Patent Document

RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/186,241, entitled “DUAL ROW IEC C13 AND/OR C19 GANG OUTLETS FOR MINIMIZING INSTALLATION SPACE,” filed on Jun. 11, 2009, which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of Invention 
     The present disclosure is directed to locking electrical outlet units, and more specifically, to power distribution unit (PDU) products which include locking electrical outlets, for example, electrical outlets conforming to the International Electrotechnical Commission (IEC) IEC 60320 standard, including IEC-C13 or IEC-C19 compliant electrical outlets. 
     2. Discussion of Related Art 
     The arrangement of outlets in many conventional locking outlet technologies includes a gap between individual (non-ganged) outlets to accommodate the locking feature. This gap between outlets limits the number of outlets that can be included within a given area and precludes the use of industry standard ganged receptacles if the locking feature is desired. 
     SUMMARY OF INVENTION 
     Embodiments and aspects of the present disclosure relate to power outlets units including ganged electrical outlets for use in equipment such as power distribution units or uninterruptible power supplies. The power outlet units disclosed herein provide for the inclusion of a locking feature in the outlets which facilitates securing power cords to the electrical outlets to help prevent accidental decoupling of the power cords from the power outlets. The power outlet units include ganged power outlets arranged in a configuration that facilitates the inclusion of a high number of power outlets within a given area. 
     In accordance with one embodiment, there is provided a power distribution unit. The power distribution unit comprises an input configured to receive input power and a housing. The housing includes a first outer edge, a second outer edge, and a top surface contained between the first outer edge and the second outer edge and having a plurality of power outlets, each of the plurality of power outlets having three output terminals, including a ground terminal, a first terminal, and a second terminal. The plurality of power outlets are arranged in two adjacent columns, including a first column and a second column with at least two power outlets in each of the first column and the second column wherein the plurality of power outlets are arranged such that the first terminals and the second terminals of the power outlets in the first column are formed along a first line, the first terminals and the second terminals of the power outlets in the second column are formed along a second line, the ground terminals of the power outlets in the first column are formed along a third line, and the ground terminals of the power outlets of the second column are formed along a fourth line. The first line, the second line, the third line, and the fourth line are arranged in parallel. The plurality of power outlets are arranged in one of an arrangement in which the third and fourth lines are positioned between the first and second lines, and an arrangement in which the first and second lines are positioned between the third and fourth lines. 
     In accordance with one aspect of the power distribution unit, the input includes a power cord having a ground conductor coupled to the ground terminals of each of the plurality of power outlets, a first conductor coupled to each of the first terminals of the plurality of power outlets, and a second conductor coupled to each of the second terminals of the plurality of power outlets. 
     In accordance with another aspect, the power distribution unit further comprises a battery contained within the housing, and wherein the power distribution unit is configured as an uninterruptible power supply configured to provide power to the first terminals and the second terminals of the power outlets from the battery upon loss of power at the input. 
     In accordance with another aspect, the housing has a width and a length, with the length being greater than the width, and wherein the length of the housing extends in a direction parallel to the first line. 
     In accordance with another aspect, the power distribution unit further comprises at least one slot formed in the housing and wherein at least one of the plurality of power outlets is associated with the at least one slot, and wherein the at least one slot is configured to mechanically retain a locking tab of a locking power cord. 
     In accordance with another aspect, each of the plurality of power outlets is electrically connected to a ground conductor, a first conductor and a second conductor and wherein at least one of the ground conductor, the first conductor and the second conductor of at least one of the plurality of power outlets is electrically isolated from each of the ground conductor, the first conductor, and the second conductor of all other of the plurality of power outlets in the power outlet unit. 
     In accordance with another aspect, the power outlets conform to the International Electrotechnical Commission IEC 60320 standard. 
     In accordance with another aspect, a spacing between adjacent power outlets is less than a spacing between the third and the fourth lines. 
     In accordance with another aspect, the power distribution unit further comprises power input terminals asymmetrically arranged about a center axis of the power outlet unit. 
     In accordance with another aspect, the power distribution unit further comprises an asymmetrically configured housing. 
     In accordance with another embodiment, there is provided a power outlet unit. The power distribution unit comprises a housing, a plurality of electrical outlets, and at least one of a slot or a recess formed in the housing, at least one of the at least one of the slot or recess associated with each of the plurality of electrical outlets, each of the at least one of the slot or recess configured to retain a locking tab of a locking power cord, wherein the housing includes four walls and two of the four walls include at least one of the at least one of the slot or recess formed therein. 
     In accordance with an aspect of the power outlet unit, the plurality of electrical outlets includes at least one group of four electrical outlets arranged in a 2×2 grid arrangement. 
