Abstract:
A switch module of built-in anti-surge disconnection structure mainly comprises an overcurrent protection switch and an anti-surge disconnection structure ingeniously built inside a heat-resisting housing. The switch module has a first connecting point and a second connecting point for operation. When overvoltage occurs, the temperature of at least one metal oxide varistor would instantly rise up to a degree higher than the melting point thereof, melting at least one thermo-sensitive piece, loosening at least one spring element, displacing a pushing element, and thus forcing the connecting points detaching from each other to turn off the switch and stop supplying the electricity power, so as to ensure more of electricity safety. Also, the switch module has the colloid thermo-sensitive piece directly fixing the spring element instead of having a band for fixing in the prior art, achieving an easier manufacturing process and better effectiveness of the switch module.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a switch module of built-in anti-surge disconnection structure, particularly to an overcurrent protection switch that has anti-surge and disconnection structures built inside. 
         [0003]    2. Description of the Related Art 
         [0004]      FIGS. 1A and 1B  disclose a conventional overcurrent protection switch  10  that has plural connecting points arranged in the middle part and comprises a housing  11  with a press button  12  on the top, a first terminal  12   a,  a second terminal  12   b,  a third terminal  12   c  separately arranged at the bottom, and a moving element  14 . The first terminal  12   a  has a bimetal plate  13  and a first contact  131 ; the second terminal  12   b  has a second contact  121  corresponding to the first contact  131 . The moving element  14  has one end linking the bottom of the press button  12  and the other linking the moving terminal of the bimetal plate  13 , whereby the pressing of the press button  12  actuates the first contact  131  connecting to the second contact  121  and therefore turns on the device; while overcurrent occurs, the bimetal plate  13  deforms due to high degree of temperature and disconnects the first and second contact  131 ,  121 , turning off the device so as to form an overcurrent protection switch  10 . Such structure can be found in Taiwan patent applications No. 540811, 367091, 320335, 262168, and 208384. However, the structure disclosed above aims at protection from overcurrent situation but is not able to protect the device when sudden overvoltage such as lightning strike occurs. 
         [0005]    Therefore, for safety concern, a usual solution to the defect is to parallel connect to a metal oxide varistor, and to connect to a thermal fuse in series. 
         [0006]      FIG. 2A  is the invention of U.S. Pat. No. 8,643,462. It discloses an anti-surge switch module applied in an electric system. The switch module comprises a power switch  105 , an insulating member  106 , a surge absorber  107  and a pyrocondensation belt  108 . The insulating member  106  engages with the power switch  105  that abutting against the surge absorber  107 ; and the pyrocondensation belt  108  ties the surge absorber  107  and the insulating member  106  together so that it could contract when receiving the heat from the surge absorber  107  and thus turn off the power switch  105  under certain degree of contracting. However, the insulating member  106 , the surge absorber  107  and the pyrocondensation belt  108  are not disposed inside the power switch  105  but are connected outside, failing to form a complete device with the power switch  105 . 
         [0007]    In short, the structures disclosed above have shortcomings as uncertain quality, possible exceeding heat due to external connection of components, slow reaction, large volumes, and complicated composition, and they require more constructing space and procedures. Besides, the protection device has to be connected independently outside instead of having one inside. 
         [0008]    In UL 1449 3 rd  Edition (2009) Type 4 was added to Surge Protective Devices (SPDs) requirements. The 3 rd  Edition also includes the Low voltage Surge Arresters under 1000 V in the requirements, and the title is also altered from Transient Voltage Surge Suppressors into Surge Protective Devices. This shows the importance of integrating the components and the surge arresters function of the device. 
         [0009]    Hence, the inventor has invented U.S. patent applications Ser. No. 14/324,432, No. 14/617,000 and No. 14/824,211 to construct an anti-surge disconnection structure built inside a heat-resisting and fireproof housing of an overcurrent protection switch so that the disconnection could be operated successfully and instantly when an overload occurs. Still, the inventor has continued to develop such feature and further designed a switch module with easier manufacturing process and better effectiveness. 
