a predetermined width. Plug blade width will not matter if ramps  1284  and/or  1462  approach the widths of their respective contact structures. 
         [0057]    The movement of the upper shutter  140  and the lower shutter  120  is effected by spring member  130 . The spring member  130  is configured to bias the frameless shutter sub-assembly, i.e., lower shutter  120  and upper shutter  140 , in the closed position. Spring member  130  is compressed further in the open position and, therefore, opposes movement of the frameless shutter sub-assembly from the closed position to the open position. Accordingly when the electrical plug is removed, the spring moves the frameless shutter sub-assembly from the open position to the closed position. Stated differently, only a single spring is necessary to effect the closed position of the shutter assembly. 
         [0058]    As alluded to above, the protective shutter assembly  100  includes a spring retainer mechanism. The spring retainer mechanism includes lower shutter retainer pocket  1280  and upper shutter retainer pocket  1460 . The spring retainer mechanism is configured to retain the spring member  130  within the frameless shutter sub-assembly and substantially prevent the spring member from being separated from the frameless shutter sub-assembly. As those of ordinary skill in the art will appreciate, the protective shutter assembly  100  may be dropped and/or exposed to vibrational and/or mechanical forces during automated assembly. As shown in  FIG. 1 , retainer pockets ( 1280 ,  1460 ) are equipped with retainer lips that prevent the spring member from being jarred loose. 
         [0059]    Referring to  FIG. 8 , a perspective view of the inside portion of the raised portion  350  of front cover  300  of the electrical wiring device shown in  FIG. 1  is disclosed. The raised portion  350  of cover assembly  300  is shown to include hot receptacle opening  352  and neutral receptacle opening  354 . Those of ordinary skill in the art will understand that the shape and size of the receptacle openings is determined by the geometry of the type of service, i.e., 15A, 20A, etc., and the corresponding plug blades. Of course, the cover  300  mates with a wiring device housing that includes a plurality of receptacle contacts. The hot  352 , neutral  354 , and ground  353  openings are in communication with their corresponding receptacle contacts in the open position. The electrical plug may include pins instead of blades in which case the corresponding receptacle openings are circular instead of rectangular. Ramps ( 1286 , 1462 ) are then configured to allow predetermined pin shapes to open the shutter assembly. 
         [0060]    The raised cover assembly  350  includes a pair of cover registration structures  3560 , each including a registration alignment key  358  disposed therein. Each alignment key  358  accommodates a lower shutter longitudinal registration member  1222  and an upper shutter longitudinal registration member  1464 . The position of alignment key  358  ensures that the protective shutter assembly  100  is positioned within the raised cover assembly  350  such that the hot shutter aperture  126 , neutral shutter aperture  124 , and the ramp structures ( 1284 ,  1462 ) and base portions ( 123 , 148 ) are correctly aligned with the receptacle openings ( 352 ,  354 ). 
         [0061]    Each registration structure  356  includes a registration groove  3560  that is configured to mate with snap-in registration member  1220  (See  FIGS. 6-7 ). As discussed above in some detail, registration member  1220  is configured to snap into registration groove  3560  to couple the frameless protective shutter assembly  100  to the raised cover assembly  350 . 
         [0062]    Referring to  FIG. 9 , a lateral cross sectional view of the electrical wiring device through the raised cover assembly  350 , the shutter assembly  100  and the separator  304  is disclosed. From top to bottom, it is seen that the raised cover portion  350  includes hot blade opening  352  and neutral blade opening  354  disposed in registered alignment with shutter  100  in the manner described above. The receptacle contacts ( 204 ),  214 ) are disposed in substantial alignment under the shutter  100  with the openings ( 352 ,  354 ). 
         [0063]    The separator  304  includes a shutter support structure  3040  that is configured to press against the under-side of the shutter when the cover  300 , separator  304  and body member  306  are fully assembled. One can imagine electrical wiring device  30  being inadvertently dropped from a height of several feet. Without the support provided by structure  3040 , the applied force may be enough to dislodge the shutter  100  from the registered interior of raised cover assembly  350 . The shutter support member  3040  holds the shutter  100  securely in place and prevents the shutter  100  from being dislodged from the registration members  356 . 
         [0064]    As embodied herein and depicted in  FIG. 10 , a schematic view of the protective circuit employed in the electrical wiring device of the present invention is disclosed. Moving from left to right in the schematic, it is seen that GFCI  501  includes hot line receptacle blade  460 , neutral line receptacle blade  480 , and ground receptacle blade  440 . On the load side of device  10 , there are a pair of user accessible receptacles, each including a hot receptacle terminal  204  and a neutral receptacle terminal  214 . As noted above, there are no external terminal elements provided by device  30 . 
