Abstract:
A power rail comprises a portion for mounting an electrical device and at least a conductor having a surface which is at least partially un-insulated and exposed for contact with a power terminal of the electrical device, for cordlessly supplying power to the electrical device when the electrical device is mounted to the portion of the power rail.

Description:
BACKGROUND 
       [0001]    In a rack-mounted computer system, each computer is mounted in a rack and each rack may house one or more computers wherein each computer has at least one power cord. Multiple power cords, e.g., as many as 5, may be required for failover protection of a single computer if the computer is an important component of the system. Thus, a rack that houses several computers will have many power cords for supplying power to the system. This leads to a need for multiple power distribution units (PDUs) and/or power strips to accommodate various plugs of the power cords which causes further installation problems. As density of power, and hence the number and/or size of the power cords, within the rack is growing, there is insufficient space left for other cables, such as network cabling the demand for which is on the rise, on the back of the system. Additionally, EMI (electromagnetic interference) or RFI (radio frequency interference) issues occur when networking cables cross multiple high power, unshielded power cords. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0002]    One or more embodiments are illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein: 
           [0003]      FIG. 1  is a simplified, perspective view of a rack according to an embodiment; 
           [0004]      FIG. 2  is a partial, perspective view showing the attachment of horizontal rails and vertical bars in a rack; 
           [0005]      FIG. 3  is a partially cutaway, perspective view of a power rail according to another embodiment; 
           [0006]      FIG. 4  is a simplified, cross-sectional view showing a power rail in use with an electrical device according to another embodiment; 
           [0007]      FIG. 5  is a simplified, perspective view of an electrical device according to another embodiment; 
           [0008]      FIG. 6  is a partial, perspective view of a power distribution bar according to another embodiment; 
           [0009]      FIG. 7  is a simplified, perspective view showing a power rail and a power distribution bar being connected by way of a connector according to another embodiment; 
           [0010]      FIG. 8  is a schematic, top plan view of a power rail, a power distribution bar, and a connector in an assembled state according to another embodiment; 
           [0011]      FIG. 9  is an enlarged view showing the connection between a conductor of a power rail and a corresponding contact of a connector according to another embodiment; 
           [0012]      FIG. 10  is a schematic top plan view of a power distribution system according to another embodiment; and 
           [0013]      FIG. 11  is a simplified, perspective view of a power distribution bar having a power usage monitoring unit according to another embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]      FIG. 1  is a simplified, perspective view of a rack  100  according to an embodiment for housing at least one electrical device  102 , such as a computer, server, tape/disk back-up device, household electronic equipment etc. Particularly, an electrical device that is rack-mountable or configurable to be rack-mountable can be used in rack  100 . 
         [0015]    Rack  100  comprises a number of vertical bars  104 , at least one of which is a power distribution bar, and a number of horizontal rails  106 , at least one of which is a power rail electrically connected to the power distribution bar for transferring power from the power distribution bar to an electrical device connected to the power rail. The horizontal rails  106  extend transversely to vertical bars  104 . Horizontal rails  106  attach to vertical bars  104  at a plurality of positions along vertical bars  104  using fasteners, e.g., screws, snap connectors, rivets, and other (removable and/or non-removable) connection/fastening devices, etc. In at least some embodiments, vertical bars  104  attach to horizontal rails  106 . 
         [0016]    Horizontal rails  106  attached to vertical bars  104  define a number of cells  108  within rack  100 . Each cell  108  is dimensioned to house at least one electrical device  102  by adjusting positions, e.g., vertical spacing, of the respective horizontal rails  106  on vertical bars  104 . Electrical device  102  is positioned, e.g., slid, into the respective cell  108 , riding on horizontal rails  106  of that cell  108 . Fasteners, e.g., screws, can be used to secure a front face  110  of electrical device  102  to at least one vertical bar  104  of rack  100 . 
