Abstract:
A triplex electrical receptacle has a flexible, compact arrangement of bus bars and phase, neutral and ground contacts associated with three outlets. Two outlets are nearest two corners of the body that share a common first side, and the third outlet is between them but closer to the opposite side of the body. A common neutral bus bar (with terminal) is connected to the neutral contacts of all three outlets. The phase bus bar (with terminal) is connected to the phase contacts of at least two of the outlets. One embodiment permanently connects the phase contact of the third outlet to the phase bus bar; another embodiment permanently isolates the third outlet, connecting its phase contact to a separate phase terminal; and an additional embodiment incorporates a separate phase terminal for the third outlet and an optionally severable connection between the third outlet and the first phase terminal.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to electrical receptacles, in particular, to multiple outlet electrical receptacles that are mountable in standard electrical wall boxes. 
       BACKGROUND OF THE INVENTION 
       [0002]    Contemporary electrical receptacles designed to fit in a NEMA-standard single electrical wall box typically have two polarized grounded outlets, with the face openings of the outlets oriented in the same direction. Such an arrangement provides ample clearance for two straight plugs and for some, but not all, types of right angle plugs, chargers and transformers. Some duplex receptacles are designed to accommodate two larger transformers or chargers and most right angle plugs by orienting the face openings of the outlets in different directions. See, e.g., U.S. Pat. No. 7,278,878 to Draggie, et al. 
         [0003]    The need to power three or more devices from a duplex receptacle usually requires the use of unwieldy cube taps or power strips. Efforts have been made to fit three or more grounded outlets, oriented in different directions, into a receptacle body that can fit into a NEMA-standard single wall box. See, e.g., U.S. Pat. No. 6,923,663 to Oddsen, et al., and U.S. Pat. No. 7,347,724 to Crupi. However, such solutions require non-standard constructions. For example, the ANSI/NEMA WD 6 (R2008) dimensional standard for popular “decorator” style wiring devices (“Dimensions for Flush Mount Rectangular Face Devices”) specifies maximum face dimensions for a duplex receptacle of 1.300 in. wide by 2.620 in. long, and a mating wall plate opening at least 0.010 in. larger in each dimension. The receptacles of Oddsen, and those of Crupi having more than two outlets, do not comply with this standard because they have oversize rectangular faces and require oversize matching wall plates. Crupi&#39;s marginal ground prong openings (and the ground prongs received therein) undesirably are disposed outside the perimeter of the wall box. Oddsen&#39;s triplex receptacle ( FIG. 1 ), with all ground prong openings centrally clustered, is prone to blockage of open slots when certain chargers, transformers or right angle plugs are used. The same problems are inherent in Oddsen&#39;s “sixplex” receptacle ( FIG. 16 ), which is sized to fit into a standard double or ganged wall box. 
         [0004]    A need therefore exists for a standard-size electrical receptacle for mounting in a standard single wall box, especially a decorator-style receptacle, having three outlets that can accommodate plugs, chargers and transformers of many sizes and types at once, with all ground prongs kept within the wall box. Similarly, a need exists for a standard-size electrical receptacle for mounting in a standard-size double wall box, especially a decorator-style receptacle, having six outlets that can also accommodate plugs, chargers and transformers of many sizes and types at once, with all ground prongs kept within the wall box. 
       SUMMARY OF THE INVENTION 
       [0005]    The above needs are met by receptacle embodiments disclosed in commonly owned U.S. Pat. No. 7,824,196. The invention claimed herein concerns the bus bar and terminal arrangements disclosed in U.S. Pat. No. 7,824,196, as well as variants thereof that enable connection of at least one of the outlets to a separate circuit. 