         [0065]    The ground fault circuitry includes a differential transformer  502  which is configured to sense load-side ground faults. Transformer  504  is configured as a grounded neutral transmitter and is employed to sense grounded-neutral fault conditions. Both transformers are disposed in toroid assembly L 1 . Both differential transformer  502  and grounded-neutral transformer  504  are coupled to detector integrated circuit  506 . Detector  506  is powered by a power supply circuit  508  connected to pin V +  on detector  506 . The detector output, provided on output pin SCR, is connected to the control input of SCR  510 . Filter  512 , comprising resistor R 10  and capacitor C 7 , low-pass filter the detector output signal. GFCI  501  also includes a snubber circuit  514  that includes resistor R 4  and capacitor C 8 . Snubber circuit  514  prevents voltage transients from triggering SCR  510 . 
         [0066]    When SCR  510  is turned ON, solenoid  516  is energized, actuating circuit interrupter  518 . Solenoid  516  remains energized for a time period that is typically less than about 25 milliseconds. Circuit interrupter  518  trips, resulting in the line terminals being disconnected from respective load terminals. After the fault condition has been eliminated, the circuit interrupter  518  may be reset by way of reset button  310 . In one embodiment, the reset button  310  functionality is purely mechanical in nature and does not include any electrical contacts for test initiation. 
         [0067]    It will be apparent to those of ordinary skill in the pertinent art that modifications and variations can be made to circuit interrupter of the present invention depending on contact structure implementation. For example, circuit interrupter  518  may be implemented using a cantilevered contact structure. The line terminals ( 400 ,  410 ) are electrically connected to the receptacle load terminals ( 204 ,  214 ) when the device  30  is reset. When in the tripped state, the line and receptacle contacts are disconnected from each of the other contacts. 
         [0068]    GFCI  501  addresses certain end of life conditions by denying power to the load when the device is unable to function. As an example of an end-of-life condition, solenoid  516  is susceptible to burn-out if SCR  510  becomes shorted out, or is permanently turned ON. Solenoid  516  may burn out if it is energized for more than about 1 second. Once the solenoid  516  burns out, the circuit interrupter  518  is incapable of being tripped. Solenoid burn-out prevention is provided by auxiliary switch  522 . Auxiliary switch  522  is configured to open when the circuit interrupter  518  is in the tripped position. If SCR  510  is shorted out, or permanently ON, auxiliary switch  522  ensures that solenoid  516  is not permanently connected to a current source. The user may attempt to reset the device  30  by depressing the reset button  310 , but the circuit interrupter  518  will immediately trip in response to the current flowing through the solenoid  516 . Because the trip mechanism  518  is coupled to the auxiliary switch  522 , auxiliary switch  522  is opened before solenoid  516  burns out. 
         [0069]    Another failure mode that is addressed by GFCI  501  relates to the end-of-life failure mode of movistor (MOV)  524 . MOV  524  is disposed in series with auxiliary switch  522  and trip solenoid  516 . This arrangement significantly reduces the probability of damage due to an over-current situation. When MOV  524  reaches end-of-life and shorts out, trip solenoid  516  is energized and auxiliary switch  522  is opened. As previously described, when auxiliary switch  522  opens, the flow of short circuit current is terminated before any damage to GFCI  501  ensues. 
         [0070]    GFCI  501  also includes trip indication circuit  526 . Trip indication circuit  526  is implemented by placing LED  1  and series resistors (R 11 -R 14 ) in parallel with auxiliary switch  522 . LED 1  is configured to emit a visual signal when circuit interrupter  518  and auxiliary switch  522  are in an open state (tripped). 
         [0071]    GFCI  501  also includes a test circuit  530 . The test circuit  530  is coupled between the line neutral terminal  480  and the hot receptacle terminal  204 . The test circuit includes a test button  311  disposed in series with test resistor R 1 . 
         [0072]    As embodied herein and depicted in  FIG. 11 , a perspective view of an electrical wiring system  10  in accordance with a third embodiment of the present invention is disclosed. The wiring device  30  is identical to the device depicted in  FIG. 1  and described herein. Note that Receptacle  308  is shaped to accommodate both plug connector  20  embodiments. As before, receptacle  308  includes hot line receptacle blade  460 , neutral line receptacle blade  480 , and ground receptacle blade  440 . Of course, each male contact blade ( 440 ,  460 ,  480 ) mates with a corresponding female contact mechanism in plug connector  20 . 
