Patent Publication Number: US-9893482-B2

Title: Branched electrical system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 14/714,805, filed May 18, 2015, now U.S. Pat. No. 9,531,145, which claims the benefit of U.S. provisional application Ser. No. 62/000,427, filed May 19, 2014, and U.S. provisional application Ser. No. 62/120,474, filed Feb. 25, 2015, all of which are hereby incorporated by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to electrical power systems and, more particularly, to electrical power systems having multiple outlets arranged along a main conductor. 
     BACKGROUND OF THE INVENTION 
     The need or desire to incorporate electrical power outlets in different locations has increased as portable electronic devices such as laptop computers, mobile phones, digital cameras, and the like have proliferated, since these devices often require frequent charging of onboard batteries. Such devices typically require access to high voltage (e.g., 110V AC or 220V AC) power outlets and/or low voltage (e.g. 2V DC to 12V DC) power outlet. 
     SUMMARY OF THE INVENTION 
     The present invention provides a branched electrical system that supplies electrical power, such as AC power at 110V AC or 220V AC, or DC power in the range of about 2V to 12V, to a plurality of outlets for providing simultaneous access to the power by multiple users with portable electronic devices or the like. To account for voltage drop along a length of DC-energized electrical wiring, one or more power boosters may be coupled along the electrical wiring, which has a plurality of branches from a main line to provide electrical power at different locations that are equipped with electrical outlets along the main line. The branches may be spliced in to the main line, or the branches may be coupled to the main line via respective detachable connectors. The electrical outlets may have any number of different configurations, such as universal serial bus (USB), co-axial connector, 12V automotive-style connector, or the like, and it is envisioned that two or more different receptacles could be provided at an end of each branch, or along a mid portion of a given branch. Optionally, an electronic signal such as an audio signal may be conveyed along the main line to the branches, with access provided at respective receptacles or connectors. It is further envisioned that the receptacles may include weatherproofing covers or design features, such as for use in areas exposed to weather or risk of liquid spills or other contaminants. The low voltage version of the electrical system may be particularly well-suited to providing multiple users with access to low voltage electrical power in high density seating areas, such as stadium or theater seating, lecture halls, commercial aircraft, or the like. 
     According to one form of the present invention, a branched electrical system includes a main line, a plurality of branch lines coupled to the main line, and electrical receptacles in electrical communication with the main line via the branch lines. The main line has at least two main line electrical conductors, a first end portion electrically coupled to a power source, and a second end portion opposite the first end. The branch lines each have at least two electrical conductors with proximal end portions that are electrically coupled to respective ones of the main line electrical conductors. The branch lines further include respective distal end portions that are spaced away from the main line and the proximal end portions. An electrical receptacle is disposed at each of the distal end portions of the electrical conductors of the branch lines. The electrical receptacle is configured to engage an electrical connector of a portable electrical or electronic device. 
     In one aspect, the system further includes a DC electrical converter disposed between the power source and the first end of the main line. The DC electrical converter is operable to convert a high voltage AC power input at the power source to a low voltage DC power output at the first end portion of the main line. 
     In another aspect, at least one DC power booster is electrically coupled to the main line between the first end portion and the second end portion thereof. 
     In yet another aspect, a first plurality of the branch lines and a corresponding first plurality of the electrical receptacles are electrically coupled to the main line between the first end portion and the DC power booster, while a second plurality of the branch lines and a corresponding second plurality of the electrical receptacles are electrically coupled to the main line between the DC power booster and the second end portion. 
     In still another aspect, each of the proximal end portions of the electrical conductors of the branch lines are electrically coupled to the respective ones of the main line electrical conductors via an electrical splice connection. Optionally, an overmolded body is formed or disposed around each of the electrical splice connections. 
     In a further aspect, the branched electrical system includes a plurality of first electrical connectors disposed along the main line, and a plurality of second electrical connectors disposed at the proximal end portions of the branch lines. The second electrical connectors are configured to engage the first electrical connectors to thereby establish an electrical connection from the main line to each of the electrical receptacles. 
