Patent Publication Number: US-2021175645-A1

Title: Electrical Connector

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date under 35 U.S.C. § 119(a)-(d) of Chinese Patent Application No. 201911270316.1, filed on Dec. 5, 2019. 
     FIELD OF THE INVENTION 
     The present invention relates to an electrical connector and, more particularly, to an electrical connector adapted to connect one or two bus bars for carrying a large current. 
     BACKGROUND 
     In order to facilitate connection, an electrical connector is usually used to realize an electrical connection between a plate-like bus bar for carrying a large current and another plate-like bus bar or cable. In order to meet the requirement of being able to transmit the large current such as a direct current of 100 A or more, or an alternating current of 45 A or more, the electrical connector generally comprises upper and lower sheet conductive terminals adapted to clamp the bus bar. Each of the sheet conductive terminals is made of a single piece of extension conductive component, and each conductive terminal includes a main body extending in a plane perpendicular to a clamping direction in which the bus bar is clamped, and a plurality of curved cantilevers, on which electrical contacts are formed. 
     In the existing electrical connector with upper and lower conductive terminals, the curved cantilever provides fewer electrical contacts, for example, 24 electrical contacts. According to circuit parallel principle, a contact resistance generated by the 24 electrical contacts is relatively large. In addition, a clamping force for clamping the bus bar is provided by the curved cantilever extending in a plane substantially parallel to the bus bar, and the clamping force is insufficient. 
     SUMMARY 
     An electrical connector includes a plurality of sheet terminals each having a main body and at least a pair of cantilevers. Each pair of the cantilevers extends from at least one of a first side and an opposite second side of the main body and has a pair of contact portions protruding toward each other inside a pair of free ends of the pair of cantilevers. The plurality of sheet terminals are assembled together in a stacked manner and a receiving chamber with an insertion opening is formed between the pair of cantilevers of the plurality of sheet terminals. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying Figures, of which: 
         FIG. 1  is a perspective view of an electrical connector according to an embodiment; 
         FIG. 2  is an enlarged view of a part A of  FIG. 1 ; 
         FIG. 3  is a perspective view of a sheet terminal according to an embodiment; 
         FIG. 4  is a perspective view of the electrical connector of  FIG. 1  clamped to a pair of bus bars; 
         FIG. 5  is a perspective view of an electrical connector according to another embodiment; 
         FIG. 6  is an exploded perspective view of the electrical connector of  FIG. 5 ; 
         FIG. 7  is a perspective view of the electrical connector of  FIG. 5  clamped to a pair of bus bars; and 
         FIG. 8  is a perspective view of a sheet terminal according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The technical solution of the disclosure will be described hereinafter in further detail with reference to the following embodiments, taken in conjunction with the accompanying drawings. In the description, the same or similar reference numerals indicate the same or similar parts. The description of the embodiments of the disclosure hereinafter with reference to the accompanying drawings is intended to explain the general inventive concept of the disclosure and should not be construed as a limitation on the disclosure. 
     In addition, in the following detailed description, for the sake of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may also be practiced without these specific details. In other instances, well-known structures and devices are illustrated schematically in order to simplify the drawing. 
     As shown in  FIGS. 1 and 2 , an electrical connector  100  according to an exemplary embodiment of the disclosure comprises a plurality of sheet terminals  2 . 
     In an exemplary embodiment of the disclosure, as shown in  FIGS. 1 to 4 , each of the sheet terminals  2  is made of, for example, a copper sheet and comprises a flat main body  21  and at least a pair of cantilevers  22 ,  23 ,  24 ,  25 . The main body  21  is provided with at least one through hole  211  with which the plurality of sheet terminals  2  stacked together are aligned. Each pair of the cantilevers  22 ,  23 ,  24 ,  25  extends from at least one of opposite first and second sides of the main body  21  and is provided with contact portions  221 ,  231 ,  241 ,  251  protruding toward each other inside of free ends thereof. 
     The plurality of sheet terminals  2  are assembled together in a stacked manner, and a receiving chamber  27  with an insertion opening  26  is formed between the pair of cantilevers  22 ,  23 ,  24 ,  25  of the plurality of sheet terminals  2 , as shown in  FIGS. 1-4 . A plate-like bus bar  10 ,  20  is inserted into the receiving chamber  27  through the insertion opening  26  and clamped between the pair of cantilevers  22 ,  23 ,  24 ,  25  so as to realize an electrical connection between the bus bar  10 ,  20  and the electrical connector  100 . The plate-like bus bar  10 ,  20  is clamped between the pair of cantilevers  22 ,  23 ,  24 ,  25  of the plurality of sheet terminals  2 , it is thus possible to reduce a contact resistance between the sheet terminal  2  and the clamped plate-like bus bar  10 ,  20  and increase a clamping force applied to the bus bar  10 ,  20 . 