         [0073]    Like the previous embodiment, plug connector  20  aligns the conductors ( 12 , 14 , 16 ) with the contacts disposed therein. What is different from the previous embodiment is the 180° configuration, i.e., conductors ( 12 , 14 , 16 ) and the internal plug contacts are arranged, substantially, in a 180° angle. Housing  200  includes latch mechanism  205 . When plug connector  20  is inserted into receptacle  308 , latch mechanism  205  prevents plug  20  from being pulled out of receptacle  308 . 
         [0074]    Latch mechanism  205  is configured to meet Underwriter&#39;s Laboratories (UL) standards for a locking connector. In this case, UL requires that a static pull test of 20 pounds be applied to the connector for one minute. During the test, plug connector  20  may not separate from receptacle  308 . During operation, latch mechanism  205  flexes upon insertion of plug connector  20 . The flexure latch mechanism  205  relaxes to a non-flexed position upon successful locking of plug connector  20  to receptacle  308 , and emits an audible snapping sound or visual indication that locking has been achieved. Flexible latch mechanism  205  may also be configured to be accessible to the finger or to a tool when plug connector  20  is locked to receptacle  308 . In this embodiment, when latch mechanism  205  is accessed and flexed manually, or by the tool, plug connector  20  can be removed from receptacle  308 . The flexure is oriented in a direction opposite to the insertion direction in order to meet requirements in Underwriters Laboratories (UL) standards. In another embodiment, plug connector  20  can be locked into receptacle  308  using screws or any number of fastening means familiar to those skilled in the art. 
         [0075]    Those of ordinary skill in the art will recognize that any suitable materials may employed in fabricating plug connector  20 . In one embodiment, plug housing  200  is formed from injection molded plastic, polycarbonate, or other polymer based materials. The plug connector contacts may be fabricated using any suitable conductive material such as a copper alloy material. Plug connector housing  200  may be fabricated by coupling an upper housing to a lower housing, i.e., the upper housing is snapped onto lower housing to thereby enclose and terminate wires ( 12 , 14 , 16 ) in plug connector  20 . 
         [0076]    In one embodiment, the female electrical contacts disposed in plug connector  20  may include a wire seat portion that accommodates the wire conductor. The wire conductor ( 12 , 14 , 16 ) is subsequently bonded to the seat portion. Each female contact also includes two exterior spring contact members and an interior spring contact member configured to hold the male contact blade therebetween. When the male receptacle contact blade ( 460 ,  480 ,  440 ) are inserted, the exterior spring contact members separate from the interior spring contact member to receive and hold the male contact blade firmly therebetween. Reference is made to U.S. Pat. No. 6,994,585, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the female contact arrangement described herein. 
         [0077]    In an alternate embodiment of the present invention, the female contacts may be pre-disposed in either the upper portion or in the lower portion of housing  200 . In this embodiment, each female contact is equipped with an insulation-displacement blade element. Of course, when the upper housing portion is snapped onto the lower housing portion, or vice-versa, the blade element cuts through and displaces the insulation on the wire ( 12 , 14 , 16 ) until electrical continuity is established between the wire ( 12 , 14 , 16 ) and the female contact. In yet another alternate embodiment of the present invention, the female contacts in plug  20  may be terminated to wire leads at the factory. The pre-terminated leads may be coupled to wires ( 12 , 14 , 16 ) using twist-on wire connectors. Reference is made to U.S. Pat. No. 6,994,585, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the plug connector termination methods employed by the present invention. 
         [0078]    As embodied herein and depicted in  FIG. 12 , a bottom perspective view of an electrical wiring device  30  in accordance with a second embodiment of the present invention is disclosed. This embodiment features a cowled external rear receptacle  308  that may be employed with the plug connector  20  shown in  FIG. 11 . Receptacle  308  includes a raised portion that is configured to accommodate the latch  205 . Comparing  FIG. 12  with  FIG. 4 , the electrical wiring device is functionally identical, the difference being the cowled external rear receptacle  308  and the mechanical configuration of the rear receptacle blades ( 440 , 460 ,  480 ) disposed therein. 
         [0079]    As embodied herein and depicted in  FIG. 13 , GFCI/Light combination device  1100  is disclosed. The electrical wiring device  1100  includes a cover member  300  coupled to a rear body portion  306 . The form factor of rear body member  306  is substantially identical to the rear portion  306  of the wiring device depicted in  FIGS. 1-12 . Wiring device  300  includes a GFCI circuit of the type disclosed in  FIGS. 1-12 , and a light source disposed under lens cover  318 . This may be accomplished by disposing the light source(s) under lens cover on either side of strap member  302 . In an aspect of the embodiment, the light source disposed under lens cover  318  functions as a pilot light by illuminating the ambient environment surrounding the electrical wiring device. The light source is connected to the line terminal elements in this embodiment. Accordingly, the light source is continuously energized as long as power is being provided to the device. 