         [0017]    Front face  110  of electrical device  102  defines a user interface  114  for allowing a user to manually control or visually monitor a status of electrical device  102 . In at least some embodiments, front face  110  lacks a user interface  114 . Electrical device  102  further comprises a rear face  112  opposite front face  110 . In the preexisting configurations, a power cord  107  is used to connect power terminals of each electrical device  102  on rear face  112  thereof to a power source, such as a PDU  116 . Such power cord is not required when a power rail according to an embodiment is provided in cell  108  accommodating electrical device  102 . The power rail(s) in rack  100  receive(s) power from either an external power source via power cord  118 , or from PDU  116  housed or incorporated in rack  100 . In the latter case, power cord  118  provides power to PDU  116  as shown in  FIG. 1 . In at least some embodiments, power cord  118  is the only power cord that emerges from rack  100 . In at least some embodiments, power cord  118  supplies power to one or more electrical devices  102  installed in rack  100  via PDU  116 . 
         [0018]      FIG. 2  is a partial, perspective view showing the attachment of horizontal rails  106 , including any power rail, to respective vertical bars  104 , including any power distribution bar, in rack  100 . In particular, horizontal rails  106 , including any power rail, attach to vertical bars  104 , including any power distribution bar, at a plurality of positions along vertical bars  104  using fasteners, e.g., screws, snap connectors, rivets, and other (removable and/or non-removable) connection/fastening devices, etc. In the embodiment of  FIG. 2 , screws  205  are used to fasten horizontal rails  106  to respective vertical bars  104 . 
         [0019]      FIG. 3  is a partially cutaway, perspective view of a power rail  320  according to an embodiment. Power rail  320 , in at least one embodiment, replaces one of horizontal rails  106  in each cell  108  of rack  100 , and supports and cordlessly supplies power to electrical device  102 . In an alternative embodiment, power rail  320  is positioned as part of cell  108  in addition to horizontal rails  106  of the particular cell, and supplies power to electrical device  102  without providing support to the electrical device. Power rail  320  can be attached to vertical bars  104  of rack  100  in a manner similar to horizontal rails  106  as illustrated in  FIG. 2 . 
         [0020]    A simplified, cross sectional view of power rail  320  is shown in  FIG. 4 . Power rail  320 , as depicted in  FIG. 4 , comprises a casing  422  which has embedded therein at least one conductor  424 . Casing  422  is made of insulating material or at least comprises insulating material in the vicinity of conductor  424 . At least one side of casing  422  is open at opening  430  to allow access to conductor  424 . In at least some embodiments, conductor  424  is flush with a surface  426  of casing  422  that faces opening  430 , e.g., an inner surface of casing  422 . (However, conductors  424  are not necessarily disposed opposite opening  430 , and can be positioned anywhere on casing  422 , as long as conductors  424  are accessible for sliding contact with power terminals of electrical device  102  as will be described herein below.) One or some or all conductor(s)  424  may be positioned at the bottom of groove  428  formed in surface  426 , as shown at  424 ′ in  FIG. 4 . The latter configuration prevents a user&#39;s fingers from touching conductor  424 ′. In at least some embodiments, conductors  424  and/or  424 ′ may be disposed at the same and/or different positions in respective grooves  428 . In the description below, conductor  424  and conductor  424 ′ will be commonly referred to as conductor  424 . 
         [0021]    The number of conductors  424  in power rail  320  can vary, depending on the power need of electrical device  102 . Generally, power rail  320  comprises two conductors  424 , one for a hot line and the other for a ground line. For example, for failover protection, three or more conductors  424  connected to at least two hot lines and a ground line, respectively, can be provided to connect two or more independent power sources to electrical device  102 , to ensure continuous power supply to electrical device  102  in the event of failure of power supplied from one of the conductors. In another embodiment, only a few, not all, of multiple conductors  424  provided in power rail  320  are used for feeding electrical device  102 , whereas the remaining conductors  424  are disabled, either by an external power source, e.g., PDU  116 , or by a connector. 