         [0006]    In a generic sense, the invention is directed to a triplex electrical receptacle comprising a substantially rectangular body of a standard size. There are phase, neutral and ground contacts within the body associated with respective first, second and third outlets and accessible via respective phase blade openings, neutral blade openings and ground prong openings in the face of the body. The contacts of the first outlet are nearest a first corner of the body bounded by the body&#39;s first side and first end; the contacts of the second outlet are nearest a second corner of the body bounded by the body&#39;s first side and second end; and the contacts of the third outlet are between the contacts of the first and second outlets and closer to the second side of the body than to its first side. A neutral bus bar within the body is connected to the neutral contacts of all three of the outlets. The neutral bus bar has a central portion extending along the second side of the body, and two arms. The central portion has a neutral terminal and supports the neutral contact of the third outlet. The first arm extends obliquely from the central portion toward the first corner and supports the neutral contact of the first outlet. The second arm extends transversely from the central portion toward the second corner and supports the neutral contact of the second outlet. At least one phase bus bar within the body is connected to the phase contacts of at least two of the outlets. The phase bus bar has a phase terminal at the second side of the body, and two arms. The first arm extends obliquely from the second side toward the first outlet and supports the phase contact of the first outlet. The second arm extends behind the first arm of the neutral bus bar longitudinally toward the third outlet, where it supports the phase contact of that outlet. 
         [0007]    In some embodiments the phase bus bar has a third arm that extends across the body toward the second outlet, where it supports and is electrically connected to the phase contact of that outlet. In one of those embodiments the third arm is connected to a second phase terminal at the first side of the body, and there is a frangible connection along the third arm that can be ruptured to electrically isolate the second phase terminal and the second outlet from the other two outlets. In another embodiment the second outlet is isolated by connection only to a second phase bus bar on the first side of the body that has its own phase terminal. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Preferred embodiments of the disclosed invention, including the best mode for carrying out the invention, are described in detail below, purely by way of example, with reference to the accompanying drawing figures.  FIGS. 1-31  and the description thereof are substantially reproduced herein from commonly owned U.S. Pat. No. 7,824,196.  FIGS. 33-61  concern new embodiments that enable connection of at least one of the outlets to a separate circuit. 
           [0009]      FIG. 1  is a front view of a first embodiment of electrical receptacle according to the invention, installed behind a wall plate; 
           [0010]      FIG. 2  is a front view similar to  FIG. 1 , showing a three-wire grounded plug installed in each outlet; 
           [0011]      FIG. 3  is a rear schematic view of the arrangement shown in  FIG. 2 ; 
           [0012]      FIG. 4  is a front view similar to  FIG. 2 , showing two three-wire grounded plugs and one transformer installed in respective outlets; 
           [0013]      FIG. 5  is a perspective view of the receptacle of  FIG. 1  without the wall plate, showing the face, one side and one end thereof; 
           [0014]      FIG. 6  is a perspective view of the receptacle of  FIG. 5 , showing the face, the opposite side and the opposite end thereof; 
           [0015]      FIG. 7  is a bottom perspective view of the receptacle of  FIG. 5 ; 
           [0016]      FIG. 8  is a front elevational view of the receptacle of  FIG. 5 ; 
           [0017]      FIG. 9  is a right-side view of the receptacle of  FIG. 5 ; 
           [0018]      FIG. 10  is a rear elevational view of the receptacle of  FIG. 5 ; 
           [0019]      FIG. 11  is a left-side view of the receptacle of  FIG. 5 ; 
           [0020]      FIG. 12  is an exploded view of the receptacle of  FIG. 5 ; 
           [0021]      FIG. 13  is a perspective view of the receptacle of  FIG. 5  with the base and the front cover removed to show the ground strap, the bus bars, the contacts and the contact separator; 
           [0022]      FIG. 14  is a top plan view of the phase and neutral bus bars and contacts per se shown in their proper spatial arrangement; 
           [0023]      FIG. 15  is a front elevational view of the phase and neutral bus bar and contact arrangement of  FIG. 14 ; 
           [0024]      FIG. 16  is a bottom plan view of the phase and neutral bus bar and contact arrangement of  FIG. 14 ; 
           [0025]      FIG. 17  is a top plan view of the ground strap, bus bar, contact and separator arrangement shown in  FIG. 13 ; 
           [0026]      FIG. 18  is a bottom plan view of the ground strap, bus bar, contact and separator arrangement shown in  FIG. 13 ; 
           [0027]      FIG. 19  is a bottom plan view of the front cover of the receptacle of  FIG. 5 , showing three tamper-resistant mechanisms installed therein, one for each outlet; 
           [0028]      FIG. 20  is an exploded view of one of the tamper-resistant mechanisms shown in  FIG. 19 ; 
           [0029]      FIG. 21  is a perspective view of one of the tamper-resistant mechanisms shown in  FIG. 19 ; 
