Patent Publication Number: US-9905943-B2

Title: Clamping cage for an edge connector

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application under 35 C.F.R. § 371 of the PCT International Application No. PCT/EP2014/069375 filed Sep. 11, 2014, which claims priority of the German application No. DE 10 2013 110 157.7 filed Sep. 16, 2013. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     A connector module includes a hollow generally-rectangular terminal cage body bent from a conductive first metal sheet to form at least one vertical generally rectangular side wall and a pair of end walls, one of the cage walls having a horizontal lower surface defining a first cage sealing surface, and a vertical interior wall surface defining a second cage sealing surface; a horizontal bus bar formed from a conductive second metal sheet and having a relatively broad horizontal top surface defining a horizontal first bus bar sealing surface, and a relatively narrow side surface defining a vertical second bus bar sealing surface; and a securing arrangement for securing one of the bus bar first and second sealing surfaces with the corresponding one of the cage first and second sealing surfaces. 
     Description of Related Art 
     For the connection of an electrical conductor to an electrical assembly, connection devices are commonly used in which the insulated end of the electrical conductor is pushed or pulled by means of a spring or a spring-mounted pressure piece against a bus bar. Here, the bus bar is connected or can be connected to the electrical assembly. 
     Such connection devices are usually produced in a modular design and then they have a terminal cage in which the clamping site is located where the spring or the pressure piece pushes or pulls the conductor end to the bus bar. 
     Numerous designs are known for the production of such connection modules. The designs differ, for example, in the materials used for the terminal cage, the spring and the bus bar. 
     Commonly, the terminal cage and the spring are produced so as to form a single part from a material with satisfactory spring properties, for example, from a spring steel, and the bus bar is produced separately from a satisfactorily conductive material, for example, from copper. These construction elements can also be produced separately, wherein, for the terminal cage, optionally a very inexpensive, preferably thin-walled material can be used. Such connection devices with separately produced bus bar are featured, for example, in the German publication No. DE 20 2011 000 714 U1. 
     It is also known to produce the bus bar and the terminal cage, and optionally also the spring, so as to form a single part. However, in these connection modules, the terminal cage is relatively complicated and for that reason requires a lot of material with a large amount of waste. In addition, satisfactorily conductive material such as copper, for example, is expensive. Moreover, single-part production of a bus bar and a terminal cage requires a large spacing between several connection modules arranged one after the other. 
     Therefore, the problem of the invention is to provide a connection module in which the terminal cage is indeed made from a satisfactorily conductive material, in particular from a copper-containing metal or from copper, but can nevertheless be produced cost-effectively, and also to provide a direct plug-in terminal with a connection module, a series connection device with several connection modules, and a method for producing the connection module. 
     SUMMARY OF THE INVENTION 
     Accordingly, a primary object of the present invention is to provide a connector module for connecting the bare end of an insulated electrical conductor with an electrical device, including a hollow generally-rectangular terminal cage body bent from a conductive first metal sheet to form at least one vertical generally rectangular side wall and a pair of end walls, one of the cage walls having a horizontal lower surface defining a first cage sealing surface, and a vertical interior wall surface defining a second cage sealing surface; a horizontal bus bar formed from a conductive second metal sheet and having a relatively broad horizontal top surface defining a horizontal first bus bar sealing surface, and a relatively narrow side surface defining a vertical second bus bar sealing surface; and a securing arrangement for securing one of the bus bar first and second sealing surfaces with the corresponding one of the cage first and second sealing surfaces. 
     Another object of the invention is to provide with such a connector module a resilient generally inverted V-shaped spring contact mounted between the cage end walls, said spring contact having a stationary first leg adapted to react with the inner surface of a first end wall, and a second leg biased away from said first leg to displace the bare end of a conductor toward electrical engagement with the inner surface of the other cage end wall. The cage body is mounted within a chamber contained in a housing formed of insulating material. 
     According to the present invention, a connection module for an electrical connection device is provided for connecting an electrical conductor to an electrical assembly, which comprises a terminal cage as well as a bus bar. The terminal cage is provided in order to provide a clamping site for the electrical conductor. The terminal cage and the bus bar are produced independently of one another, in each case forming a single part, from a satisfactorily electrically conductive flat strip. As a satisfactorily electrically conductive flat strip material it is preferable to use a copper alloy for the flat strips. The flat strips, from which the terminal cage and the bus bar are produced, in each case present two broad sides facing one another and narrow sides that connect said broad sides. The terminal cage and the bus bar are provided for carrying an electrical current. 
