Abstract:
The present invention relates to power input housings and assemblies for power distribution panels. The power input assemblies provide separate cavities with a centerwall for the power input cables to be led into and a cover closing the cavities. The cavities allow power cables to enter through either a top open end or a bottom open end and the cover is adapted to close the other open end when installed. Alternatively, the housing can be oriented with the open ends of the cavities to the sides, permitting cables to enter through either side and the cover closing the other side.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to power input structures for power distribution panels. 
     BACKGROUND OF THE INVENTION 
     Power distribution panels are generally mounted in an electronic equipment rack with other devices requiring a source of electric power. The basic function of such a distribution panel is to receive electric power, typically DC power, from an external power source and distribute this power through a bus bar to a series of individual circuits for delivery to the equipment mounted in the rack or in nearby equipment racks. Typically, these individual circuits are protected by fuses or circuit breakers. Common voltages for these panels are 24 and 48 Volts DC. The bus bars commonly handle up to 300 amps or more and the individual circuits are protected by circuit breakers capable of handling of up to 100 amps or more or by fuses capable of handling up to 125 amps or more. In addition, a power distribution panel may have two separate bus bars, meaning the total current being supplied to a panel could be up to 600 Amps. 
     The amount of electrical current being supplied to a power distribution panel is sufficient to cause injury to persons working around these panels or to adjacent devices. Protective devices or shields are desirable to guard against accidental contact with the exposed power and return current feeds linking the external power sources to the bus bars within the distribution panels. However, depending on the environment where a particular rack might be installed, these external power feeds may come from above, below or the side of the distribution panel. A distribution panel having a power input structure capable of being easily adapted for receiving and protecting power feeds from multiple directions is desirable. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a power input housing with an open ended cavity divided by a centerwall, and a cover for the housing having an extension to close one of the open ends of the cavity when the cover is mounted to the housing. Another aspect of the present invention relates to a power input assembly including a housing with an open ended cavity divided by a centerwall into return and power chambers with conductors mounted within each chamber. A cover for the assembly is provided having an extension to close one of the open ends of the cavity when the cover is mounted to the housing. A further aspect of the present invention relates to a method of attaching power input cables to a power distribution panel using a power input assembly including a housing with an open ended cavity divided by a centerwall into power and return chambers with conductors mounted within each chamber and a cover for the housing having an extension to close one of the open ends of the cavity when the cover is mounted to the housing. The cables are led into either one of the open ends and the cover is used to close off the other open end. 
     A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the invention and together with the description, serve to explain the principles of the invention. A brief description of the drawings is as follows: 
         FIG. 1  is a rear perspective view of an embodiment of a power distribution panel in accordance with the present invention. 
         FIG. 2  is a rear view of the power distribution of  FIG. 1 , with the mounting flanges removed. 
         FIG. 3  is a front view of the power distribution panel of FIG.  1 . 
         FIG. 4  is a top view of the power distribution panel of  FIG. 1  with the top cover removed. 
         FIG. 5  is a rear perspective view of a power input housing in accordance with the present invention. 
         FIG. 6  is a front perspective view of the power input housing of FIG.  5 . 
         FIG. 7  is a front view of the power input housing of FIG.  5 . 
         FIG. 8  is a rear view of the power input housing of FIG.  5 . 
         FIG. 9  is a top view of the power input housing of FIG.  5 . 
         FIG. 10  is a cross-sectional view of the power input housing of  FIG. 8  taken along line A—A. 
         FIG. 11  is a rear perspective view of an alternative power input housing in accordance with the present invention. 
         FIG. 12  is a front perspective view of the power input housing of FIG.  11 . 
         FIG. 13  is a front view of the power input housing of FIG.  11 . 
         FIG. 14  is a rear view of the power input housing of FIG.  11 . 
         FIG. 15  is a side view of the power input housing of FIG.  11 . 
         FIG. 16  is a cross-sectional view of the power input housing of  FIG. 14  taken along line A—A. 
