Patent Publication Number: US-2023143348-A1

Title: Circuit breaker

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of low-voltage appliance, in particular to a circuit breaker. 
     BACKGROUND OF THE INVENTION 
     Circuit breakers can effectively improve the use safety of electrical equipment, and can be sorted into a plug-in type, a fixed-type and a drawer-type according to their installation ways. With the development of the electrical equipment&#39;s miniaturization, correspondingly, the overall structures and operation modes of the circuit breakers also have to be gradually upgraded. Among them, plug-in circuit breakers are widely used in communication equipment due to their advantages of compact structure, space saving and convenient installation. However, with the development of the IoT technology, the plug-in circuit breakers of the existing technology cannot meet the requirements of remote monitoring and control. 
     SUMMARY OF THE INVENTION 
     The present invention aims to overcome the defects of the prior art, providing a circuit breaker, of which an electric mechanism realizes the remote control of the circuit breaker. 
     In order to achieve the above object, the technical scheme adopted in the present invention is as follows: 
     A circuit breaker, comprising a circuit breaker housing  1 ; and a button mechanism  2 , an operating mechanism connected with the button mechanism  2 , a movable contact  60  connected with the operating mechanism, and a static contact  61  co-operated with the movable contact  60  are all arranged in said breaker housing  1 ; operating the button mechanism  2  enables the circuit breaker to switch on/switch off by means of the operating mechanism; the circuit breaker further includes an electric mechanism  2   c  arranged inside the circuit breaker housing  1 , the electric mechanism  2   c  is drivingly co-operated with the button mechanism  2  or the operating mechanism, the electric mechanism  2   c  can actuate the circuit breaker to switch on/switch off by means of the operating mechanism, or the electric mechanism  2   c  can actuate the circuit breaker to switch on/switch off by means of the button mechanism  2 . 
     Preferably, the operating mechanism includes a bar linkage, and a transmission member  4  and a lever mechanism pivotally arranged on the circuit breaker housing  1 , the bar linkage includes a connecting rod structure  33  and a transmission connecting rod  32 , the button mechanism  2  is drivingly connected to the transmission member  4  through the connecting rod structure  33 , the transmission member  4  is drivingly connected to the lever mechanism through the transmission connecting rod  32 ; and the lever mechanism is drivingly connected with the movable contact  60 ; when operating the button mechanism  2  to enable the circuit breaker to switch on/switch off, the button mechanism  2  drives the transmission member  4  to rotate in a first direction/second direction through the connecting rod structure  33 , and said second direction and said first direction are opposite to each other. 
     Preferably, the button mechanism  2  includes a first button  20  slidably arranged inside the circuit breaker housing  1 , the connecting rod structure  33  includes a first connecting rod  30 , the first button  20  is drivingly connected to the transmission member  4  through the first connecting rod  30 ; when pressing the first button  20  toward the inside of the circuit breaker housing  1  enables the circuit breaker to switch on, the first button  20  drives the transmission member  4  to rotate in the first direction; when pulling the first button  20  toward the outside of the circuit breaker housing  1  to enable the circuit breaker to switch off, the first button  20  drives the transmission member  4  to rotate in the second direction; the electric mechanism  2   c  is drivingly cooperated with the first button  20  to drive the circuit breaker to switch on/switch off. 
     Preferably, the button mechanism  2  includes a first button  20  and a second button  21  slidably arranged inside the circuit breaker housing  1  respectively, and the first button  20  and the second button  21  are parallelly arranged and synchronously move in two directions opposite to one another; the connecting rod structure  33  includes a first connecting rod  30  and a second connecting rod  31 , the first button  20  is drivingly connected to the transmission member  4  through the first connecting rod  30 , and the second button  21  is drivingly connected to the transmission member  4  through the second connecting rod  31 ; when pressing the first button  20  toward the inside of the circuit breaker housing  1  to enable the circuit breaker to switch on, the first button  20  drives the transmission member  4  to rotate in the first direction, meanwhile the second button  21  moves toward the outside of the circuit breaker; when pressing the second button  21  toward the inside of the circuit breaker housing  1  to enable the circuit breaker to switch off, the second button  21  drives the transmission member  4  to rotate in the second direction through the second connecting rod  31 , meanwhile the first button  20  moves toward the outside of the circuit breaker; the electric mechanism  2   c  drivingly cooperates with said first button  20  or said second button  21  to enable the circuit breaker to switch on/switch off. 
     Preferably, the electric mechanism  2   c  includes a driving motor  20   c , a transmission gear set and a transmission rack  26   c , the driving motor  20   c  is drivingly co-operated with the transmission rack  26   c  through the transmission gear set, and the transmission rack  26   c  is drivingly co-operated with the button mechanism  2 . 
     Preferably, the first button  20  includes a rack limiting groove  2030  arranged on one side thereof, the transmission rack  26   c  is arranged in the rack limiting groove  2030 , and the rack limiting groove  2030  includes a switch-on side surface  2032  and a switch-off side surface  2031  respectively arranged at both ends thereof; 
     when the circuit breaker switches on, the transmission rack  26   c  moves from a first initial position toward the switch-on side surface  2032  till said transmission rack  26   c  contacts with the latter, then the transmission rack  26   c  continues to move and drives the first button  20  to move toward the inside of the circuit breaker housing  1  through the switch-on side surface  2032 , after the circuit breaker has switched on, the transmission rack  26   c  returns back to the first initial position; when the circuit breaker switches off, the transmission rack  26   c  moves toward the switch-off side surface  2031  to contact with the latter, then the transmission rack  26   c  continues to move and drives the first button  20  to move toward the outside of the circuit breaker housing  1  through the switch-off side surface  2031 , after the circuit breaker has broken contact, the transmission rack  26   c  returns to the first initial position. 
     Preferably, the first button  20  and the transmission rack  26   c  are fixedly connected to each other, and the transmission gear set includes a first fan-shaped gear  251   c  drivingly engaged with the transmission rack  26   c;    
     when the circuit breaker switches on, the first fan-shaped gear  251   c  rotates in the first direction and drives the first button  20  to move toward the inside of the circuit breaker housing  1  through the transmission rack  26   c , thus the circuit breaker switches on and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission rack  26   c ; when the circuit breaker switches off, the first fan-shaped gear  251   c  rotates in the second direction and drives the first button  20  to move toward the outside of the circuit breaker housing  1  through the transmission rack  26   c , thus the circuit breaker switches off and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission rack  26   c.    
     Preferably, the electric mechanism  2   c  is drivingly co-operated with the transmission member  4  to drive the circuit breaker to switch on/switch off, the electric mechanism  2   c  includes a motor  20   c , a transmission gear set and a transmission member&#39;s gear  27   c  coaxially arranged with the transmission member  4 , and the transmission gear set includes a switch-on and switch-off driving gear drivingly co-operated with the transmission member&#39;s gear  27   c;    
     the switch-on and switch-off driving gear drives the transmission member&#39;s gear  27   c  to rotate, and the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate, so as to enable the circuit breaker to switch on/switch off. 
     Preferably, the operating mechanism further includes a jump buckle  50 , a lock catch  51  and a rotating plate  52  pivotally arranged on the circuit breaker housing  1 , the jump buckle  50  and the lock catch  51  are pivotally arranged on the rotating plate  52 , respectively, the jump buckle  50  and the lock catch  51  are locked with each other, and the rotating plate  52  is drivingly connected with the movable contact  60 ; 
     the electric mechanism  2   c  is drivingly co-operated with the transmission member  4  to drive the circuit breaker to switch on, and with the lock catch  51  to drive the circuit breaker to switch off, the electric mechanism  2   c  includes a driving motor  20   c , a transmission gear set and a transmission member&#39;s gear  27   c  coaxially arranged with the transmission member  4 , and the transmission gear set includes a fourth transmission gear  250   c  drivingly co-operated with the transmission gear  27   c  and a first fan-shaped gear  251   c  is coaxial linkage with the fourth transmission gear  250   c ; the operating mechanism further includes a trip-off lever  3   c  drivingly connected to the lock catch  51  and pivotally arranged; the fourth transmission gear  250   c  drives the trip-off lever  3   c  to rotate, and the trip-off lever  3   c  simultaneously drives the lock catch  51  to rotate, so as to release the locking co-operation of the lock catch  51  with the jump lock  50  and enable the circuit to switch off; 
     when the circuit breaker switches on, the first fan-shaped gear  251   c  rotates from a third initial position toward the second direction to its engagement with the transmission member&#39;s gear  27   c  and drives the transmission member&#39;s gear  27   c  to rotate from a second initial position toward the first direction, the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate in the first direction, the circuit breaker switches on and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission member&#39;s gear  27   c , then the transmission member&#39;s gear  27   c  automatically rotates to the second initial position and the transmission member  4  stays at a position by which said transmission member  4  stands on the moment that the circuit breaker switches on; when the circuit breaker switches off, the first fan-shaped gear  251   c  and the fourth transmission gear  250   c  continue to rotate in the second direction, the fourth transmission gear  250   c  drives the trip-off lever  3   c  to rotate, said trip-off lever  3   c  drives said lock catch  51  to rotates, so as to release the locking co-operation of the lock catch  51  with the jump buckle  50 , thus the circuit breaker switches off and the first fan-shaped gear  251   c  continues to rotate to the third initial position. 
