Abstract:
Disclosed is a position indicating device for a pull-out type circuit breaker used to cut off a current, the position indicating device including a position indicating plate installed at a lower surface of the circuit breaker to be rotatable up and down and having an arrow marked thereon, an indication supporter installed at a cradle and having stepped pressing surfaces for pressing up the position indicating plate, and a frame portion of a movable carriage, the frame portion having windows for externally showing a rotated state of the position indicating plate, whereby when the circuit breaker is docked with the cradle, the position to indicating plate is rotated by the indication supporter so as to indicate the position of the circuit breaker through the windows, thereby allowing a fast and precise recognition of the position of the circuit breaker.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    Pursuant to 35 U.S.C. §119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2008-0138669, filed on Dec. 31, 2008, the contents of which is incorporated by reference herein in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a position indicating device for a circuit breaker, and particularly, to a position indicating device for a circuit breaker capable of fast and precisely indicating a position of the circuit breaker moved is within a cradle in which the circuit breaker is accommodated. 
         [0004]    2. Background of the Invention 
         [0005]    In general, a circuit breaker for high voltage is categorized into a pull-out type and a stationary type. The stationary type circuit breaker merely has a breaker main body secured at a position within an electric power distributing board. The pull-out type circuit breaker includes a movable carriage for conveying a breaker main body to facilitate maintenance and repair of the circuit breaker, terminals electrically connected to a power source side and a load side of a circuit and an outer case, called a cradle, having terminals electrically connected to the breaker main body, structure of which allows push-in and pull-out of the breaker main body. 
         [0006]    Here, the pull-out type circuit breaker is employed in a distributing board, by which various electric devices, including the circuit breaker, all disposed therein, are managed so as to drive or control a power station, a substation and the like and to drive a motor. Also, the circuit breaker is accommodated in the cradle secured with the distributing board, and has a run position and a test position. At the run position, a power source side terminal and a load side terminal of the circuit breaker are connected to those of the cradle to thereby be connected to a power source and a load of a circuit so that the circuit breaker is operable, while at the test position, those terminals of the circuit breaker are separated from the terminals of the cradle so that a switching operation of the breaker main body is merely tested. 
         [0007]    In order for an operator to move the breaker main body to the test position with respect to the cradle, first, an interlock link provided at the breaker main body is held up and the breaker main body is pulled out. The interlock link is then inserted in a test position determining groove of an interlock plate provided at the cradle. At the position, the power source side terminal and the load side terminal of the breaker main body are separated from those of the cradle. Accordingly, control power is merely supplied to the breaker main body, thereby merely allowing the switching test of the circuit breaker main body. Here, the operator can identify the corresponding position of the breaker main body by viewing a word, which is written on an indication sticker for indicating a test position, the indication sticker located on an upper surface of the interlock plate of the cradle. 
         [0008]    Also, the operator may connect the terminals of the breaker main body to those of the crank so as to change the position of the circuit breaker from the test position to the run position at which the circuit is connected to the breaker main body. Here, the operator holds up the interlock link to separate the same from the test position determining groove and then pushes the breaker main body toward the cradle terminals, thereby moving the breaker main body. Afterwards, the interlock link is inserted into a run position determining groove of the cradle so that the breaker main body is located at the run position. After the breaker main body is moved to the run position, the operator can identify the corresponding position by viewing a word, which is written on an indication sticker for indicating the run position, the indication sticker also located on the upper surface of the interlock plate of the cradle. 
         [0009]    Here, the circuit breaker, as aforementioned, includes the circuit breaker main body and the movable carriage. The circuit breaker main body includes a plurality of terminals connectable to a power source side terminal and a load side terminal of the cradle, respectively, a main circuit portion provided with contacts prepared for each AC phase, a vacuum interrupter and the like for breaking a circuit between a power source and a load upon occurrence of a fault current on the circuit, and a switching mechanism for switching by closing or opening the main circuit portion. The movable carriage is employed to move the circuit breaker main body to the run position or the test position. 
         [0010]    In the configuration of the cradle and the circuit breaker according to the related art, the indication sticker for indicating a position (run or test position) of the breaker main body is attached onto the upper surface of the interlock plate, which is located at a bottom surface of the cradle and the operator identifies the position of the breaker main body by checking the indication sticker attached on the position after moving the breaker main body to the corresponding position. However, the position indication sticker is not easily viewed due to being obscured by the circuit breaker main body, which results in difficulty in the fast and precise recognition of the position of the circuit breaker main body. 