           [0030]      FIG. 22  is a top plan view of the tamper-resistant mechanism shown in  FIG. 21 ; 
           [0031]      FIG. 23  is a cross-sectional view of the tamper-resistant mechanism taken along line  23 - 23  in  FIG. 22 ; 
           [0032]      FIG. 24  is a schematic front view of the outlet face opening arrangement of the preferred embodiment of  FIG. 1 ; 
           [0033]      FIG. 25  is a schematic front view of an outlet face opening arrangement according to a second embodiment; 
           [0034]      FIG. 26  is a schematic front view of an outlet face opening arrangement according to a third embodiment; 
           [0035]      FIG. 27  is a schematic front view of an outlet face opening arrangement according to a fourth embodiment; 
           [0036]      FIG. 28  is a schematic front view of an outlet face opening arrangement according to a fifth embodiment; 
           [0037]      FIG. 29  is a schematic front view of an outlet face opening arrangement according to a sixth embodiment; 
           [0038]      FIG. 30  is a schematic front view of an outlet face opening arrangement according to a seventh embodiment; 
           [0039]      FIG. 31  is a schematic front view of an outlet face opening arrangement according to an eighth embodiment; 
           [0040]      FIG. 32  is a schematic front view of an outlet face opening arrangement according to a ninth embodiment; 
           [0041]      FIG. 33  is a front view of a tenth embodiment of electrical receptacle according to the invention (installed behind a wall plate) adapted for connection of at least one outlet thereof to a separate circuit; 
           [0042]      FIG. 34  is a perspective view of the receptacle of  FIG. 33  without the wall plate, showing the face, one side and one end thereof; 
           [0043]      FIG. 35  is a perspective view of the receptacle of  FIG. 34 , showing the face, the opposite side and the opposite end thereof; 
           [0044]      FIG. 36  is a bottom perspective view of the receptacle of  FIG. 34 ; 
           [0045]      FIG. 37  is a front elevational view of the receptacle of  FIG. 34 ; 
           [0046]      FIG. 38  is a right-side view of the receptacle of  FIG. 34 ; 
           [0047]      FIG. 39  is a rear elevational view of the receptacle of  FIG. 34 ; 
           [0048]      FIG. 40  is a left-side view of the receptacle of  FIG. 34 ; 
           [0049]      FIG. 41  is an exploded view of the receptacle of  FIG. 34 ; 
           [0050]      FIG. 42  is a perspective view of the receptacle of  FIG. 34  with the base and the front cover removed to show the ground strap, the bus bars, the contacts and the contact separator; 
           [0051]      FIG. 43  is a top plan view of the phase and neutral bus bars and contacts per se shown in their proper spatial arrangement; 
           [0052]      FIG. 44  is a front elevational view of the phase and neutral bus bar and contact arrangement of  FIG. 43 ; 
           [0053]      FIG. 45  is a bottom plan view of the phase and neutral bus bar and contact arrangement of  FIG. 43 ; 
           [0054]      FIG. 46  is a top plan view of the ground strap, bus bar, contact and separator arrangement shown in  FIG. 42 ; 
           [0055]      FIG. 47  is a bottom plan view of the ground strap, bus bar, contact and separator arrangement shown in  FIG. 42 ; 
           [0056]      FIG. 48  is a perspective view of an eleventh embodiment of electrical receptacle according to the invention adapted for connection of at least one outlet thereof to a separate circuit, showing the face, one side and one end thereof; 
           [0057]      FIG. 49  is a perspective view of the receptacle of  FIG. 48 , showing the face, the opposite side and the opposite end thereof; 
           [0058]      FIG. 50  is a bottom perspective view of the receptacle of  FIG. 48 ; 
           [0059]      FIG. 51  is a front elevational view of the receptacle of  FIG. 48 ; 
           [0060]      FIG. 52  is a right-side view of the receptacle of  FIG. 48 ; 
           [0061]      FIG. 53  is a rear elevational view of the receptacle of  FIG. 48 ; 
           [0062]      FIG. 54  is a left-side view of the receptacle of  FIG. 48 ; 
           [0063]      FIG. 55  is an exploded view of the receptacle of  FIG. 48 ; 
           [0064]      FIG. 56  is a perspective view of the receptacle of  FIG. 48  with the base and the front cover removed to show the ground strap, the bus bars, the contacts and the contact separator; 
           [0065]      FIG. 57  is a top plan view of the phase and neutral bus bars and contacts per se shown in their proper spatial arrangement; 
           [0066]      FIG. 58  is a front elevational view of the phase and neutral bus bar and contact arrangement of  FIG. 57 ; 
           [0067]      FIG. 59  is a bottom plan view of the phase and neutral bus bar and contact arrangement of  FIG. 57 ; 
           [0068]      FIG. 60  is a top plan view of the ground strap, bus bar, contact and separator arrangement shown in  FIG. 56 ; and 
           [0069]      FIG. 61  is a bottom plan view of the ground strap, bus bar, contact and separator arrangement shown in  FIG. 56 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0070]    As used in this application, terms such as “front,” “rear,” “side,” “top,” “bottom,” “above,” “below,” “upwardly” and “downwardly” are intended to facilitate the description of the electrical receptacle of the invention, and are not intended to limit the structure of the invention to any particular position or orientation. 