       SUMMARY OF THE INVENTION 
       [0010]    A primary object of the present invention is to provide a switch module of built-in anti-surge disconnection structure that has the original function of overcurrent protection and further includes an anti-surge and disconnection structure to ensure more of electricity safety. Also, the switch module has a colloid thermo-sensitive piece directly fixing the spring element instead of having a band for fixing, thus achieving an easier manufacturing process and better effectiveness. 
         [0011]    To achieve the objects mentioned above, the present invention comprises a housing having a press button arranged atop thereof, and a first conductive plate, a second conductive plate and a third conductive plate arranged at a lower section thereof; the first conductive plate being connected to a binary alloy conductive plate and having a first connecting point, and the second conductive plate having a second connecting point on the surface of an upper section thereof corresponding to the first connecting point; a moving rod linking up the bottom of the press button with one end and the binary alloy conductive plate with the other end for the first connecting point to contact the second connecting point, consequently turning on the switch, and for the first connecting point to detach from the second connecting point when current overload occurs and the binary alloy conductive plate is deformed due to high temperature, consequently turning off the switch, so as to form an overcurrent protection switch; 
         [0012]    Wherein an anti-surge disconnection structure is built inside the housing, including at least one metal oxide varistor being disposed under a plate and having a first surface and an opposite second surface; at least one spring element having an outer periphery with an extended portion connecting the first surface of the metal oxide varistor with the second conductive plate, and a springy section being compressed on the first surface of the metal oxide varistor; at least one thermo-sensitive piece being solid colloid to be adhered on the first surface of the metal oxide varistor for fixedly adhering the springy section of the spring element on the first surface of the metal oxide varistor for the spring element to be ready for ejection; a pushing element having a first end thereof arranged correspondingly to the metal oxide varistor and the springy section of the spring element, and a second end thereof arranged correspondingly to the binary alloy conductive plate for pushing; 
         [0013]    Whereby when the first connecting point is contacting the second connecting point and an overvoltage occurs, the temperature of the metal oxide varistor would instantly rise up to a degree higher than the melting point thereof, therefore melting the thermo-sensitive piece, loosening the springy section of the spring element and displacing the pushing element to force the first connecting point detaching from the second connecting point and turn off the switch. 
         [0014]    Furthermore, in a second embodiment, the anti-surge disconnection structure includes a first metal oxide varistor being disposed under a plate and having a first surface and an opposite second surface; at least one spring element having an outer periphery with a first extended portion connecting the first surface of the first metal oxide varistor with the second conductive plate, and a springy section being compressed on the first surface of the first metal oxide varistor; at least one thermo-sensitive piece being solid colloid to be adhered on the first surface of the first metal oxide varistor for fixedly adhering the springy section of the spring element on the first surface of the first metal oxide varistor for the spring element to be ready for ejection; a second metal oxide varistor having a first surface and a opposite second surface; the first surface thereof compressing the spring element; an electrical connector abutting on the second surface of the second metal oxide varistor and having a second extended portion arranged aside for electrical connection between the second surface of the second metal oxide varistor and the third conductive plate; a pushing element having a first end thereof arranged correspondingly to the middle of the electrical connector and the second surface of the second metal oxide varistor, and a second end thereof arranged correspondingly to the binary alloy conductive plate for pushing. 
         [0015]    What&#39;s more, in a third embodiment, the anti-surge disconnection structure includes at least one metal oxide varistor being disposed under a plate and having a first surface and an opposite second surface; at least one spring element having an outer periphery with an extended portion connecting the first surface of the metal oxide varistor with the second conductive plate, and a springy section being compressed on the first surface of the metal oxide varistor; at least one thermo-sensitive piece being solid colloid to be adhered on the first surface of the metal oxide varistor for fixedly adhering the springy section of the spring element on the first surface of the metal oxide varistor for the spring element to be ready for ejection; a pushing element having a first end thereof arranged correspondingly to the metal oxide varistor and the springy section of the spring element, and a second end thereof arranged correspondingly to the binary alloy conductive plate for pushing. 