     In accordance with another aspect, the plurality of electrical outlets includes at least one group of six electrical outlets arranged in a 2×3 grid arrangement. The at least one group of six electrical outlets may be arranged within a surface having a surface area of less than 60 square centimeters. 
     In accordance with another embodiment, there is provided a method of distributing power. The method of distributing power comprises mounting a power distribution unit in an electrical equipment rack containing electrical equipment, the power distribution unit including a plurality of power outlets each having an opening to receive a locking tab of a locking power cord, providing a plurality of locking power cords each having a first end and a second end, the second end having a locking tab, and the second end having a first terminal, a second terminal, and a ground terminal, coupling the first end of a first locking power cord to a first electrical equipment unit mounted in the electrical equipment rack, coupling the second end of the first locking power cord into a first one of the plurality of power outlets such that the locking tab of the first locking power cord mates with the opening of the first one of the plurality of power outlets, and such that the first terminal, the second terminal and the ground terminal of the first one of the plurality of power outlets are in a first rotational position, and coupling the first end of a second locking power cord of the plurality of locking power cords to a second electrical equipment unit mounted in the electrical equipment rack, coupling the second end of the second locking power cord into a second one of the plurality of power outlets such that the locking tab of the second locking power cord mates with the opening of the second one of the plurality of power outlets, and such that the first terminal, the second terminal and the ground terminal of the second one of the plurality of power outlets are in a second rotational position offset from the first rotational position by 180 degrees. 
     In accordance with an aspect of the a method of distributing power, the plurality of power outlets includes at least one group of four power outlets arranged in a 2×2 grid arrangement. 
     In accordance with another aspect, the a method of distributing power further comprises coupling the second end of a third locking power cord into a third one of the plurality of power outlets such that the locking tab of the third locking power cord mates with the opening of the third one of the plurality of power outlets, and such that the first terminal, the second terminal and the ground terminal of the third one of the plurality of power outlets are in the first rotational position. The method may further comprising coupling the second end of a fourth locking power cord into a fourth one of the plurality of power outlets such that the locking tab of the fourth locking power cord mates with the opening of the fourth one of the plurality of power outlets, and such that the first terminal, the second terminal and the ground terminal of the fourth one of the plurality of power outlets are in the second rotational position. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings, are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings: 
         FIG. 1A  is a isometric view of a conventional ganged outlet unit from the front side; 
         FIG. 1B  is a isometric view of a conventional ganged outlet unit from the rear side; 
         FIG. 2A  is a isometric view of a second type of conventional ganged outlet unit from the front side; 
         FIG. 2B  is a isometric view of a second type of conventional ganged outlet unit from the rear side; 
         FIG. 3  illustrates a portion of a conventional unit showing the spacing between individual (non-ganged) outlets required if the outlet unit is to be used in conjunction with a lock-in-place electrical cord; 
         FIG. 4  is a plan view of a ganged outlet unit according to an embodiment of the present disclosure; 
         FIG. 5  is a plan view of the rear side of the ganged outlet unit of  FIG. 4 ; 
         FIG. 6  is an isometric view of the front side of the ganged outlet unit of  FIG. 4 ; 
         FIG. 7  is an isometric view of the rear side of the ganged outlet unit of  FIG. 4 ; 
         FIG. 8  is an alternate isometric view of the rear side of the ganged outlet unit of  FIG. 4 ; 
         FIG. 9  illustrates a locking power cord and outlet in accordance with an embodiment of the present disclosure in a connected, locked configuration; 
         FIG. 10  illustrates the locking power cord and outlet of  FIG. 9  in a separated configuration; 
         FIG. 11  is an isometric view of a power distribution unit including six ganged outlet units in accordance with an embodiment of the present invention; and 
         FIG. 12  is an isometric view of the power distribution unit of  FIG. 11  from the rear side. 
     
    
    
     DETAILED DESCRIPTION 
     This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing,” “involving,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
     The present disclosure is directed toward locking electrical outlet units and to power distribution unit (PDU) or uninterruptible power supply (UPS) products which include locking electrical outlets, for example, electrical outlets conforming to the International Electrotechnical Commission (IEC) IEC-C13 or IEC-C19 standards. These outlets may be used in conjunction with locking electrical cords such as those developed by Volex Group plc of Birchwood Science Park, Warrington, WA3 7JX, England, for example, those described in U.S. Patent Application Publication No. 2009/0137142 A1, entitled “POSITIVE LOCK CONNECTOR.” Locking outlets and locking power cords provide a method of securing power cords without the use of bulky brackets or alternative methods of securing power cords to, for example, an electrical equipment rack power distribution source. Some locking outlets are designed to be used with power cords including a locking tab, such as power cord  50 , illustrated in  FIGS. 3 ,  9 , and  10 . When inserted into an outlet, a locking tab  60  on the power cord  50  secures the power cord  50  to the outlet. The locking tab  60  may engage a slot or recess  70  in an outlet into which the power cord  50  is inserted to lock the power cord  50  in place in the outlet. To remove the power cord  50 , the locking tab  60  may be manually depressed. Although Volex locking power cords and outlets are described herein, this disclosure is not limited to Volex-type power cords and outlets. Other locking outlet technologies may also be utilized in conjunction with embodiments of the present disclosure. 