         [0022]    Each conductor  424  has a surface  431  at least partially uninsulated and exposed for contact with and providing power to a respective power terminal  432  of electrical device  102 . Power terminals  432  are connected by electrical conducting connecting lines  434  to a power supply unit (PSU)  436  of electrical device  102 . Connecting lines  434  extend inside a case  438  of electrical device  102 . Power terminals  432  are provided on a side wall  440  of case  438 . In at least some embodiments, power terminals  432  may be provided elsewhere, e.g., on top wall  442  or bottom wall  444 , of case  438 . Power terminals  432  can be flush with or project outwardly from the outer surface of side wall  440 . Power terminals  432  are provided inside case  438  and exposed through openings  446  for safety reasons. An adapter  448  is used to electrically connect power terminals  432  of electrical device  102  with respective conductors  424  of power rail  320 . 
         [0023]    Adapter  448  comprises two sets of contacts, namely  450  and  452 , for electrical connection to conductors  424  and power terminals  432 , respectively. Contacts  450  and  452  are respectively electrically connected to each other within adapter  448  as schematically shown at  454 . A spring  456  biasing contacts  450  and  452  in each pair away from each other, toward the respective conductor  424  and power terminal  432 , in use, to ensure reliable contact and power supply from power rail  320  to electrical device  102 . An individual spring can be provided for each contact  450  or  452 , i.e., two springs for each pair of contacts  450 ,  452 . In alternative embodiments, springs  46  are omitted and/or incorporated in contacts  450 ,  452 . In the latter case, each contact  450  or  452  is configured as a leaf spring which, in use, presses against the respective conductor  424  or power terminal  432 . In a further embodiment, only one set of contacts, e.g.,  450 , are moving contacts or spring-loaded, whereas the other set of contacts, i.e.,  452 , are stationary contacts. 
         [0024]    Adapter  448  can be attached to case  438 , in a particular embodiment to side wall  440 , in any appropriate manner including, but not limited to, screw connection, snap connection, adhesive bonding, welding, molding etc. In at least some embodiments, adapter  448  may be an integral part of case  438 . 
         [0025]    Adapter  448  and power rail  320  have matching coupling elements that allow adapter  448 , and hence, electrical device  102  to be moveable along power rail  320  while maintaining a predetermined distance between electrical device  102  and power rail  320 , thereby effecting reliable surface-to-surface contact between power terminals  432  and conductors  424 . The coupling elements comprise wheels  458  rotatably supported in casing  422  of power rail  320 , and matching grooves  460  formed in adapter  448 . In use, adapter  448  is attached to electrical device  102  and then inserted in power rail  320  through a front, open end of power rail  320 . Adapter  448  is thus received in an interior  462  of power rail  320  as shown at  448 ′ in  FIG. 4 . In such assembled state, wheels  458  ride in respective grooves  460  to guide adapter  448  moving along power rail  320 . 
         [0026]    During movement of adapter  448  along power rail  320 , contacts  450  are in sliding contact with respective conductors  424 , thereby powering electrical device  102  while electrical device  102  moves relative to power rail  320 . Power is thus transferred cordlessly from power rail  320  to electrical device  102 . 
         [0027]    In an embodiment, conductors  424  are elongated in the longitudinal direction of power rail  320 , and extend a substantial length of power rail  320 . Thus, electrical device  102  is powered by conductor  424  as electrical device  102  moves along the substantial length of power rail  320 . In at least some other embodiments, conductor  424  extends only a partial length of power rail  320  near the final destination of electrical device  102 . Thus, electrical device  102  is not powered by power rail  320  at the beginning of its movement along the power rail, and is powered by conductor  424  as it approaches the final destination. 
         [0028]    In an embodiment, wheels  458  are omitted and replaced by ridges slidable in grooves  460 . In at least some other embodiments, the positions of the coupling elements are switched, i.e., wheels or ridges  458  are provided on adapter  448 , whereas grooves  460  are formed inside casing  422  of power rail  320 . 
