Abstract:
A plurality of lighting pendants and a distributor are arranged in a cluster and hung vertically. The distributor includes a plurality of sockets, one socket being connected to a hanger for receiving power and the remaining sockets being connected to the pendants to support the pendants and to provide power thereto. The pendants include parallel rods terminating in rod ends that slide into the respective sockets and then are attached to the distributor using set screws.

Description:
RELATED APPLICATIONS 
     This application is a divisional application to U.S. application Ser. No. 15/197,919 filed Jun. 30, 2016 which in turn claims priority to U.S. Provisional Application 62/275,921 filed Jan. 7, 2016, all incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     A. Field of Invention 
     This invention pertains to a modular system that can be assembled to form multi-level lights of various sizes, shapes and configurations and the components of this system. The main elements are canopies supporting the system, hangers, power bars, and pendants, preferably including light engines driving LED bulbs. More particularly, the present invention pertains to a support for a plurality of pendants arranged in a cluster that may be used in the modular lighting system. 
     B. Description of the Prior Art 
     Designing lighting for a space has always been an interesting challenge because the lighting equipment has to meet utilitarian, technical and esthetic needs. Thus, any such endeavor is successful only if combining technical, architectural and artistic skills. 
     Several different types of ceiling lights are presently available, including surface mounted lights, recessed lights and hanging lights disposed on tracks either attached to the ceiling or suspended below the ceiling. The first two light categories are very conventional and are disadvantageous because the positions of the lights are fixed and the configurations available for each light are very limited. Conventional track lighting provides a little more flexibility especially as far as the positions of the lights are concerned. However, because of power requirements and other factors, the number, size and shape of light fixtures that can be used in such systems is fairly limited. 
     In some instances it is advantageous to have a plurality of pendants grouped together for esthetic purposes and/or to provide more light for a particular space. However conventional track systems could accommodate such clusters only if they were factory assembled. It would be very helpful to have a support for a light cluster that could accommodate several pendants and that could be assembled in the field. 
     SUMMARY OF THE INVENTION 
     Briefly, a modular lighting system for providing light in a space includes canopies connectable to a power source; a plurality of horizontal bars; a plurality of hangers, including a first set of hangers supporting bars from said canopy and a second set of hangers, each said hangers including a first end disposed between and engaging said bar segment. The system further includes a plurality of pendants supported by the second set of hangers from the bars. The hangers and bars cooperate to provide electric power to said pendants from said canopy. 
     Preferably, each bar includes two bar segments facing each other and being made of a non-conductive material. Conductive rails are provided on the inner surface of each bar segment. The hangers include a base configured to form an interference fit with the bar segments. In one embodiment, the hangers are made of conductive rods or cables that are in electrical contact with the rails through the respective bases. 
     Preferably, at least one of the canopies is connected to a line voltage and transformer is used to step down the line voltage to a lower voltage such as 24 vac which is then distributed to the pendants through the hangers and bars. 
     The pendants include light emitting elements such as LEDs, electronic circuitry for driving the LEDs, and are preferably shaped for heat dissipation. Since the LEDs have a long life, they are not replaceable but instead the whole pendant is replaced as needed. 