     Conventional locking outlet technologies often require the inclusion of a gap  40  between outlets  20  to accommodate the locking feature. This gap  40  between representative conventional locking outlets  20  is shown in  FIG. 3 . This arrangement of outlets is contrasted with conventional individual (non-ganged) outlet units for use with non-locking power cords which may include IEC outlets arranged in a linear pattern. Examples of such conventional ganged IEC outlet units  10 ,  15  are illustrated in  FIGS. 1A ,  1 B,  2 A, and  2 B. These conventional outlet units  10 ,  15  can have outlets  20  closely spaced, as they need not accommodate a locking feature on a power cord. These conventional outlet units  10 ,  15  may include electrical conductors  30  to deliver power to the individual outlets  20  and/or to provide a connection to ground. 
     Many rack mountable PDUs  110  are designed to fit within industry standard enclosures, such as a 42U enclosure, which limits the total length of vertical mount rack PDUs  110  which may be used. Due to the spacing gap required between outlets  20  to accommodate the Volex locking feature, the total number of outlets  20  which can be placed on a standard electrical equipment rack PDU  110  is limited to a number smaller than consumers may desire. Embodiments of the present disclosure facilitate the provision of an increased number of locking electrical outlets  20  that can fit in a limited amount of space. Embodiments of the present disclosure are applicable to, for example, electrical equipment rack power distribution units  110  and uninterruptible power source (UPS) devices as well as other power distribution devices. 
     At least some embodiments of PDUs  110  described in this disclosure include novel electrical outlet orientations and layouts which allow a greater number of locking electrical outlets  20  to be provided within a given space. 
     Illustrated in  FIGS. 4-8  is an example of an electrical outlet configuration that may be utilized in some embodiments of ganged outlet units  80  in accordance with the present disclosure. The outlet configuration illustrated in  FIGS. 4-8  includes two adjacent columns of electrical outlets  20  facing opposite of one another. In one column of electrical outlets  20 , the electrical outlets  20  are rotated 180 degrees from the electrical outlets  20  in the other column. The outlets  20  illustrated in  FIGS. 4-8  are arranged in a 2×3 grid arrangement. In alternate embodiments, greater or fewer than six outlets  20  may be present. For example, a ganged outlet unit  80  could include four outlets, such as the four outlets in the top two rows illustrated in  FIG. 4 , which are arranged in a 2×2 grid arrangement. Each outlet  20  includes two power terminals and one ground terminal. The present disclosure is not limited to the type of outlets illustrated. Different outlets, such as those configured for use with, for example, European or Chinese style plugs may also be utilized in different embodiments of the present disclosure.  FIGS. 4-8  illustrate a ganged outlet unit  80  with six outlets, however, different embodiments may have different numbers of outlets  20  (e.g. 2 columns of 3 outlets as shown or 2 columns of X outlets, with X being equal to 1, 2, 3, 4, etc.). Further, different embodiments of ganged outlet units  80  may have outlets  20  configured differently than illustrated. For example, in some embodiments of a ganged outlet unit  80 , one or more outlets  20  may be rotated 180 degrees from what is illustrated in  FIGS. 4-8 . 
     In some embodiments of a ganged outlet unit  80 , one or more additional locking outlets  20  may be included with a space between the outlets  20  arranged in the adjacent columns and the additional outlets  20 , such as the space  40  illustrated in  FIG. 3 . In some embodiments of a ganged outlet unit  80 , one or more additional locking outlets  20  may be included rotated 90 degrees from the other outlets  20  and located adjacent to the other locking outlets  20 , but with an open space on the side of the additional outlets not adjacent the other outlets  20 . In other embodiments of a ganged outlet unit  80 , non-locking outlets may be included along with locking outlets  20 . In some embodiments, the columns of outlets  20  may be offset from one another such that outlets  20  in one column are not aligned with outlets  20  in another column Some embodiments of a ganged outlet unit  80  may include more than two columns of outlets. In the example ganged outlet unit  80  of  FIGS. 4-8 , the outlets  20  are in dual column arrangement with the ground terminals facing each other. In other embodiments, the outlets  20  could be arranged such that the ground terminals face away from each other. 