     It is preferable that the terminal cage and/or the bus bar are produced as punched parts or as punched and folded parts. The narrow sides of the flat strip of the bus bar in this way form narrow sides of the bus bar, and the narrow sides of the flat strip of the terminal cage in this way form narrow sides of the terminal cage. 
     Here, both a production of the terminal cage and of the bus bar from the same flat strip, and also a production of the terminal cage and of the bus bar from different flat strips, particularly flat strips having different thicknesses, are preferable. Here, the thickness of the bus bar and of the terminal cage is dimensioned so that both the bus bar and also the terminal cage have sufficient mechanical stability as well as sufficient current carrying capacity. 
     The terminal cage has at least three walls arranged at a right angle with respect to one another, which extend parallel or substantially parallel to a conductor entry direction. Here, the formulation “substantially parallel” covers a terminal cage in which at least one of the walls is arranged at an acute angle relative to the conductor entry direction, in particular at an angle of 0°-60°. However, it is particularly preferable that all the walls of the terminal cage extend parallel to the conductor entry direction. Here, the walls are preferably arranged at a right angle with respect to one another. 
     The connection module is characterized in that either the terminal cage is fastened permanently on a narrow side of the bus bar or the bus bar is fastened permanently (in particularly, firmly bonded) on a narrow side of the terminal cage. 
     In comparison to a single-part production of the terminal cage with bus bar, in this design of the connection module, there is hardly any waste, so that the proportion of waste and thus the material consumption in the production can be clearly reduced. Although the production of this connection module requires an additional method step, in which the terminal cage and the bus bar are fastened permanently to one another, the production of the connection module can nevertheless be considerably more cost-effective due to the saving of expensive flat strip material. 
     Since the narrow sides of the flat strip for the terminal cage are the narrow sides of the terminal cage, and since the narrow sides of the flat strip for the bus bar are the narrow sides of the bus bar, the narrow sides of the terminal cage have the thickness of the flat strip used for the terminal cage, and the narrow sides of the bus bar have the thickness of the narrow sides of the flat strip used for the bus bar. 
     In a preferred embodiment, the terminal cage is designed so that it is U-shaped. Here it is preferable that two of the walls are narrow walls which are connected by the third wall, referred to below as connecting wall. One of the narrow walls is preferably provided for supporting a spring. Moreover, between the second narrow wall and the spring, a clamping site for the electrical conductor is preferably provided. In another preferred embodiment, the terminal cage is designed so that it is square in cross section. In this embodiment, it is preferably designed circumferentially closed or also preferably circumferentially open. 
     In the embodiment in which the terminal cage is designed so that it is U-shaped, it encloses the clamping site to a large extent. In the embodiment in which the terminal cage is designed so that it is square in cross section, it encloses the clamping site nearly completely or even completely. 
     It is preferable that the terminal cage and the bus bar are fastened to one another at a linear connection seam. They are particularly preferably fastened firmly bonded, most particularly preferably by welding, particularly by resistance welding or by laser welding. 
     The terminal cage preferably has a longitudinal extent. It is preferable that it encloses at least partially an inner space in a circumferential direction relative to the longitudinal extent. Preferably, in the interior space, the clamping site for clamping the electrical conductor is arranged on the terminal cage or on the bus bar. 
     In a particularly material-saving embodiment, the terminal cage is moreover designed to be open on two end faces facing one another that are arranged transversely to the longitudinal extent. It is preferable that the bus bar is arranged on one of the end faces and, in particular, parallel to said end face. The interior space of the terminal cage in this embodiment as well remains accessible, at least from the facing end face. 
     In order to be able to fasten the bus bar particularly simply to the terminal cage, it is preferable that the terminal cage has a first wall which is extended relative to at least one additional wall or a portion of the first wall of the terminal cage, so that this wall has an extension. The extension is preferably designed in the shape of a rectangular tongue. Preferably, the extension is extended relative to at least one upper edge, lower edge or side edge of a wall of the terminal cage. It is preferable that the bus bar is fastened to the extension on the terminal cage. As a result, the bus bar is at a distance from the upper edge, the lower edge or the side edge, and it can be placed highly flexibly in the connection module in accordance with a specific application. 
     The problem is moreover solved by a direct plug-in terminal which comprises such a connection module. The direct plug-in terminal is preferably a spring-loaded terminal which has a spring. The spring is preferably arranged at least partially in the interior space of the terminal cage and provided in order to press an electrical conductor against the bus bar or to pull said electrical conductor onto the bus bar. It is preferable that the direct plug-in terminal comprises a housing made of an insulation material. The housing made of an insulation material preferably encloses the entire circumference of the terminal cage. In addition, it is preferable that, in the insulation material housing, a conductor entry opening is provided, through which an electrical conductor can be introduced into the terminal cage, in particular into the clamping site. 