         FIG. 17  is an exploded rear view of a power input assembly in accordance with the present invention with the cover positioned for entry of power cables from above the assembly. 
         FIG. 18  is a rear view of the power input assembly of  FIG. 17  with the cover removed. 
         FIG. 19  is a side view of the power input assembly of FIG.  18 . 
         FIG. 19A  is a side view of the power input assembly of  FIG. 19  with the cover in a first position. 
         FIG. 19B  is a side view of the power input assembly of  FIG. 19A  with the cover in a second position. 
         FIG. 20  is a top view of the power input assembly of FIG.  18 . 
         FIG. 21  is a front perspective view of a cover for a power input assembly in accordance with the present invention. 
         FIG. 22  is a rear view of the cover of FIG.  21 . 
         FIG. 23  is a bottom view of the cover of FIG.  21 . 
         FIG. 24  is a rear perspective view of an alternative power distribution bus in accordance to the present invention for use with the power distribution panel of FIG.  1 . 
         FIG. 25  is a top view of the power distribution bus of FIG.  24 . 
         FIG. 26  is a front perspective view of the power distribution bus of FIG.  24 . 
         FIG. 27  is a front perspective view of a portion of the power distribution bus of FIG.  24 . 
         FIG. 28  is a rear perspective view of the portion of the power distribution bus of FIG.  26 . 
         FIG. 29  is a front view of the portion of the power distribution bus of FIG.  26 . 
         FIG. 30  is a rear view of the portion of the power distribution bus of FIG.  26 . 
         FIG. 31  is a top view of the portion of the power distribution bus of FIG.  26 . 
         FIG. 32  is a bottom view of the portion of the power distribution bus of FIG.  26 . 
         FIG. 33  is a rear perspective view of the power output assembly of FIG.  1 . 
         FIG. 34  is a top view of the power output assembly of FIG.  33 . 
         FIG. 35  is a front perspective view of the power output assembly of FIG.  33 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be ma de in detail to exemplary aspects of the present invention 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. 
     To prevent accidental contact with the power and return power leads supplying electrical power to a power distribution panel  1 , a power input assembly  10  is provided about each power input location. Assembly  10  is designed to provide separation and isolation of the power or battery and return leads from each other and prevent people and/or other devices from contacting the leads and receiving an electrical shock, causing harm to personnel or property. 
     Internally, due to the amount of current in the power distribution buses  60  and  160 , some shielding of the individual power leads  166  prevents unwanted arcing or current induction between adjacent leads. This shielding can be accomplished by coating the leads with an electrically insulative material or by providing sufficient separation of the leads. Providing separation of leads  166  also provides improved access to components within panel  1  for users. 
     Referring now to  FIGS. 1 through 4 , a power distribution panel  1  with two power busses and two power input assemblies  10  installed is shown. A first power input assembly  10  is shown with cover  14  in place and a second assembly  10  is shown with cover  14  removed. Panel  1  includes a housing with a rear face  28 , a front face  34 , a top  26 , a bottom  44  and two opposing sides  20 . Mounted to each side  20  proximate front face  34  are mounting flanges  18  for mounting panel  1  to a telecommunications equipment rack. Because telecommunications equipment racks vary in width, flanges  18  include several columns of mounting holes and may be mounted in different orientations. Flange  18  includes long side  21  and short side  19 . Long side  21  includes two columns of mounting holes  23  and  24 . Short side  19  includes a single column of mounting holes  22 . Panel  1  can be mounted to a variety of different width mounting racks by altering the orientation of flanges  18  mounted on either side  20  of panel  1 . For example, mounting flanges  18  with short flange  19  adjacent both sides  20  would allow panel  1  to mounted to a relatively wider rack, while mounting flanges  18  with long side  21  adjacent sides  20  would permit panel  1  to be mounted to a relatively narrower rack. Additional sizes and configurations of flanges  18  are anticipated which would permit panel  1  to be mounted to telecommunications racks of different widths. 