     Preferably, the circuit breaker further includes a short-circuit protection mechanism  7  and an overload protection mechanism  9  arranged inside the circuit breaker housing  1  and respectively drivingly co-operated with the operating mechanism, arc extinguishing system  8 , a wire-inlet terminal  1   i  and a wire-outlet terminal  1   o ; the circuit breaker further includes an electric mechanism  2   c  drivingly co-operated with the button mechanism  2  or the operating mechanism; the wire-outlet terminal  1   o  and the button mechanism  2  are arranged at one end of the circuit breaker housing  1 , and the wire-inlet terminal  1   i  is arranged at the other end of the circuit breaker housing  1 ; the operating mechanism is positioned between the button mechanism  2  and the wire-inlet terminal  1   i ; the arc extinguishing system  8  and the short-circuit protection mechanism  7  are arranged side by side between the operating mechanism and the wire-inlet terminal  1   i ; the electric mechanism  2   c  is positioned between the operating mechanism and the wire-outlet terminal  1   o , and the electric mechanism  2   c  and the wire-outlet terminal  1   o  are positioned on the same side of the button mechanism  2 ; the overload protection mechanism  9  is positioned on one side of the operating mechanism and between the arc extinguishing system  8  and the wire-outlet terminal  1   o.    
     Preferably, the circuit breaker further includes a control circuit board  1   c  connected to the electric mechanism  2   c ; the control circuit board  1   c  is arranged between the bottom plate of the circuit breaker housing  1  and the electric mechanism  2   c , the control circuit board  1   c  and the electric mechanism  2   c  are positioned on the same side of the button mechanism  2 , and the control circuit board  1   c  is positioned between the wire-outlet terminal  1   o  and the operating mechanism. 
     Preferably, the circuit breaker further includes a control circuit board  1   c  connected to the electric mechanism  2   c ; the bottom plate of the circuit breaker housing  1  is positioned on one side of the control circuit board  1   c , and the electric mechanism  2   c , the operating mechanism and the arc extinguishing system  8  are positioned on the other side of the control circuit board  1   c.    
     Preferably, the button mechanism  2  is arranged opposite to the short-circuit protection mechanism  7  and positioned on one side of the circuit breaker housing  1 ; the wire-outlet terminal  1   o  is arranged opposite to the arc extinguishing system  8  and positioned on the other side of the circuit breaker housing  1 . 
     Preferably, the short-circuit protection mechanism  7  is an electromagnetic release; the overload protection mechanism  9  is a bimetallic strip drivingly co-operated with the jump buckle  51  of the operating mechanism, or the overload protection mechanism  9  is a current transformer coupled to the L-pole circuit of the circuit breaker and connected to the control circuit board  1   c , or the overload protection mechanism  9  is a manganin resistor in series connection with the L-pole circuit of the circuit breaker, and the manganin resistor is connected to the control circuit board  1   c ; the circuit breaker further includes the control circuit board  1   c  connected to the electric mechanism  2   c  and a signal terminal connected to the control circuit board  1   c , the signal terminal and the wire-inlet terminal  1   i  are arranged at the same end of the circuit breaker housing  1 , and the signal terminal is positioned between the two wire-inlet terminals  1   i.    
     The circuit breaker of the present invention comprises a button mechanism, an operating mechanism, an electric mechanism, and the electric mechanism being drivingly co-operated with the button mechanism or the operating mechanism, users can either manually operate the button mechanism to drive the circuit breaker to switch on/switch off, or actuate the circuit breaker to switch on/switch off by means of the co-operation of the electric mechanism and the operating mechanism or the co-operation of the electric mechanism and the button mechanism. Firstly, the operation method of the circuit breaker is diversified; secondly, the electric mechanism enables the circuit breaker to be remotely controlled. 
     In addition, the circuit breaker of the present invention includes a first button and a second button, which correspond to the switch-on and switch-off operations of the circuit breaker, respectively, and which bring about the following advantages. 1. Users can judge the switch-on/switch-off state of the circuit breaker by observing the states of the two buttons (that is, when the first button is pressed down and the second button comes up, the circuit breaker is in the switch-on state; when the first button comes up and the second button is pressed down, the circuit breaker is in the switch-off state). 2. Compared with the existing circuit breakers which switches off by pulling button, the circuit breaker of the present invention enables the circuit breaker to switch on and switch off by pressing the first button and the second button respectively, thus preventing the circuit breaker from being pulled out from the assembling position of the circuit breaker (such as a cabinet, etc.) due to the excessive force of pulling the buttons. 
     In addition, a wire-inlet terminal and a wire-outlet terminal are arranged at both ends of the circuit breaker housing respectively, helping to increase the creepage distance between the two terminals and improve the electrical safety of circuit breakers. The electric mechanism is positioned between the operating mechanism and the wire-out terminal, and the electric mechanism and the wire-out terminal are positioned on the same side of the button mechanism. The internal space of the circuit breaker housing is reasonably designed, and the layout of each part is compact, enabling the internal space of the circuit breaker housing to be utilized to the greatest extent, and helping to reduce the overall volume of the circuit breaker. 
     In addition, the bottom plate of the circuit breaker housing is positioned on one side of the control circuit board, and the electric mechanism, button mechanism, operating mechanism, short-circuit protection mechanism and the arc extinguishing system are positioned on the other side of the control circuit board; the above-mentioned stacking arrangement enables the control circuit board to take enough assembly space, so as to increase the size of the control circuit board, and abate the difficulty of arranging components on the control circuit board and the complexity of wiring on the control circuit board; more importantly, directly connecting to the wire-inlet terminal through the conductive lines arranged on the control circuit board excludes the difficulty of welding and wiring caused by the connection of separate flexible wires, and the control circuit board enables the circuit breaker to be remotely monitored and controlled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a structure diagram of the first embodiment of the circuit breaker of the present invention. 
         FIG.  2    is a structure diagram of the first embodiment of the circuit breaker of the present invention, at least showing the structure of the track groove. 
         FIG.  3    is a structure diagram of the transmission rack of the present invention. 
         FIG.  4    is a structure diagram of the first button of the present invention. 
         FIG.  5    is a structure diagram of the second button of the present invention. 
         FIG.  6    is a structure diagram of the transmission member of the present invention. 
         FIG.  7 A  is a schematic diagram of the principle that the circuit breaker switches on in the first embodiment of the circuit breaker of the present invention. 
         FIG.  7 B  is a schematic diagram of the transmission rack reset after the circuit breaker of the present invention has switched on in the first embodiment. 
         FIG.  8 A  is a schematic diagram of the principle that the circuit breaker switches off in the first embodiment of the circuit breaker of the present invention. 
         FIG.  8 B  is a schematic diagram of the transmission rack reset after the circuit breaker of the present invention has broken contact in the first embodiment. 
         FIG.  9    is a structure diagram of the second embodiment of the circuit breaker of the present invention. 
         FIG.  10 A  is a structure diagram of the third embodiment of the circuit breaker of the present invention, where the circuit breaker is in the switch-off state. 
         FIG.  10 B  is a structure diagram of the third embodiment of the circuit breaker of the present invention, where the circuit breaker is in the switch-on state. 
         FIG.  11 A  is a structure diagram of the fourth embodiment of the circuit breaker of the present invention, where the circuit breaker is in the switch-off state. 
         FIG.  11 B  is a structure diagram of the fourth embodiment of the circuit breaker of the present invention, where the circuit breaker is in the switch-on state. 
         FIG.  12 A  is a structure diagram of the sixth embodiment of the circuit breaker of the present invention, where the circuit breaker is in the switch-on state. 
         FIG.  12 B  is a structure diagram where the fourth transmission gear of the transmission gear set drives the lock catch through the trip-off lever in the sixth embodiment of the circuit breaker of the present invention. 
         FIG.  13 A  is a structure diagram of the circuit breaker of the present invention, showing the cooperation relation between the first locking member and the unlocking mechanism. 
         FIG.  13 B  is an enlarged structure diagram at A in  FIG.  13 A  of the present invention. 
         FIG.  14    is a structure diagram of the of the circuit breaker of the present invention, showing the position of the control circuit board. 
         FIG.  15 A  is a structure diagram of the fifth embodiment of the circuit breaker of the present invention, where the circuit breaker is in the switch-off state. 
         FIG.  15 B  is a structure diagram of the fifth embodiment of the circuit breaker of the present invention, where the circuit breaker is at the conversion form the switch-off state to the switch-on state. 
         FIG.  15 C  is a structure diagram of the fifth embodiment of the circuit breaker of the present invention, where the circuit breaker is in the switch-on state. 