     The problem is moreover solved by a series connection device with at least two such connection modules. The series connection device is characterized in that the connection modules have a common bus bar, and a distance between adjacent terminal cages of the connection module is smaller than a width of one of the terminal cages, in particular of a narrow side of the terminal cage. In comparison to a single-part production of a series connection device with several connection modules arranged adjacently along the bus bar, the terminal cages of the series connection device according to the invention can be produced independently of their width, in particular of the width of their narrow walls. Therefore, they can be arranged closer to one another. Preferably, a distance between adjacent terminal cages of the series connection device according to the invention is less than 0.7 times the width of a narrow wall of one of the terminal cages, particularly preferably less than 0.5 times the width of the narrow wall. 
     The problem is solved moreover by a method for producing such a connection module, in which a terminal cage and a bus bar are produced independently of one another in each case as a single part made from a satisfactorily electrically conductive flat strip, and in which, thereafter, either the terminal cage is fastened firmly bonded on a narrow side of the bus bar formed by a narrow side of the flat strip of the bus bar, or the bus bar is fastened firmly bonded on narrow side of the terminal cage formed by a narrow side of the flat strip of the terminal cage. The fastening occurs preferably in a firmly bonded manner by welding, preferably by resistance welding or laser welding. 
     In spite of the several method steps needed in this production method, namely the mutually independent production of a terminal cage and a bus bar and their subsequent connection to one another, the production of the connection module using expensive materials can be clearly more cost-effective due to the considerable material savings in comparison to single-part production of the connection module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and advantages of the invention will become apparent from a study of the following specification, when viewed in the light of the accompanying drawing, in which: 
         FIG. 1 a    is an explodeed perspective view of a plug in terminal block including a first connector module embodiment, and  FIG. 1 b    is a perspective view of a second connector module embodiment; 
         FIGS. 1 c  and 1 d    are perspective views of the conductive sheets from which the bus bar and the cage body are formed, respectively; 
         FIG. 1 e    is an end view of a cage body formed by bending the sheet of  FIG. 1   d;    
         FIGS. 1 f  and 1 g    are cross sectional views of three-sided and four-sided embodiments of the invention, respectively; 
         FIGS. 2 and 3  are side views of embodiments of the invention wherein the conductor entry directions are vertical and horizontal, respectively, relative to a horizontally arranged bus bar; 
         FIGS. 4 a -4 d    are perspective views illustrating embodiments having a plurality of connector modules mounted on a common bus bar; 
         FIG. 5 a    is a perspective view illustrating the connector module arrangement of  FIG. 4 b    mounted in a terminal block housing; and 
         FIG. 5 b    is a perspective view of the connector module arrangement of  FIG. 4 c    mounted in a terminal block housing. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to  FIGS. 1 a  and 1 b   , a terminal block connector  10  includes a housing  12  formed of electrically insulating material, which housing contains a chamber  13  in which is mounted a connector module  1 , and a first conductor inlet opening  11  for introducing the bare end  81  of an insulated conductor into the chamber along a longitudinal entry axis  80 . As best shown in  FIG. 1 b   , the connector module  1  includes a cage body  2  that is formed by bending a planar sheet  200  ( FIG. 1 d   ) of conductive metal, thereby to define at least one side wall  221 , and a pair of orthogonally arranged end walls  222 ,  223 . One end of a horizontal bus bar  3  is introduced into housing chamber  13  via a second inlet opening  11   a . As shown in  FIG. 1 c   , the bus bar  3  is formed from a conductive metal strip  300  having a rectangular cross section to define a pair of relatively wide horizontal top and bottom wall surfaces  320 , and a pair of relatively narrow vertical side wall surfaces  310 . 
     Also mounted in the chamber  13  on a fixed support pin  14  is an inverted V-shaped spring  4  having a first leg  42  in engagement with one end wall  223  of the cage body  2  of the connector module  1 , and a second leg  41  biased toward the other end wall  222  of the cage body. A manually operable release member  5  is vertically slideably mounted in the housing  12  for displacing the spring leg  41  toward the spring leg  42 , thereby to permit insertion and removal of the conductor bare end into the chamber  13 . Consequently, when the release member  5  is in the released condition of  FIG. 1 b   , the spring leg  41  biases the conductor bare end  81  toward electrical engagement with the end wall  222  of cage body  2 . 