         [0071]    Referring to  FIGS. 1 and 24 , an electrical receptacle according to a preferred first embodiment of the invention has a body sized to fit in a NEMA-standard single wall box. The body has a front cover  2  with rectangular face F, which is exposed through a slightly larger rectangular opening in a wall plate W having mounting screw holes S. The dimensions of face F comply with the ANSI/NEMA WD 6 (R2008) dimensional standard for popular “decorator” style wiring devices (“Dimensions for Flush Mount Rectangular Face Devices”), which specifies maximum face dimensions for a duplex receptacle of 1.300 in. wide by 2.620 in. long, and a mating wall plate opening at least 0.010 in. larger in each dimension. In this and all other embodiments specifically disclosed herein, the duplex-sized face of the receptacle preferably is 1.290 in. wide by 2.604 in. long. The face F has three outlets associated with respective phase, neutral and ground contacts (not shown), which are accessible through respective phase blade openings  6 , neutral blade openings  4  and ground prong openings  8  in the face. 
         [0072]    The size and spacing of the openings for each outlet also comply with ANSI/NEMA WD 6 (R2008); thus, the neutral blade openings  4  are illustrated as longer that the phase blade openings  6 . Phase blade openings  6  are illustrated as simple straight slots, which is the standard configuration for 15 ampere receptacles. If the receptacle is intended for use in a 20 ampere circuit with 15 ampere and/or 20 ampere plugs, one or more of the outlets would have a NEMA-standard T-shaped phase blade opening. 
         [0073]    Each outlet has a centerline CL (see  FIG. 24 ) that passes through its ground prong opening  8  and is parallel to its phase and neutral blade openings  6 ,  4 . The two outer outlets are positioned with their laterally open ground prong openings  8  at the corners of the face F, and with their centerlines oblique to the edges of the face, preferably at an angle of about 45°. The centerline of the central outlet is parallel to the shorter edges of the face, and bisects the face. Thus, the centerlines of the outlets are mutually nonparallel; and those of the corner outlets are disposed at an angle a of about 45° to the centerline of the center outlet. 
         [0074]      FIGS. 2 and 3  illustrate how the receptacle of  FIG. 1  can simultaneously accommodate three plugs, all of the grounded (three-wire) type P, or all of the two-wire type, or any combination of those types. The dashed lines in  FIG. 2  show the nominal outline of the face of a two-wire general-use plug as specified by ANSI/UL 817-2007, §25.2.1 (1.000 in. by 0.750 in., maximum corner radius of 7/32 in.).  FIG. 3  shows the blades and the ground prongs of the plugs received in the face openings  4 ,  6 ,  8 .  FIG. 4  illustrates how the receptacle of  FIG. 1  can simultaneously accommodate at least one transformer T in combination with three-wire plugs P and/or two-wire plugs (dashed lines). It will be appreciated that two such transformers, one in each corner outlet (not shown), can be accommodated along with a plug in the center outlet. 