     In at least one embodiment, all the line, neutral and ground terminals are connected by three separate metal conductors  90 . These connectors may be seen in the rear views of the ganged outlet unit  80  illustrated in  FIGS. 5 ,  7 , and  8 . In some embodiments, there are only three quick connect terminals  100  for the entire ganged outlet unit  80 , that is, one line, one neutral, and one ground. Other embodiments may have a greater number of terminals  100 . Optionally, the unit  80  could also be configured by using quick connect or solder terminals connected to a secondary PCB board for ganging (bussing) the line, neutral, or ground features. Also optionally, line and/or neutral terminals on different outlets  20  can remain unganged to allow connection to individual or different power sources. 
     The configuration of outlets  20  illustrated in  FIGS. 4-8  provides advantages over electrical outlet configurations such as those illustrated in  FIGS. 1A-3 . This is because ganged outlets  20  in a single column or row arrangement, such as those illustrated in  FIGS. 1A-3  cannot accommodate the self-locking feature of self-locking power cords  50 , such as those provided by Volex Group plc. Single column or row gang outlets require more chassis length for the same number of outlets  20  as ganged outlet units  80  according to the present disclosure. As such, at least some embodiments of the present disclosure facilitate fitting more locking outlets  20  in a small compact space than was previously achievable. 
     In the configuration of outlets  20  illustrated in  FIGS. 4-8 , adjacent outlets may be abutted against each other so that there is little or no spacing between outlets. In one embodiment, a spacing between adjacent outlets, e.g. a spacing between outlets in a vertical direction in  FIG. 4 , may be about 2.2 mm, and a spacing between opposite outlets, e.g. a spacing between outlets in a horizontal direction in  FIG. 4 , may be about 1.1 mm. This spacing may facilitate easier insertion or removal of power cords from the ganged outlet than would be possible if the outlets were more closely spaced. In at least one embodiment, the spacing and arrangement of outlets may result in a ganged outlet configuration with six outlets included in an outlet unit with a length of about 10.1 cm, a width of about 5.5 cm, and a surface area of about 55.5 square centimeters. Greater spacing between outlets may be provided in some embodiments, which would result in a lower density of power outlets in the ganged outlet unit. 
     In some embodiments, a ganged outlet unit  80  in accordance with the present disclosure may include one or more features that permit installation of the gang outlet  80  in a single direction only. To this end, the ganged outlet unit  80  may include an asymmetric electrical connector configuration, as is illustrated in  FIGS. 7 and 8 . Alternatively or additionally, opposite ends of the ganged outlet unit  80  may have different features which allow for the ganged outlet unit  80  to be installed in an outlet mount and/or PDU  110  in only a single direction. Features according to the present disclosure which permit installation of gang outlets  80  in a single direction only may facilitate maintaining line and neutral terminals being in the same position in corresponding electrical outlets in each gang outlet  80  installed in a PDU. 
     The self-locking feature of the ganged outlet unit  80  is illustrated in  FIGS. 9 and 10 . There is a cutout  70 , or in some embodiments, a slot, recess, or depression formed in the side wall of the housing of the ganged outlet unit  80  corresponding to each locking outlet  20 . The mating power cord  50  has a self-locking tab  60 . A protrusion on the tab  60  engages the cutout, slot, recess, or depression  70  in the housing corresponding to an outlet  20  when the power cord  50  is plugged into the outlet  20 . The engagement of the protrusion on the tab  60  with the cutout, slot, recess, or depression  70  locks the power cord  50  in place in the outlet  20 . The self-locking tab  60  can be manually depressed to disengage the protrusion from the cutout, slot, recess, or depression  70  and allow the power cord  50  to be removed from the outlet  20 , as illustrated in  FIG. 10 . 
     The ganged outlet unit  80  according to embodiments of the present disclosure may be used on a PDU  110  configured for mounting on an electronics equipment rack. One example of such a PDU  110  is illustrated in  FIGS. 11 and 12 . The PDU of  FIGS. 11 and 12  includes six ganged outlet units  80  having six electrical outlets  20  each. In alternate embodiments, PDUs may include more or fewer ganged outlet units  80  and the ganged outlet units may include more or fewer than six electrical outlets  20  each. Not all ganged outlet units  80  mounted to a PDU  110  need be configured in the same manner or with the same number of electrical outlets  20 . The PDU  110  of  FIGS. 11 and 12  includes electrical bus lines (not shown) for delivering electrical power and providing ground to the electrical connections of the ganged outlet units  80  installed thereon. Ganged outlet units  80  according to embodiments of the present invention can also be used more broadly in other applications including UPS devices and other power distribution devices. 
     Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.

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