         [0016]    With structures disclosed above, the present invention complements the defect of a conventional overcurrent protection switch that it has to connect to a metal oxide varistor from the outside by having the anti-surge disconnection structure ingeniously built inside the heat-resisting and fireproof housing. When receiving exceedingly high voltages, the heating metal oxide varistor would instantly melt down the thermo-sensitive piece, loosening the springy section of the spring element for ejection and further displacing the pushing element, therefore forcing the first connecting point detaching from the second connecting point and turning off the switch immediately. Therefore, the present invention is not only overcurrent protective but also overvoltage protective and surge absorbing, ensuring more electricity safety and conveniences in using. Also, the switch module has the colloid thermo-sensitive piece directly fixing the spring element instead of having a band for fixing as in the prior art, thus achieving an easier manufacturing process and better effectiveness. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1A  is a perspective view of an overcurrent protection switch according to the prior art; 
           [0018]      FIG. 1B  is a section view of an overcurrent protection switch according to the prior art; 
           [0019]      FIG. 2  is a perspective view of an anti-surge disconnection structure according to U.S. Pat. No. 8,643,462; 
           [0020]      FIG. 3  is a sectional view of the present invention in a first embodiment in an OFF status; 
           [0021]      FIG. 3A  is a perspective view illustrating the thermo-sensitive piece adhering the springy section of the spring element on the metal oxide varistor in  FIG. 3 ; 
           [0022]      FIG. 4  is a sectional view of the present invention in the first embodiment in an ON status; 
           [0023]      FIG. 5  is an application example of the present invention illustrating the thermo-sensitive piece melting, loosening the spring element, displacing the pushing element, and further turning the switch off; 
           [0024]      FIG. 5A  is a perspective view illustrating the thermo-sensitive piece melting, loosening the springy section of the spring element in  FIG. 5 ; 
           [0025]      FIG. 6  is an exploded view of the major components of the present invention in the first embodiment; 
           [0026]      FIG. 6A  is a schematic diagram illustrating the pushing element formed in one-piece with the spring element; 
           [0027]      FIG. 7  is a schematic diagram of the present invention with two metal dioxide varistors; 
           [0028]      FIG. 7A  is a partially enlarged view of  FIG. 7 ; 
           [0029]      FIG. 8  is a schematic diagram illustrating the thermo-sensitive piece melting, loosening the spring element, displacing the pushing element, and further turning the switch off in  FIG. 7 ; 
           [0030]      FIG. 8A  is a partially enlarged view of  FIG. 8 ; 
           [0031]      FIG. 9  is an exploded view of the major components of the present invention in a second embodiment; 
           [0032]      FIG. 10  a sectional view of the present invention in a third embodiment with three metal oxide varistors; 
           [0033]      FIG. 10A  is a sectional view along line  10 A- 10 A in  FIG. 10 ; 
           [0034]      FIG. 11  is a schematic diagram illustrating the thermo-sensitive pieces melting, loosening the spring element, displacing the pushing element, and further turning the switch off in  FIG. 10 ; 
           [0035]      FIG. 11A  is a sectional view along line  11 A- 11 A in  FIG. 11 ; and 
           [0036]      FIG. 12  is an exploded view of the major components of the present invention in a third embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    Referring to  FIGS. 3-6 , in a first embodiment, the present invention mainly includes a housing  31 , a moving rod  33 , and an anti-surge disconnection structure  70 . 
         [0038]    The housing  31  has a press button  32  arranged atop thereof, and a first conductive plate  40  for positive electrode input, a second conductive plate  50  for positive electrode output and a third conductive plate  60  for negative electrode input arranged at a lower section thereof. The first conductive plate  40  is connected to a binary alloy conductive plate  41  that has a spring leaf  42  and a first connecting point  421 , and the second conductive plate  50  has a second connecting point  511  corresponding to the first connecting point  421 . 