         [0029]    In at least one further embodiment, the coupling elements are omitted when the distance between electrical device  102  and power rail  320  is maintained by another engagement between electrical device  102  and rack  100 . For example, electrical device  102  in this embodiment is slidably supported by two horizontal rails  106  of rack  100 , and power rail  320  is provided adjacent to and in parallel to at least one of the horizontal rails  106  (as shown at  320 ′ in  FIG. 1 ) only for the purpose of powering electrical device  102 . 
         [0030]      FIG. 5  is a simplified, perspective view of electrical device  102  according to at least one embodiment. Electrical device  102  comprises front face  110  on which a user interface is provided for allowing a user to manually control or monitor operation of electrical device  102 . In a particular embodiment, the user interface comprises at least one of a power button  564 , a screen or see-through window  566 , a number of control buttons  568 , and one or more disk drive or tape cartridge slot  570 . PSU  436  is positioned inside case  438  of electrical device  102 , and connected to adapter  448  via connecting line(s)  434 . Adapter  448  is elongated in the sliding direction of electrical device  102  and provided on side wall  440  of case  438 . Contact(s)  450  and the matching contact(s)  452  are provided at one or more positions on adapter  448 . One of the coupling elements, e.g., grooves  460 , extends longitudinally of adapter  448  for moveable engagement with the matching coupling element, e.g., wheels  458 , of power rail  320 . Electrical device  102  is thus both supported for sliding movement and powered by power rail  320 . A similar adapter  448  in an alternative embodiment is provided on the opposite side wall  440 ′ of case  438 , and hence, electrical device  102  rides on and receives power from two power rails  320 . In another alternative embodiment, adapter  448  is provided on only one side wall  440 , and the electrical device  102  is slidably supported on the opposite side by a horizontal rail  106  which is not a power rail  320 . 
         [0031]    In at least some embodiments, a kit comprising a power rail, such as power rail  320 , and an adapter, such as adapter  448 , is provided. The kit is usable to upgrade an electrical device, such as  102 , which is initially configured to receive power supply via a power cord, to be cordlessly powerable. In use, adapter  448  is attached to side wall  440  of electrical device  102  so that contacts  452  are in electrical contact with respective power terminals  432 . Electrical device  102  is then slid into a cell  108  of rack  100 , where power rail  320  has been installed, to cordlessly receive power from power rail  320 . No power cord, such as  107  in  FIG. 1 , is used to supply power to electrical device  102 . Electrical device  102  is disconnected from the power supply simply by removing electrical device  102  from cell  108 , and hence, disengaging/disconnecting adapter  448  from power rail  320 . 
         [0032]    In at least one other embodiment, a kit further comprises a side panel comprising power terminals, such as  432 , to replace a side wall  440  of electrical device  102 . Such replacement side panel in an embodiment comes with connecting lines  434  for connection with PSU  436  by a plug/receptacle connection. Since connecting lines  434  are within case  438 , no power cord sticks out. The replacement side panel can be detachably attachable to or permanently integrated with adapter  448 . 
         [0033]    In yet further embodiments, a kit also comprises a power distribution bar and/or a connector. 
         [0034]      FIG. 6  is a partial, perspective view of a power distribution bar  672  according to a further embodiment. Power distribution bar  672  replaces at least one of vertical bars  104  of rack  100 . In another embodiment, power distribution bar  672  is added to rack  100  as an additional component. Several power distribution bars  672  are used in a single rack in accordance with a further embodiment for satisfying the varying power consumption demand of the equipment installed in the rack. 
         [0035]    Similar to power rail  320 , power distribution bar  672  comprises a casing  674  having embedded therein a number of elongated conductors  676  extending longitudinally of power distribution bar  672 . An opening  678  is provided on a wall of casing  674  to allow access to conductors  676 . The number of conductors  676  is dictated by the specific application and is customizable and/or controllably disabled/enabled as discussed above with respect to conductors  424  of power rail  320 . In an embodiment, opening  678  extends the whole or substantial length of power distribution bar  672 . In another embodiment, there are several openings  678  distributed along power distribution bar  672  at positions where electrical connection to power rails, such as  320 , is desirable. A power rail  320  is electrically connectable to power distribution bar  672  at any place along the length of power distribution bar  672 , or at any of the desirable positions mentioned above. Power distribution bar  672  is electrically connected to either PDU  116  or power cord  118  for receiving power from an external power source, and for subsequently distributing the received power to one or more power rails  320  attached at various positions to said power distribution bar  672 . 