     
    
    
     DETAILED DESCRIPTION OF SOME EMBODIMENTS 
     We further describe the embodiments of the plug-in circuit breaker according to the present invention as follows in combination with the examples shown in  FIGS.  1 - 15 C . The plug-in circuit breaker of the present invention is not limited to the description of the following embodiments. 
     The circuit breaker of the present invention includes the circuit breaker housing  1 , the button mechanism  2 , an operating mechanism connected with the button mechanism  2 , the movable contact  60  connected with the operating mechanism, the static contact  61  co-operated with the movable contact  60 , which are arranged in the circuit breaker housing  1  respectively; and the button mechanism  2  is operated to enable the circuit breaker to switch on/switch off by means of the operating mechanism; the circuit breaker also includes the electric mechanism  2   c  arranged in the circuit breaker housing  1 ; the electric mechanism  2   c  is drivingly co-operated with the button mechanism  2  or the operating mechanism; the electric mechanism  2   c  can actuate the circuit breaker to switch on/switch off by means of the operating mechanism, or the electric mechanism  2   c  can actuate the circuit breaker to switch on/switch off by means of the cooperation of the button mechanism  2  and the operating mechanism. The circuit breaker of the present invention includes the button mechanism  2 , the operating mechanism, the electric mechanism  2   c , and the electric mechanism  2   c  being drivingly co-operated with the button mechanism  2  or the operating mechanism; users can either manually operate the button mechanism  2  to drive the circuit breaker to switch on/switch off, or actuate the circuit breaker to switch on/switch off by means of the co-operation of the electric mechanism  2   c  and the operating mechanism or the co-operation of the electric mechanism  2   c  and the button mechanism  2 . Firstly, the operation method of the circuit breaker is diversified; secondly, the electric mechanism  2   c  enables the circuit breaker to be remotely controlled. 
     Further, as a preferred solution of the present invention, the button mechanism  2  includes the first button  20  and the second button  21  respectively slidably arranged inside the circuit breaker housing  1 ; the operating mechanism includes a bar linkage, and the transmission member  4  and the lever mechanism pivotally arranged on the circuit breaker housing  1 ; the bar linkage includes the connecting rod structure  33  and the transmission connecting rod  32 , and the connecting rod structure  33  includes the first connecting rod  30  and the second connecting rod  31 ; the first button  20  is drivingly connected to the transmission member  4  through the first connecting rod  30 , the second button  21  is drivingly connected to the transmission member  4  through the second first connecting rod  31 , the transmission member  4  is drivingly connected to the lever mechanism through the transmission connecting rod  32 , and the lever mechanism is drivingly connected with the movable contact  60 ; when pressing the first button  20 /second button  21  toward the inside of the circuit breaker housing  1  to enable the circuit breaker to switch on/switch off, the first button  20 /second button  21  drives the transmission member  4  to rotate in a first direction/a second direction through the first connecting rod  30 /the second connecting rod  31 , and the second direction and the first direction are opposite to each other. The circuit breaker of the present invention includes the first button  20  and the second button  21 , which correspond to the switch-on and switch-off operations of the circuit breaker, respectively, and which bring about the following advantages: 1. Users can judge the switch-on/switch-off state of the circuit breaker by observing the states of the two buttons (that is, when the first button  20  is pressed down and the second button  21  comes up, the circuit breaker is in the switch-on state; when the first button  20  comes up and the second button  21  is pressed down, the circuit breaker is in the switch-off state). 2. Compared with the existing circuit breakers which switch off by pulling button, the circuit breaker of the present invention enables the circuit breaker to switch on and switch off by pressing the first button  20  and the second button  21  respectively, thus preventing the circuit breaker from being pulled out from the assembling position of the circuit breaker (such as a cabinet, etc.) due to the excessive force on pulling the buttons. 
     The circuit breaker of the present invention further includes the short circuit protection mechanism  7 , the overload protection mechanism  9 , the arc extinguishing system  8 , the wire-inlet terminal  1   i  and the wire-outlet terminal  10  all arranged in the circuit breaker housing  1 ; the short-circuit protection mechanism  7  and the overload protection mechanism  9  are drivingly co-operated with the operating mechanism respectively; the wire-outlet terminal  1   o  and the button mechanism  2  are arranged at one end of the circuit breaker housing  1 , and the wire-inlet terminal  1   i  is arranged at the other end of the circuit breaker housing  1 ; the operating mechanism is positioned between the button mechanism  2  and the wire-inlet terminal  1   i ; the arc extinguishing system  8  and the short-circuit protection mechanism  7  are arranged side by side between the operating mechanism and the wire-inlet terminal  1   i ; the electric mechanism  2   c  is positioned between the operating mechanism and the wire-outlet terminal  1   o , and the electric mechanism  2   c  and the wire-outlet terminal  1   o  are positioned on the same side of the button mechanism  2 ; the overload protection mechanism is positioned on one side of the operating mechanism and between the arc extinguishing system  8  and the wire-outlet terminal  1   o . Of the present invention, the wire-inlet terminal  1   i  and the wire-outlet terminal  1   o  are arranged at both ends of the circuit breaker housing  1  respectively, helping to increase the creepage distance between the two terminals and improve the electrical safety of circuit breakers, the electric mechanism  2   c  is positioned between the operating mechanism and the wire-out terminal  1   o , and the electric mechanism  2   c  and the wire-out terminal  1   o  are positioned on the same side of the button mechanism  2 , so that the internal space of the circuit breaker housing  1  is reasonably designed, and the layout of each part is compact, enabling the internal space of the circuit breaker housing  1  to be utilized to the greatest extent, and helping to reduce the overall volume of the circuit breaker. 
     Further, the circuit breaker of the present invention also includes the control circuit board  1   c  connected to the electric mechanism  2   c , the bottom plate of the circuit breaker housing  1  is positioned on one side of the control circuit board  1   c , and the electric mechanism  2   c , the operating mechanism and the arc extinguishing system  8  are positioned on the other side of the control circuit board  1   c . The above-mentioned stacking arrangement enables the control circuit board  1   c  to take enough assembly space, so as to increase the size of the control circuit board  1   c , and abate the difficulty of arranging components on the control circuit board  1   c  and the complexity of wiring process on the control circuit board  1   c . More importantly, directly connecting to the wire-inlet terminal  1   i  by means of the conductive lines arranged on the control circuit board  1   c  excludes the difficulty of welding and wiring caused by the connection of separate flexible wires. 
     We shall further describe the circuit breaker of the present invention with reference to the figures and specific examples as follows. 
     As shown in  FIGS.  1 ,  9 - 15 C , the circuit breaker of the present invention includes the circuit breaker housing  1 , the button mechanism  2  arranged inside the circuit breaker housing  1 , an operating mechanism connected with the button mechanism  2 , the movable contact  60  connected with the operating mechanism, the static contact  61  co-operated with the movable contact  60 , and the button mechanism  2  being operated to enable the circuit breaker to switch on/switch off by means of the operating mechanism, so as to enable the movable contact  60  and the static contact  61  to be connected/disconnected. 
     Preferably, as shown in  FIG.  1   , the operating mechanism includes the bar linkage, and the transmission member  4  and the lever mechanism pivotally arranged on the circuit breaker housing  1 ; the bar linkage includes the connecting rod structure  33  and the transmission connecting rod  32 ; the button mechanism  2  is drivingly connected to the transmission member  4  through the connecting rod structure  33 , the transmission member  4  is drivingly connected to the lever mechanism through the transmission connecting rod  32 , and the lever mechanism is drivingly connected with the movable contact  60 ; when operating the button mechanism  2  to enable the circuit breaker to switch on/switch off, the button mechanism  2  drives the transmission member  4  to rotate in a first direction/second direction through the connecting rod structure  33 , and the second direction and the first direction are opposite to each other; the electric mechanism  2   c  is drivingly co-operated with the button mechanism  2  or the transmission member  4 . 
     Preferably, as shown in  FIG.  1   , the lever mechanism includes the jump buckle  50 , the lock catch  5  land the rotating plate  52  pivotally arranged on the circuit breaker housing  1 , the jump buckle  50  and the lock catch  51  are locked with each other and pivotally arranged on the rotating plate  52  respectively; the rotating plate  52  is drivingly connected with the movable contact  60 . It should be pointed that the lever mechanism may adopt a four-bar linkage and other multi-bar linkages, as they pertain to the prior art in the art, details for them are not described herein again. 
     Specifically, as shown in  FIG.  1   , the first direction is a clockwise direction, and the second direction is a counterclockwise direction. 