         [0039]    The moving rod  33  has a top end arranged at the bottom of the press button  32  and a bottom end connecting to a movable end  411  of the binary alloy conductive plate  41 . With reference to  FIG. 4 , when pressing the press button  32 , the binary alloy conductive plate  41  ejects upwards and the spring leaf  42  ejects downwards to make the first connecting point  421  contacting the second connecting point  511  and thus turn on the switch; when current overload occurs, the binary alloy conductive plate  41  deforms due to high temperature and detach the first connecting point  421  from the second connecting point  511  to turn the switch off back to the original status as shown in  FIG. 3 , so as to form a switch module  30  with an overcurrent protection switch. 
         [0040]    The arrangement of the binary alloy conductive plate  41  and the press button  32  is different in various switch modules. In this embodiment, the binary alloy conductive plate  41  has the first connecting point  421  arranged on the spring leaf  42  but it is not limited to such application. The binary alloy conductive plate  41  can eject without the spring leaf  42  and the first connecting point  421  can be arranged aside the binary alloy conductive plate  41 . 
         [0041]    The features of the present invention lies in that the anti-surge disconnection structure  70  is built inside the housing  31  and includes at least one metal oxide varistor  71 , at least one spring element  73 , at least one thermo-sensitive piece  72 , and a pushing element  75 . 
         [0042]    The metal oxide varistor  71  is disposed under a plate  74  and has a first surface  711  and an opposite second surface  712 . In this embodiment, the first surface  711  is the positive electrode and the second surface  712  is the negative electrode; they are electrically connected to the second conductive plate  50  and the third conductive plate  60  by a pre-determined connector which can be a conductive wire, a conductive plate, or a conductive element extended from the surface of the metal oxide varistor  71 . 
         [0043]    The spring element  73  has an outer periphery  731  and a springy section  732  compressed on the first surface  711  of the metal oxide varistor  71  as shown in  FIG. 3A .In this embodiment, there is one spring element  73  and the second surface  712  of the metal oxide varistor  71  is arranged under the plate  74 ; the plate  74  is arranged as a fixed surface for ejection and therefore it can be a conductive plate, a positioning plate together formed in one-piece with the housing  31 , or an extended portion from the third conductive plate  60 . The outer periphery  731  of the spring element  73  further has an extended portion  733  that is arranged as a bended portion  734  and connects the first surface  711  of the metal oxide varistor  71  with the second conductive plate  50 . As shown in  FIG. 6 , the extended portion  733  has the bended portion  734  for engaging a first slot  52  arranged on the second conductive plate  50  so that when the spring element  73  is ejected, the bended portion  734  will provide stronger elasticity for ejection and then return to a straight status without affecting the operation. The second surface  712  of the metal oxide varistor  71  is connected to the third conductive plate  60  by the plate  74  and a conductive wire  741 ; in this embodiment, the plate  74  and conductive wire  741  are formed in one-piece extended from the third conductive plate  60 . 
         [0044]    The thermo-sensitive piece  72  is solid colloid to be adhered on the first surface  711  of the metal oxide varistor  71  for fixedly adhering the springy section  732  of the spring element  73  thereon for the spring element  73  to be ready for ejection. In this embodiment, the thermos-sensitive piece  72  is made of metal compounds that are fast-acting in low temperature, e.g. common metal compounds in producing fuses, but the present invention is not limited to such application; it can also be made of non-metal thermo-sensitive materials. In other words, materials those would melt at a pre-determined degree before the temperature of the metal oxide varistor  71  rises up to a high number would apply, conductive or not. 
         [0045]    The pushing element  75  has a first end  751  arranged correspondingly to the metal oxide varistor  71  and the springy section  732  of the spring element  73 , and a second end  752  arranged correspondingly to the binary alloy conductive plate  41  for pushing. In this embodiment, the pushing element  75  is an isolated pushing rod and the first end  751  is contacting the springy section  732 . Furthermore, the first end  751  is arranged for engaging the springy section  732  in a preferred embodiment. When the spring element  73  is ejected, the first connecting point  421  on the binary alloy conductive plate  41  would be forced to detach from the second connecting point  511 . In another applicable embodiment as shown in  FIG. 6A , the pushing element  75  is formed in one-piece with the spring element  73  as a protruding section arranged at the front of the spring element  732 . 