     In one embodiment, a cluster of pendants is provided. Preferably, the cluster is hung from the bars described above. The cluster includes a plurality of pendants and a distributor. The pendants may be identical or may be different and all include a pendant body and a pair or rods extending in parallel away from the body and having free rod ends. The distributor is formed with a plurality of sockets. One socket is used to connect the distributor to a power supply such as a hanger connected to a power bar. The remaining sockets include holes for receiving the rod ends from the pendants. The sockets are used to engage and support the pendants as well as to provide power to the same. The rod ends are selectively inserted into the sockets and secured by set screws. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an isometric view a modular lighting system constructed in accordance with this invention with two parallel bars suspended from a single canopy; 
         FIG. 2  shows an isometric view of another embodiment with bars disposed at an angle with each other in a single tier and suspended from a single canopy; 
         FIG. 3  shows an isometric view of another embodiment of the invention in which six bars disposed at various tiers and angles are suspended from a single canopy; 
         FIG. 4  shows an isometric view of another embodiment of the invention in which several different bars are disposed at right angle and are supported by a canopy and other ceiling supports; 
         FIG. 5  shows an isometric view another embodiment of the invention in which two circular bars are disposed at different tiers and supported by a single canopy; 
         FIG. 6  shows another embodiment of the invention in which a single bar disposed at a right angle with respect to wall and supported by a wall-mounted canopy; 
         FIGS. 7A-7K  show an isometric and a cross-sectional view of a bar used in the embodiments of  FIGS. 1-6 ; 
         FIG. 7L  shows an isometric view of a connector used to connect three bars in the embodiments of  FIGS. 2 and 3 ; 
         FIGS. 8A-8E  show details of a canopy used in the embodiments of  FIGS. 1-6 ; 
         FIG. 9A-9J  show details of a bar hanger used for interconnecting two bars in the embodiments of  FIGS. 1-6 ; 
         FIG. 10  shows a front view of a hanger used for connecting a bar to a pendant or a canopy in the embodiments of  FIGS. 1-6 ; 
         FIG. 11  shows an isometric view of a hanger with a single rod for the embodiment of  FIG. 4 ; 
         FIGS. 12A-12C  show views of a non-conductive hanger with a single rod for the embodiment of  FIG. 4 ; 
         FIGS. 13A-13C  show a top, front and isometric view of a pendant cluster used in the embodiment of  FIG. 1 ; 
         FIGS. 14A-14P  show details of a bayonet-type hanger and a pendant that is mounted using a twisting of the hanger and is used in the embodiment of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention pertains to a modular lighting system having a plurality of interchangeable elements that can be combined in many different ways to obtain a large variety of configurations.  FIGS. 1-6  show four such systems identified respectively as  10 A,  10 B,  10 C,  10 D,  10 E and  10 F. Generally speaking, each system includes one or more canopies  100 , a plurality of hangers  200 , a plurality of power bars  300  and a plurality of pendants  400 . In addition, some systems may also include optional connectors  500 . Unless otherwise noted, all the hangers and all power bars consist of two elements that have dual functions, they support the pendants  400  and they provide power to the pendants, with one elements forming the positive or hot power connection and the other element defining the negative or ground power connection. 
     For example, system  10  in the  FIG. 1 , system  10 A includes a canopy  100  that supports the system from a ceiling or other similar architectural member in a conventional manner. In this case, the canopy also provides power to the system. Canopy  100  includes a conventional power supply connected to standard AC lines for providing power to the LED tubes in the pendants as discussed below. The power supply is hidden within the canopy. 
     Two hangers  202 ,  204  extend downwardly from the canopy. In one embodiment, each hanger discussed hereinafter consists of two solid bars or rods. These hangers are termed the power feed hangers. In an alternate embodiment the hangers are replaced by multi-strand twisted cables. As explained above, each hanger is formed of two elements (e.g., rods or cables). Preferably only two of the four elements (e.g., the rods of hanger  202 ) carry power and the other two elements are used for support. 
     The hangers  202 ,  204  are used to support a power bar  302 . Two hangers  206 ,  208  are used to support a second power bar  304  and are termed bar hangers. 
     Another set of hangers  210 - 218  are used to support a plurality of pendants  402 - 410 . These hangers are termed pendant hangers. The pendants  402 - 410  preferably include LED. 
     Included in canopy  100  is a transformer steps down the line voltage from a standard power line to 24 VAC for the pendants  402 - 410 . The other hanger  204  may be electrically floating. The power from the hanger  202  flows through the bar segments of bar  302 , hanger  206 , bar  304  and hangers  210 - 212  to the pendants. Thus, in this embodiment, only some of the pendants carry power but all the power bars do. 
       FIG. 2  shows a system  10 B in which three bars  306  are connected at a common connector  308  that keeps the bars at a specific angle with respect to each other to form a Y-shaped arrangement. This angle could be 120°, 45°, 135°, etc. and the bars may but need not be disposed at a constant angle between each other. Bars  306  are supported by respective hangers  202 ,  204 ,  206  from the canopy  102  as shown. The pendants and hangers supporting them have been omitted in this figure for the sake of simplicity. 
       FIG. 3  shows a system  100  with pendants arranged at several levels and extending in different directions from a central point below the canopy  102 . This is achieved by starting with a Y-shaped bar arrangement of  FIG. 2  formed again of three bars  306  supported by hangers  202 ,  204 ,  206  and joined by a connector  308 . However, in this case, each bar  306  is used to support another bar  310 , each bar  310  being supported by a pair of hangers  208 ,  210 . Hanging from each bar  310  are a plurality of pendants  410  supported by hangers  212 . All of pendants  410  supported by the same bar  310  can be disposed at different height, or different hangers may be disposed at different heights. 