       SUMMARY OF THE INVENTION 
       [0011]    Therefore, in order to obviate the problem of the related art, an object of the present invention is to provide a position indicating device for a circuit breaker, by which a position of the circuit breaker can be identified fast and precisely. 
         [0012]    To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a position indicating device including a position indicating plate installed at a lower surface of the movable carriage to be rotatable up and down and having a portion for indicating a position of the breaker main body, an indication supporter installed at the cradle and having stepped pressing surfaces for contacting the position indicating plate, and a frame portion of the movable carriage, the frame portion having windows for externally showing the portion for indicating the position of the breaker main body in accordance to the rotation of the position indicating plate. 
         [0013]    The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
           [0015]    In the drawings: 
           [0016]      FIG. 1  is a perspective view showing a pull-out type circuit breaker having a circuit breaker main body having a position indicating device and a movable carriage in accordance with one embodiment of the present invention; 
           [0017]      FIG. 2  is a low perspective view showing a structure of a lower surface of the movable carriage of  FIG. 1  by turning over the movable carriage; 
           [0018]      FIG. 3  is a perspective view showing a position indicating plate and a bracket installed at a right lower portion of the movable carriage of  FIG. 2 ; 
           [0019]      FIG. 4  is a perspective view of a cradle connected to the pull-out type circuit breaker of  FIG. 1 ; and 
           [0020]      FIG. 5  is a perspective view showing an interrelation between the indicating plate of  FIG. 3  and an indicating supporter of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Description will now be given in detail of the present invention, with reference to the accompanying drawings. 
         [0022]    Hereinafter, the preferred embodiment of a position indicating device for a circuit breaker according to the present invention will be described with reference to the accompanying drawings. Throughout the description, thickness of each line, a size of each component shown in the drawings may be overdrawn for the brief description and convenience. Also, terms to be explained later may be defined in consideration of functions in the present invention, so the terms may differ depending on a user&#39;s intension or an operator&#39;s intension or according to custom. Therefore, such terms should be defined based upon the contents over the entire specification of the present invention. 
         [0023]    Also, the following embodiment may not limit the scope of the claims of the present invention but be merely illustrative for components disclosed in the to claims of the present invention. Also, the following embodiment may comply with a technical field over the entire specification of the present invention and other embodiments including equivalent components substitutable for the components of the claims can be embraced by the scope of the claims of the present invention. 
       Embodiment 
       [0024]    Description will be given with reference to  FIGS. 1 to 3 . As shown in  FIGS. 1 to 3 , a circuit breaker having a position indicating device in accordance with one embodiment of the present invention may include a breaker main body  100  having a switching mechanism for closing or opening an electrical circuit and contacts, the main body  100  being movable, a cradle  110  (see  FIG. 4 ) having terminals electrically connected to an electrical power source and an electrical load of an electric circuit and terminals electrically connected to the breaker main body  100 , and a movable carriage  170  for supporting the breaker main body  100  and conveying the breaker main body  100  to a run position at which the breaker main body  100  is electrically connected to the terminals of the cradle and a test position at which the breaker main body  100  is separated from the terminals of the cradle and is allowed to be tested. 
         [0025]    Referring to  FIG. 1 , the reference numerals  104 ,  105  and  106  designate terminals electrically connected to the terminals of the cradle  110  (see  FIG. 4 ). The reference numeral  171  designates a window disposed on a front plate of a frame of the movable carriage  170 . The reference numeral  101 , in  FIGS. 1 and 2 , designates a handle coupling member for coupling a manipulation handle when the breaker main body  100  is manually moved to the test position or to the run position. 
         [0026]    The reference numeral  107  in  FIG. 2  designates an interlock rod connected to an interlock lever (reference numeral not given). When being pulled (taken) down, the interlock rod is inserted in a test position determining groove  111   a  or a run position determining groove  111   b  both on an interlock plate  111  (see  FIG. 4 ). On the other hand, when being taken up, the interlock rod is separated from the test position determining groove  111   a  and the run position determining groove  111   b.    