     Preferably, as shown in  FIG.  9   , an embodiment is provided, of which the button mechanism  2  only includes one button. The button mechanism  2  includes the first button  20  slidably arranged inside the circuit breaker housing  1 , the connecting rod structure  33  includes the first connecting rod  30 , the first button  20  is drivingly connected to the transmission member  4  through the first connecting rod  30 ; when pressing the first button  20  toward the inside of the circuit breaker housing  1  to enable the circuit breaker to switch on, the first button  20  drives the transmission member  4  to rotate in a first direction; when pulling the first button  20  toward the outside of the circuit breaker housing  1  to enable the circuit breaker to switch off, the first button  20  drives the transmission member  4  to rotate in a second direction. Further, as shown in  FIG.  9   , of the first button  20 , one end protrudes outside the circuit breaker housing  1 , and the other end is drivingly connected to the transmission member  4  through the first connecting rod  30 ; when pressing down the first button  20  to enable the circuit breaker to switch on, the first button  20  drives the transmission member  4  to rotate clockwise through the first connecting rod  30 ; when pulling up the first button  20  to enable the circuit breaker to switch off, the first button  20  drives the transmission member  4  to rotate counterclockwise through the first connecting rod  30 . 
     Preferably, as shown in  FIGS.  1 ,  7 A- 8 B,  10 A- 13 A and  15 A- 15 C , another embodiment is provided, of which the button mechanism  2  includes two buttons, which is a preferred solution of the present invention. The button mechanism  2  includes the first button  20  and the second button  21  all slidably arranged inside the circuit breaker housing  1 , and the first button  20  and the second button  21  are parallelly arranged and synchronously move in two directions opposite to one another; the connecting rod structure  33  includes the first connecting rod  30  and the second connecting rod  31 , the first button  20  is drivingly connected to the transmission member  4  through the first connecting rod  30 , and the second button  21  is drivingly connected to the transmission member  4  through the second connecting rod  31 ; when pressing the first button  20  toward the inside of the circuit breaker housing  1  to enable the circuit breaker to switch on, the first button  20  drives the transmission member  4  to rotate in the first direction, meanwhile the second button  21  moves toward the outside of the circuit breaker; when pressing the second button  21  toward the inside of the circuit breaker housing  1  to enable the circuit breaker to switch off, the second button  21  drives the transmission member  4  to rotate in the second direction through the second connecting rod  31 , meanwhile the first button  20  moves toward the outside of the circuit breaker. 
     The basic processes of the circuit breaker normally switching on, normally switching off and switching off with fault in the present invention are shown as follows. 
     As shown in  FIG.  10 A , the circuit breaker is in the switch-off state. During the switch-on operation, pressing down the first button  20  enables the first button  20  to drive the transmission member  4  to rotate clockwise through the first connecting rod  30 , and the transmission member  4  drives lever mechanism to rotate clockwise in its entirety through the transmission connecting rod  32 ; thus the lever mechanism drives the movable contact  60  to sway clockwise to join the movable contact  60  to the static contact  61 , the circuit breaker finishes switching on (as shown in  FIG.  10 B ), meanwhile the second button  21  moves toward the outside of the circuit breaker. As shown in  FIG.  10 B , the circuit breaker is in the switch-on state. During the switch-off operation, pressing down the second button  21  enables the second button  21  to drive the transmission member  4  to rotate counterclockwise through the second connecting rod  31 , the transmission member  4  drives the jump buckle  50  and the lock catch  51  to release the locking co-operation between them through the transmission connecting rod  32 , the rotating plate  52  drives the movable contact  60  to sway counterclockwise to separate the movable contact  60  from the static contact  61 , the circuit breaker finishes switching off (as shown in  FIG.  10 A ), meanwhile the first button  20  moves toward the outside of the circuit breaker. 
     When a short-circuit or overload fault occurs in the circuit breaker, the short-circuit protection mechanism  7  or the overload protection mechanism  9  drives the lock catch  51  to rotate counterclockwise, so that the jump buckle  50  and the lock catch  51  are released from each other; the rotating plate  52  drives the movable contact  60  to sway counterclockwise, to separate the movable contact  60  from the static contact  61 , so that the circuit breaker switches off (as shown in  FIG.  10 A ). 
     Preferably, as shown in  FIG.  6   , an embodiment of the transmission member  4  is provided. 
     As shown in  FIG.  6   , the transmission member  4  includes the transmission member axle hole  400  arranged in the middle thereof, and the first connection hole  40 , the second connection hole  41 , and the third connection hole  42  all arranged around the transmission member axle hole  400 . The first connection hole  41 , the second connection hole  4  land the third connection hole  42  are positioned at three vertices of a triangle thereon, respectively. The second connection hole  41  is arranged at one end of the transmission member  4 , and the first connection hole  40  and the third connection hole  42  are arranged at the other end of the transmission member  4 . Specifically, in the directions shown in  FIG.  6   , The transmission member axle hole  400  is arranged in the middle of the transmission member  4 , the second connection hole  41  is arranged at the left end of the transmission member  4  and positioned on the left side of the transmission member axle hole  400 , and the first connection hole  40  and the third connection hole  42  are arranged at the right end of the transmission member  4  and positioned on the right side of the transmission member axle hole  400 . 
     Preferably, as shown in  FIGS.  13 A- 13 B , the circuit breaker of the present invention further includes the first locking member  1   a  with one end protruding outside the circuit breaker housing  1 ; the circuit breaker housing  1  includes the locking member opening co-operated with the first locking member  1   a , and the first resetting spring  5   a  drives one end of the first locking member  1   a  to protrude outside the circuit breaker housing  1  through the locking member opening; when the circuit breaker is in the switch-off state, the first locking member  1   a  can retract into the inside of the circuit breaker housing  1  under the function of an external force for retraction, and after retracting into the inside of the circuit breaker housing  1 , the first locking member  1   a  can be co-operated with the first button  20  and/or the second button  21  in a position-limit way and enables the circuit breaker not to switch on; when the circuit breaker is in the switch-on state, the first locking member  1   a  protrudes outside the circuit breaker housing  1 , and the first locking member  1   a  is limited by the first button  20  and/or the second button  21  in a position-limit way and cannot retract into the circuit breaker housing  1 . For example, while the circuit breaker is being installed to the assembling position for the circuit breaker in the switch-off state, the assembling position housing for the circuit breaker squeezes the first locking member  1   a  to enable it move toward the inside of the circuit breaker housing  1  (the assembling position housing applies a external force for retraction on the first locking member  1   a ) during this assembling process, so as to enable the first locking member  1   a  to be co-operated with the first button  20  and/or the second button  21  in a position-limit way, and lock the first button  20  and/or the second button  21 ; after the circuit breaker has been assembled to the designated position, the locking member opening corresponds to the assembling limiting hole of the assembling position housing, so the first locking member  1   a  protrudes outside the circuit breaker housing  1  again and releases its position-limiting co-operation with the first button  20  and/or the second button  21 , and the first button  20  and/or the second button  21  being unlocked and co-operating the first locking member  1   a  with the assembling position housing in a position-limit way enable the circuit breaker to normally switch on and switch off through the first button  20  and/or the second button  21 , and prevent the circuit breaker from being pulled out from its assembling position at will. 
     Further, as shown in  FIGS.  13 A- 13 B , the circuit breaker further includes an unlocking mechanism, and the unlocking mechanism includes the independent pulling member  2   a  arranged inside the circuit breaker housing  1  and drivingly co-operated with the first locking member  1   a ; when the circuit breaker is in the switch-off state, the pulling member  2   a  is pulled out of the circuit breaker housing  1 , thus the pulling member  2   a  drives the first locking member to move toward the inside of the circuit breaker housing  1  against the elastic force of the first resetting spring Sa, retract into the inside of the circuit breaker housing, release its position-limiting co-operation with the assembling position housing, and co-operate with the first button  20  and/or the second button  21  in a position-limit way; at this time, further pulling the pulling member  2   a  enables the circuit breaker to be pulled out from the assembling position of the circuit breaker. When the circuit breaker is in the switch-on state, the first button  20  and/or the second button  21  prevent the first locking member  1   a  from moving toward the inside of the circuit breaker housing  1 , and at this time, the first locking member  1   a  cannot retract into the inside of the circuit breaker the housing  1  through the unlocking mechanism. Further, as shown in  FIGS.  13 A- 13 B , the unlocking mechanism further includes the linkage member  3   a  and the lever support  4   a  arranged on the circuit breaker housing  1 ; of the linkage member  3   a , one end is drivingly connected with the first locking member  1   a , the other end is drivingly co-operated with the pulling member  2   a , and the middle part is contacting co-operated with the lever support  4   a ; the pulling member  2   a  is pulled toward the outside of the circuit breaker housing  1 , thus the pulling member  2   a  drives the linkage member  3   a  to rotate around the lever support  4   a , and the linkage member  3   a  drives the first locking member  1   a  to move toward the inside of the circuit breaker housing  1  and release its position-limiting co-operation with the assembling position housing. Further, as shown in  FIG.  13 A , the pulling member  2   a  is placed on one side of the button mechanism  2  in overlap in the thickness direction of the circuit breaker housing  1 , helping to improve the compactness of the circuit breaker structure. Further, as shown in  FIGS.  13 A and  13 B , the movement direction of the pulling member  2  is parallel to the movement direction of the first button  20  and the second button  21 , and perpendicular to the movement direction of the first locking member  1   a.    