       FIG. 4  shows yet another system  10 D. This system  10 D includes a canopy  104  with a transformer  106 . Attached to the canopy  104  is a first bar  302 A using two hangers  214 . As opposed to the hangers discussed previously, hangers  214  have a single extended element, such as bar, as described in more detail later. Each of the hangers  214  provides power to one of the elements of bar  302 A. However because the bar  302 A is not centered below the canopy  104  but extends in one direction away therefrom, another hanger  216 , which may be referred to as a ceiling hanger, is used to support a distal end  314  of bar  302 . At its top, hanger  216  is attached to a sleeve  106  secured to the ceiling in a conventional manner. 
     Hangers  218  are used to attach respective pendants  402  from bus  302 . Another hanger  220  is used to support a cluster of pendants  410 . 
     A second bar  304 A is also provided. This bar  304 A is supported at one end by a hanger  222  from bar  302 A. This hanger  222  also provides power to bar  304 A. A third bar  306  is also provided that is supported from the ceiling by ceiling hangers  216  (only one such ceiling hanger is being shown for the sake of clarity). Bar  306  supports the second end of bar  304 A and receives power from said bus  304  through hanger  224 . Each of the bars  302 A,  304 A,  306  can be used to hang pendants of various sizes and shapes and arranged in different configurations as desired. 
       FIG. 5  shows another system  10 E having a canopy  100 E supporting two ring-shaped, rather than rectilinear bars  330 ,  332  arranged at two levels and with various shapes and types of pendants  420  extending downwardly from the respective bars  330 ,  332 , each being supported and powered by a respective hanger  218 . Since the diameters of the ring-shaped bars  330 ,  332  are larger than the diameter of the canopy  100 E, rods or cables  221 . 
       FIG. 6  shows a wall-mounted system  10 F with a wall mounted canopy  112 . A horizontal bar  321  attached directly to and extending away from the canopy  112  provides power and supports a pendant  402  via a hanger  221 . Alternately, other horizontal bars may be supported from bar  321  for hanging various pendants (not shown). 
     Details of a generic bar  300  are shown in  FIGS. 7A-7K . Unless otherwise noted, all the bars discussed here have the same configuration. In these Figures, bar  300  is shown as being straight however, it can be circular ellipsoid or can have other geometric shape. The bar  300  includes two identical longitudinal segments  354 ,  356  facing each other and defining a space  352  therebetween with identical top and bottom openings  352 A,  352 B. A cross-sectional view of bar  300  is seen in  FIG. 7E . Segment  354  is formed of a C-shaped main body  355  made of a non-conductive material, such as a plastic material that is light weight but strong so that it can support various pendants, other bars, etc. Imbedded in this main body  355  is a rail  357  made of a light weight conductive material such as aluminum. Preferably rail  357  is formed with a rectangular channel  360 . Bar segment  356  has an identical rail  357 . The two segments  354 ,  356  are joined together at the two ends by end connectors  362 . The connectors  362  are attached to the bars by conventional means, such as screws  364 , by an adhesive or other means. 
     Preferably, the two segments  352 ,  354  have inner surfaces spaced at a nominal distance d throughout the length of the bar  300 . The bar  300  is made in standard lengths ranging from to 12 to 48 inches. For very long bars, for example in excess of 24 inches, a spacer  366  is placed between the segments. The spacer  366  may be held in place by screws or other means. 
       FIG. 7C  shows details of a connector  370  used to connect three bars, for example for the systems of  FIGS. 2 and 3 . The connector  370  is formed of three arms  372  disposed at an angle of 120 degrees. The inner surfaces of the arms  372  are provided with rails  374  having the size and shape to fit into the channels of the rails of bars  300 . Three bars having the same, or different length are attached telescopically to the connector  370 . 
     Details of a typical canopy  100  are shown in  FIGS. 8A-8C . Each canopy  100  includes a cup-shaped housing  120  that can be cylindrical, square, rectangular, etc. The housing  120  holds a transformer  122  receiving power from line wires  124  and outputting power at a lower voltage on output wires  126 . The output wires  126  are connected to a terminal strip  127  used to distributed the low ac voltage power through a plurality of lines  129 . As will be discussed in more detail below, preferably transformer  122  outputs power at about 24 vac. On its bottom surface  128 , the housing  120  is provided with a plurality of ferrules  130 . Depending on the exact required configuration, these ferrules  130  may be arranged single or in pairs, and a canopy may be provided with two four, six, eight ferrules, etc. Some of the ferrules provide power to the respective hangers or cables and also provide structural support. Other ferrules do not provide power but merely provide structural support. 