         [0046]    Further referring to  FIGS. 5 and 5A , when the first connecting point  421  is contacting the second connecting point  511  and an overvoltage occurs, the temperature of the metal oxide varistor  71  would instantly rise up to a degree higher than the melting point of the thermo-sensitive piece  72 , melting the thermo-sensitive piece  72 , counterbalancing the compressing force on the spring element  73  and further displacing the pushing element  75 , therefore forcing the first connecting point  421  detaching from the second connecting point  511  and turning off the switch without having the first conductive plate  40  deformed due to the high degree of temperature. Consequently, the metal oxide varistor  71  stops heating up and stops supplying electricity power for the device as well. 
         [0047]      FIGS. 7-9  illustrate an exploded view of the main elements of the present invention in a second embodiment. In this embodiment, the anti-surge disconnection structure  70  mainly comprises a first metal oxide varistor  71   a,  a second metal oxide varistor  71   b,  at least one spring element  73   a,  at least one thermo-sensitive piece  72 , an electrical connector  73   c,  and a pushing element  75 . 
         [0048]    The first metal oxide varistor  71   a  is disposed under a plate  74  and has a first surface  711  and an opposite second surface  712 . The spring element  73   a  has an a springy section  732  compressed on the first surface  711  of the first metal oxide varistor  71   a,  and an outer periphery  731  with a first extended portion  733   a  connecting the first surface  711  of the first metal oxide varistor  73   a  with the second conductive plate  50 . 
         [0049]    The thermo-sensitive piece  72  is solid colloid to be adhered on the first surface  711  of the first metal oxide varistor  71   a  for fixedly adhering the springy section  732  thereon for the spring element  73   a  to be ready for ejection. The second metal oxide varistors  71   b  has a first surface  711  compressing the spring element  73   a.  The electrical connector  73   c  is abutting on a second surface  712  of the second metal oxide varistor  71   b  and has a second extended portion  733   b  arranged aside for electrical connection between the second surface  712  of the second metal oxide varistor  71   b  and the third conductive plate  60 . In this embodiment, the first extended portion  733   a  and the second extended portion  733   b  are arranged as bended portions  734  for respectively engaging a first slot  52  arranged on the second conductive plate  50  and a second slot  61  arranged on the third conductive plate  60  as shown in  FIG. 9 , so that when the spring element  73  is ejected, the bended portions  734  will provide stronger elasticity for ejection and then return to a straight status without affecting the operation. 
         [0050]    The pushing element  75  has a first end  751  arranged correspondingly to the middle of the electrical connector  73   c  and the second surface  712  of the second metal oxide varistor  71   b,  and a second end  752  arranged correspondingly to the binary alloy conductive plate  41  for pushing. In this embodiment, the electrical connector  73   c  has a positioning hole  735  arranged in the middle thereof and the pushing element  75  is an isolated pushing rod; the first end  751  thereof is fixedly engaging the positioning hole  735  so that when the spring element  73  is ejected, the first connecting point  421  on the binary alloy conductive plate  41  would be forced to detach from the second connecting point  511 , stopping the first metal oxide varistor  71   a  and the second metal oxide varistor  71   b  from heating up and stopping supplying electricity power for the device as well, as shown in  FIG. 7 . 
         [0051]      FIG. 8  is a schematic diagram illustrating the thermo-sensitive piece melting, loosening the spring element, displacing the pushing element, and further turning the switch off in  FIG. 7 ; and  FIG. 8A  is a partially enlarged view of  FIG. 8 . In this embodiment, the plate  74  does not have to be parallel connected to the third conductive plate  60 ; it is also applicable to connect the second extended portion  733   b  with the third conductive plate  60  and to have the plate  74  being the ground for connection. 