         [0075]      FIGS. 5-11  depict the external features of the receptacle of  FIGS. 1 and 24 . Receptacle body  10  has an insulating plastic base  12  and an insulating plastic front cover  2  attached to a conducting metallic ground strap  14  sandwiched between the base and the front cover. Flanges  16  of ground strap  14  have standard mounting holes for attaching the receptacle to a wall box with screws, and standard threaded holes for attaching a wall plate W with screws through screw holes S. Screw terminals, which provide connections to line conductors, consist of a ground terminal  18  on the left side of the base  12 , and a phase terminal  22  and a neutral terminal  202  on the right side. The face F of front cover  2  has openings  4 ,  6 ,  8  as described above. The laterally open ground prong openings  8  at the corners of the face are aligned with corner grooves  24  in the base  12  so as to accommodate the ground prongs of plugs that penetrate corner openings  8  and ground contacts  26 , which are carried by two protruding corners  28  of ground strap  14 . Assembly screws  30 , along with other fastening elements (described below), secure base  12 , ground strap  14  and front cover  2  together. 
         [0076]    Referring to  FIGS. 12-18 , three phase contacts  36  are riveted or otherwise secured to a phase bus bar  38 , and three neutral contacts  32  are riveted or otherwise secured to a neutral bus bar  34 . Bus bars  34 ,  38  are flat brass stampings. An insulating plastic contact separator  40  fits within base  12  and has a bottom wall  42  and upstanding dividers  44  that insulate the phase and neutral bus bars and contacts from one another. Base  12  has a bottom wall  46 ; a central upstanding side wall  48  at the phase terminal and neutral terminal side of the receptacle; two upstanding side walls  50  at the opposite side of the receptacle defining a gap  52  therebetween (in which ground terminal  18  resides); and upstanding end walls  54  joined to walls  50  and defining therewith corner grooves  24 . Side wall  48  and end walls  54  define two gaps  56 ,  58 . Neutral bus bar  34  is disposed above the bottom wall  42  of contact separator  40 . The upstanding side portion  60  of neutral bus bar  34  runs behind side wall  48 , with neutral terminal  20  exposed in gap  56 . Phase terminal  22  is exposed in gap  58 . The flat S-shaped portion  62  of phase bus bar  38  lies between the bottom wall  42  of contact separator  40  and the bottom wall  46  of base  12 . 
         [0077]    Assembly screws  30  pass through holes (not shown) in bottom wall  46  of base  12 , holes  64  in bottom wall  42  of contact separator  40 , and holes  66  in ground strap  14 . Screws  30  engage bosses  68  on the underside of front cover  2  (see  FIG. 19 ) to secure the parts together. Four snap fasteners also hold the parts together. These consist of four shouldered tabs  70  on front cover  2  that fit into and lock against mating structures (not shown) within slots  72  on base  12 . 
         [0078]    Referring to  FIG. 19 , a tamper-resistant assembly  74  for each outlet is secured to the underside of front cover  2  between the phase blade and neutral blade face openings  6 ,  4  and the phase and neutral contacts  36 ,  32 . Each tamper-resistant assembly  74  is snapped into place and held in a recess defined by two end walls  76 , an inner wall  78  and an outer wall  80  that are integrally molded with front cover  2 . The purpose of the tamper-resistant assemblies is to minimize the risk of electric shock by inhibiting or preventing access to the contacts  32 ,  36  by anything other than an electrical plug, i.e., allowing access only by the prongs of an electrical plug that are simultaneously inserted into the face openings  4 ,  6 . 
         [0079]    The structure of each tamper-resistant assembly  74  is depicted in  FIGS. 20-23 . A cradle  82  is defined by a generally trapezoidal bottom wall  84 , a short side wall  86 , end walls  88  and a long side wall  90  joined to end walls  88 . Slots  91  in bottom wall  84  are aligned with face openings  4 ,  6  in front cover  2  and with contacts  32 ,  36  in base  12 . Slidable within cradle  82  are two complementary shutters  92 , each biased by a coil spring  94  captured at one end wall  88  toward the opposite end wall  88 . Each shutter  92  has a cam surface  96  and a blocking step  98  interconnected by a side panel  100 . In the at-rest positions shown in the figures, the cam surface  96  of each shutter is positioned in front of the blocking step  98  of the other shutter, which blocks an opening  91  in base  74 . Concurrent insertion of two plug blades acts against the two cam surfaces  96  simultaneously to unblock both slots  91 , allowing blade access to the contacts  32 ,  36 . However, if only one shutter cam surface  96  is contacted by an inserted object, only that shutter will slide to move its blocking step away from the other slot  91 , but that slot will remain blocked by the cam surface  96  of the other shutter. 