     As shown in  FIGS. 8C and 8E , each conducting ferrule  130  terminates in a threaded bolt  132 . An eyelet  134  is attached to each bolt  132  using a threaded nut  133  or other conventional means. Each eyelet is connected to one of the output wires  129 . 
     As seen in  FIGS. 8C, 8D and 8E , each ferule  130  further includes cylindrical sleeve  140  with a ferule body  147  attached to bolt  132  and extending through the housing  120  and below surface  128 . The sleeve  140  is electrically insulated from the housing  120  and receives the conductive end of a rod  142  forming a part of a hanger as described below or a cable. A set screw  144  is used to secure the rod  142  in the sleeve  140 . A washer  139  is disposed below nut  133  and is insulated from the housing  120  by an insulating disc  143 . A second insulating disc  145  is disposed above the ferule body  147  to insulate it from the housing  120  as well. The rod  142  is preferably covered with an insulator  149 . 
     The non-conductive ferrules have a similar configuration but are not connected to any output wires  126 . The ferrules receive rods similar to rod  142  but these latter rods do not provide power. 
     There are several different types of bar hangers are provided: hangers for supporting bars from canopies, hangers for supporting bars from ceilings (without a power connection), hangers for supporting one bar from another bar and hangers for supporting pendants. All these hangers have must be able to interface with a bar at least at one end as described below. 
     There are two types bar-to-bar hangers: parallel hangers for connecting two parallel bars and perpendicular hangers connecting two bars running perpendicular two each other. 
       FIGS. 9A-9G  show details of parallel bar hanger such as hanger  206  supporting bar  304  from bar  302  in  FIG. 1 . The hanger  206  includes two vertical segments  230 A,  230 B. At the top and the bottom, the two segments  230 A,  230 B have their ends imbedded in identical W-shaped bases or heads  232 , shown in more detail in  FIGS. 9B-9E . More particularly, each base or head  232  is formed with a horizontal wall  232 X, two vertical external walls  232 Y (each having an inner surface  232 XX) and an inner or central wall  232 C. Each base or head  232  forms two channels  234 ,  236  between inner surfaces  232 XX, horizontal wall  232 X and inner wall,  232 C with inner wall  232 C separating the two channels  234 ,  236  as clearly shown in  FIG. 9B . The base  232  is further formed with two metallic springs or clips  240 ,  242  disposed adjacent to the interior wall  238 . Clip  240  is electrically attached to segment  230 A within the base  232 , and clip  242  is connected to segment  230 B. Preferably, base  232  is made of a non-conductive material and is overmolded by horizontal wall  232 X and external walls  232 Y to cover portions of the clips  240 ,  242  and segments  230 A,  230 B. In one embodiment, the two bases  232  have a single, unitary structure. In another embodiment, at least the top base is made of two sections  232 A,  232 B that snap together along line  232 Z forming an interference fit therebetween. 
     As can be seen in  FIGS. 9F and 9G , the bases  232  as sized and shaped so that they fit over and engage the bars  302 ,  304 . Importantly, the clips  240 ,  242  are sized and shaped so that they engage the rails  354 ,  356 . The clips  240 ,  242  have a flat section  244  sized and shaped to snap into the channels  360  of the bar segments  354 ,  356 . In this manner not only do the clips  240 ,  242  provide a solid electrical contact with the rails  354 ,  356  but they also stabilize the hangers on the bars and insure that the lower bar  304  remains stiff and does move around in use. The clips may be made from beryllium copper. 
     Hanger  208  has a similar configuration however the clips need not be connected electrically to the hanger segments. In other cases, for example, in the configuration shown in  FIG. 4 , hangers  222  do provide electrical connection to bars  304 A and  306 . 
     The hanger segments  230 A,  230 B are provided in various lengths as required to obtain the various systems described above, and they are preferably made in the shape of rods of a stiff but somewhat springy material having shape memory such as a phosphor/bronze alloy. Preferably except where an electrical contact is required, the rods are covered or painted with with a thin electrically insulating material. 
     The hangers can be installed by separating the two segments  230 A,  230 B, passing the ends of the respective bars  302 ,  304  . . . between the segments, then lowering or raising the bars toward the respective bases  232  and then snapping the bases onto the bars into the configurations shown in  FIGS. 9F and 9G . 
