Abstract:
In a preferred embodiment, an integrated DC shunt and contactor, including; a contactor ( 30 ); a shunt assembly ( 52 ): and the shunt assembly being connected directly to the contactor without any intervening electrically conductive materials disposed therebetween.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    Benefit is claimed of the filing date of U.S. Provisional Application Serial No. 60/295,266, filed Jun. 1, 2001, and titled INTEGRATED DC SHUNT AND CONTACTOR. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to power distribution units generally and, more particularly, but not by way of limitation, to a novel integrated DC shunt and contactor useful for power distribution units.  
           [0004]    2. Background Art  
           [0005]    Power distribution units (PDUs) typically employ various rectifiers, ammeters, shunts, contactors, buses, and the like. In known power distribution units, shunts and contactors are separate, discrete elements that require interconnecting wiring. This somewhat complicates installation in that the shunts and contactors require interconnecting wiring.  
           [0006]    As is well known in the art, in PDUs, generally the DC contactor resides next to the rectifiers as disconnect between the system load and the battery pack. It allows a small charge current to flow from the rectifiers to the batteries during normal operation of the rectifiers. It also disconnects the battery from the load when the batteries drop below a certain voltage, hence protecting the battery from failure. The DC shunt is used with the controller in the system, the purpose of which controller is to measure the current during both the charging and the discharging phases.  
           [0007]    Accordingly, it is a principal object of the present invention to provide an integrated DC shunt and contactor that does not require interconnecting wiring or bus bars between the contactor and the shunt.  
           [0008]    It is a further object of the invention to provide such an integrated DC shunt and contactor that is simply constructed.  
           [0009]    Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention achieves the above objects, among others, by providing, in a preferred embodiment, an integrated DC shunt and contactor, comprising; a contactor; a shunt assembly: and said shunt assembly being connected directly to said contactor without any intervening electrically conductive materials disposed therebetween.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0011]    Understanding of the present invention and the various aspects thereof will be facilitated by reference to the accompanying drawing figures, provided for purposes of illustration only and not intended to define the scope of the invention, on which:  
         [0012]    [0012]FIG. 1 is an isometric view of one embodiment of the present invention.  
         [0013]    [0013]FIG. 2 is an isometric view of another embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    Reference should now be made to the drawing figures on which similar or identical elements are given consistent identifying numerals throughout the various figures thereof, and on which parenthetical references to figure numbers direct the reader to the view(s) on which the element(s) being described is (are) best seen, although the element(s) may be seen on other figures also.  
         [0015]    [0015]FIG. 1 illustrates one embodiment of an integrated DC shunt and contactor, the device being generally indicated by the reference numeral  20 . Device  20  includes a standard contactor  30  which may be a Model SW180-507L w/200A-30 mV.tif, as furnished by Curtis Instruments, Inc., of Mt. Kisco, N.Y. Device  20  includes first and second load studs  40  and  42 .  
         [0016]    Removably attached to second load stud  42  by suitable means is a first end  50  of a shunt assembly  52 , the shunt assembly having a second end  54  with a threaded opening defined therein for the connection thereto of electrical apparatus (not shown), and with the shunt itself  56  disposed between the first and second ends. Connections  60  and  62  are provided, respectively, on first and second ends  50  and  54  of shunt assembly  52  for connection to an ammeter (not shown) of the power distribution unit (PDU). It will be understood that shunt assembly is a “bolt-on” unit that can be installed on a standard contactor  30  during manufacturing or in the field.  
         [0017]    [0017]FIG. 2 illustrates another embodiment of the present invention, the elements of this device,  20 ′, having similar structure or function to elements of device  20  (FIG. 1) being given primed reference numerals. Device  20 ′ may be a Model SW600-6 w/600A-30 mV.tif, as furnished by Curtis Instruments, Inc., of Mt. Kisco, N.Y. Device  20 ′ is similar to device  20  except that first and second load studs  40  and  42  have been replaced with first and second bus mounting bars  40 ′ and  42 ′. Shunt  56 ′, in this case, is disposed between second bus mounting bar  42 ′ and second end  54 ′ which has a pair of threaded openings defined therethrough for the attachment of electrical apparatus (not shown). Connections  60 ′ and  62 ′ are provided for connection to an ammeter (not shown). It will be understood that device  20 ′ can be easily manufactured.  
         [0018]    The advantages of the present invention over the convention arrangement are:  
         [0019]    It provides a substantial reduction in wiring.  
         [0020]    It is easier to install, eliminating installation steps.  
         [0021]    It saves space by providing a single component configuration which reduces overall footprint, maximizes optimum space, and installation efficiency.  
         [0022]    These advantages accrue, in part, because the invention eliminates the testing at connection points. Also, at each connection point, there is some resistance that contributes to heat buildup in the power distribution cabinet.  
         [0023]    In the embodiments of the present invention described above, it will be recognized that individual elements and/or features thereof are not necessarily limited to a particular embodiment but, where applicable, are interchangeable and can be used in any selected embodiment even though such may not be specifically shown.  
         [0024]    Terms such as “upper”, “lower”, “inner”, “outer”, “inwardly”, “outwardly”, “vertical”, “horizontal”, and the like, when used herein, refer to the positions of the respective elements shown on the accompanying drawing figures and the present invention is not necessarily limited to such positions.  
         [0025]    It will thus be seen that the objects set forth above, among those elucidated in, or made apparent from, the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown on the accompanying drawing figures shall be interpreted as illustrative only and not in a limiting sense.  
         [0026]    It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.