     As will be explained in greater detail below, in the embodiment of  FIGS. 1 b  and 1 e   , the bus bar  3  vertical side wall  310  ( FIG. 1 c   ) is permanently welded to the inside vertical surface of the cage tongue portion  27  that extends downwardly from the lower edge  281  ( FIGS. 1 b  and 1 d   ) from the cage side wall  221 . The cage tongue portion  27  terminates at its lower end in a horizontal lower edge  21 . The bus bar is welded to the tongue portion flush with this lower horizontal edge  21  so that a spacing distance A ( FIG. 1 e   ) is provided between the upper surface  320  of the bus bar and the lower edges  281  of the end walls. 
     The terminal cage body  2  and the bus bar  3  are produced independently of one another and are then fastened permanently to one another. The terminal cage body extends in a longitudinal direction  60  which is here opposite the conductor entry direction  80 . The bus bar  3  in this embodiment is arranged on the terminal cage body  2  in such a way that it extends transversely to the conductor entry direction  80 . 
     For pivoting the first spring arm  41  in the pivoting direction  141  ( FIG. 1 a   ), the pressure member  5  can be actuated manually, in particular with a tool such as the tip of a screwdriver (not shown). Here, the first spring arm  41  is actuated by actuating the pressure piece  5  in a conductor entry direction  80  so that a clamping site (not shown), which is arranged in the interior space  24  of the terminal cage  2 , opens. In this state, an electrical conductor  8  can be introduced into the clamping site. By releasing the pressure piece  5 , the first spring arm  41  is pivoted back due to the restoring force of the spring  4  against the pivoting direction  141 , and the electrical conductor  8  introduced into the clamping site is clamped between the spring  4  and the terminal cage  2 . Therefore, the terminal cage body  2  is provided here for providing the clamping site. 
     The insulated electrical conductor  8  is represented diagrammatically in  FIG. 1 a   . It has a bare conductor end  81  by means of which it can be introduced into the clamping site. In  FIG. 1 b   , the spring  4  and the pressure piece  5  are arranged in the position relative to the connection module  1  in which they are arranged in the connector terminal block  10 . 
       FIG. 1 c    shows the flat strip  300  from which the bus bar  3  is produced. The flat strip  300  extends in an unrolling direction  330 , wherein the narrow vertical sides  310  extend transversely to and along the unrolling direction  330 . The flat strip  300  has a constant thickness D 3  which corresponds to the height H 3  of the narrow sides  310 . 
     In order to produce a bus bar  3  for the connection module  1  of  FIG. 1 b    from this flat strip  300 , the flat strip  300  is merely cut to length. Therefore, the bus bar  3  is preferably produced as a punched part. Therefore, the narrow sides  310  of the flat strip  300  are the narrow sides  31  of the bus bar  3 . Moreover, the broad sides  320  of the flat strip  300  are also the broad sides  32  of the bus bar  3 . 
     Similarly, the terminal cage  2  is produced from a flat strip  200  unrolled in the unrolling direction  230 . Here, the shape of the broad sides  220  is adapted, for example, by punching or sawing. Subsequently, the flat strip  200  is folded to form the terminal cage body  2 . Therefore, the terminal cage body  2  is produced as a punched and folded part. The narrow sides  210  of the flat strip  200  which has been adapted and folded in this way are the narrow sides  210  of the terminal cage  2 . They have a height H 2  which corresponds to the thickness D 2  of the flat strip  200 .  FIG. 1 d    shows the unrolled view of the terminal cage body  2 . 
     The terminal cage body  2  of  FIGS. 1 b  and 1 e    is designed so that it has a square cross section. Therefore, it has either four walls  221 ,  221   a ,  222 ,  223  ( FIG. 1 g   ), or three walls  221 ,  222 ,  223  ( FIG. 1 f   ). The walls  221 - 223  are arranged at an approximately right angle relative to one another. They in each case have an extension component  602  in the longitudinal direction  60  as well as an extension component  601  transversely to the longitudinal direction  60  of the terminal cage  2 . Here as well, the longitudinal direction  60  extends opposite the conductor entry direction  80 . The walls  221 - 223  are therefore provided parallel to the conductor entry direction  80 . 
     In order to be able to produce the smallest possible direct plug-in terminal  10  with the connection module  1 , the terminal cage  2  has two walls  222 ,  223  facing one another which have a width B W , which here corresponds to a width B S  of the bus bar  3  plus the height H 2  of the narrow sides  21  of the terminal cage  2 . The end walls  222 ,  223  facing one another are also referred to as narrow walls. 