     As discussed above, and illustrated in more detail below, in some instances, the power bars extend perpendicularly to each other. For example, in  FIG. 4 , bars  302  and  304  are perpendicular to each other. These bars are interconnected using a hanger  222  shown in  FIGS. 9H-9J . This hanger  222  has two segments  272 A,  272 B and a base  232  similar to the base  232  in  FIGS. 9A-9G . However, at the bottom hanger  222  is provided with a different base  274 . This base  274  is formed with two side wings  274 A,  274 B and a center wall  274 C. Clips  276 ,  278  are provided on the center wall  274 C and are connected electrically with segments  272 A,  272 B, respectively as show in  FIG. 9J . The center wall  274 C is made with two holes  280 A,  280 B with the lower ends of segments  272 A,  272 B extending into the holes and being secured to the base  222 . The base  270  is sized and shaped to engage and support the power bar segments  304 A,  304 B of a bar  304 A with the segments  272 A,  272 B providing power to these power bar segments. The base  232  engages the segments of the bar  302  in the manner discussed above. 
     In addition to the bar hangers, other types of hangers are used in the system as well.  FIG. 10  shows a side view of a hanger having a base  232  and two segments  252 A,  252 B. The difference between this hanger and the hanger in  FIG. 9A  is that the ends of segments  252 A,  252 B are straight bare ends of the conductive rods. This bare ends are then inserted into the ferrules  130  as shown in  FIG. 8D . (Of course, for this use, the hanger is turned upside down). Alternatively, the hanger is used to support a pendant cluster such as cluster  410  in  FIG. 4  or other pendants. 
       FIG. 11  shows a single rod hanger  214 . This hanger  214  includes a base  274 A similar to base  274  shown in  FIGS. 9H, 9J . The base  274 A has two clips  276 ,  278 . When the base  274  is mounted on a bar (such as bar  302 A), the clips  276 ,  278  engage the rail within the bar  302 A as discussed above. However only one of the clips (say clip  276 ) is connected to rod  272 C. The free end  272 D of the rod  272 C is attached to the ferrule of a canopy. Two such hangers  214  are used to support bar  302 A (as seen in  FIG. 4 ), with each of the hangers feeding power to one of the rails of the bar. 
       FIG. 12A-12C  show a nonconductive hanger  216  used for supporting a bar, such as bar  304 A in  FIG. 4  from a ceiling. This hanger  216  provides only support and therefore it can have an elongated member  272 D which may but need not be identical to the rod  272 C in  FIG. 11 . The member  272 D ends in a base  274 B that is similar to the base  274  but need not have any clips since there is no need to connect to the rails of the bus  304 A. Since there are no clips provided for the base  274 B, a cover  274 C is attached to the body  274 D of the base  274 B to insure that the bar does not slip out. The cover  274 C is attached to the body  274 D by screws  274 E or other conventional means. The other end of the elongated member  272 D is attached to a sleeve  277  via a set screw  277 A. Preferably, the ferrule  277  is similar to the ferrules of the canopy  100  in that it has a similar sleeve for capturing the end of the member  272 D. A small screw (not shown) is used as an attachment means. A large screw  279  or other conventional means may be used to attach the sleeve  277  directly to the ceiling or other architectural surface. Alternatively, the screw  279  is attached to a mounting post  281  and an anchor  283  ( FIG. 12C ). 
       FIGS. 13A-13C  show a top, plan and isometric view of pendant or lamp cluster  410 . The cluster  410  includes a distributor  430 , and three pairs of connectors  432  connecting the distributor  430  to three pendants  402 A,  402 B,  402 C. The pendants can have the same or different shapes. Importantly, the distributor has two-top holes or sockets  434 ,  436 . The ends  254 A,  254 B of the rods  252 A,  252 B shown in  FIG. 10  are inserted into the holes  434 ,  436  and then set screws on the sides of the distributor, such as at  438  are tightened thereby attaching and mechanically securing the pendant cluster  410  to the hanger  220  (see  FIG. 4 ). The hanger  220  and the cluster  410  can now be hanged from a bar  300 . 
     Other structures may be used for attaching pendants to the hangers. One such structure is shown in  FIGS. 14A-14O .  FIG. 14A  shows an orthogonal view of hanger  210  being inserted into pendant  402 . As shown in  FIGS. 14A, 14B   14 C and  14 D, the hanger  210  includes two vertical segments  602 A,  602 B joined by standard base  232 . The segment  602 A is terminated at the bottom with a connecting spade  604  that has a generally flat, rectangular cross section (as seen in  FIG. 14D ) of thickness t 1 . Spade  604  includes a narrow shank  606  having a height h 1  and a generally square tip having a width w 1 . Segment  602 B has the same shape as segment  602 A and the two spades  604  are normally aligned in parallel to each other and perpendicular to the plane formed by the two parallel segments  602 A,  602 B, as seen in  FIG. 14A . 