     In an exemplary embodiment of the disclosure, the electrical connector  100  further comprises at least one connection rod  1  configured to pass through the through hole  211  provided in the main body  21  of each sheet terminal  2  to assemble the plurality sheet terminals  2  together, as shown in  FIG. 1 . The connection rod  1  may be fixed by a screw connection, riveting, soldering or the like at both ends thereof. 
     Although the embodiment in which the plurality of sheet terminals  2  are assembled together by the connection rod  1  is described above, the disclosure is not limited thereto. In an alternative embodiment of the disclosure, the plurality of sheet terminals  2  may be connected together sequentially by soldering (for example, an ultrasonic soldering). In another alternative embodiment of the disclosure, the plurality of stacked sheet terminals  2  may be pressed and held in a holding frame. 
     In an exemplary embodiment of the disclosure, as shown in  FIG. 3 , the at least a pair of cantilevers  22 ,  23 ,  24 ,  25  of each of the sheet terminals  2  comprises at least a pair of main cantilevers  22 ,  24  outside the sheet terminal  2 . Each pair of main cantilevers  22 ,  24  is provided with main contact portions  221 ,  241  protruding toward each other inside free ends thereof. The main contact portion  221 ,  241  is in electrical contact with the bus bar  10 ,  20 , thereby achieving the electrical connection between the bus bar  10 ,  20  and the electrical connector  100 . 
     In an exemplary embodiment of the disclosure, as shown in  FIG. 3 , the at least a pair of cantilevers  22 ,  23 ,  24 ,  25  of each of the sheet terminals  2  further comprises at least a pair of auxiliary cantilevers  23  or  25  each disposed inside the at least a pair of main cantilevers  22  and  24 . Each of the auxiliary cantilevers  23 ,  25  is spaced apart from the adjacent main cantilever  22 ,  24  to allow the auxiliary cantilever  23 ,  25  to move relative to the main cantilever  22 ,  24 . Each pair of auxiliary cantilevers  23 ,  25  is provided with auxiliary contact portions  231  or  251  protruding toward each other inside free ends thereof. Further, a length of the auxiliary cantilever  23  or  25  extending from the first side or the second side of the main body  21  is smaller than that of the main cantilever  22 ,  24  extending from the first side or the second side of the main body  21 . A distance between the auxiliary contact portions  231 ,  251  of the pair of auxiliary cantilevers  23 ,  25  is smaller than that between the main contact portions  221 ,  241  of the pair of main cantilevers  22 ,  24 . In an alternative embodiment of the disclosure, two or three pairs of auxiliary cantilevers  23 ,  25  having auxiliary contact portions  231 ,  251  may be provided between the pair of main cantilevers  22 ,  24  to increase the electrical contact with the bus bar  10 ,  20 . 
     In this way, during inserting the bus bar  10  or  20  into the electrical connector  100 , as shown in  FIGS. 3 and 4 , the bus bar  10 ,  20  firstly passes through the main contact portions  221 ,  241  of the main cantilever  22  or  24  and is brought in contact with the auxiliary contact portions  231 ,  251  so that the auxiliary cantilever  23  or  25  is biased outwardly. Thereafter, the bus bar  10  or  20  is brought in contact with the main contact portions  221 ,  241  so that the bus bar  10  or  20  is held within the receiving chamber  27  formed by the plurality of cantilevers  22 ,  23 ,  24 ,  25 . 
     In an exemplary embodiment of the disclosure, as shown in  FIGS. 2 and 3 , the contact portions  221 ,  241 ,  231 ,  251  of the plurality of sheet terminals  2  are arranged in rows in a direction parallel to the connection rod  1  so that the contact portions  221 ,  241 ,  231 ,  251  in each row are in contact with the bus bar  10 ,  20  at the same time. 
     In an exemplary embodiment of the disclosure shown in  FIG. 3 , in each sheet terminal  2 , the at least a pair of main cantilevers  22 ,  24  includes a pair of first main cantilevers  22  provided on the first side of the main body  21 , and the at least a pair of auxiliary cantilevers  23 ,  25  includes a pair of first auxiliary cantilevers  23  provided inside the pair of first main cantilevers  22 . In this way, there are four contact portions to be in contact with the bus bar  10  on the first side of the main body  21  of each sheet terminal  2 . 
     In an exemplary embodiment of the disclosure shown in  FIG. 3 , in each of the sheet terminals  2 , the at least one pair of main cantilevers  22 ,  24  includes a pair of second main cantilevers  24  provided on the second side of the main body  21 . Further, the at least one pair of auxiliary cantilevers  23 ,  25  includes a pair of second auxiliary cantilevers  25  provided inside the pair of second main cantilevers  24 . In this way, there are four contact portions to be in contact with the bus bar  20  on the second side of the main body  21  of each sheet terminal  2 . 