     In a still further aspect, the second electrical connectors are detachable from the first electrical connectors. 
     In another aspect, the electrical connectors include low voltage electrical connectors including at least one chosen from (i) a USB connector, (ii) a co-axial connector, and (iii) an automotive 12V connector. Optionally, at least one of the electrical connectors is an audio connector. 
     In a further aspect, the branched electrical system is combined with high density seating, such as stadium or arena seating, theater seating, or commercial vehicle seating. Optionally, the high density seating includes a plurality of seating surfaces and a plurality of armrests disposed between the seating surfaces. The electrical receptacles include low voltage DC receptacles mounted at respective ones of the armrests. Optionally, at least two of the low voltage electrical receptacles are mounted in each of the armrests. Optionally, the low voltage electrical receptacles are at least partially recessed in the armrests. 
     In yet another aspect, the electrical receptacles include high voltage AC receptacles. Optionally, the electrical receptacles include outlet blocks having high voltage AC outlets, low voltage DC outlets, and DC transformers in communication with the low voltage DC outlets and the electrical conductors of the branch lines. 
     In still another aspect, the branched electrical system includes an overmolded branch junction where each of the branch lines couples to the main line, and an optional C-shaped resilient clip may be provided for releasably engaging the overmolded branch junction, to facilitate securing the overmolded branch junctions to a work surface. 
     Thus, the branched electrical system of the present invention provides multiple users in with access to high or low voltage receptacles for charging portable electronic devices and/or supplying power to other power consumers, such as lamps, headphones, and the like. The branched electrical system may be particularly well-suited to providing multiple users with access to electrical power in high density seating areas, such as stadium or theater seating, lecture halls, and public transportation vehicles. By adding power boosters along a main line of a low voltage DC embodiment of the system, the length of the low voltage system can be extended to substantially any desired length. 
     These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front elevation of a low voltage branched electrical system in accordance with the present invention, shown in a section of high density stadium or theater seating; 
         FIG. 2  provides two enlarged views of the area designated II in  FIG. 1 , showing two different options for low-voltage connections; 
         FIG. 3  provides four enlarged views of the area designated III in  FIG. 1 , showing four different options for low-voltage electrical connectors in an armrest portion of the seating; 
         FIG. 4  is a top perspective view of a work table with a high and low voltage branched electrical system in accordance with the present invention; 
         FIG. 5  is a bottom perspective view of the work table and electrical system of  FIG. 4 , including enlarged views of a branch junction; 
         FIG. 6  is a perspective view of the branched electrical system of  FIGS. 4 and 5 ; 
         FIG. 7  is a perspective view of another high and low voltage branched electrical system configured for hard-wiring and with armored cables; 
         FIG. 8  is a perspective view of another high and low voltage branched electrical system configured for modular installation; 
         FIGS. 9 and 10  are perspective views of the branch junction in  FIG. 5 ; 
         FIG. 11  is a top plan view of the branch junction; 
         FIGS. 12A-12E  depict six sequential steps of forming the branch junction; 
         FIGS. 13-17  are perspective views of different branch junctions; 
         FIG. 18  is a perspective view of a high voltage branched electrical system; 
         FIGS. 19A-19D  are enlarged views depicting four sequential steps of installing an electrical outlet at the end of a branch at the area designated XIX in  FIG. 18 ; 
         FIG. 20  is another perspective view of the high voltage branched electrical system of  FIG. 18 , in which each branch end includes an electrical outlet; 
         FIG. 21  is a perspective view of a modular outlet assembly that is compatible for use with the high voltage branched electrical system of  FIG. 18 ; 
         FIG. 22  is a perspective view of a high voltage AC grommet-style outlet that is compatible for use with the high voltage branched electrical system of  FIG. 18 ; 
         FIG. 23  is a perspective view of a low voltage DC grommet-style outlet that is compatible for use with either of the low voltage branched electrical system of  FIG. 1  and the high voltage branched electrical system of  FIG. 18 ; and 
         FIG. 24  is a perspective view of a 3-outlet high voltage AC power strip that is compatible for use with the high voltage branched electrical system of  FIG. 18 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A branched electrical system is configurable to provide multiple user with access to electrical power in different environments including indoor work areas, public transit vehicles (e.g., buses, trains, ferries, commercial aircraft), auditoriums or theaters, indoor or outdoor stadiums or arenas, bleachers, or the like. The branched electrical systems may be configured to carry high voltage electrical power, such as 110V AC or 220V AC power, or may be configured to carry low voltage electrical power, such as about 2V DC to about 12V DC. In still other embodiments, a branched electrical system can be configured to carry or provide access to both high voltage AC power outlets and low voltage DC power outlets. This can be accomplished by providing one or more DC transformers at each branched electrical system, or by providing the branched electrical system with both high and low voltage conductors for the respective high and low voltage outlets. In the case of low voltage branched electrical systems having sufficient length that would otherwise result in an unacceptable amount of voltage drop, it is envisioned that a voltage booster may be electrically coupled to the system at a location spaced downstream from an upstream main power source. Moreover, the branched electrical systems are configurable as modular systems in which branches can be added or removed as desired, or may be configured as spliced-together systems in which the number of branches is generally set during manufacturing and not readily modifiable thereafter. 
