Patent Publication Number: US-9425567-B2

Title: Assembly for conducting electrical power to or from electrically active ceiling grid

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority of U.S. provisional patent application Ser. No. 61/973,459, filed Apr. 1, 2014, the entire contents of which are hereby incorporated herein by reference thereto. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to an assembly for conducting electrical power to or from an electrically active ceiling grid, and, more particularly, to distributing low voltage direct current (DC) via one or more industry standard, electrical connectors or interfaces. 
     BACKGROUND 
     The electrical grid connecting America&#39;s power plants, transmission lines and substations to homes, businesses and factories operate almost entirely within the realm of high voltage alternating current (AC). Yet, an increasing fraction of electrical devices found in those buildings actually operate on low voltage direct current (DC). Those devices include, but are not limited to, digital displays, remote controls, touch-sensitive controls, transmitters, receivers, timers, light emitting diodes (LEDs), audio amplifiers, microprocessors, other digital electronics, and virtually all products utilizing rechargeable or disposable batteries, such as smartphones, tablets, laptop computers, etc. 
     Installation of devices utilizing low DC voltage has been typically limited to locations in which a pair of wires is routed from a DC voltage source. Increased versatility in placement and powering of low DC voltage devices is desirable. Specifically, there is an increasing desire to have electrical functionality, such as DC power, in the interior building environment, and specifically in the ceiling environment, without the drawbacks of existing systems. 
     A conventional ceiling grid framework, such as one used in a surface covering system, includes main grid elements intersected by cross grid elements therebetween. The main and cross elements form a mutually orthogonal grid of polygonal openings into which devices or components, such as panels, light fixtures, speakers, motion detectors and the like can be inserted and supported. Known systems that provide electrification to devices, such as lighting components, in conventional framework systems utilize a means of routing discrete wires or cables, principally on an “as needed” point-to-point basis via conduits, cable trays and electrical junctions located in the space behind the ceiling grid framework. These known systems suffer from the drawback that the required network of wires occupy the limited space behind the ceiling grid framework and are difficult to service or reconfigure. Further, the electrical power levels that are typically available are not safe to work with for those not trained, licensed and/or certified. 
     It is known from U.S. Pat. No. 7,997,910 to provide an electrified ceiling grid framework system connected to a low DC voltage source. Each grid element in the system supports along its length a pair of electrical conductors or busses having opposing polarity and disposed on opposing surfaces of each grid element. An electrical grid connector or power tap is mounted on one or more of the grid elements and is electrically connected to the pair of conductors. A pair of wires extends from the grid connector to a remote electrical device for supplying low DC voltage directly to the device. 
     As advantageous as the known electrified ceiling grid framework systems have been, the techniques currently used are somewhat constrained in that the direct connection from the wires to the remote electrical device dictated the length of the wires. The wire length was thus customized for each device. If it was desired to connect to another device at a different location, then the wire length had to be changed. If a longer length was needed, then another set of wires had to be provided and hard-wired into the grid connector. In addition, the wires in the known systems were not reasonably accessible from all directions relative to the framework plane. 
     Accordingly, it would be desirable to enable the connection between the wires and the remote device to be more versatile, and to be more accessible. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments. 
         FIG. 1  is a partially broken-away, perspective view of a grid element of an electrified ceiling grid framework system, assembled with a grid connector thereon, in accordance with the prior art. 
         FIG. 2  is an exploded perspective view of the assembly of  FIG. 1 , together with an added adapter in accordance with this disclosure. 
         FIG. 3  is an enlarged, front perspective view of the adapter of  FIG. 2  mounted on the grid connector of  FIG. 2 . 
         FIG. 4  is a view analogous to  FIG. 3 , but of a different embodiment. 
     
    
    
     Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. 
     The assembly components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. 