     Mounted to rear face  28  are two sets of power output terminals  12 . Output terminals  12  are then connected to the power input terminals of telecommunications devices to supply power to those devices. In  FIGS. 2 and 4 , one of the sets of output terminals  12  is covered by a protective housing  16  to prevent accidental contact with the terminals. Chassis grounds  30  are provided on rear face  28  and allow panel  1  to be electrically connected to a ground. Panel  1  includes an internal circuitry which senses interruptions or other problems with the power flowing through the panel. This circuitry is tied to an alarm which can provide a visible, audible or electronic signal when a power flow problem is detected. The electronic alarm signals allow the alarm status of a power panel to be remotely or centrally monitored. Power alarm connector  32  is provided on rear face  28  for the transmission of the electronic signals for remote or central monitoring. 
     On the front face of panel  1  are circuit breakers  38  and fuses  42  to provide protection for the equipment to which panel  1  is supplying power. Additional breaker locations  36  are available to allow more breakers to be mounted to panel  1 . Circuit breakers  38  could alternatively replaced by fuses. Signal lamps  40  are connected with the alarm in panel  1  to provide the visible signal if a power flow problem is detected. Holder  46  is provided on front face  34  to maintain indicia regarding the devices which are being supplied power by panel  1 . 
     Power input assembly  10  includes a power conductor  52  with posts  48  and a return conductor  54  with posts  50 . Conductors  52  and  54  are attached to buses  60  inside panel  1 . Posts  48  are connected with the power terminal of the power source supplying panel  1  and posts  50  are connected with the return terminal of the power source supplying the panel. Posts  48  are electrically connected to conductor  52 , which are in turn electrically connected with a power bus end  56  of bus  60 . Posts  50  are electrically connected to conductor  54 , which are in turn electrically connected with a return bus end  58  of bus  60 . 
     Referring now to  FIGS. 1 through 10 , assembly  10  includes a housing  70  with  defining a cavity ( the housing cavity defined by cavities  71  and  77   ) . The housing  70  includes  opposing sidewalls  72 , a base  76  extending between the sidewalls and a centerwall  74  parallel to the sidewalls and generally bisecting the base into two halves. In centerwall  74  is an opening  94  for receiving a fastener holding cover  14  in place on housing  70 . Between sidewalls  72  on either side of centerwall  74  are defined the cavities  71  and  77  for receiving power cables from an external power supply. Each sidewall  72  has a first end  73  and a second end  75 . Between first ends  72  is endwall  88  which cooperates with base  76  to form conductor openings  78  proximate first ends  73 . Likewise, between second ends  75  is endwall  88  which cooperates with base  76  to form conductor openings  78  proximate second ends  75 . Extending from each endwall  88  is mounting tab  80 , which include openings  82  to receive fasteners such as screws to mount housing  70  to rear face  28 . Along endwalls  88  opposite base  76  are openings  92 , which receive fasteners such as screws for holding conductors  52  and  54  to housing  70 , as is discussed below. Along the bottom of base  76  and extending between the opposing sidewalls  72  and opposing endwalls  88  are reinforcing ribs  84 . Ribs  84  provide added strength and stiffness to housing  70 . Likewise, along the bottom of mounting tabs  80  are reinforcing ribs  86 , and extending from the top of base  76  along centerwall  74  are reinforcing ribs  96 . Proximate the junctions of endwalls  88  and reinforcing rib  84  are opening  90  for receiving fasteners such as screws. 
     As shown in  FIGS. 5  though  10 , mounting tabs  80  are located proximate conductor openings  78 , and cavities  71  and  77  are oriented to receive power cables from above or below panel  1 . As shown in  FIG. 1 , housing  70  is mounted to rear face  28  so that mounting tabs  80  are on the inside of panel  1  and sidewalls  72  and centerwall  74  extend through rear face  28  outside of panel  1 . Mounting openings  15  in rear face  28  are located above and below housing  70  and are located so that a fastener such as a screw can be inserted through an opening  15  and engage opening  82  to hold housing  70  to rear face  28 . 