     Referring to the drawings and the illustrative embodiments depicted therein, a branched low voltage electrical system  10  is configured for mounting along a high density seating row  12  or similar arrangement, and includes a main line  14 , a plurality of branch lines  16 , and a plurality of low voltage electrical receptacles  18  at the ends of the branch lines ( FIG. 1 ). Main line  14  may extend a substantial length and typically carries low voltage DC power that, in some cases, may exhibit an unacceptable voltage drop along its length, so that it may be desirable to install one or more DC power boosters  20  along main line  14  to maintain a sufficiently high DC voltage at each receptacle  18  that is serviced by main line  14 . 
     Main line  14  has two main line electrical conductors of opposite polarities, and has a first end portion  14   a  that is electrically coupled to a power source  22  and a second end portion  14   b  opposite the first end portion, such as shown in  FIG. 1 . For applications where power source  22  is a high voltage AC power source, for example, a DC electrical power converter or power supply  24  may be coupled between power source  22  and main line  14 , to supply main line  14  with low voltage electrical power, typically in the range of about 2V to 12V DC, although other voltages are equally possible. Main line  14  may have one or more additional conductors, such as to provide different voltages at different outlets, or to provide an electrical ground. Moreover, it is envisioned that it may be sufficient to provide only a single wire conductor of one polarity, while the opposite polarity is provided by electrically conductive structure associated with seating  12 , similar to the arrangement that is common to automotive or other vehicular electrical systems. 
     In the illustrated embodiment of  FIG. 1 , DC electrical converter  24  is disposed between the power source  22 , which is a hardwired connection to a high voltage AC circuit (such as at 110V or 220V AC), and the first end portion  14   a  of main line  14 , so that DC electrical converter  24  converts a high voltage AC power input at the power source  22  to a low voltage DC power output at the first end portion  14   a  of main line  14 . It is further envisioned that low voltage electrical system  10  may be coupled to a power supply via a conventional plug for connecting to a conventional AC wall outlet or floor outlet, instead of a hardwired connection, or may instead be supplied with power from a DC power source such as a battery, photovoltaic cells, combinations of the above, or the like. DC power booster  20  is electrically coupled along the main line  14  between the first end portion  14   a  and the second end portion  14   b . Optionally, additional DC power boosters may be placed at desired intervals along main line  14 , to extend main line  14  to substantially any desired length. For example, main line  14  may supply power to a first set of branch lines  16  and a corresponding set of low voltage electrical receptacles  18  between first end portion  14   a  and DC power booster  20 , while a second set of branch lines  16  and a corresponding set of low voltage electrical receptacles  18  are electrically coupled to the main line  14  between DC power booster  20  and second or distal end portion  14   b  of main line  14 . 