         [0036]    The electric connection between power distribution bar  672  and power rail  320  is effected by a connector  680  partially shown in  FIG. 6 . A simplified, perspective view showing connector  680  is provided in  FIG. 7  which also depicts a power rail  320  and a power distribution bar  672  being connected by way of connector  680  according to a further embodiment. Connector  680  comprises a first connecting member  782  and a second connecting member  784  for electrical connection to power distribution bar  672  and power rail  320 , respectively. 
         [0037]    First connecting member  782  comprises a plurality of first terminals  789  for electrical connection with respective conductors  676  of power distribution bar  672 . As best seen in  FIG. 6 , second connecting member  784  has four first terminals  789  (only two are visible in  FIG. 6 ), two on each side, to correspond to conductors  676  of power distribution bar  672  which are also distributed two on each side within the interior of power distribution bar  672 . In at least some embodiments, first terminals  789  are positioned all on one side of first connecting member  782  as shown in the embodiment of  FIG. 7 . 
         [0038]    Returning to  FIG. 6 , first connecting member  782  is insertable, e.g., by a user, into the interior of power distribution bar  672  through opening  678 , with first terminals  789  projecting generally axially of power distribution bar  672 . Once first connecting member  782  has reached a position that aligns first terminals  789  with conductors  676 , first connecting member  782  is rotatable, e.g., by a user, about 90 degrees, to force first terminals  789  into contact with respective conductors  676 , and at the same time, fix first connecting member  782 , and hence connector  680 , in place relative to power distribution bar  672 . Thus, a twist-lock connection is effected between connector  680  and power distribution bar  672 . In an embodiment, first terminals  789  are spring-loaded for reliable contact with respective conductors  676  in the twist-lock connection. Power is thus cordlessly transferred from power distribution bar  672  to connector  680 . 
         [0039]    Second connecting member  784  comprises a plurality of second terminals  786  connected to respective first terminals  789  as schematically illustrated at  795  in  FIG. 7 . Second terminals  786  are further electrically connectable to conductors  424  of power rail  320 , either directly or through matching terminals formed at a rear end  787  of power rail  320 . 
         [0040]      FIG. 9  depicts a configuration of a terminal  988  formed at rear end  787  of power rail  320 . The corresponding second terminal  786  has a shape  990  generally complementary to that of terminal  988 . In particular, second terminal  786  is press-fit inside terminal  988  to form a plug/socket connection. Thus, a reliable connection between power rail  320  and second connecting member  784  can be effected simply by sliding power rail  320  towards connector  680  until second terminals  786  are snapped in and make contact with respective terminals  988 . In this embodiment, again, power is cordlessly transferred, this time from connector  680  to power rail  320 . 
         [0041]      FIG. 8  depicts a complete, assembled state between power distribution bar  672 , connector  680  and power rail  320 . 
         [0042]    In at least some embodiments, connector  680  is integrated with one of power rail  320  and power distribution bar  672 . However, the above disclosed embodiments with separate connector  680 , power rail  320  and power distribution bar  672 , which are releasably connectable, allows for desirable flexibility in the rack&#39;s configuration where connector  680 , and hence power rail  320 , can be attached at a position along a substantially entire length of power distribution bar  672 . 
         [0043]    In a further embodiment, connector  680  is configurable to enable or disable one or more of connections  795 , thereby selectively transferring power only from desired conductors  676  of power distribution bar  672  to corresponding desired conductors  424  of power rail  320 , depending on the power need of the electrical device  102  being installed. 
