Abstract:
Disclosed is a transfer device for an automatic transfer switch. With the configuration of the transfer device, the transfer device, which is installed between a plurality of air circuit breakers to allow switching of a closed state and a tripped state of the plurality of air circuit breakers, can be modularized so as to be easily assembled. A length of a transmission rod can be adjusted so as to facilitate assembly and maintenance of the transfer device and also minimize the probability of occurring an assembly error, allowing accurate closing and trip operations. The transmission rod may be provided with a buffer to reduce impact noise generated upon switching of the closing and trip operations of each air circuit breaker and enhance reliability of the device. Also, the transmission rod can be formed with a preset thickness without being curved (bent), thereby avoiding the transmission rod from being curved (bent), resulting in preventing a mis-operation from occurring during the closing and trip operations.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     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. 10-2009-0075299, filed on Aug. 14, 2009, the contents of which is incorporated by reference herein in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a transfer device for an automatic transfer switch, and particularly, to a transfer device for an automatic transfer switch, by which various electric components are allowed to be continuously supplied with stable power in a manner of blocking one air circuit breaker from being mechanically electrically closed when another air circuit breaker is closed due to a switching of states between the two air circuit breakers. 
     2. Background of the Invention 
     In general, hospitals or telephone offices, in which power failure should not happen, use an automatic transfer switch (hereinafter, referred to as ATS) in order to ensure stable power supply. The ATS includes therein a regular air circuit breaker (hereinafter, referred to as a first ACB) and an emergency air circuit breaker (hereinafter, referred to as a second ACB). The first and second ACBs are mechanically connected to each other to be switched to each other. Accordingly, when a fault current is applied to one of the two ACBs, such fault current is detected. Consequently, a closed ACB is tripped and simultaneously another ACB is closed so as to be switched to each other. The switching of the ACBs allows a constant supply of stable power. 
     Upon allowing the switching of the two ACBs for use, the two ACBs are typically connected to each other via a wire or a thin iron bar for allowing an interlocking of the ACBs. 
       FIGS. 1 and 2  are perspective views showing an example of a related art device for interlocking two ACBs using a thin iron bar. Referring to  FIGS. 1 and 2 , the related art ATS includes frames  11  and  21  installed at the ACBs  1  and  2 , respectively, closing links  12  and  22  rotatably coupled to the frames  11  and  21 , respectively, to be rotatable by respective closing levers (not shown) installed within each ACB  1  and  2 , trip links  13  and  23  rotatably installed in the frames  11  and  21 , respectively, at one sides of the corresponding closing links  12  and  22  so as to cooperate with respective trip levers (not shown) installed in each ACB  1  and  2 , and transmission rods  14  and  24  connected between the closing links  12  and  22  and the trip links  13  and  23  so as to transfer a rotational force. Here, the closing links  12  and  22  and the trip links  13  and  23  are installed independent of each other, and each of the transmission rods  14  and  24  is made of an integrally rigid material. 
     With the configuration of the related art ATS, when the first ACB  1  is closed, the first closing link  12  is rotated counterclockwise in the drawing due to the first closing lever installed in the first ACB  1 . Responsive to this, the first transmission rod  14  is pulled upwardly such that the second trip link  23  of the second ACB  2  installed at a lower side in the drawing is moved upwardly. Here, an interlock lever is also moved upwardly by the second trip link  23 , accordingly, the second trip lever installed in the second ACB  2  is pushed up such that the second ACB  2  is switched (transferred) to a tripped state. 
     When the first closing link  12  is restored by a restoring spring (not shown), the pulled first transmission rod  14  is moved back to its original position and the second trip link  23  is also moved back to its original position, thereby releasing the tripped state of the second ACB  2 . 
     In the meantime, a procedure that the second ACB  2  is switched to a closed state and the first ACB  1  to a tripped state is performed in an opposite manner to the aforesaid procedure. 
     However, in the structure of the ATS of the related art, since the closing links  12  and  22  and the trip links  13  and  23  are independently installed, a problem is caused that a process of assembling the closing links  12  and  22  and the trip links  13  and  23  becomes complicated. 
     Also, a length of each transmission rod  14 ,  24  should be adjusted by cutting off the transmission rod  14 ,  24 , which makes it difficult to fabricate the transmission rods  14  and  24  with exactly the same length between the closing links  12  and  22  and the trip links  13  and  23 , and also makes it difficult to adjust an error occurred during the assembly operation, which may cause a mis-operation to occur due to a defective assembly. 
