Abstract:
A ceiling system including a grid framework having a plurality of grid elements arranged in a substantially horizontal plane. A conductive material is embedded in one of the plurality of grid elements. The grid element in which the conductive material is embedded includes at least one slot such that portions of the conductive material are exposed. A tap is attached to the grid element so that it is in alignment with the slot, and, in turn, with the conductive material. The tap includes a housing, a conductor engaging means and a tap conductor. The conductor engaging means forms a connection with the conductive material embedded in the grid element and the tap conductor.

Description:
BACKGROUND 
   The invention relates to a suspended ceiling system, and, in particular, to a ceiling having conductive material embedded in the grid framework. By using electrical taps in combination with the conductive material, the ceiling system is able to distribute low voltage electricity above, below and within the plane of the grid framework. 
   A conventional ceiling grid framework includes main grid elements running the length of the ceiling with cross grid elements therebetween. The main and cross elements form the ceiling into a grid of polygonal shaped openings into which functional devices such as ceiling tiles, light fixtures, speakers and the like can be inserted and supported. The grid framework and ceiling tile system may provide a visual barrier between the living or working space and the infrastructure systems mounted overhead. 
   There is an increasing desire to have electrical functionality, such as power and signal transmission, in the ceiling environment. For several reasons, including aesthetic appeal, conventional techniques include mounting cable trays and electrical junction boxes in the plenum space above the ceiling grid framework. Such systems result in a complex network of wires which occupy the limited space above the ceiling grid, and, once installed, are difficult to service and reconfigure. Moreover, these techniques are limited in that the electricity they provide to the ceiling environment is not accessible from all directions relative the ceiling plane. In other words, electricity can be easily accessed from the plenum but not from areas within or below the plane of the grid framework. Thus, there is a need to provide electrical functionality to the ceiling which can be accessed from above, below and within the plane of the grid framework. 
   SUMMARY 
   The ceiling system of the invention includes a grid framework having a plurality of grid elements arranged in a substantially horizontal plane. A conductive material is embedded in at least one of the plurality of grid elements. The grid element in which the conductive material is embedded includes at least one slot such that portions of the conductive material are exposed. At least one tap is attached to the grid element so that it is in alignment with the slot, and, in turn, with the conductive material. Each tap includes a housing, a conductor engaging means and a tap conductor. The conductor engaging means forms a connection with the conductive material embedded in the grid element and the tap conductor. 
   The ceiling system provides several advantages which include, but are not limited to: a simplified manner in which electricity is accessed from all directions relative the plane of the grid framework; the preservation of the aesthetics of the ceiling due to the ability to distribute electricity using a standard grid profile; and the ability to replace or relocate devices without having to modify the grid. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a fragmentary perspective view from above of the ceiling system in accordance with an exemplary embodiment of the invention, and showing various optional features of the invention. 
       FIG. 2  is a perspective view of a grid element forming part of the ceiling system shown in  FIG. 1 , and showing various optional features of the invention. 
       FIG. 3  is a cross sectional view of a grid element in accordance with an exemplary embodiment of the invention. 
       FIG. 4  is a cross sectional view of a grid element in accordance with a second exemplary embodiment of the invention. 
       FIG. 5  is a cross sectional view of a grid element in accordance with a third exemplary embodiment of the invention. 
       FIG. 6   a  is a cross sectional view of a grid element having a track. 
       FIG. 6   b  is a cross sectional view of an alternative grid element having a track. 
   

   DETAILED DESCRIPTION 
   Reference is now made to the drawings wherein similar components bear the same reference numerals throughout the several views.  FIG. 1  illustrates a portion of the ceiling system, showing various optional features of the invention. A conventional suspended ceiling system includes a plurality of grid elements which form a conventional grid framework. Each grid element can be formed from a single piece of sheet metal, such as steel or aluminum, by conventional means such as folding and stamping. 
   In the example embodiment illustrated in  FIGS. 1-4 , each grid element  10  includes a vertical web portion  12  which is integral with a hollow bulb portion  30  at top edge  14  and with a flange portion  20  at bottom edge  15 . The flange portion  20  is formed on and centered along the bottom edge  15 . The flange portion  20  has a top surface  21  and a bottom surface  23 . 