         [0027]    A position indicating device for the circuit breaker according to the present invention may include a position indicating plate  120  installed at a lower surface of the movable carriage  170  to be rotatable up and down and having a portion on which a position of the breaker main body  100  is indicated (informed), an indication supporter  150  installed at the cradle  110  (see  FIG. 4 ) having stepped pressing surfaces for contacting the position indicating plate  120  by stages, and a frame portion of the movable carriage  170  having windows for externally showing the portion for indicating the position of the breaker main body  100  in accordance to the rotation of the position indicating plate  120 . 
         [0028]    As shown in  FIGS. 2 and 3 , the position indicating plate  120  may be installed at the lower surface of the movable carriage  170  to be rotatable up and down, and have a section (region) with an arrow for indicating the position of the breaker main body  100 . 
         [0029]    Still referring to  FIGS. 2 and 3 , the position indicating device according to the present invention may further include a pivot pin  130  and a return spring  131 . 
         [0030]    The pivot pin  130  may be disposed at the lower surface of the movable carriage  170  to support the position indicating plate  120  rotatable. The return spring  131  may be disposed at the lower surface of the movable carriage  170  to apply an elastic force to the position indicating plate  120  so as to be rotated, namely, biased in one direction (i.e., a clockwise direction in  FIG. 3 , i.e., a downward direction). 
         [0031]    Also, the position indicating device according to the present invention may further include a bracket  140  having supporting plate portions  141  for supporting both end portions of the pivot pin  130  at the lower surface of the movable carriage  170 . Here, the bracket  140  may further include a fixed plate  142  and a restricting plate  143 . 
         [0032]    The fixed plate  142  may be fixed to the lower surface of the movable carriage  170  and provided with the supporting plate portions  141  extending downwardly from both side surfaces thereof. The restricting plate  143  may face the fixed plate  142  and be disposed in parallel to the supporting plate portions  141 . Also, the restricting plate  143  may provide a space in which the position indicating plate  120  is rotatable, and cooperate with the fixed plate  142  to define a rotation range of the position indicating plate  120 . In other words, the position indicating plate  120  may be rotatably installed at the supporting plates  141  of the bracket  140  by the pivot pin  130  and rotated within the limited range between the fixed plate  142  and the restricting plate  143  facing each other with an inclination angle. Here, the return spring  131  may include an upper wire  132  supported by the fixed plate  142  and a lower wire  133  supported by the position indicating plate  120 . A connection portion between the upper wire  132  and the lower wire  133  may be wound on the pivot pin  130 . 
         [0033]    As shown in  FIGS. 4 and 5 , the indication supporter  150  may include a plurality of pressing surfaces (in other words contacting surfaces or guide surfaces)  161 ,  162  and  163 , which are stepped each other with different heights so as to contact the position indicating plate  120 . The indication supporter  150  may be installed at a bottom surface of the cradle  110 . 
         [0034]    Still referring to  FIGS. 4 and 5 , the indication supporter  150  may further include coupling plate portions  151  disposed at both sides in a proceeding direction of the movable carriage  170 , and a pressing plate portion  152  disposed between the both coupling plate portions  151  for contacting the position indicating plate  120  in stages. When the breaker main body  100  is connected to the cradle  110  (more precisely speaking, when terminals of the breaker main body  100  is connected to terminals of the cradle  110 ), the pressing plate portion  152  functions to press the position indicating plate  120  in stages so as to hold up or down the same. The arrow on the position indicating plate  120  is moved to upper and lower windows  171  of the movable carriage  170 . Position marking portions  172 , such as TEST and RUN, may be marked at sides of the windows  171 . 
         [0035]    Here, the pressing plate portion  152  may include a first guiding surface  161  coming in contact with the position indicating plate  120  to guide the position indicating plate  120  to indicate a test position, a second guiding surface  162  connected to the first guiding surface  161  and protruding higher than the first guiding surface  161 , and a third guiding surface  163  protruding higher than the second guide surface  162  in a connected state with the second guiding surface  162  and coming in contact with the position indicating plate  120  to guide the position indicating plate  120  to indicate a run position. 
         [0036]    Referring to  FIG. 5 , windows  171  for externally showing a rotated state of the position indicating plate  120  may be formed at a front surface of the frame portion of the movable carriage  170 . 