     Branch lines  16  each have two electrical conductors with proximal end portions  16   a  that are electrically coupled to the electrical conductors of main line  14 . Branch lines  16  have distal end portions  16   b  that are spaced away from main line  14  and the proximal end portions  16   a . Low voltage electrical receptacles  18  are disposed at distal end portions  16   b  of branch lines  16 , and are mounted at or along a portion of seating  12 , such as shown in  FIGS. 1 and 3 . Low voltage electrical receptacles  18  are configured to engage and supply power to a low voltage electrical connector of a portable electronic device, such as a hand-held computer, a tablet device, a mobile phone, laptop computer, a small appliance such as a low voltage lamp, audio headphones, or the like. For example, receptacles  18  may take the form of a USB-style low voltage DC connector, a co-axial DC connector, an automotive 12V connector, or the like. Optionally, the low voltage electrical receptacles or outlets may be fitted with weatherproofing covers or other weather-resistant design features, or with tamper-resistant design features, such as for use in areas that are exposed to weather or have an increased risk of liquid spills or other contaminants. 
     Branch lines  16  are electrically coupled at their proximal end portions  16   a  to main line  14  at respective electrical splice connections  26  ( FIG. 1  and  FIG. 2 , at left) or, optionally, the branch lines  16  may be electrically coupled to main line  14  via a modular connector arrangement  28  including a first connector  28   a  (such as a female connector) associated with main line  14  and a second connector  28   b  (such as a male connector) associated with branch line  16 , such as shown in  FIG. 2 , at right. In the case of splice connections  26 , the electrical connections between the individual electrical conductors may be housed or contained within respective overmolded bodies  30  (at left in  FIG. 2 ) that permanently seal, protect, and provide strain relief for the electrical connections throughout the life of the low voltage electrical system. Overmolded bodies  30  may be substantially solid rubber or polymeric material that is molded directly over and around the spliced electrical connections and around an outer insulating jacket of main line  14  on either side of the respective splice. However, it is envisioned that other types of protective housings or covers may be used, without departing from the spirit and scope of the present invention. In the case of modular connector arrangement  28 , first connector  28   a  may establish a substantially permanent mechanical and electrical connection to second connector  28   b  upon full engagement, or may be configured to be removable from second connector  28   b , such as upon depressing a resilient latch tab that normally secures the connectors to one another when they are in use. 
     As noted above, electrical system  10  is envisioned for use in high-density arrangements such as stadium or arena seating, theater seating, public transit seating, or the like. In the illustrated embodiment, high density seating arrangement  12  is configured as stadium, arena, or theater seating, and includes a plurality of seating surfaces  32  with corresponding seatbacks  34  and a plurality of armrests  36  disposed between seating surfaces  32 , such as shown in  FIG. 1 . Low voltage electrical receptacles  18  are mounted at respective ones of the armrests  36 , such as shown in  FIGS. 1 and 3 . Different arrangements and/or placement locations of low voltage electrical receptacles  18  are envisioned, such as shown in  FIG. 3 . For example, a dual-USB outlet  18   a  or a quad-USB outlet  18   b  may be provided in respective raised housings  38   a ,  38   b  at an upper surface  40  of a given armrest  36 . Another armrest  36   a  ( FIG. 3 ) may be configured with an upper surface  40   a  having a recessed region  42  with one or more low voltage electrical connectors  18 , while another armrest  36   b  may be configured with one of dual-USB outlets  18   a  disposed in a forward surface  44 . Optionally, outlets  18  may be mounted in the seating surfaces, seatbacks, structural components or aesthetic panels, without departing from the spirit and scope of the present invention. 
     Referring now to  FIGS. 4 and 5 , a high and low voltage branched electrical system  46  is attached to the underside of a work table  48  and includes three branches  50  extending outwardly from a main line  52 . Each branch  50  terminates at a respective outlet block or assembly  54  located at a distal end portion  50   a  of each branch  50 . Main line  52  has a power plug  56  at an upstream end  52   a  for receiving power from an upstream power cable or system  46 ′ ( FIG. 4 ). Main line  52  also has an electrical receptacle  58  at a downstream end  52   b  for conveying power to a downstream electrical cable or system  46 ″ ( FIG. 5 ). Each branch  50  is electrically and mechanically coupled to main line  52  at a branch junction  60  through which passes electrical conductors of main line  52 , and from which branch electrical conductors extend, as will be described in more detail below. 