     Furthermore, while each of the ACBs  1  and  2  is repeatedly closed and tripped, upon rotation of the closing links  12  and  22  and the trip links  13  and  23 , an impact transferred to each transmission rod  14 ,  24  cannot be absorbed, thereby generating impact noise or degrading durability. 
     In addition, each transmission rod  14 ,  24  is formed of a thin rod, so it has a low intensity. Also, since each of the transmission rods  14 ,  24  has a structurally bent portion, it may have high possibility of being curved during operation, which may cause a mis-operation. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present disclosure is to provide a transfer device for an automatic transfer switch capable of reducing the number of assembly processes by modularizing a closing link and a trip link of each ACB. 
     Another object of the present disclosure is to provide a transfer device for an automatic transfer switch capable of avoiding beforehand a mis-operation by facilitating adjustment of a length of a transmission rod between the closing link and the trip link. 
     Another object of the present disclosure is to provide a transfer device for an automatic transfer switch capable of reducing noise and increasing durability by allowing an impact generated upon repetition of closing and tripling of each ACB to be absorbed at the transmission rod. 
     Another object of the present disclosure is to provide a transfer device for an automatic transfer switch, capable of avoiding in advance (minimizing) a mis-operation caused due to a transmission rod being curved or the like upon a switching operation, in a manner of increasing an intensity of the transmission rod. 
     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 transfer device for an automatic transfer switch including closing links and trip links disposed to be rotatable in cooperation with a closing operation and a trip operation of a plurality of air circuit breakers, respectively, and transmission rods each having both ends coupled to the corresponding closing link and trip link to allow cooperation of the closing operation and the trip operation of the plurality of air circuit breakers, wherein each of the transmission rods comprises a length-adjusting unit configured to allow adjustment of the length of the transmission rod in a state that both ends thereof are coupled the corresponding closing link and trip link. 
     Each of the transmission rods may be configured by a plurality of links provided in pair, one ends of the links provided in pair may be coupled to the closing links and the trip links, respectively, and another ends thereof may be screw-coupled to each other so as to adjust lengths of the transmission rods. 
     Each of the transmission rods may be provided with a closing side transmission link and a trip side transmission link, and a nut-type length-adjusting unit may be provided between the closing side transmission link and the trip side is transmission link so as to couple the same in a manner of coupling with a nut. 
     Each of the transmission rods may include a buffer configured to absorb an impact generated when a position of the transmission rod is changed in response to operations of the closing link and the trip link. 
     Each of the plurality of air circuit breakers may include a frame base, and a frame cover may be coupled to one side surface of each frame base with a preset interval, the closing link and the trip link being rotatably coupled between the frame base and the frame cover. 
     The closing link may be rotatably coupled to one side surface of each frame base, a link configuring the transmission rod may be rotatably coupled to one side of the closing link, and a closing lever for selectively rotating the closing link may be slidably coupled to another side of the closing link. 
     The trip link may be rotatably coupled to one side surface of each frame base, a trip lever for operating an interlock lever for maintaining and releasing a tripped state of each air circuit breaker may be rotatably coupled to another side surface of the frame base, and the trip link and the trip lever may be coupled to each other with interposing the frame base therebetween so as to cooperate with each other. 
     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 
       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. 
       In the drawings: 
         FIG. 1  is a perspective view of an automatic transfer switch according to the related art; 
         FIG. 2  is a perspective view showing a transfer device of  FIG. 1 ; 
         FIG. 3  is a front view showing an automatic transfer switch in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 4  is a perspective view of a transfer device disassembled from the automatic transfer switch of  FIG. 3 ; 
         FIG. 5  is a front view showing a partially assembled state of the transfer device of  FIG. 3 ; 
         FIGS. 6 and 7  are an overview and a perspective view, respectively, showing a coupled state between a link and a lever of the transfer device of  FIG. 5 ; and 
         FIG. 8  is a front view showing an operation of the transfer device of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Description will now be given in detail of a transfer device for an automatic transfer switch according to the exemplary embodiment, with reference to the accompanying drawings. 
       FIG. 3  is a front view showing an automatic transfer switch in accordance is with an exemplary embodiment, and  FIG. 4  is a perspective view of a transfer device disassembled from the automatic transfer switch of  FIG. 3 . 
     Referring to  FIG. 3 , an automatic transfer switch (ATS)  100  may include a case  101  having an accommodation space partitioned into upper and lower spaces, a regular ACB (first ACB)  110  disposed in the upper accommodation space of the case  101 , and an emergency ACB (second ACB)  120  disposed in the lower accommodation space of the case  101 . A transfer device  200  for alternately closing or tripping both the ACBs  110  and  120  may be installed in one side of the inner space of the case  101 , namely, in one sides of the first and second ACBs  110  and  120 . 