         [0044]      FIG. 10  is a schematic top plan view of a power distribution system  1000  according to a further embodiment. System  1000  comprises a plurality of racks  100  arranged as an array having a plurality of rows  1031 - 1033 . All electrical devices  102  held in each rack  100  are cordlessly powered by one or more power rails and/or power distribution bars and/or connectors and adapters. Each rack is, in turn, powered via, e.g., a power cord  118 . Racks  100  in a row, e.g.,  1031 , can be individually connected to a power source schematically designated at  1051 . Racks  100  in a row, e.g.,  1032 , can be connected in cascade to power source  1051 . A power strip, such as  1055 , can be used to connect racks  100  in a row to power source  1051 . System or array  1000  of racks  100  therefore greatly reduces the number of power cords that would be otherwise necessary to feed all equipment held by racks  100 . In addition, installation or removal of equipment is also greatly simplified by merely inserting or withdrawing the equipment to/from a rack without having to plug or unplug a power cord on the back of the equipment to/from a power socket. 
         [0045]    In at least some embodiments, power source  1051  is a breaker panel connected to one or more independent 1- or multiple-phase power sources. 
         [0046]    System  1000 , in a further embodiment, allows to distribute load on demand, and to create an adaptive power solution. The system is modular and the rows are expandable to create a modular power grid. 
         [0047]    In at least another embodiment, each rack  100  or row  1031 - 1033  comprises a unit for monitoring power usage. A power profile for entire row of racks  100  is obtainable on line, e.g., with a cabinet monitoring system (CMS). 
         [0048]    Power usage monitoring can also be performed at the rack/cabinet level.  FIG. 11  is a simplified, perspective view of a power distribution bar  672  comprising a power usage monitoring unit  1181  according to a further embodiment. Power usage monitoring unit  1181  in the embodiment of  FIG. 11  is placed at an upper end, in use, of power distribution bar  672 . In at least some embodiments, power usage monitoring unit  1181  can be positioned anywhere along power distribution bar  672 , e.g., in the middle, at the eye level, or at the lower end. 
         [0049]    Power usage monitoring unit  1181  comprises a detector electrically coupled to one or more of conductors  676  of power distribution bar  672  for detecting at least one parameter of the power transmission through the particular conductor  676 . In the embodiment of  FIG. 11 , the detector is a power and/or voltage and/or current meter that measures, in use, the power transmission through the entire power distribution bar  672 . 
         [0050]    Power usage monitoring unit  1181  further comprises at least an indicator  1183 , visual or audible, for conveying information related to the detected parameter(s) to a user or operator. In the embodiment of  FIG. 11 , indicator  1183  comprises at least one of a display  1185 , a visual load indicator  1187 , one or more control button  1189 , and a sound generating device  1179 , such as a speaker or alarm. 
         [0051]    Visual load indicator  1187  indicates a ratio, in percentage, of the current load and maximum load of power distribution bar  672 . The ratio is presented as a lighted bar or blocks that change(s) color, e.g., from green to red, when the ratio reaches or exceeds a predetermined value, e.g., 80%, to warn that no further equipment should be connected to that power distribution bar  672 . At the same time or at a higher current load/maximum load ratio, an audible alarm is generated through speaker  1179  to alert the operator of the critical situation. 
         [0052]    Display  1185  indicates the measured value of the detected parameter. In the embodiment of  FIG. 11 , display  1185  is divided into two displaying areas  1175  and  1177 , one ( 1177 ) for displaying the measured value and the other ( 1175 ) for indicating the conductor(s)  676  where the value is measured. for example, if conductors  676  of power distribution bar  672  are connected to phases A, B and C of a three-phase power source, displaying area  1175  indicates the phase (or conductor  676 ) being monitored and displaying area  1177  displays the current on that phase. 
         [0053]    Control button(s)  1189  is/are provided for allowing the operator to switch display  1185  among a number of parameters monitored by power usage monitoring unit  1181 , such as total KVA, input voltage, current etc. Control button(s)  1189  can also be used to input certain settings, such as the current load/maximum load ratio at which the alarm  1179  is triggered.