   In the example embodiment shown in  FIGS. 2 and 3 , formed in each side of the vertical web portion  12  are upper and lower conductor access slots  22 ,  22 ′,  24 ,  24 ′. Upper conductor access slot  22 , which is formed in a first side  13  of the vertical web portion  12 , may be longitudinally aligned with, or longitudinally offset from, lower conductor access slot  24 .  FIG. 2  illustrates slots  22  and  24  as longitudinally offset. Similarly, upper conductor access slot  22 ′ may be aligned with, or longitudinally offset from, lower conductor access slot  24 ′. In either case, as shown in  FIG. 3 , the upper conductor access slots,  22  and  22 ′, are transversely aligned with one another on opposing sides of the vertical web portion  12 . Likewise, the lower conductor access slots,  24  and  24 ′, are transversely aligned with one another. 
   A conventional conductive strip  40  is embedded within the vertical web portion  12 . The conductive strip  40  includes an insulator  44  which encapsulates first and second conductors,  46  and  48  respectively, which can be formed from materials such as, but not limited to, copper, conductive plastic and conductive fiber. For polarity, one conductor is positive and the other is negative. The conductors  46 ,  48  are vertically spaced and extend in parallel relation to one another, such that the upper slots  22  and  22 ′ are transversely aligned with conductor  46  and lower slots  24  and  24 ′ are transversely aligned with conductor  48 . 
   Turning to  FIG. 3 , a tap  60  is attached to the web  12  and flange portion  20  of the grid element  10 . The tap includes a housing  62  which covers the vertical web portion  12  and flange portion  20  of the grid element  10 . Housing  62  is preferably shaped to closely conform to the grid element  10  to provide ease in crimping, as described below. The conforming shape of the housing  62  provides clearance for a ceiling panel  8 , which is manufactured for use in the ceiling system, to be installed without having to modify the size of the panel. 
   The tap  60  further includes a conductor engaging means  50 . In the configuration illustrated in  FIG. 3 , the conductor engaging means is a plurality crimp connectors. Each crimp connector  50  is at least partially embedded in the housing  62  and is positioned in the housing  62  such that when the housing is attached to the grid element, each crimp connector is in transverse alignment with a conductor access slot  22 ,  22 ′,  24 ,  24 ′ and, in turn, in transverse alignment with a respective flat wire conductor  46 ,  48 . Each conductor access slot  22 ,  22 ′,  24 ,  24 ′ allows for insertion of a crimp connector  50  into the vertical web portion  12 . Thus, when the tap housing  62  is crimped using a conventional crimping tool, the crimp connector  50  is able to pierce the insulation  44  of the conductive strip  40  and make electrical contact with either conductor  46  or  48 . Insulator  44  is formed from materials soft enough to be pieced easily by a crimp connector  50 . Example materials for insulator  44  include plastic, rubber and organic foam. 
   The tap  60  also includes tap conductors  64  and  65  which are preferably embedded in the tap housing  62 . Similar to conductors  46  and  48  of conductive strip  40 , for polarity, one tap conductor is positive and the other is negative. Each tap conductor  64 ,  65  is attached to a crimp connector  50  at one end and to a connecting stud  66  at the opposite end. Each connecting stud  66 , is partially embedded in the housing  62 , extends outwardly from the outer surface of the housing  62  and serves as a connector for electrically powered devices. Exemplary electrically powered devices include light fixtures, low voltage light fixtures, speakers, cameras, motors, motion sensors and smoke detectors. 
     FIGS. 2 and 5  illustrate an alternative example configuration in which the conductive strip  40  is embedded in the lower flange portion  20  of the grid element  10 . In this configuration, the conductor access slots  52  and  54  are formed in the lower flange portion  20  of the grid element  10 . More specifically, access slots  52  and  54  are formed in the upper surface  21  of the lower flange portion  20  on opposing sides of the vertical web portion  12 . Conductor access slots  52  and  54  may either be longitudinally aligned or longitudinally offset from one another. Optionally, conductor access slots (not shown) can be formed in the bottom surface  23  of the lower flange portion  20 , such that a conductor access slot is in transverse alignment with conductor access slot  52  and conductor access slot is in transverse alignment with conductor access slot  54 . 