     Preferably, the first button  20  and/or the second button  21  is provided with a locking member limiting groove, and the first locking member  1   a  is provided with a locking member limiting protrusion; when the circuit breaker switches on, the movement of the first button  20  and the second button  21  enables the locking member limiting groove to be misaligned with the locking member limiting protrusion, and the locking member limiting protrusion cannot slide into the locking member limiting groove; when the circuit breaker switches off, the movement of the first button  20  and the second button  21  causes the locking member limiting groove and the locking member limiting protrusion to be opposite to each other, and the pulling member  2  is pulled to drive the first locking member  1   a  to move toward the inside of the circuit breaker housing  1 , so as to enable the locking member limiting protrusion to slide into the locking member limiting groove, and the first locking member  1   a  to lock the first button  20  and/or or the second button  21 , so that the circuit breaker cannot switch on. 
     As shown in  FIGS.  1 - 8 B , the first embodiment of the circuit breaker of the present invention is provided. 
     As shown in  FIGS.  1 ,  7 A- 8 B , the button mechanism  2  of the circuit breaker of this embodiment includes the first button  20  and the second button  21 ; the electric mechanism  2   c  includes the driving motor  20   c , the transmission gear set and the transmission rack  26   c ; the driving motor  20   c  is drivingly co-operated with the transmission rack  26   c  through the transmission gear set, and the transmission rack  26   c  is drivingly co-operated with the first button  20 . Further, as shown in  FIG.  4   , the first button  20  includes the rack limiting groove  2030  arranged on one side thereof, the transmission rack  26   c  is arranged in the rack limiting groove  2030 , and the rack limiting groove  2030  includes the switch-on side surface  2032  and the switch-off side surface  2031  respectively arranged at both ends thereof; the driving motor  20   c  drives the transmission rack  26   c  to slide in the rack limiting groove  2030 , and drives the first button  20  through the switch-on side surface  2032  and the switch-off side surface  2031  to enable the circuit breaker to switch on/switch off; when the circuit breaker switches on, the transmission rack  26   c  moves from the first initial position toward the switch-on side surface  2032  till the transmission rack  26   c  contacts with the latter, then the transmission rack  26   c  continues to move and drives the first button  20  to move toward the inside of the circuit breaker housing  1  through the switch-on side surface  2032 ; after the circuit breaker has switched on, the transmission rack  26   c  returns back to the first initial position; when the circuit breaker switches off, the transmission rack  26   c  moves toward the switch-off side surface  2031  to contact with the latter, then the transmission rack  26   c  continues to move and drives the first button  20  to move toward the outside of the circuit breaker housing  1  through the switch-off side surface  2031 ; after the circuit breaker has switched off, the transmission rack  26   c  returns back to the first initial position. In the circuit breaker of the present invention, the electric mechanism  2   c  performs the switch-on/switch-off operation through the cooperation of the transmission rack  26   c  and the button mechanism, and after completing the switch-on/switch-off operation, the electric mechanism  2   c  continues to drive the transmission rack  26   c  to return back to the first initial position without interference with the first button  20 . Firstly, users can still manually perform the switch-on/switch-off operation on the circuit breaker; secondly, when the circuit breaker trips off due to a short circuit or overload fault, the transmission rack  26   c  will not affect the operation of the operating mechanism, ensuring the protection performance of the circuit breaker. It should be pointed out that the transmission rack  26   c  is not limited to co-operate with the first button  20 , as wells as cooperates with the second button  21 , and the rack limiting groove  2030  is arranged on one side of the second button  21 . Thus, when the circuit breaker switches on/switches off, the movement direction of the transmission rack  26   c  is opposite to that of the transmission rack  26   c  in the first embodiment. 
     We shall further describe the switch-on/switch-off process of the circuit breaker in this embodiment with reference to  FIGS.  1 - 2  and  7 A- 8 B  as follows. 
     As shown in  FIGS.  1  and  2   , the upper side wall of the circuit breaker housing  1  serves as the operation interface; as shown in  FIGS.  7 A- 8 B , of the first button  20 , moving toward the operation interface corresponds to moving toward the outside of the circuit breaker housing  1 , and moving away from the operation interface corresponds to moving toward the inside of the circuit breaker housing  1 ; Specifically, as shown in  FIG.  8 B , while the circuit breaker is in the switch-off state, the transmission rack  26   c  is at the first initial position, and the driving motor  20   c  drives the transmission rack  26   c  to move rightwards to contact with the switch-on side surface  2032  of the rack limiting groove  2030 , thus the transmission rack  26   c  is driven to continue to move rightwards and drives the first button  20  to move rightwards through the switch-on side surface  2032 ; as shown in  FIG.  7 A , the circuit breaker completes switching on, and the transmission rack  26   c  is driven to move leftwards to the first initial position (as shown in  FIG.  7 B ); as shown in  FIG.  7 B , while the circuit breaker is in the switch-on state, the transmission rack  26   c  is at the first initial position, and the driving motor  20   c  drives the transmission rack  26   c  to move leftwards to contact with the switch-off side surface  2032  of the rack limiting groove  2030 ; as shown in  FIG.  8 A , the transmission rack  26   c  is driven to continue to move leftwards and drives the first button  20  to move leftwards through the switch-off side surface  2032 ; as shown in  FIG.  8 B , the circuit breaker completes switching off, and the transmission rack  26   c  is driven to move rightwards to the first initial position. 
     Preferably, as shown in  FIGS.  2 - 4   , the circuit breaker housing  1  includes the first button hole, the second button hole and the track groove  101  all arranged thereon. One end of the first button  20  is slidably arranged in the first button hole, and one end of the second button  21  is slidably arranged in the second button hole. The first button  20  includes the first button&#39;s track protrusion  201  arranged at the other end thereof, and the first button&#39;s track protrusion  201  is slidably arranged in the track groove  101 ; the transmission rack  26   c  includes the rack track bar  261   c  arranged on one side thereof, and the rack track bar  261   c  is slidably arranged in the rail groove  101 . Further, as shown in  FIG.  2   , the circuit breaker housing  1  includes the first rib  1010 , and the track groove  101  is arranged in the middle of the first rib  1010  and extends in the length direction of the first rib  1010 . Further, as shown in  FIG.  4   , the first button  20  further includes the second button&#39;s track bar  205  arranged thereon and extending in the length direction of the first button  20 . As shown in  FIG.  5   , the second button  21  includes the second button&#39;s track portion  215 , and one side of the second button&#39;s track portion  215  facing the first button  20  is provided with the second button&#39;s track groove. The second button&#39;s track groove is slidably co-operated with the second button&#39;s track bar  205 . 
     Specifically, as shown in  FIG.  1   , the side of  FIG.  1    facing the reader serves as the front side of the circuit breaker; the first rib  1010  is arranged on the bottom plate of the circuit breaker housing  1 , and the first button hole is arranged on the upper side wall of the circuit breaker housing; of the first button  21 , the upper end of is slidably arranged in the first button hole, and the first button rail protrusion  201  of the lower end is slidably arranged in the track groove  101 . The arrangements of the transmission rack  26   c  on the front side of the first rib  1010 , the first button  21  on the front side of the transmission rack  26   c , and the second button&#39;s track portion  215  on the front side of the first button  21  form the reliable position-limiting co-operation of the transmission rack  26   c  with the track groove  101 , the first button  20  with the track groove  101 , the first button  20  with the transmission rack  26   c , and the second button  21  with the first button  20 , ensuring the operational reliability of the operating mechanism. 
     Preferably, as shown in  FIG.  1   , the transmission gear set includes the worm wheel  21   c  drivingly connected to the driving motor  20   c , the first transmission gear  22   c  meshing with the worm wheel  21   c , the second transmission gear  23   c  is coaxial linkage with the first transmission gear  22   c , the third upper transmission gear  240   c  meshing with the second transmission gear  23   c , the third lower transmission gear  241   c  is coaxial linkage with the third upper transmission gear  240   c , and the driving gear  25   c  meshing with the third lower transmission gear  241   c . The driving gear  25   c  meshes with the transmission rack  26   c . It should be pointed out that the transmission gear set may increase or decrease as required. 
     Preferably, as shown in  FIG.  3   , an embodiment of the transmission rack  26   c  is provided. 
     The transmission rack  26   c  in a strip-shape is slidably arranged inside the circuit breaker housing  1 , including the transmission rack block  260   c , the rack arranged on one side of the transmission rack block  260   c  and co-operated with the transmission gear set, and rack track bar  261   c  arranged on another side of the transmission rack block  260   c . Preferably, the sliding direction of the transmission rack  26   c  is parallel to the first button  20  and the second button  21 , and the transmission rack  26   c  is arranged between the first button  20  and the second button  21 . 
     Preferably, as shown in  FIG.  4   , an embodiment of the first button  20  is provided. 