         [0080]    In another embodiment, the light source functions as a circuit status indicator and is connected to the load terminal elements. The light is, therefore, energized when device  30  is in the reset state and the light is OFF when the device is tripped. The light source may be implemented using any suitable device, such as an LED. However, the light source may be implemented using a neon source, an incandescent source, etc. 
         [0081]    The light source may be implemented using a single-element light source or a multi-element light source. For example, twin LEDs may be disposed under lens cover  318 . Those of ordinary skill in the art will understand that the wavelength of the illumination produced by the light source will depend on the type of source used, and may be selected as a function of the task being performed by the light source; e.g., a night-light, a status indicator, a room illuminator, etc. 
         [0082]    Those of ordinary skill in the art will also understand that the lens cover  318  may be made of a either a clear or a translucent material in accordance with design factors such as the type of light source, the wavelength radiated by the light source, the desired intensity, or softness, of the illumination, the function of the light, and other considerations. The lens cover  318  may be removable from the housing cover  300  for access to the light source. 
         [0083]    Referring to  FIG. 14 , an exploded view of the electrical wiring device depicted in  FIG. 13  is disclosed. The electrical wiring device  30  includes only one receptacle disposed in cover member  300 . The receptacle is configured to accommodate a single shutter assembly  100  as shown. 
         [0084]    At the other end of the device  30 , lens element  318  is disposed within light aperture  3180 . Of course, the light reflector element  3182  is also disposed in aperture  3180  under the lens  318 . LEDS  3186 , which are disposed on an auxiliary PCB  384 , are mounted within apertures  3183  formed in the reflector  3182 . Sensor element  3200  is also mounted on the PCB  3184  as shown. Sensor  3200  includes a flexible lead that allows it to be mounted within sensor lens element  320 . 
         [0085]    Cover member  300  also includes lateral skirt portions  355  which are configured to cover the lateral portions of the face receptacle terminal structures ( 200 ,  210 ). In the exploded view, the reset button  310  and reset pin  313  are clearly shown. The reset button  310  is accessible via the front cover. The pin portion  313  of reset button  310  is inserted into spring member  312  and a corresponding aperture  3042  within separator  304 . The reset pin  313 , of course, is ultimately disposed within the latch block  412  and is configured to actuate the latch block  412  between a reset position and a tripped position. 
         [0086]    The test button  311  is also accessible via the front cover and is employed by a user to move the test blade  316  in a downward direction. A lead from a test resistor R 1  (not shown in this Figure) extends from tower  3044 . When the test blade  316  is pressed by the user in a downward direction such that it contacts the lead of resistor R 1 , a current path is established between the line neutral and the load hot to simulate a fault condition. See also  FIG. 10 . 
         [0087]    The separator member accommodates the hot receptacle terminal structure  201  and the neutral receptacle terminal structure  210 . These terminal structures are different than the ones employed in earlier embodiments. The hot receptacle terminal structure  201  includes a hot fixed contact  202  disposed at one end thereof, and hot receptacle contact structures  204  formed at the other end. In similar fashion, the neutral receptacle terminal structure  210  includes a neutral fixed contact  212  disposed at one end thereof and neutral receptacle contact structure  214  formed at the other end. Therefore, only one end of device  30  includes a shutter assembly  100  disposed between receptacle portion  350  and the lone set of hot and neutral receptacle contacts ( 204 ,  214 ). Finally, leads  220  extend from the fixed contact end of each terminal structure ( 201 ,  210 ) and are terminated at corresponding contact locations on PCB  3184 . The leads  220 , of course, provide PCB  3184  with AC power. 
         [0088]    As described previously, separator  304  includes a shutter support structure  3040  disposed at either end of the protective shutter assembly  100 . The mounting strap  302  is also disposed within the separator member  304  between the hot receptacle terminal structure  201  and the neutral receptacle terminal structure  210 . Separator  304  also includes an aperture  3046  that is configured to support and accommodate reflector element  3182 . 
         [0089]    The electromechanical assembly  500 , the back body  306  and the remaining components shown in  FIG. 14  are either identical or substantially similar to those described in the text associated with  FIG. 4  and elsewhere in this specification. 
         [0090]    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. 
         [0091]    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. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. 
         [0092]    The 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. 
         [0093]    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 embodiments of the invention and does not impose 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. 
         [0094]    It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. There is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.