     Pendant  410  is formed with an upper and a lower section  610 ,  612  (see  FIG. 14L ). The upper section  610  contains a light engine (not shown) that is powered by the 24 vac source provided by the segments  602 A,  602 B and generates appropriate power to light generators (such as LEDs—not shown) disposed in the lower section  612 . The walls of the lower section are translucent or transparent to allow the light from the light sources to be projected outwardly and provide space illumination. Various pendants may have sections of different shapes and sizes. In one embodiment, the upper section  610  includes a cavity  620  with two holes  622 ,  624 . 
     The cavity  620  holds two contacts  630 ,  640  (see  FIGS. 14E, 14F ). Each contact is connected to the light engine (not shown). Contact  630  is formed with two facing blades having flat portions  632 ,  634 . The distance between the blade portions  632 ,  634  is t 2  which is preferably equal or slightly larger than t 1  but smaller than w. Contact  640  has two similar blades with flat portions  642 ,  644 . The blade portions  632 ,  634 ,  642 ,  644  have a height h 2  that is slightly smaller than height h 1 . 
     The pendant  410  is attached to the hanger  210  as follows. First, the hanger  210  is positioned on top of pendant  410  with the tips of spades  604  inserted into holes  622 ,  624  as seen in  FIG. 14A, 14G . In this orientation, the spades  604  come into contact with the top pf respective blades  630 ,  640 , as shown in  FIG. 14H  and stop because they can go no further. 
     Next, the pendant  610  and top of the hanger  210  is rotated in direction A by a quarter turn (90 degrees). This rotation causes the spades  604  to turn by the same angle so that they are now in parallel with the blade sections  632 ,  634 , or  642 , 644  respectively, as seen in  FIGS. 14I and 14J . At this point, the hanger  210  can be and is pushed further downward so that the spades  604  enter into cavity  620  between the blades. This motion downward can continue until the tips  608  pass the blade sections  632 ,  634 ,  642 ,  644  ( FIG. 14K ). 
     Now the hanger  210  is released and the spring action of the two segments  602 A,  602 B cause the top of the hanger  210  to rotate back in direction B ( FIG. 14L ) toward its natural or rest configuration. This action causes the spades  604  to rotate as well. As this action is completed, the tips  608  become trapped under the blade sections (see  FIGS. 14M-14O ). In this manner the hanger  210  and pendant  410  become interlocked. The hanger  210  and pendant  410  can be attached to any bus  300  as required. If necessary, the pendant  410  can be separated from the hanger  210  by twisting it by a quarter turn and reversing the sequence discussed above. 
     As discussed above, and illustrated in the drawings, the various components or elements described above can be combined into numerous different kinds of configurations. The figures show some systems that include several subsystems that are attached so that they can be extend in three dimensions, to create a linear or circular configurations, or combinations thereof. Moreover, while the systems discussed above are all suspended from a ceiling, other systems are shown and described (together with any special components, if any) that are attached to vertical walls—e.g. sconce-type systems. 
     Electrically, all these systems have one or more canopies, buses, and hangers that provide a power supply for the canopies. As discussed above, preferably power within the system is distributed at 24 vac to the individual pendants. Light engines within the pendants the use this source to generate light via LEDs or other similar efficient, long life light elements. The systems do not use any conventional bulbs that need replacement. It is presently estimated that the linear distance between a canopy and the furthest pendant can be up to about 30 feet. For larger systems, it is advisable to use two or more canopies. As indicated above, for two or more source-systems, the bars can be interconnected mechanically but isolated electrically as needed. As discussed above, in conjunction with  FIG. 3 , one bar of a system, for example bar  306  can have two sections  306 A,  306 B that are electrically insulated from each other with the rails of each section being fed and electrically connected to a different canopy  100 . 
     In this manner, the modular presented herein can be used to make systems having different configurations. Because the hangers can be attached easily in the field to the canopies, the bars and the pendants, each system can be assembled very quickly and efficiently using the various components described above. Moreover, many different kinds of pendants can be used with the system. As long as each pendant is capable of being connected to any of the hangers described above, it can be incorporated into a system without any changes to any of its other components. 
     Obviously numerous modifications may be made to the invention without departing from its scope as defined in the appended claims.