     DETAILED DESCRIPTION 
     In accordance with one feature of this invention, an assembly distributes electrical power between an electrically active grid element of a grid framework and an electrical device. The assembly comprises a grid connector for making electrical contact with a pair of electrical conductors on the grid element, and an adapter mounted on the grid connector. The adapter includes an industry standard interface electrically connected to the grid connector. The interface is adapted to receive a power connector at one end of a power cable whose opposite end is connected to the electrical device. If the electrical device is a DC power supply, then the assembly supplies DC voltage to the grid element. If the electrical device consumes DC power, then the assembly supplies DC voltage to the electrical device. One suitable interface is the Universal Serial Bus (USB) protocol, Versions 1.0, 2.0, or 3.0. Types of USB interfaces or connectors include: Standard-A plug/receptacle, Standard-B plug/receptacle, Micro-A or -B plug/receptacle, and Mini-A or -B plug/receptacle. 
     Turning now to the drawings, reference numeral  109  generally identifies a representative grid element of an electrified grid framework that supports a suspended ceiling. Any system having a framework of mutually orthogonal grid elements can utilize the technology of the invention. The framework may support decorative tiles, acoustical tiles, insulative tiles, other ceiling elements, covers, or combinations thereof, or any electrical device that consumes electricity, such as lights, heating ventilation and air conditioning (HVAC) vents, or any electrical device that supplies electricity, such as a power supply. A pair of conductors or busses, such as flattened strips  108  and  108 ′ of positive and negative DC voltage polarity, are disposed on the grid element  109 , and specifically, on a top portion  112  thereof. A voltage power supply (not illustrated) is connected to the strips  108  and  108 ′ to render them electrically active with any desired voltage. 
     An electrical grid connector  120  provides a means for bringing DC power to the strips  108  and  108 ′ from the power supply, or from the strips  108  and  108 ′ to various low DC voltage electrically consuming devices. Those devices include, but are not limited to, digital displays, remote controls, touch-sensitive controls, transmitters, receivers, timers, light emitting diodes (LEDs), audio amplifiers, microprocessors, other digital electronics, and virtually all products utilizing rechargeable or disposable batteries, such as smartphones, tablets, laptop computers, etc. Low voltage devices, such as light emitting diode (LED) lights, speakers, smoke or carbon monoxide detectors, wireless access points, still or video cameras, or other low voltage devices, may also be powered by, and mounted on, the electrified grid framework. 
     As best seen in  FIG. 2 , the grid connector  120  includes two conductive wire crimp contacts  122  and  122 ′, a non-conductive insulative housing  124 , and an outer clamp  126 . Each conductive wire crimp contact  122  and  122 ′ includes first and second contacting portions. The first contacting portion  128  of each wire crimp contact  122  and  122 ′ includes a contact spring  130  which is resilient and, upon installation, is brought into contact with, i.e., taps, the strips  108  and  108 ′ disposed on the grid element  109 . The second contacting portion  132  of each crimp contact  122  and  122 ′ is also in contact with the strips  108  and  108 ′. The second contacting portion of each crimp contact  122  and  122 ′ is a receptacle  132 , which is attachable to wires  134  that transport the low DC voltage either to, or away from, the grid connector  120 . 
     The insulative housing  124  is flexible and U-shaped, and is mounted to the grid element  109  over the top portion  112 . The housing  124  accepts, i.e., houses, the wire crimp contacts  122  and  122 ′ and aligns the contacts into the proper position so as to mate each with strips  108  and  108 ′. When the grid connector  120  is mounted onto the grid element  109 , each of the first contacting portions of the wire crimp contacts is aligned with the strips  108  and  108 ′. As the wire crimp contacts are mounted to an interior wall of the insulative housing  124 , the insulative housing essentially provides isolation of the wire crimp contacts from one another, which, in turn, prevents the wire crimp contacts from shorting with each other. 
     The outer clamp  126  is made of rigid, yet somewhat compliant material, and snaps over the insulative housing  124 . Although the clamp  126  can be installed, or even pre-assembled, on the housing  124  prior to attaching the grid connector  120  to the grid element  109 , the clamp  126  can be installed in at least two other ways to minimize insertion forces. First, the clamp  126  can be installed after fully seating the housing  124  on the grid element  109  to provide for low insertion forces. Alternatively, the clamp  126  can be partially installed on the housing  124  in an up position and then fully seated after the housing  124  is in the fully mated position, which also provides low insertion forces, but requires the clamp  126  to be pre-assembled on the housing  124 . 