     The transfer device  200  may be modularized to be easily installed between the first ACB  110  and the second ACB  120 . For instance, referring to  FIG. 4 , the transfer device  200  may include a first frame base  211  and a second frame base  221  disposed at one side surfaces of the first ACB  110  and the second ACB  120 , respectively, a first frame cover  212  and a second frame cover  222  coupled to one side surfaces of the first and second frame bases  211  and  221 , respectively, with preset intervals, a first closing link  213  and a first trip link  214  coupled to be present between the frame bases  211  and  221  and the frame covers  212  and  222 , respectively, so as to selectively perform a closing operation and a trip operation, a second closing link  223  and a second trip link  224  coupled to be present between the frame bases  211  and  221  and the frame covers  212  and  222 , respectively, so as to selectively perform the closing operation and the trip operation with moving opposite to the first closing link  213  and the first trip link  214 , and a first transmission rod  215  and a second transmission rod  225  respectively having both ends coupled to the first closing link  213  and the first trip link  214  and is the second closing link  223  and the second trip link  224 , respectively, so as to allow cooperation of the closing operation and the trip operation of both of the ACBs  110  and  120 . 
     Each of the first frame base  211  and the second frame base  221  may be formed in a shape of an approximately rectangular panel. Near edges of the first and second frame bases  211  and  221  are shown, respectively having coupling holes  211   a  and  221   a  for fixing the first and second frame bases  211  and  221  to one side surfaces of the ACBs  110  and  120 , respectively, through holes  211   b  and  221   b  for coupling of the closing links  213  and  223 , respectively, coupling holes  211   c  and  221   c  for fixing the frame covers  212  and  222 , respectively, and the like. At central portions of the frame bases  211  and  221  are shown, having through holes  211   d  and  221   d  for coupling of the trip links  224  and  214 , respectively. At one sides of the through holes  211   d  and  221   d  for coupling of the trip links  224  and  214 , respectively, are shown, having sliding holes  211   e  and  221   e  coupled with the trip links  224  and  214  and the trip levers  112  and  122 , respectively, so as to allow rotation of the trip links  224  and  214  and the trip levers  112  and  122 . 
     The first frame cover  212  and the second frame cover  222  may be coupled to outer side surfaces of the frame bases  211  and  221 , respectively, with preset intervals. To this end, a plurality of pins  216  and  226  for maintaining the intervals may be disposed along edges of each frame base  211  and  221  and each frame cover  212  and  222 , so as to be fixed by bolts  217  and  227 , respectively. Some of the plurality of pins  216  and  226  may be engaged with one side surfaces of the ACBs  110  and  120 , respectively, via the frame bases  211  and  221 . 
     The first closing link  213  may be rotatably installed at the through hole  211   b  disposed at the edge of the first frame base  211 . A first closing side is transmission link  215   a  of the first transmission rod  215  to be explained later may be rotatably coupled to one end of the first closing link  213 . A coupling groove  213   a  for allowing a closing lever  111  (see  FIG. 6 ) of the first ACB  110  to be slidably rotated may be formed at another end of the first closing link  213  long in a lengthwise direction. 
     The first trip link  214  may be rotatably installed at the through hole  221   d  present at the central portion of the second frame base  221 . A first trip side transmission link  215   b  of the first transmission rod  215  to be explained later may be rotatably coupled to one end of the first trip link  214 . A pin  214   a  inserted through the sliding hole  221   e  of the second frame base  221  may be coupled to another end of the first trip link  214 . The pin  214   a  may be slidably coupled to the trip lever  122  of the second ACB  120 . The trip lever  122  of the second ACB  120  may be coupled to an interlock lever  123  (see  FIG. 6 ) of the second ACB  120  so as to operate the interlock lever  123  for maintaining or releasing a tripped state of the second ACB  120 . 
     The first transmission rod  215  may be provided with a plurality of links having one ends coupled to the first closing link  213  and the first trip link  214 , respectively. For example, the first transmission rod  215  may include a first closing side transmission link  215   a  and a first trip side transmission link  215   b . The first closing side transmission link  215   a , as aforesaid, may have one end, which is rotatably coupled to the first closing link  213  so as to be movable up and down responsive to a direction that the first closing link  213  rotates. A nut-type length-adjusting unit  215   c  may be formed at another end of the first closing side transmission link  215   a , namely, at another end which is not coupled to the first closing link  213 , such that an end of the first trip side transmission link  215   b  is inserted thereinto to be coupled by a screw. 