     The first button  20  includes the first button operating portion  202 , the first button&#39;s transmission portion  203  and the second button&#39;s track bar  205 . Of the first button operating portion  202 , one end is the first button operating end, and the other end is connected to one end of the first button&#39;s transmission portion  203  in overlap, the other end of which is provided with the first button connecting hole  204  and the first button&#39;s track protrusion  201 ; the second button&#39;s track bar  205  is arranged on one side of the first button&#39;s transmission portion  203 , and the second button&#39;s track bar  205  and the first button operating portion  202  are positioned on the same side of the first button&#39;s transmission portion  203 ; the first button connecting hole  204  is connected to one end of the first connecting rod  30  of the operating mechanism, and the first button&#39;s track ridge  201  is slidably arranged in the track groove  101  of the circuit breaker housing  1 . Further, as shown in  FIG.  4   , the first button  20  further includes the rack limiting groove  2030  arranged on one side of the first button&#39;s transmission portion  203 , and the rack limiting groove  2030  and the second button&#39;s track bar  205  are positioned on the both sides of the first button&#39;s transmission portion  203  respectively. Further, as shown in  FIG.  4   , the first button&#39;s transmission portion  203  further includes the switch-on side wall  207  and the switch-off side wall  206  arranged at the both ends of the rack limiting groove  2030 ; the inner side of switch-on side wall  207  is the switch-on side surface  2032 , the inner side of the switch-off side wall  206  is the switch-off side surface  2031 ; the first button&#39;s track ridge  201  is arranged at one end of the switch-on side wall  207 . 
     Preferably, as shown in  FIG.  5   , an embodiment of the second button  21  is provided. 
     The second button  21  includes the second button operating portion  212 , the second button&#39;s transmission portion  213 , the second button&#39;s track portion  215  and the second button connecting hole  214 ; of the second button operating portion  211 , one end is the second button operating end, and the other end is connected to one end of the second button&#39;s transmission portion  213 , the other end of which is provided with the second button connecting hole  214 ; the second button&#39;s track portion  215  is arranged on the side of the second button&#39;s transmission portion  213 , and the side of the second button&#39;s track portion  215  facing the first button&#39;s transmission portion  203  is provided with the second button&#39;s track groove slidingly co-operated with the second button&#39;s track bar  205 . Specifically, in the directions shown in  FIG.  5   , the second button&#39;s track portion  215  is arranged on the right side of the second button&#39;s transmission portion  213 . 
     Preferably, the first button  20  and the second button  21  are positioned inside the first button hole and the second button hole during the switch-on and switch-off operation, respectively, and do not protrude from the circuit breaker housing  1 , so as to avoid accidental touch. 
     As shown in  FIG.  9   , the second embodiment of the circuit breaker of the present invention is provided. 
     This embodiment is different from the first embodiment in that the button mechanism  2  only includes the first button  20 , and one end of the first button  20  protrudes outside the circuit breaker housing  1 , enabling the switch-on operation and switch-off operation by pressing and pulling respectively; the connecting rod structure  33  only includes the first connecting rod  30 , through which the first button  20  is drivingly connected to the transmission member  4 . 
     Specifically, as shown in  FIG.  9   , of the first button  20 , the upper end protrudes outside the circuit breaker housing  1 , and the lower end is drivingly connected to the transmission member  4  through the first connecting rod  30 . The electric mechanism  2   c  is co-operated with the first button  20  through the transmission rack  26   c , so as to enable the switch-on operation and switch-off operation. 
     As shown in  FIGS.  10 A and  10 B , the third embodiment of the circuit breaker of the present invention is provided. 
     This embodiment is different from the first embodiment in that the first button  20  and the transmission rack  26   c  are fixedly connected to each other, or the first button  20  and the transmission rack  26   c  are integrally shaped; the transmission gear set includes the first fan-shaped gear  251   c  drivingly engaged with the transmission rack  26   c ; when the circuit breaker switches on, the first fan-shaped gear  251   c  rotates in the first direction and drives the first button  20  to move toward the inside of the circuit breaker housing  1  through the transmission rack  26   c , thus the circuit breaker switches on and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission rack  26   c ; when the circuit breaker switches off, the first fan-shaped gear  251   c  rotates in the second direction and drives the first button  20  to move toward the outside of the circuit breaker housing  1  through the transmission rack  26   c , thus the circuit breaker switches off and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission rack  26   c . In the circuit breaker of the present invention, the first fan-shaped gear  250   c  drives the operating mechanism through the transmission rack  26   c , so that after ending the switch-on/switch-off operation on the circuit breaker the first fan-shaped gear  251   c  rotates to its disengagement from the transmission rack  26   c , thereby bringing out no interference with the first button  20 . Firstly, users can still manually perform the switch-on/switch-off operation on the circuit breaker; secondly, when the circuit breaker trips off due to a short circuit or overload fault, the first fan-shaped gear  251   c  will not affect the operation of the operating mechanism, ensuring the protection performance of the circuit breaker. 
     Specifically, as shown in  FIG.  10 A , the circuit breaker is in the switch-off state, the first fan-shaped gear  251   c  is disengaged from the transmission rack  26   c , the driving motor  20   c  drives the first fan-shaped gear  251   c  to rotate clockwise, then the first fan-shaped gear  251   c  rotates to its engagement with the transmission rack  26   c  and continues to rotate, driving the first button  20  to move downwards by the transmission rack  26   c , as shown in  FIG.  10 B , after the circuit breaker switches on, the first fan-shaped gear  251   c  continues to rotate to its disengagement from the transmission rack  26   c ; as shown in  FIG.  10 B , the circuit breaker is in the switch-on state, the first fan-shaped gear  251   c  is disengaged from the transmission rack  26   c , the driving motor  20   c  drives the first fan-shaped gear  251   c  to rotate counterclockwise, then the first fan-shaped gear  251   c  rotates to its engagement with the transmission rack  26   c  and continues to rotate, driving the first button  20  to move upwards by the transmission rack  26   c , as shown in  FIG.  10 A , after the circuit breaker switches off, the first fan-shaped gear  251   c  continues to rotate to its disengagement from the transmission rack  26   c.    
     Preferably, as shown in  FIG.  10 A , the transmission gear set of this embodiment is different from that of the first embodiment in that the driving gear  25   c  includes the first fan-shaped gear  251   c  and the fourth transmission gear  250   c  is coaxial linkage with each other, and the fourth transmission gear  250   c  meshes with the third transmission gear  24   c.    
     As shown in  FIGS.  11 A and  11 B , the fourth embodiment of the circuit breaker of the present invention is provided. 
     This embodiment is different from the first embodiment in that the electric mechanism  2   c  enables the circuit breaker to electrically switch on and switch off by driving the transmission member  4  of the operating mechanism for remote control. The electric mechanism  2   c  includes the driving motor  20   c , the transmission gear set, and the transmission member&#39;s gear  27   c  coaxially arranged with the transmission member  4 . The transmission gear set includes the switch-on and switch-off driving gear drivingly co-operated with the transmission member&#39;s gear  27   c , the switch-on and switch-off driving gear drives the transmission member&#39;s gear  27   c  to rotate, and the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate, enabling the circuit breaker to switch on/switch off. 
     Preferably, the transmission member  4  and the transmission member&#39;s gear  27   c  coaxially interact with each other, and the switch-on and switch-off driving gear is the first fan-shaped gear  251   c ; when the circuit breaker switches on, the first fan-shaped gear  251   c  rotates in the second direction to its engagement with the transmission member&#39;s gear  27   c  and drives the transmission member&#39;s gear  27   c  to rotate in the first direction, thus the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate in the first direction, the circuit breaker switches on and the first fan-shaped gear  251   c  rotates to disengagement from the transmission member&#39;s gear  27   c ; then the circuit breaker switches off, the first fan-shaped gear  251   c  rotates in the first direction to its engagement with the transmission member&#39;s gear  27   c  and drives the transmission member&#39;s gear  27   c  to rotate in the second direction, thus the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate in the second direction, the circuit breaker switches off and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission member&#39;s gear  27   c . In the circuit breaker of the present invention, the first fan-shaped gear  251   c  drives the operating mechanism through the transmission member&#39;s gear  27   c , so that ending the switch-on and switch-off operation on the circuit breaker, the first fan-shaped gear  251   c  rotates to its disengagement from the transmission member&#39;s gear  27   c , thereby bringing out no interference with the transmission member&#39;s gear  27   c  (and the transmission member  4  interacting with the transmission member&#39;s gear  27   c ). Firstly, users can still manually perform the switch-on/switch-off operation on the circuit breaker; secondly, when the circuit breaker trips off due to a short circuit or overload fault, the first fan-shaped gear  251   c  will not affect the operation of the operating mechanism, ensuring the protection performance of the circuit breaker. Further, as shown in  FIGS.  11 A and  11 B , the transmission member&#39;s gear  27   c  is a fan-shaped gear. 