         [0052]      FIGS. 10-12  illustrate a third embodiment of the present invention. In this embodiment, the anti-surge disconnection structure  70  mainly comprises a first metal oxide varistor  71   a,  a second metal oxide varistor  71   b,  a third metal oxide varistor  71   c,  a first spring element  73   a,  a second spring element  73   b,  a first thermo-sensitive piece  72   a,  a second thermo-sensitive piece  72   b,  an electrical connector  73   c,  and a pushing element  75 . 
         [0053]    The first thermo-sensitive piece  72   a  is solid colloid to be adhered on the first surface  711  of the first metal oxide varistor  71   a  for fixedly adhering the springy section  732  of the first spring element  73   a  on the first surface  711  of the first metal oxide varistor  71  for the first spring element  73   a  to be ready for ejection. The first spring element  73   a  further has an outer periphery  731  with a first extended portion  733   a  connecting the first surface  711  of the first metal oxide varistor  71  with the second conductive plate  50 . The second metal oxide varistor  71   b  has a first surface  711  and an opposite second surface  712 ; the first surface  711  thereof is compressing the first spring element  73   a.  The second thermo-sensitive piece  72   b  is solid colloid to be adhered on the second surface  712  of the second metal oxide varistor  71   b  for fixedly adhering the springy section  732  of the second spring element  73   b  on the second surface  712  of the second metal oxide varistor  71   b  for the second spring element  73   b  to be ready for ejection. The second spring element  73   b  further has an outer periphery  731  with a second extended portion  733   b  connecting the second surface  712  of the second metal oxide varistor  71   b  with the third conductive plate  60 . The third metal oxide varistor  73   c  has a first surface  711  and a opposite second surface  712  and the second surface  712  thereof is compressing the second spring element  73   b.  The electrical connector  73   c  is abutting on the first surface  711  of the third metal oxide varistor  71   c  and has a third extended portion  733   c  arranged aside for electrical connection between the third metal oxide varistor  71   c  and the plate  74 . The pushing element  75  has a first end  751  arranged correspondingly to the middle of the electrical connector  73   c  and the first surface  711  of the third metal oxide varistor  71   c,  and a second end  752  arranged correspondingly to the binary alloy conductive plate  41  for pushing. In this embodiment, the plate  74  further has a conductive element  742  to be electrically connected to the electrical connector  73   c,  and the electrical connector  73   c  has a positioning hole  735  arranged in the middle thereof for engaging the first end  751  of the pushing element  75 ; the third extended portion  733   c  further has a contacting point  736  for contacting and simultaneously detaching from an bottom end of the conductive element  742 . 
         [0054]    In this embodiment, the first extended portion  733   a  and the second extended portion  733   b  are arranged as bended portions  734  for respectively engaging the second conductive plate  50  and the third conductive plate  60 , so that when any of the thermo-sensitive pieces melts down and loosens the springy section  732  of either spring elements, the bended portions  734  would will provide strong elasticity for ejection and then return to a straight status without affecting the operation. The plate  74  may further have a fourth conductive plate  743  disposed aside and extended to the outside of the housing  31  (not shown) for further application. 
         [0055]    With structures disclosed above, the present invention complements the defect of a conventional overcurrent protection switch that it has to connect to a metal oxide varistor and a thermal fuse from the outside by having an anti-surge disconnection structure  70  including at least one metal oxide varistor, at least one thermo-sensitive pieces, and at least spring element ingeniously built inside so that when receiving exceedingly high voltages, the heating metal oxide varistor would instantly melt the thermo-sensitive piece, counterbalancing the compressing force on the spring element and further displacing the pushing element, therefore forcing the connecting points to detach and turning off the switch immediately. Hence, the present invention has the original function of overcurrent protection and further has the overvoltage protection and anti-surge disconnection structures built inside, ensuring more electricity safety and conveniences in using. 
         [0056]    Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.