     The first trip side transmission link  215   b , as aforesaid, may have one end rotatably coupled to the first trip link  214 . A screw thread, which is to be inserted into the length-adjusting unit  215   c  of the first closing side transmission link  215   a  to be screw-coupled, may be formed at another end of the first trip side transmission link  215   b , namely, at another end which is not coupled to the first trip link  214 . At one ends of the first and second transmission rods  215  and  225  coupled with the first and second trip links  214  and  224 , respectively, are shown, having buffers  215   d  and  225   d  configured as compression coil springs for attenuating impacts applied to the transmission rods  215  and  225 , respectively, when the first and second transmission rods  215  and  225  are closed or tripped. 
     Here, the second closing link  223  may be substantially the same as the aforesaid first closing link  213  in its shape and assembled position except for being coupled to the second frame base  221  and coupled to a second closing side transmission link  225   a  of the second transmission rod  225 . 
     Also, the second trip link  224  may be substantially the same as the aforesaid first trip link  214  in its shape and assembled position except for being coupled to the first frame base  211  and coupled to a second trip side transmission link  225   b  of the second transmission rod  225 . 
     The second transmission rod  225  may be substantially the same as the first transmission rod  215  in its configuration and operation principle excluding members assembled thereto and its position. 
     Hereinafter, description will be given of a process that the first ACB  110  and the second ACB  120  are alternately tripped and closed in the automatic transfer switch. 
     First, when the first ACB  110  is closed, as shown in  FIG. 8A , a closing link driving lever  111  connected to the first ACB  110  rotates in a counterclockwise direction in the drawing. The first closing link  213  accordingly rotates in a counterclockwise direction in the drawing, and the first transmission rod  215  connected between the first closing link  213  of the first ACB  110  and the first trip link  214  of the second ACB  120  moves upwardly. In response to the upward movement of the first transmission rod  215 , the first trip link  214  rotates in the counterclockwise direction in the drawing. The trip lever  122  of the second ACB  120  is pushed up due to the rotation of the first trip link  214 . As the trip lever  122  of the second ACB  120  is pushed up, the interlock lever  123  of the second ACB  120  operates such that the second ACB  120  is tripped. 
     When the first ACB  110  is tripped, the first closing link  213  moves back to its original position and the first trip link  214  of the second ACB  120  is also restored to its original position by virtue of the first transmission rod  215 . When the first trip link  214  is restored, the trip lever  122  of the second ACB  120  is moved back to its original position. Accordingly, the second ACB  120  is released from the interlocked state, thereby being able to be closed. 
     On the other hand, referring to  FIG. 8B , when the second ACB  120  is closed, as aforesaid, a closing link driving lever  121  of the second ACB  120  rotates in a counterclockwise direction in the drawing and simultaneously the second closing link  223  rotates in a counterclockwise direction in the drawing. Accordingly, the second transmission rod  225  connected between the second closing link  223  of the second ACB  120  and the second trip link  224  of the first ACB  110  moves upwardly. In response to the upward movement of the second transmission rod  225 , the second trip link  224  rotates in the counterclockwise direction in the drawing to push up the trip lever  112  of the first ACB  110 . Consequently, the trip lever  112  installed in the first ACB  110  operates to mechanically interlock the first ACB  110  to prevent the first ACB  120  from being electrically closed. 
     When the second ACB  120  is tripped, the second closing link  224  moves back to its original position and the second trip link  224  of the first ACB  110  is also restored to its original position by virtue of the second transmission rod  225 . In response to the restoring of the second trip link  224 , the trip lever  112  of the first ACB  110  moves back to its original position. Accordingly, the first ACB  120  is uninterlocked, thereby being able to be closed. 
     As described above, a transfer device which is installed between plural ACBs to make the plural ACBs alternately switched to a closed state and a tripped state may be modularized, thereby facilitating an assembly of the transfer device. 
     A length of a transmission rod configuring part of the transfer device can be adjusted, which allows the transfer device to be easily assembled and repaired or maintained and also reduces the probability of occurrence of an assembly error so as to enable more accurate closing and trip operations. 
     Also, as a buffer is installed at the transmission rod, an impact, which may occur upon switching the closing and trip operations of each ACB, can be absorbed, thereby reducing impact noise and enhancing reliability. 
     In addition, the transmission rod is formed with a preset thickness without being curved, so curving or bending of the transmission rod can be avoided in advance, whereby a mis-operation during the closing and trip operations may not occur. 
     The foregoing embodiments and advantages are merely exemplary and is 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. 
     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.