     Referring now to  FIGS. 11 through 16 , housing  170  is shown. Housing  170  is similarly constructed to housing  70 , with mounting tabs  80  located on different opposing walls. If housing  170  were mounted to rear face  28  of panel  1 , cavities  71  and  77  would be oriented to receive power cables from either the left side or right side of panel  1 . Both housing  70  and housing  170  are made of electrically insulative material. 
     Referring now to  FIGS. 17 through 20 , a power input assembly is shown. In  FIG. 17 , conductors  52  and  54  include of a first leg  106 , a cross leg  108  and a second leg  110 . First and second legs  106  and  110  extend through openings  78  of housing  70  and cross leg  108  lies along the top of base  76 . Conductor  52  is placed within cavity  71  and conductor  54  is placed within cavity  77 . Posts  48  extend from cross leg  108  of conductor  52  opposite base  76  and posts  50  extend from cross leg  108  of conductor  54  opposite base  76 . Second leg  110  and first leg  106  include openings  102 . Fasteners such as screws  100  are inserted through openings  92  in endwalls  88  and engage openings  102 , holdings the straps to housing  70 . Proximate an end of second leg  110  opposite cross leg  108  are openings  104  for attaching and electrically connecting conductor  52  to power bus end  56  of bus  60 , and for attaching and electrically connecting conductor  54  to return bus end  58  of bus  60 . Conductors  52  and  54  are held by housing  70  and are separated from potential contact by centerwall  74 . 
       FIGS. 21 through 23  show cover  14 . References to housing  70  are intended to apply also for housing  170 . Cover  14  includes a top  120  and a lower extension  122 . Top  120  is sized to fit on housing  70  covering cavities  71  and  77 , so that ledges  126  rest just outside of the top of sidewalls  72 , extension  122  is proximate one of first end  73  or second end  75  of sidewalls  72  and ledge  134  is at the other of first end  73  or second end  75 . When mounted to housing  70 , extension  122  extends between sidewalls  72  across both cavities  71  and  77  and between top  120  and endwall  88 . Ledges  124  rest just outside of first or second ends  73  or  75  of sidewalls  72  when cover  14  is mounted to housing  70 . Ledge  134  extends between parallel to extension  122  on the opposite open end of housing  70  but does not extend far enough to close the open end. In this position, cover  14  closes off access to cavities  71  and  77  from the rear and from one of the two ends. Ledges  126  and  134  are shown as the same size but may be of different sizes. Ledges  126  may extend up to the same extent as extension  122  while ledge  134  may not be made so large as to block the open end opposite extension  122 . 
     Mounting opening  128  in top  120  includes a narrow end  130  and a wide end  132 . Opening  128  is sized and located to receive a fastener extending from opening  94  in housing  70  to hold cover  14  to housing  70 . The shape of opening  128  is sized to allow cover  14  to be removed from housing  70  without completely removing the screw from opening  94 . Narrow end  130  and wide end  132  are oriented to be generally parallel to ledges  126 . 
     Cover  14  and housing  70  are designed so that cover  14  may be mounted to housing  70  with extension  122  at either first end  73  (as shown in  FIG. 19A ) or second end  75  (as shown in  FIG. 19B ) of sidewalls  72 . This will permit power supply cables from an external power source to enter from above or below as the installation environment dictates without requiring a different version of cover  14  for each direction of entry. With regard to housing  170 , power cables can enter the housing from either end and cover  14  will be installed with extension  122  covering the opposite end. Cover  14  is made of an electrically insulative material. 