     Optionally, branch junctions  60  are releasably securable to an underside of work table  48  via resilient C-shaped clips  62  ( FIG. 5 , enlarged views). Clips  62  have generally straight or planar central portions  62   a  that engage table  48 , and may be secured to the table using mechanical fasteners such as threaded screws, rivets, snaps, hook-and-loop fasteners, magnets, or the like. Clips  62  have curved opposite end portions  62   b  on either side of central portion  62   a , which curved end portions  62   b  are configured to extend partially around respective sides of a central body portion  60   a  of branch junction  60 . Clips  62  may be made of resilient material such as spring steel, resinous plastic, or the like, so that curved end portions  62   b  can be spread apart to receive central body portion  60   a , and then released so that curved end portions  62   b  grasp or clamp onto central body portion  60   a . In the illustrated embodiment, central body portion  60   a  includes a recess  64  on each side thereof (also shown in  FIGS. 9-11 ), which is sized and shaped to receive a respective one of curved end portions  62   b  so that central body portion  60   a  will be substantially secured without slipping relative to its respective clip  62 . 
     In the illustrated embodiments of  FIGS. 4-8 , each outlet block or assembly  54  includes a high voltage AC receptacle  66  and a pair of USB-style low voltage DC receptacles  68 . Each outlet block  54  is supplied with high voltage AC power via a respective branch  50 , and contains a DC transformer (not shown) for converting the AC power input received by outlet block  54  into a low voltage DC output at low voltage DC receptacles  68 . AC receptacle  66  is supplied with power directly from the conductors of branch  50 . However, it will be appreciated that the output voltage at AC receptacle  66  may be changed as desired using electrical circuitry, as is known in the art. Outlet block assemblies  54  include attachment features in the form of keyhole openings or slots  70  ( FIGS. 6-8 ) that are slid or urged into engagement with respective fastener heads that are protruding from an underside of table  48  and are provided for this purpose. 
     Branch junctions  60  are formed by first establishing electrical connections between main line conductors  72   a ,  72   b  and branch line conductors  74  ( FIGS. 12A and 12B ), securing the electrical connections with a strain relief  76  that also helps protect against short circuits ( FIGS. 12B-12D ), and overmolding the secured electrical connections to provide further strain relief and protection from environmental damage ( FIG. 12E ). Referring to  FIG. 12A , an upstream or power supply side  52   a  of main line  52  includes hot, neutral, and ground conductors  72   a , while a downstream side  52   b  of main line  52  includes corresponding hot, neutral, and ground conductors  72   b . Branch line  50  includes hot, neutral, and ground branch line conductors  74 . Downstream main line conductors  72   b  and branch line conductors  74  are electrically and mechanically coupled to corresponding ones of the upstream main line conductors  72   a  using crimping elements  78  or the like. 
     Conductors  72   a ,  72   b ,  74  and crimping elements  78  are then inserted into respective channels  80  of strain relief  76  made of non-conducting material, such as shown in  FIGS. 12B and 12C . Channels  80  are defined between a proximal end wall  82   a , a distal end wall  82   b , and a pair of central walls  84  that extend or project upwardly from a base wall  86 , such as shown in  FIG. 12B . A top cover  88  is pivotably coupled to proximal end wall  82   a  via a living hinge, and a latch tab  90  extends downwardly to engage distal end wall  82   b  so that cover  88  will be retained in a closed position such as shown in  FIG. 12D . Once the conductors  72   a ,  72   b ,  74  are secured using crimping elements  78  and strain relief  76  ( FIG. 12D ), the region can be overmolded with a non-conductive material such as resinous plastic, natural or synthetic rubber, or the like, including central body  60   a , a main line input arm  60   b , a main line output arm  60   c , and a branch arm  60   d  ( FIGS. 9-11 ). Central body  60   a  and arms  60   b - d  may be unitarily formed in a molding process in which the main line, branch line, and electrical junction of  FIG. 12D  is placed in a mold, whereupon liquid material is injected and cured around the electrical wiring and insulating jacket materials. Thus, the material of central body  60   a  seals around strain relief  76  and the individual conductors  72   a ,  72   b ,  74  to provide a moisture-resistant and impact-resistant casing around the junction, while the material of arms  60   b - d  seal around the insulative outer jackets of main lines  52  and branch line  50 , such as shown in  FIG. 12E . 