     In the embodiment shown in  FIGS. 1-4 , two bus bars  10 ,  20  may be electrically connected to the first side and the second side of the electrical connector  100 , respectively, thereby achieving the electrical connection between the two bus bars  10 ,  20 . The bus bar  10 ,  20  may transmit a large current such as a direct current of 100 A or more, or an alternating current of 45 A or more. 
     In the electrical connector  100  of the embodiment shown in  FIGS. 1-4 , the plurality of stacked sheet terminals  2  are assembled together by the connection rod  1 , and each pair of cantilevers  22 ,  23 ,  24 ,  25  has one or more elastic contact portions  221 ,  231 ,  241 ,  251  to be connected with the bus bar  10 ,  20 . An appropriate number of sheet terminals  2  may be selected and the sheet terminals  2  are stacked together in a limited space according to a size of a working space. The one or more elastic contact portions  221 ,  231 ,  241 ,  251  provided on each pair of cantilevers  22 ,  23 ,  24 ,  25  double the number of the contact portions  221 ,  231 ,  241 ,  251  of the electrical connector  100  to be in contact with the bus bar  10 ,  20 . It should be understood that these elastic contact portions  221 ,  231 ,  241 ,  251  are connected in parallel in a connection circuit. According to the principle of the parallel circuit, the contact resistance formed by one contact portion  221 ,  231 ,  241 ,  251  may be relatively large. However, the parallel connection of the plurality of identical contact portions  221 ,  231 ,  241 ,  251  may significantly reduce the contact resistance. 
     For example, in the electrical connector  100  shown in  FIGS. 1 to 4 , the first main cantilever  22  and the first auxiliary cantilever  23  on the first side of the sheet terminal  2  are provided with four contact portions. If the electrical connector  100  includes two hundred sheet terminals  2 , the sheet terminal  2  will be provided with eight hundred contact portions to be electrically connected to the bus bar  10  on the first side thereof. Generally, the contact resistance of the electrical connection of one contact portion with the bus bar  10  is 0.55 milliohms. Thus, the total contact resistance generated by the two hundred sheet terminals  2  of the electrical connector  100  is: 
       0.55/(200*4)=0.0006875 (milliohm). 
     On the other hand, in a conventional electrical connector having two upper and lower conductive terminals, each conductive terminal comprises a main body extending in a plane perpendicular to the clamping direction in which the clamping bus bar is clamped, and twelve curved cantilevers extending from the main body. Each of the curved cantilevers is provided with a contact portion. In this way, the conventional electrical connector has twenty four contact portions to be in electrical contact with the bus bar, and the total contact resistance is 0.0208 milliohms. Therefore, the electrical connector  100  according to the embodiment of the disclosure significantly reduces the contact resistance of electrical contact with the bus bar. 
     Further, since the cantilevers  22 ,  23 ,  24 ,  25  (the main cantilever and the auxiliary cantilever) of each sheet terminal  2  of the electrical connector  100  extend in the plane perpendicular to the bus bar  10 ,  20 , each cantilever  22 ,  23 ,  24 ,  25  may provide a larger elastic clamping force to the bus bar  10 ,  20 . In this way, the bus bar  10 ,  20  may be reliably clamped in the receiving chamber  27 , and each contact portion  22 ,  23 ,  24 ,  25  may be kept to be reliably electrically connected to the bus bar  10 ,  20 , thereby improving the electrical transmission performance of the electrical connector  100 . 
     In another exemplary embodiment of the disclosure, as shown in  FIG. 5-7 , the electrical connector  100  further comprises two protective frames  3  each mounted outside the two outermost sheet terminals  2  by the connection rod  1 . In this way, the sheet terminals  2  may be protected. 
     In an exemplary embodiment of the disclosure, each of the protective frames  3  is provided with an auxiliary slot  31  communicating with the receiving chamber  27  between the pair of cantilevers  22 ,  23 ,  24 ,  25  on at least one end thereof, as shown in  FIG. 5 . In this way, a width of the connected bus bar  10  may be allowed to be greater than that of the electrical connector  100 , and the bus bar  10  may pass through the receiving chamber  27  and the auxiliary slot  31  in the width direction of the electrical connector  100 . 
     In another exemplary embodiment of the disclosure, as shown in  FIGS. 5-7 , each of the protective frames  3  comprises an upper frame  32  and a lower frame  33  each mounted outside the two outermost sheet terminals  2  by the connection rod  1  passing through a through-hole  34  in each of the frames  32 ,  33 . The connection rod  1  is connected to the protective frame  3  by a nut  11  on at least end thereof. Further, an extended conductive component  4  is mounted at an end of the protective frame  3  to be electrically connected with the cantilevers  22 ,  23 ,  24 ,  25  of the plurality of sheet terminals  2  on the second side. The bus bar  10 ,  20  or other conductive components such as cables may be electrically connected by the extended conductive member  4 . 