     Referring now to  FIGS. 24 through 26 , an alternative power distribution bus  160  is shown. Bus  160  shown would be used in place of the right-side bus  60  in  FIG. 4 , above, and includes the same rear power input assembly  10  and rear power output assembly  12 . Power conductor  42  is electrically connected with power bus end  56 , which in turn feeds the power into a protective device mount  162 . Protective device mount  162  permits protective devices such as circuit breakers  38  to be mounted in the electrical path. Leads  166  carry the power from protective device mount  162  to offset connectors  168  and  170    169  of power output assembly  12 . Offset connectors  168  and  170    169  are configured to allow adjacent leads  166  to connect with rear output assembly  12  in staggered columns. Three offset connectors  168  are located in a first column and three offset connectors  170    169  are located in a second column. This offsetting of adjacent leads and power output connectors provides added space between the connections. This added space reduces the possibility of current in one lead inducing current in an adjacent lead in the area of the connection with power output assembly  12 . Leads  166  as shown are crafted from bar stock. To reduce corrosion and other related occurrences, this bar stock may be plated with tin, lead or another suitable material. 
     Referring now to  FIGS. 27 through 32 , protective device mount  162  and leads  166  are shown with the other components of power distribution bus  160  removed. Leads  166  are individually numbered as leads  171  through  176 , with lead  171  being the topmost lead and lead  176  being the bottommost lead. Leads  171 ,  173 , and  175  are configured to connect with offset connectors  168  of power output assembly  12 , while leads  172 ,  174  and  176  are configured to connect with offset connectors  170    169 . Each of the leads is comprised of five sections,  181 ,  183 ,  185 ,  187  and  189 , connected at four angles,  182 ,  184 ,  186  and  188 . A connector section  181  of each lead  171  through  176  is electrically attached to protective device mount  162 . An angle  182  then links connector segment  181  with a riser segment  183 . An angle  184  in turn connects riser segment  183  with a twisted segment  185 . An angle  186  connects twisted segment  185  with a transverse segment  187 . An angle  188  connects transverse segment  187  with output connector segment  189 . Posts  190  are mounted on output connector segments  189  to the electrical and physical contact between leads  166  and offset connectors  168  and  170    169 . Posts  192  are mounted on connector segment  181  to improve electrical and physical contact between leads  166  and protective device mount  162 . 
     Referring now to  FIGS. 33 through 35 , output power assembly  12  is shown in greater detail, with leads  166  removed. Output power assembly  12  includes an output housing  206  with an inner face  208  and an outer face  210 . Return terminals  200  and battery terminals  202  are in parallel columns on outer face  210  and located to different planes,  212  and  214 , respectively, to provide separation and improved organization of battery and return cables from telecommunications equipment receiving power from panel  1 . 
     As shown, output power assembly  12  is configured to supply power to six such devices, having six pairs of battery terminals  202  and six pairs of return terminals  200 . Alternative configurations having more or fewer pairs of terminals can be used depending on size constraints and the number of devices requiring power. Output housing  206  is a uni-body housing, so that the same housing includes provisions for both battery and return terminals. 
     Terminals  200  and  202  are grouped in pairs to improve the quality and physical surface area of contact between the cables to and from the devices and the terminals, and to prevent rotation of the cables attached to the terminals. Return terminals  200  are all linked to a common return strap  204  which extends through output housing  206  from outer face  210  beyond inner face  208 . When output power assembly  12  is mounted to panel  1 , return strap  204  is electrically connected to return bus end  58 . 
     Each pair of battery terminals  202  are connected to a conductor strap  220  which extends through output housing  206  from outer face  210  beyond inner face  208  and includes an offset connector  168  or  170    169 . As detailed above, offset connectors  168  and  170    169  are electrically connected with segments  189  of leads  166  when output power assembly  12  is mounted to panel  1 . 
     Flanges  216  and fastener openings  218  are provided on output housing  206  to allow power output assembly  12  to be securely and removably fastened to rear face  28  of panel  1 , as shown in FIG.  1 . 
     Having described preferred aspects and embodiments of the present invention, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.