     Specifically, as shown in  FIG.  11 A , the circuit breaker is in the switch-off state, the first fan-shaped gear  251   c  is disengaged from the transmission member&#39;s gear  27   c ; when the circuit breaker switches on, the driving motor  20   c  drives the first fan-shaped gear  251   c  to rotate counterclockwise to its engagement with the transmission member&#39;s gear  27   c , then the first fan-shaped gear  251   c  is driven to continue to rotate and drives the transmission member&#39;s gear  27   c  to rotate clockwise, and the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate clockwise, as shown in  FIG.  11 B , the circuit breaker has switched on and the first fan-shaped gear  251   c  is driven to continue to rotate to its disengagement from the transmission member&#39;s gear  27   c ; as shown in  FIG.  11 B , the circuit breaker is in the switch-on state, the first fan-shaped gear  251   c  is disengaged from the transmission member&#39;s gear  27   c , when the circuit breaker switches on, the driving motor  20   c  drives the first fan-shaped gear  251   c  to rotate clockwise to its engagement with the transmission member&#39;s gear  27   c , then the first fan-shaped gear  251   c  is driven to continue to rotate and drives the transmission member&#39;s gear  27   c  to rotate counterclockwise, and the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate counterclockwise, as shown in  FIG.  11 A , the circuit breaker has broken contact, and the first fan-shaped gear  251   c  is driven to continue to rotate to its disengagement from the transmission member&#39;s gear  27   c.    
     Preferably, this embodiment is the same with the third embodiment in the aspect of the transmission gear set, but different in that each gear has different positional relationship and size from each other, and the number of gears is adjustable. 
     As shown in  FIGS.  15 A- 15 C , the fifth embodiment of the circuit breaker of the present invention is provided. 
     This embodiment is different from the fourth embodiment in that the transmission member&#39;s gear  27   c  and the transmission member  4  are coaxially arranged, and there is an idle stroke therebetween. 
     When the circuit breaker switches on, the switch-on and switch-off driving gear rotates in the second direction and drives the transmission member&#39;s gear  27   c  to rotate from the second initial position to the first direction to its position-limiting co-operation with the transmission member  4 ; the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate in the first direction, thus the circuit breaker switches on and the switch-on and switch-off driving gear rotates in the first direction, so as to drive the transmission member&#39;s gear  27   c  to rotate back to the second initial position; when the circuit breaker switches off, the switch-on and switch-off driving gear rotates in the first direction and drives the transmission member&#39;s gear  27   c  to rotate from the second initial position to the second direction to its position-limiting co-operation with the transmission member  4 , the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate in the second direction, thus the circuit breaker switches off and the switch-on and switch-off driving gear rotates in the second direction, so as to drive the transmission member&#39;s gear  27   c  to rotate back to the second initial position. Further, the switch-on and switch-off driving gear is the first fan-shaped gear  251   c  or a full-shaped gear. 
     Specifically, as shown in  FIG.  15 A , the circuit breaker is in the switch-off state, when the circuit breaker switches on, the driving motor  20   c  drives the switch-on and switch-off driving gear to rotate counterclockwise, thus the switch-on and switch-off driving gear drives the transmission member&#39;s gear  27   c  to rotate clockwise from the second initial position to its position-limiting co-operation with the transmission member  4 , and the transmission member&#39;s gear  27   c  continues to rotate and drives the transmission member  4  to rotate clockwise, so that the circuit breaker completes switching on as shown in  FIG.  15 B , as shown in  FIG.  15 C , the switch-on and switch-off driving gear is driven to rotate clockwise and drives the transmission member&#39;s gear  27   c  to rotate counterclockwise back to the second initial position. As shown in  FIG.  15 C , the circuit breaker is in the switch-on state, when the circuit breaker switches off, the driving motor  20   c  drives the switch-on and switch-off driving gear to rotate clockwise, thus the switch-on and switch-off driving gear drives the transmission member&#39;s gear  27   c  to rotate counterclockwise to its position-limiting co-operation with the transmission member  4 , and the transmission member&#39;s gear  27   c  continues to rotate and drives the transmission member  4  to rotate counterclockwise, so that the circuit breaker completes switching off, as shown in  FIG.  15 A , the switch-on and switch-off driving gear is driven to rotate counterclockwise and drives the transmission member&#39;s gear  27   c  to rotate back to the second initial position. 
     The circuit breaker of the present invention has an idle stroke between the transmission member&#39;s gear  27   c  and the transmission member  4  (that is, only after rotating with a certain angle, the transmission member&#39;s gear  27   c  can drive the transmission member  4  to synchronously rotate, before the transmission member  4  starts to rotate, the transmission member&#39;s gear  27   c  has rotated with the angle as an idle stroke), therefore, after the operating mechanism actuates the circuit breaker to switch on and switch off through the electric mechanism  2   c , the transmission member&#39;s gear  27   c  rotates back to the second initial position, thereby bringing out no interference with the transmission member  4 ; firstly, users can still manually perform the switch-on/switch-off operation on the circuit breaker; secondly, when a short circuit or overload fault occurs, the circuit breaker can successfully trips off, ensuring the protection performance of the circuit breaker. 
     As shown in  FIGS.  12 A and  12 B , the sixth embodiments of the invention cutter is provided. 
     This embodiment is different from the fourth embodiment in that the electric mechanism  2   c  also includes the fourth transmission gear  250   c  is coaxial linkage with the first fan-shaped gear  251   c , the transmission member  4  is arranged coaxially with the transmission member&#39;s gear  27   c , the operating mechanism also includes the trip-off lever  3   c  drivingly connected to the lock catch  51  and pivotally arranged; when the circuit breaker switches on, the first fan-shaped gear  251   c  rotates from the third initial position toward the second direction to its engagement with the transmission member&#39;s gear  27   c  and drives the transmission member&#39;s gear  27   c  to rotate from the second initial position toward the first direction, thus the transmission member&#39;s gear  27   c  drives the transmission member  4  to rotate in the first direction, the circuit breaker switches on and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission member&#39;s gear  27   c , then the transmission member&#39;s gear  27   c  automatically rotates to the second initial position and the transmission member  4  stays at the position by which the transmission member  4  stands on the moment that the circuit breaker switches on (That is, in the first direction, the transmission member&#39;s gear  27   c  coaxially interacts with the transmission member  4 ; in the second direction, the transmission member&#39;s gear  27   c  can automatically rotate in the second direction and return back to the second initial position when the transmission member  4  stays still.); when the circuit breaker switches off, the first fan-shaped gear  251   c  and the fourth transmission gear  250   c  continue to rotate in the second direction, the fourth transmission gear  250   c  drives the trip-off lever  3   c  to rotate, the trip-off lever  3   c  drives the lock catch  51  to rotate in the second direction, so as to release the locking co-operation of the lock catch  51  with the jump buckle  50 , thus the circuit breaker switches off and the first fan-shaped gear  251   c  continues to rotate to the third initial position that nearly engages with the transmission member&#39;s gear  27   c  but not yet engages with it. Further, the electric mechanism  2   c  also includes the transmission member&#39;s gear resetting spring used to reset the transmission member&#39;s gear  27   c.    
     Specifically, as shown in  FIG.  12 A , the circuit breaker is in the switch-on state, the transmission member&#39;s gear  27   c  is at the second initial position, the first fan-shaped gear  251   c  is disengaged from the transmission member&#39;s gear  27   c , when the circuit breaker switches off, the driving motor  20   c  drives the fourth transmission gear  250   c  and the first fan-shaped gear  251   c  to rotate synchronously counterclockwise, and the fourth transmission gear  250   c  drives the lock catch  51  to rotate counterclockwise through the trip-off lever  3   c  during its rotation process, to enable the lock catch  51  to release its locking co-operation with the jump buckle  50 , thus the circuit breaker switches off and the first fan-shaped gear  251   c  continues to the third initial position (the same as shown in  FIG.  11 A ); referring to  FIG.  11 A , when the circuit breaker is in the switch-off state, the first fan-shaped gear  251   c  is at the third initial position, the transmission member&#39;s gear  27   c  is at the second initial position, and the first fan-shaped gear  251   c  does not engage with the transmission member&#39;s gear  27   c ; when the circuit breaker switches on, the driving motor  20   c  drives the first fan-shaped gear  251   c  to rotate counterclockwise to its engagement with the transmission member&#39;s gear  27   c  and drives the transmission member&#39;s gear  27   c  to rotate clockwise, thus the transmission member&#39;s gear  27   c  is driven and enables the transmission member  4  to rotate clockwise, referring to  FIG.  11 B , the circuit breaker switches on and the first fan-shaped gear  251   c  rotates to its disengagement from the transmission member&#39;s gear  27   c , afterward as shown in  FIG.  12 A , the transmission member&#39;s gear  27   c  can be driven by the transmission member&#39;s gear resetting spring to automatically return to the second initial position, and the transmission member  4  stays at the switch-on position. 
     Preferably, as shown in  FIG.  12 B , an embodiment of the trip-off lever  3   c  is provided. 