         [0080]    Alternative outlet face opening arrangements according to the invention are depicted in  FIGS. 25-31 . The same reference characters used to denote the three face openings ( 4 ,  6 ,  8 ) and the centerlines (CL) of the first embodiment ( FIG. 24 ) are used in connection with the other embodiments. Bus bars and contact separators for these alternative arrangements are not illustrated; however, those skilled in art can readily envision their configurations, which simply would have to accommodate the alternate locations of the face openings. 
         [0081]    The arrangement of  FIG. 25  is similar to that of the first embodiment, but the ground prong openings  8  of the corner outlets are slightly inboard of the corners, and are therefore laterally fully enclosed. Further, the centerlines of the corner outlets are angled more toward the center of the face, forming an angle β of about 60° with the centerline of the center outlet, whose centerline bisects the face as in the first embodiment. 
         [0082]    In the arrangement of  FIG. 26 , the centerline of the center outlet is parallel to the shorter edges of the face as in the first embodiment, but is displaced from the center of the face, away from the oblique upper corner outlet. That corner outlet has a laterally fully enclosed ground prong opening  8  slightly inboard of the corner, and a centerline that forms an angle γ of about 45° with the centerline of the center outlet. The centerline of the other (lower) corner outlet is perpendicular to that of the center outlet, and its ground prong opening  8  is further from the adjacent short edge of the face than its phase and neutral blade openings  6 ,  4 . 
         [0083]    The arrangement of  FIG. 27  is similar to that of  FIG. 26 , but the center outlet is turned 90° so that its centerline is parallel to the longer edges of the face, and parallel to that of the lower corner outlet. Also, the centerline of the upper corner outlet is angled further from the center of the face, forming an angle δ of about 65° with that of the center outlet. 
         [0084]    The arrangement of  FIG. 28  is similar to that of the first embodiment ( FIG. 24 ), but the center outlet is turned counterclockwise about 125° so that its centerline forms an angle of about 80° with that of the lower left outlet and an angle of about 10° with that of the upper left outlet, with its ground prong opening at the right edge of the face. 
         [0085]    The embodiment of  FIG. 29  is similar to the first embodiment, but it replaces the center outlet with an electronic space for housing an electrical device, which may have a user-accessible or visible interface on the face of the receptacle. Examples of such devices include, without limitation, a timer; a dimmer; a power monitoring device; a circuit breaker; a power indicator light; a signal port; an integral night light; an over-current protection device; a ground fault circuit interrupter (GFCI); and a transient voltage surge suppressor (TVSS). 
         [0086]      FIG. 30  depicts an arrangement providing six outlets housed in a receptacle body sized to fit in a NEMA-standard double wall box. Each face F is identical to that of the first embodiment in terms of its dimensions and its arrangement of openings  4 ,  6 ,  8 . Preferably, there is a gap G of 0.502 in. between the faces so that the faces are 1.792 in. on center, and the overall width from the left edge of the left face to the right edge of the right face is 3.082 in. Single terminals on the body (not shown) are provided for attaching each of phase, neutral and ground line conductors. The phase and neutral bus bars and the ground straps associated with the two faces are interconnected by respective spot welded brass shunts or other welded conductors (not shown). 
         [0087]      FIGS. 31 and 32  depict embodiments identical to that of  FIG. 30 , except that the electronic space feature of  FIG. 29  is incorporated on one or both sides of the receptacle, respectively. In the embodiment of  FIG. 31 , the electronics spaces may house the same or different electrical devices. 
         [0088]    The triplex receptacle embodiment of  FIGS. 33-47  has the same body size and outlet blade opening arrangement as the embodiment of  FIGS. 1-24 , but is adapted for connection of one outlet to a separate circuit, which could be controlled by, for example, a current monitoring, energy saving device that turns off power to unattended loads. Common parts are designated by the same reference numbers used in  FIGS. 1-24 . 