     This firm, yet compliant, clamp  126  provides strength to this otherwise flexible U-shaped housing  124  to assure a tight and electrically sound electromechanical connection to the strips  108 ,  108 ′. The clamp  126  also assists in assuring that the connection is sufficiently strong to prevent it from being dislodged from the grid element  109  upon entry and/or removal of devices, such as ceiling tiles or electrical devices. In addition, an optional sloping surface of the top portion of the clamp  126  provides ease of entry for devices such as ceiling tiles when the connector  120  interferes with the insertion of the device into the openings formed by the grid framework. Similarly, the bottom, or perch, end of the housing  124  has a sloping surface to assist in removal of devices without causing accidental dislodging of the connector  120 . 
     As described above, in the prior art, the direct connection from the wires  134  to the remote electrical device dictated the length of the wires  134 . The wire length was thus customized for each device. If it was desired to connect to another device at a different location, then the wire length had to be changed. If a longer length was needed, then another set of wires had to be provided and hard-wired into the connector. In addition, the wires  134  in the known systems were not reasonably accessible from all directions relative to the framework plane. 
     Hence, in accordance with this disclosure, an adapter is mounted on the grid connector  120 . The adapter includes a support plate  140  that is fixed to the clamp  126 , and at least one industry standard interface or bidirectional connector mounted on the plate  140  and electrically connected to the grid connector  120  via the wires  134 . As illustrated in  FIGS. 2-4 , the industry standard interface is preferably the Universal Serial Bus (USB) protocol, Versions 1.0, 2.0, or 3.0. Types of USB interfaces or connectors include: Standard-A plug/receptacle, Standard-B plug/receptacle, Micro-A or -B plug/receptacle, and Mini-A or -B plug/receptacle. A USB 2.0 Standard-A type of USB receptacle  142  is illustrated and has a generally rectangular socket. This receptacle  142  is frequently seen on a computer to which computer peripherals, such as a keyboard, a mouse, or a flash drive, are connected by a USB plug, such as plug  146 , at the end of a power cable  148  in  FIG. 2 . The USB receptacle has multiple pins, two of which, typically pins  1  and  4 , are the power pins that are connected to the wires  134 . 
     Another receptacle  144  is optionally mounted on the plate  140  and illustrates a generic, industry standard, bidirectional connector. In  FIG. 4 , the plate  140  is non-planar so that the receptacles  142 ,  144  are located on a bent portion  150  and face upwardly, in contrast to  FIG. 3  where the receptacles  142 ,  144  face off to the side. The bent portion  150  can also be hinged to the plate  140  for even greater versatility in orienting the receptacles. 
     Once the adapter and the grid connector  120  are mounted on a grid element  109 , the USB plug  146  of the power cable  148  may be readily inserted into the receptacle  142 . If the opposite end of the power cable  148  is connected to a DC power supply, then the assembly supplies DC voltage at any desired value to the grid element  109 . If the opposite end of the power cable  148  is connected to an electrical device that consumes DC power, then the assembly supplies DC voltage to the electrical device. Power cables of different lengths may be provided to simplify the connections. In addition, the different orientations of the receptacles  142 ,  144  in  FIGS. 3-4  renders them reasonably accessible from all directions relative to the framework plane. 
     The support plate  140  may also conveniently support one or more circuit boards and/or one or more electrical components, such as a voltage regulator  152  (see  FIG. 2 ) to insure that the low voltage does not exceed certain limits. For example, it is preferred that the low DC voltage not exceed 24 VDC at 100 watts, and the regulator configured, for example, by a zener diode and a resistor, can insure that such a limit will not be exceeded. The voltage regulator  152  may also include a current limiter for limiting the electrical current to any desired value. 
     In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings. 
     The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued. 
     Moreover in this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has,” “having,” “includes,” “including,” “contains,” “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, or contains a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a,” “has . . . a,” “includes . . . a,” or “contains . . . a,” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, or contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially,” “essentially,” “approximately,” “about,” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1%, and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed. 
     The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.