     As shown in  FIG.  12 B , the trip-off lever  3   c  is pivotally installed inside the circuit breaker housing  1 , and has the two ends co-operated with the fourth transmission gear  250   c  and the lock catch  51  respectively; the backside of the lock catch  51  is provided with the lock catch driving protrusion  511  correspondingly co-operated with one end of the trip-off lever  3   c ; the backside of the fourth transmission gear  250   c  is provided with the fourth transmission gear driving protrusion  2500   c  correspondingly co-operated with the other end of the trip-off lever  3   c ; as shown in  FIG.  12 A , when the circuit breaker switches off, the driving motor  20   c  drives the first fan gear  251   c  and the fourth transmission gear  250   c  to rotate counterclockwise (clockwise as shown in  FIG.  12 B ); the fourth transmission gear driving protrusion  2500   c  drives the trip-off lever  3   c  to rotate clockwise (counterclockwise as shown in  FIG.  12 B ); the trip-off lever  3   c  drives the lock catch  51  to rotate counterclockwise (clockwise as shown in  FIG.  12 B ), so as to be set off to trip off and switch off. Further, as shown in  FIG.  12 B , the trip-off lever  3   c  has a V-shaped structure, and a trip-off lever axle hole in its middle portion. Of course, the trip-off lever  3   c  may also adopt other similar structures. 
     Preferably, the transmission gear set of this embodiment has the same structure as that of the fourth embodiment. 
     As shown in  FIGS.  1  and  9 - 13 A , the seventh embodiment of the circuit breaker of the present invention is provided. 
     The circuit breaker of the present invention further includes the arc extinguishing system  8 , the short-circuit protection mechanism  7  and the overload protection mechanism  9  drivingly cooperated with the operating mechanism respectively, the wire-inlet terminal  1   i  and the wire-outlet terminal  1   o , which are arranged in the circuit breaking housing; the wire-outlet terminal  1   o  and the button mechanism  2  are arranged at one end of the circuit breaker housing  1 , and the wire-inlet terminal  1   i  is arranged at the other end of the circuit breaker housing  1 ; the arc extinguishing system  8  and the short-circuit protection mechanism  7  are arranged side by side between the operating mechanism and the wire-inlet terminal  1   i , and the electric mechanism  2   c  and the overload protection mechanism  9  are positioned on one side of the operating mechanism and between the arc extinguishing system  8  and the wire-outlet terminal  1   o . Further, as shown in  FIG.  1   , the button mechanism  2  is arranged opposite to the short-circuit protection mechanism  7  and positioned on one side of the circuit breaker housing  1 ; the wire-outlet terminal  1   o  and the arc extinguishing system  8  are arranged opposite to each other and positioned on the other side of the circuit breaker housing  1 . Specifically, as shown in  FIG.  1   , the upper, lower, left, and right sides of  FIG.  1    corresponding to the upper, lower, left, and right sides of the circuit breaker respectively, and the side of  FIG.  1    facing the reader corresponds to the front side of the circuit breaker; the wire-outlet terminal  1   o  and the button mechanism  2  are arranged side by side on the upper end of the circuit breaker housing  1 , and the wire-outlet terminal  1   i  is arranged at the lower end of the circuit breaker housing  1 ; the arc extinguishing system  8  and the short-circuit protection mechanism  7  are arranged side by side between the operating mechanism and the wire-inlet terminal  1   i , and the electric mechanism  2   c  and the overload protection mechanism  9  are positioned on the left side of the operating mechanism and between the arc extinguishing system  8  and the wire-outlet terminal  1   o.    
     Preferably, as shown in  FIGS.  1  and  14   , the circuit breaker further includes the control circuit board  1   c  connected to the electric mechanism  2   c.    
     Preferably, as shown in  FIG.  1   , the control circuit board  1   c  is arranged between the bottom plate of the circuit breaker housing  1  and the electric mechanism  2   c , the control circuit board  1   c  and the electric mechanism  2   c  are positioned on the same side of the operating mechanism, and the control circuit board  1   c  is positioned between the wire-outlet terminal  1   o  and the arc extinguishing system  8 . Specifically, as shown in  FIG.  1   , the upper, lower, left, and right sides of  FIG.  1    correspond to the upper, lower, left, and right sides of the circuit breaker, respectively, and the side of  FIG.  1    facing the reader corresponds to the front side of the circuit breaker. The control circuit board  1   c  and the electric mechanism  2   c  are positioned on the left side of the button mechanism  2  of the operating mechanism, the control circuit board  1   c  is positioned on the front side of the bottom plate of the circuit breaker housing  1 , and the electric mechanism  2   c  is positioned on the front side of the control circuit board  1   c . The control circuit board  1   c  basically overlaps the electric mechanism  2   c , so the space of the circuit board is small. 
     Preferably, as shown in  FIG.  1   , the circuit breaker further includes the signal terminal connected to the control circuit board  1   c , the signal terminal and the wire-inlet terminal  1   i  are arranged at the same end of the circuit breaker housing  1 , and the signal terminal is positioned between the two wire-inlet terminals  1   i.    
     Preferably, as shown in  FIG.  13 A , the short-circuit protection mechanism  7  is an electromagnetic release. 
     Preferably, as shown in  FIG.  13 A , the overload protection mechanism  9  is a manganin resistor in series connection with the L-pole circuit of the circuit breaker, and the manganin resistor is connected to the control circuit board  1   c , and transmits signals to the control circuit board  1   c . If an overload fault occurs, the electric mechanism  2   c  drives the circuit breaker to switch off. 
     Preferably, the overload protection mechanism  9  is a current transformer coupled to the L-pole circuit of the circuit breaker and connected to the control circuit board  1   c , and the current transformer collects the current signals of the L-pole circuit and transmits them to the control circuit board  1   c . When an overload fault occurs, the electric mechanism  2   c  drives the circuit breaker to switch off. 
     Preferably, the overload protection mechanism  9  is a bimetallic strip drivingly co-operated with the jump buckle  51 . When an overload fault occurs, the bimetallic strip bends and drives the jump buckle  51  to rotate, so that the lock catch  50  and the jump buckle  51  release the locking co-operation with each other, and the circuit breaker switches off. 
     Preferably, as shown in  FIG.  1   , the circuit breaker housing  1  includes the wire-inlet terminal hole  14  and the signal terminal hole  15  arranged at one end thereof, and the wire-outlet terminal hole, the first button hole and the second button hole arranged at the other end of the circuit breaker housing  1 . The wire-inlet terminal, the signal terminal and the wire-outlet terminal are arranged in the corresponding openings, respectively; of the first button  20 , one end is slidably arranged in the first button hole, and the other end is connected with the first connecting rod  30 ; and of the second button  21 , one end is slidably arranged in the second button hole, and the other end is connected with the second connecting rod  31 . 
     As the control circuit board  1   c  not only needs to be connected to the electric mechanism  2   c  and the overload protection mechanism  9  (such as a manganin resistance or a current transformer), but also needs to be connected to the wire-inlet terminal  1   i  to take electricity, and to the signal terminal to transmit signals. If the control circuit board  1   c  adopts the embodiment shown in  FIG.  1   , when the control circuit board  1   c  is connected with the wire-inlet terminal  1   i  and the signal terminal, wiring will run far away and connects with flexible wires, resulting in the more troubles in wiring and welding during assembly. Thus, whether manual assembly or automatic assembly, it is difficult to control the position of the wires. 
     Preferably, as shown in the preferred embodiment of the control circuit board  1   c  shown in  FIG.  14   , the bottom plate of the circuit breaker housing  1  is positioned on one side of the control circuit board  1   c , and the electric mechanism  2   c , the operating mechanism and the arc extinguishing system  8  are positioned on the other side of the control circuit board. The control circuit board  1   c  extends at least beyond the short-circuit protection mechanism  7  and the arc extinguishing system  8  and is adjacent to the wire-inlet terminal  1   i  and the signal terminal, and the printed wires extending beyond the arc extinguishing system  8  and used to connect with the wire-inlet terminal  1   i  and the signal terminal are arranged on the control circuit board  1   c . Specifically, as shown in  FIG.  1   , the upper, lower, left, and right sides of  FIG.  1    correspond to the upper, lower, left, and right sides of the circuit breaker, respectively. The bottom plate of the circuit breaker housing  1  is positioned on the left side of the control circuit board  1   c , and the electric mechanism  2   c , the operating mechanism and the arc extinguishing system  8  are positioned on the right side of the control circuit board. Further, the button mechanism  2  and the short-circuit protection mechanism  7  are both directly arranged on the bottom plate of the circuit breaker housing  1 . It should be pointed out that, according to actual needs, the button mechanism  2  and the short-circuit protection mechanism  7  can also be arranged on the other side of the control circuit board  1   c , in the same way as the electric mechanism  2   c , the operating mechanism, and the arc extinguishing system  8 , so as to further expand the installation space for the control circuit board  1   c.    
     We have made further detailed description of the present invention mentioned above in combination with specific preferred embodiments, but it is not deemed that the specific embodiments of the present invention is only limited to these descriptions. A person skilled in the art can also, without departing from the concept of the present invention, make several simple deductions or substitutions, which all be deemed to fall within the protection scope of the present invention.