     Although the angles and/or orientation of main line input arm  60   b , main line output arm  60   c , and branch arm  60   d  are not considered a factor for the electrical function of junction  60 , the relative angles may be selected according to the general direction of an outlet receptacle at the end of each branch line  50 . In addition, the angle of branch arm  60   d  relative to main line input arm  60   b  and main line output arm  60   c  can provide a visual cue to an installer of the general direction of the flow of electrical current through the branched electrical system, so that the proper orientation of one branched electrical system relative to another can be readily ascertained without reference to power plug  56  and electrical receptacle  58 . Optionally, other types of junctions are envisioned, without departing from the spirit and scope of the present invention. For example, similar techniques as described above may be used to form a 90-degree branch junction  92  ( FIG. 13 ), a 45-degree branch junction  94  ( FIG. 14 ), a two-way 45-degree branch junction  96  ( FIG. 15 ), a two-way 90-degree branch junction  98  ( FIG. 16 ), or a six-way 90-degree branch junction  100  ( FIG. 17 ). 
     It will be appreciated that electrical outlets may be provided at distal end portions  50   a  of branches  50  using various different techniques. For example, a high voltage branched electrical system  102  initially has exposed branch line conductors  74  ( FIG. 18 ) that can be terminated with simplex receptacles  104  ( FIG. 20 ), such as via a process shown in  FIGS. 19A-19D . Each simplex receptacle  104  is formed by attaching respective terminals  106  on the ends of branch line conductors  74  and an optional fixture plate  108  is positioned in front of the hot and neutral terminals ( FIGS. 19A and 19B ). A rubber or rubber-like or resinous plastic housing  110  is then molded around terminals  106 , fixture plate  108 , and branch line conductors  74  to form a sealed and moisture-resistant body, such as shown in  FIGS. 19C and 19D . 
     Other types of electrical outlets may be provided at one or more distal end portions  50   a  of branches  50 . For example, a modular outlet assembly  112  can be fitted with a plurality of simplex receptacles  104 , with extra spaces  114  provided for other types of receptacles or jacks or outlets, such as low voltage outlet receptacles (similar to receptacles  68 ), data and/or voice jacks, or the like. Such outlet assemblies are more fully described, for example, in commonly-owned U.S. Pat. Nos. 8,444,432 and 8,480,429, both of which are incorporated herein by reference in their entireties. Other electrical outlets may include, for example, a high voltage AC grommet-style outlet  116  ( FIG. 22 ) configured for mounting in an opening formed or established in a work surface, a low voltage DC grommet-style outlet  118  ( FIG. 23 ) also configured for mounting in an opening that is formed or established in a work surface, and a high voltage AC power strip  120  ( FIG. 24 ). It is also envisioned that the high voltage and/or low voltage branched electrical systems may be configured for different installation locations, such as with reinforced or armored flex-conduit  122  used to protect main line  52  and branch lines  50  ( FIG. 7 ), or with modular power connectors  124   a ,  124   b  that may be used for routing power through modular work areas or the like, and optionally with abrasion-resistant cord cover material  126  or the like ( FIG. 8 ). 
     Accordingly, the branched electrical systems of the present invention provide multiple users with access to high and/or low voltage receptacles for charging portable electronic devices and/or supplying power to other high or low voltage power consumers, such as lamps, projectors, power tools, computers, headphones, and the like. The low voltage electrical system may be particularly well-suited to providing multiple users with access to electrical power in high density seating or work areas, such as stadium or theater seating, lecture halls, and public transportation vehicles. 
     Changes and modifications in the specifically-described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law including the doctrine of equivalents.