         [0089]    The separate circuit capability of this embodiment is afforded by its bus bar and terminal configuration, which is best seen in  FIGS. 41-47 . Three neutral contacts  132  (one for each outlet  9 ,  11 ,  13 —see  FIG. 33 ) are riveted or otherwise secured to a common neutral bus bar  134 , which has a neutral terminal  120  for connection to a common neutral line conductor. Phase contact  136  (for center outlet  9 ) and phase contact  137  (for first corner outlet  11 ) are riveted or otherwise secured to a first phase bus bar  138 , which has a terminal  122  for connection to the phase conductor of a first circuit. Phase contact  133  (for second corner outlet  13 ) is riveted or otherwise secured to a second (separate) phase bus bar  135 , which has its own terminal  123  for connection to the phase conductor of a second circuit. An identifying symbol  139 , which can be molded into the face F at the factory or be applied as a label at installation, indicates the separately powered, switch-controlled outlet  13 . If the receptacle is wired for switch control of outlets  9  and  11  instead, only those two outlets would be so labeled. If electrical isolation of outlet  13  from the others is not desired, it is a simple matter to place all outlets on the same circuit by bridging phase terminals  122 ,  123  with an external jumper wire or by directly connecting each of them to the phase conductor of a single circuit. 
         [0090]    Bus bars  134 ,  135  and  138  are flat brass stampings. An insulating plastic contact separator  140  fits within base  112  and has a bottom wall  142  and upstanding dividers  144  that insulate the phase and neutral bus bars and contacts from one another. Base  112  has a bottom wall  146 ; a central upstanding side wall  148  at the neutral terminal  120  and first phase terminal  122  side of the receptacle; an upstanding side wall  150  at the opposite side of the receptacle defining a gap  152  in which ground terminal  118  (of ground strap  116 ) resides and a gap  153  in which second phase terminal  123  resides; and upstanding end walls  154 . Side wall  148  and end walls  154  define two gaps  156 ,  158 . Neutral bus bar  134 , which is substantially identical to neutral bus bar  34  of the first embodiment (see  FIGS. 14-16 ), is disposed above the bottom wall  142  of contact separator  140 . The upstanding portion  160  of neutral bus bar  134  runs lengthwise of the receptacle behind side wall  148 , with neutral terminal  120  exposed in gap  158 ; then obliquely at  161 ; and then obliquely in the reverse direction at  162 , ending in a right-angle tab  162   a  that supports neutral contact  132  of first corner outlet  11 . A short arm  163  at the other end of neutral bus bar  134  extends transversely toward neutral contact  132  of second corner outlet  13 , terminating in an oblique tip  163   a.  A short intermediate transverse arm  164  connects to neutral contact  132  of center outlet  9 . 
         [0091]    Y-shaped first phase bus bar  138  is disposed between the bottom wall  142  of contact separator  140  and the bottom wall  146  of base  112 , with first phase terminal  122  residing in gap  156 . One branch  138   a  of first phase bus bar  138  extends obliquely to phase contact  137  of first corner outlet  11 ; the other branch  138   b  extends longitudinally to phase contact  136  of center outlet  9 , crossing beneath oblique portion  161  of neutral bus bar  134 . Second phase bus bar  135  also is disposed between the bottom wall  142  of contact separator  140  and the bottom wall  146  of base  112 , and extends obliquely a short distance to phase contact  133  of second corner outlet  13 . 
         [0092]      FIGS. 48-61  show another embodiment of a triplex receptacle adapted for connection of one outlet to a separate circuit. This embodiment, too, has the same body size and outlet blade opening arrangement as the embodiment of  FIGS. 1-24 , and is identical in many respects to the embodiment of  FIGS. 33-47 . Common parts are designated by the same reference numbers used in  FIGS. 1-24  and  33 - 47 . Commonality is evident from the following pairs of substantially identical figures:  FIGS. 34 and 48 ;  FIGS. 35 and 49 ;  FIGS. 37 and 51 ;  FIGS. 42 and 56 ; and  FIGS. 46 and 60 . The face F of the receptacle of  FIGS. 48-61  has the appearance shown in  FIG. 33 , but the separate circuit symbol has a different meaning because the outlet it denotes is initially electrically connected internally to the other outlets. Thus, symbol  239  on the face of the embodiment of  FIGS. 48-61  identifies the outlet that can be isolated, if desired, when the receptacle is installed. The major structural differences are in the arrangement of the phase bus bars and the adjacent parts of the base  212 , as described below. 