   In this configuration, conductors  46  and  48  are spaced horizontally and extend in parallel relation to one another in the longitudinal direction of the grid element, such that access slot  52  is in transverse alignment with conductor  46  and access slots  54  is in transverse alignment with conductor  48 . In addition, the tap  60  is attached to the flange portion  20  of the grid element  10 . It should be noted that a tap  60  which covers the flange portion  20 , as well as, the vertical web portion  12  can also be used. In either case, each crimp connector  50  is positioned in housing  62  such that the crimp connector  50  is in transverse alignment with a respective conductor access slot  52 ,  54 , and, thus, in turn with a respective conductor  46 ,  48 . 
   A third example embodiment is shown in  FIGS. 2 and 4 . Embedded within the bulb portion  30  are first and second vertically spaced conductors,  76  and  78  respectively. Each of the vertically spaced conductors,  76 ,  78  is contained in an insulator  74 . Formed in hollow bulb portion  30  of grid element  10  are first and second conductor access slots,  72  and  73  respectively. The first and second conductor access slots  72 ,  73  are formed in opposite sides of the bulb portion  30  and are transversely offset from one another. Thus, the first conductor access slot  72  is aligned with conductor  76  and the second access slot  73  is aligned with conductor  78 . 
   Turning to  FIG. 4 , a tap  80  is attached to the bulb portion  30  of the grid element  10  and is shaped to closely conform to at least the bulb portion  30  of the grid element  10 . The tap  80  includes a housing  82  which may be constructed of multiple components or a single piece. In the example embodiment shown in  FIG. 4 , the tap housing  82  includes a first half body  85  and a second half body  87 . The housing  82  is formed from an insulating material such as plastic or rubber. Each half body  85 ,  87  is formed to cover at least one side of the bulb portion  30 . 
   Partially embedded in each of the first and second half bodies  85 ,  87  are U-shaped contacts  90  and  92  respectively. Each contact  90 ,  92  has the same components and will described herein with reference to contact  90 . Contact  90  has a lower arm  94  having a notch  96  adapted to engage the lower surface of conductor  78  and a pointed end  98  for piercing insulator  74 . Contact  90  also has an upper arm  95  having a notch  97  adapted to engage the upper surface of conductor  78  and a pointed end  99  for piercing insulator  74 . The lower arm  94  and upper arm  95  of the contact  90  are joined by base  100 . Base  100  is embedded in half body  85  and the lower and upper arms  94  and  95  extend through conductor access slot  73  in bulb portion  30 . Connected to base  100  of contact  90  is connecting stud  102  which extends outwardly from the outer surface of the half body  85  and serves as a connecting device for electrical appliances and the like. 
   The description of the example embodiments of the present invention is given above for the understanding of the present invention. It will be understood that the invention is not limited to the particular embodiments described herein, but is capable of various modifications, rearrangements and substitutions which will now become apparent to those skilled in the art without departing from the scope of the invention. 
   For example, for illustrative purposes, T-bar grid elements are shown throughout the drawings, however, it should be noted that grid elements of various configurations may also be used, such as those sold by Armstrong World Industries, Inc. More particularly, the lower flange portion  20  of the grid element  10  may form a track  120 , or bracket, as shown in  FIGS. 5A and 5B . Similarly, a cap in the form of a track may be mounted on the lower flange portion  20  of a grid element  10 . The entire track  120  length is available for insertion of functional devices from below the ceiling plane. The flat wire conductive strips  40  are housed in the track as shown in  FIGS. 5A and 5B . In order to access the flat wire conductive strips  40  from above the plane of the grid framework, apertures  122  can be formed in track  120 . 
   It is intended that the following claims cover all such modifications and changes as fall within the true spirit and scope of the invention.