     In an exemplary embodiment of the disclosure, as shown in  FIGS. 5-7 , the extended conductive component  4  comprises two conductive plates. Each of the conductive plates includes a clamped portion  41  inserted and clamped between the pair of cantilevers  22 ,  23 ,  24 ,  25  of the plurality of sheet terminals  2 , a clamping portion  42  provided outside the plurality of sheet terminals  2  and configured to clamp the plate-like bus bar  30 , and a transition portion  43  integrally connected between the clamping portion  41  and the clamped portion  42  so that the two clamped portions  41  are brought in contact with each other and the two clamping portions  42  are separated from each other. The bus bar  30  is fixed between the clamping portions  42  by bolt members  5  and through holes  421  provided in the clamping portion  42  to be electrically connected to the electrical connector  100 . 
     In an exemplary embodiment, a distance between the clamping portions  42  of the two conductive plates is greater than a maximum distance between the pair of cantilevers  22 ,  23 ,  24 ,  25 . In this way, a thickness of the bus bar  30  clamped between the clamping portions  42  may be allowed to be greater than that of the bus bar  10  or  20  clamped between the cantilevers  22 ,  23 ,  24 ,  25 . 
     In a case where a current from a main conductive path needs to be shunted into one or more sub-conductive paths, one or more electrical connectors  100  according to the embodiments of the disclosure may be used to carry larger current and electrically connect the bus bar  30  of larger thickness to one or more bus bars  10  for carrying branch currents and having a smaller thickness. The distance between the clamping portions  42  of the two conductive plates of the extended conductive component  4  may be changed as desired so that the extended conductive component  4  is electrically connected with the bus bars  10 ,  20 ,  30  having different thicknesses, thereby increasing the application range of the electrical connector  100 . 
     In a sheet terminal  2 ′ according to another embodiment, as shown in  FIG. 8 , the main body  21  of each sheet terminal  2 ′ is provided with a connection hole  28  at the second side thereof, and the connection holes  28  of the plurality of sheet terminals  2  are aligned with each other. The cantilever of the sheet terminal  2 ′ of the embodiment shown in  FIG. 8  on the first side has the same structure as that of the sheet terminal  2  of the embodiment shown in  FIG. 3 . That is, in each of the sheet terminals  2 ′, the main body  21  is provided with a pair of first main cantilevers  22  on the first side thereof, and a pair of first auxiliary cantilevers  23  is provided inside the pair of first main cantilevers  22 . In this way, there are four contact portions to be in contact with the bus bar  10  on the first side of the main body  21  of each of the sheet terminal  2 ′. 
     The plurality of stacked sheet terminals  2 ′ are assembled together by the connection rod  1  passing through the through hole  211  of each of the sheet terminal  2 ′ to form the electrical connector according to another embodiment of the disclosure. The bus bar may be connected at the first side of the plurality of sheet terminals  2 ′, and a cable or a conductive rod may be electrically connected at the second side of the plurality of sheet terminals  2 ′ through the connection hole  28  by welding or screwing, thereby realizing the electrical connection between the bus bar and the cable. 
     As shown in  FIGS. 1-8 , each pair of cantilevers  22 ,  23 ,  24 ,  25  is configured to be symmetrical about a plane between the pair of cantilevers  22 ,  23 ,  24 ,  25 . In this way, the electrical connector  100  may be mounted properly without taking inconsideration of an upper or lower structure thereof. The bus bar  10 ,  20  thus may be easily inserted into the electrical connector  100 . 
     It should be appreciated by those skilled in this art that the above embodiments are intended to be illustrative, and many modifications may be made to the above embodiments by those skilled in this art. Further, various structures described in various embodiments may be freely combined with each other without conflicting in configuration or principle. 
     Although the disclosure has been described hereinbefore in detail with reference to the attached drawings, it should be appreciated that the disclosed embodiments in the attached drawings are intended to illustrate embodiments of the disclosure by way of example, and should not be construed as limiting the disclosure. 
     Although a few embodiments of the general inventive concept of the disclosure have been shown and described, it would be appreciated by those skilled in the art that changes or modifications may be made to these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined by claims and their equivalents. 
     It should be noted that, the word “comprise” doesn&#39;t exclude other elements or steps, and the word “a” or “an” doesn&#39;t exclude more than one. In addition, any reference numerals in the claims should not be interpreted as the limitation to the scope of the disclosure.