         [0093]    Referring to  FIGS. 55-61 , three neutral contacts  132  (one for each outlet  9 ,  11 ,  13 ) are riveted or otherwise secured to a common neutral bus bar  134 , which has a neutral terminal  120  for connection to a common neutral line conductor. Neutral bus bar  134 , which is substantially identical to the neutral bus bars of the other embodiments, is disposed above the bottom wall  242  of insulating contact separator  240 , which fits within base  212  above its bottom wall  246  and has upstanding dividers  244  that insulate the phase and neutral bus bars and contacts from one another. The upstanding portion  160  of neutral bus bar  134  runs lengthwise of the receptacle behind central upstanding side wall  248  of base  212 ; then obliquely at  161 ; and then obliquely in the reverse direction at  162 , ending in a right-angle tab  162   a  that supports neutral contact  132  of first corner outlet  11 . A short arm  163  at the other end of neutral bus bar  134  extends transversely toward neutral contact  132  of second corner outlet  13 , terminating in an oblique tip  163   a.  A short intermediate transverse arm  164  connects to neutral contact  132  of center outlet  9 . Neutral terminal  120  resides in a gap  258  defined by base side wall  248  and a base end wall  254 . Ground terminal  118  (of ground strap  116 ) resides in a gap  252  at the opposite side of the receptacle adjacent central upstanding base side wall  250 . 
         [0094]    Phase contact  236  (for center outlet  9 ) and phase contact  237  (for first corner outlet  11 ) are riveted or otherwise secured to a first phase bus bar  238 , which has a terminal  222  for connection to the phase conductor of a first circuit. Terminal  222  resides in a gap  256  defined by base side wall  248  and a base end wall  254 . Phase contact  233  (for second corner outlet  13 ) is riveted or otherwise secured to a second phase bus bar  235 , which has its own terminal  223  for connection to the phase conductor of a second circuit, if desired. Terminal  223  resides in a gap  253  at the opposite side of the receptacle adjacent central base side wall  250 . First phase bus bar  238  is disposed between the bottom wall  242  of contact separator  240  and the bottom wall  246  of base  212 . One branch  238   a  of first phase bus bar  238  extends obliquely to phase contact  237  of first corner outlet  11 ; the other branch  238   b  extends longitudinally to phase contact  236  of center outlet  9 , crossing beneath oblique portion  161  of neutral bus bar  134 . Second phase bus bar  235  also is disposed between the bottom wall  242  of contact separator  240  and the bottom wall  246  of base  212 , and extends obliquely a short distance to phase contact  233  of second corner outlet  13 . 
         [0095]    First and second phase bus bars  238 ,  235  initially are electrically connected through a frangible connection. First phase bus bar  238  has a transverse tongue  238   c  extending from phase contact  236  almost to the longitudinal center of the receptacle. Second phase bus bar  235  has a preferably L-shaped extension with a transverse tongue  235   a,  which also extends almost to the longitudinal center of the receptacle. The two tongues  235   a,    238   c  are aligned with a gap  241  between their distal ends. Gap  241  is bridged by a break-off tab  243  having weakened sections  244  that enable tab  243  to be removed using an appropriate hand tool, typically during installation of the receptacle, if electrical isolation of one outlet from the others is desired. Break-off tab  243  is accessible for this purpose through a window  260  in the bottom wall  246  of base  212  (see  FIGS. 50 and 53 ). All parts of first and second phase bus bars  238 ,  235  and break-off tab  243  preferably are fabricated together as one piece thus effectively forming, initially, a single phase bus bar having two terminals  222 ,  223 . 
         [0096]    While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims. By way of example only, while the faces F and bus bar arrangements of the various embodiments have been described as preferably being dimensioned to comply with the ANSI/NEMA WD 6 (R2008) dimensional standard for popular “decorator” style wiring devices, any of the specifically disclosed face and/or bus bar arrangements, or any other arrangement within the scope of the claims, can be used in receptacles having faces of other sizes. Furthermore, standard quick-connect insertion-type terminals may be provided at the rear of the base, near its sides, in addition to or lieu of the disclosed screw terminals for connection to line conductors.