         [0037]    Hereinafter, description will be given of an operation of the position indicating device for the circuit breaker in accordance with the present invention having such configuration. 
         [0038]    As aforementioned, the breaker main body  100  for the circuit breaker according to the one embodiment of the present invention is configured to be movable to a run position at which terminals  104 ,  105  and  106  of the breaker main body  100  are connected to a power source side terminal and a load side terminal of the cradle  110  and to a test position at which the terminals  104 ,  105  and  106  of the breaker main body  100  are separated from the power source side terminal and the load side terminal of the cradle  110  so as to allow only testing of a switching operation of the breaker main body  110 . 
         [0039]    Hence, when the breaker main body  110  is moved to the run position and to the test position with being loaded on the movable carriage  170 , the run position and the test position of the breaker main body  110  can be automatically indicated by virtue of the indication supporter  150  provided at the cradle  110 , and the position indicating arrow of the position indicating plate  120 , which is mounted at the movable carriage  170  and viewed through the windows  171  of the movable carriage  170 . 
         [0040]    First, in order for an operator to move the breaker main body  100  from a run position to a test position with respect to the cradle  110 , the interlock lever provided at the breaker main body  100  is held up to separate the interlock rod  107  from the run position determining groove  111   b  of the interlock plate  111 , and the interlock rod  107  is then inserted into the test position determining groove  111   a  of the interlock plate  107  disposed at the cradle  110  by pulling out the breaker main body  100  by use of the manipulation handle. Here, the test position designates a position at which the terminals  104 ,  105  and  106  of the breaker main body  100  are separated from the corresponding power source side terminal and load side terminal of the cradle  110 . At the test position, only a switching operation test of the breaker main body  100  is executable in a state of control power being merely supplied. Consequently, the position indicating plate  120  installed at the lower surface of the movable carriage  170  is rotated down based upon the pivot pin  130 , by contacting the first guiding surface  161  of the indication supporter  150 . 
         [0041]    Here, the position indicating arrow of the position indicating plate  120  is appeared through the lower window  171  of the movable carriage  170 . That is, the arrow indicates TEST of the marking portions  172  marked at the sides of the windows  171 . Therefore, the operator can identify through the window  171  that the breaker main body  100  is located at the test position. 
         [0042]    Now, description will be given of an operation that the operator changes a position of the breaker main body  100  from the test position to the run position at which the terminals  104 ,  105  and  106  of the breaker main body  100  are connected to the power source side terminal and the load side terminal of the cradle  110  so as to be connected to an external circuit between a power source and a load. 
         [0043]    The operator holds up the interlock rod  107  to separate the interlock rod  107  from the test position determining groove  111   a . Then, if the operator pushes the breaker main body  110  toward the terminals of the cradle  110 , the breaker main body  100  is moved towards the terminals of the cradle  110  as wheels of the movable carriage  170  are rolled. Accordingly, the terminals  104 ,  105  and  106  of the breaker main body  100  are electrically and mechanically connected to the power source side terminal and the load side terminal of the cradle  110 , such that the breaker main body  100  is electrically connected to the external circuit between the power source and the load. Here, the interlock rod  107  is inserted into the run position determining groove  111   b  of the cradle  110 . 
         [0044]    Accordingly, the position indicating plate  120  attached onto the movable carriage  170  of the breaker main body  100  is rotated based upon the pivot pin  130  to be held up, by contacting the third guiding surface  163  via the second guiding surface  162  of the indication supporter  150 . Consequently, the position indicating arrow of the position indicating plate  120  is appeared through the upper window  171  so as to indicate the run position through the window  171 . That is, the operator can identify through the window  171  that the circuit breaker is located at the run position. 
         [0045]    As described above, the position indicating device for the circuit breaker according to the present invention is configured such that the indication supporter disposed at the cradle and having the first, second and third guiding surfaces and the arrow of the position indicating plate mounted at the movable carriage and rotated based upon the pivot pin disposed at the bracket are employed so as to indicate the test position and the run position through the windows of the frame portion. Therefore, the position of the circuit breaker can be automatically indicated in response to the movement of the breaker main body and accordingly the operator can identify the position of the circuit breaker fast and precisely. 
         [0046]    The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments. 
         [0047]    As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.