     The spring  4  is supported on a first of the two narrow walls  223 . The clamping site is arranged between the spring  4  and a second of the two narrow walls  222 . 
     The narrow walls  222 ,  223  are connected to one another by a connecting wall  221 . The connecting wall  221  has a larger width B V , as determined by the spring and a clamping angle  41  of the spring  4 , than the narrow walls  222 ,  223 . 
     Here, a first wall  221  of the terminal cage body  2  is extended relative to its other walls  222 ,  223 , so that this wall  221  has an extension  27  designed as a rectangular tongue. The terms extension  27  and tongue are used synonymously below. The tongue  27  therefore extends over a lower edge  281  of the terminal cage  2 , viewed in the conductor entry direction  80 . 
     In the represented embodiment example of  FIGS. 1 b  and 1 e   , the bus bar  3  is fastened on the extension  27  on the terminal cage  2 . In particular, it is fastened with one of its narrow sides  31  on the extension  27  on the terminal cage  2 . Here, it is provided flush with an edge  271  of the extension  27 . As a result, it is at a distance from the lower edge  281 . The distance A is represented in  FIG. 1   e.    
     The fastening occurs preferably in a firmly bonded manner, preferably by welding. As a result, a connection seam  7 , along which the bus bar  3  is arranged on the terminal cage body  2 , has a linear design. By laser welding or resistance welding, a very precise and accurate production of the connection seam  7  is possible. 
       FIGS. 2 and 3  show two additional embodiments of connector modules  1  according to the invention. In both embodiments, in contrast to the embodiment of  FIGS. 1 b  and 1 e   , the bus bar  3  is arranged on a narrow side  21  of the terminal cage body  2 . 
     Here, the bus bar  3  of  FIG. 2  extends transversely to the longitudinal direction  60  of the terminal cage body  2 , that is to say parallel to the end faces  25 ,  26  of the terminal cage  2 , and, in  FIG. 3 , in the longitudinal direction  60 , that is to say transversely to the end faces  25 ,  26  of the terminal cage body  2 . As a result, the terminal cage  2  of  FIG. 2  is accessible from outside from one of the end faces  25 , and the terminal cage body  2  of  FIG. 3  is accessible from both end faces  25 ,  26 . 
     In both embodiments, the first side wall  221  is extended. In the embodiment of  FIG. 2 , the first side wall  221  is extended so that, when viewed in the conductor entry direction  80 , it projects relative to a lower edge  281  of a wall  222 ,  223  of the terminal cage  2 . The bus bar  3  is here provided flush with an edge  271  of the extension  27 . Therefore, it is separated in this embodiment from the lower edge  281  by the distance A. 
     On the other hand, in the embodiment of  FIG. 3 , the first wall  221  is extended so that, viewed in the conductor entry direction  80 , it projects over a side edge  282  of the terminal cage  2 . Therefore, in this embodiment, the bus bar  3  is at a distance A from the side edge  282 . 
     The connection modules  1  produced in this manner have the advantage, compared to the connection modules known to date (not shown), that, in their production, a considerable material savings of approximately 15%-25% is possible. 
       FIGS. 4 a  to 4 d    show, in each case, a series connection device  100  with at least two such connection modules  1  each without a housing  12 . The connection modules  1  in each case have a common bus bar  3  as well as at least two or more terminal cage bodies  2 . In the embodiments of  FIGS. 4 a -4 c   , the terminal cage body  2  is welded in each case on the narrow side  31  of the bus bar  3 . In the embodiment of  FIG. 4 d   , on the other hand, it is welded with its narrow side  21  on the bus bar  3 . In both cases, the terminal cage  2  is connected at its tongue  27  to the bus bar  3 . 
     In the embodiment of  FIG. 4 a   , two connection modules  1  are provided. The terminal cage bodies  2  of the two connection modules  1  are arranged on the common bus bar  3 . Between the terminal cages  2 , the bus bar  3  has a bend  32 , so that the conductor entry directions  80  of an electrical conductor into the terminal cages  2  are arranged with respect to one another at an angle (not marked) determined by the bend  32 . 
     Moreover, the two terminal cages  2  here are in a mirror symmetrical arrangement with respect to an axis of symmetry  9 . As a result, they are oriented opposite one another. Their conductor entry openings  11  are arranged, therefore, on the side facing away from their adjacent terminal cage  2 . 
     In the series connection device  100  of  FIG. 4 b   , in each case two connection modules  1  oriented in the same direction are arranged grouped with respect to one another at the smallest possible distance apart A 1 . The series connection device  100  has two such groups of connection modules  1 , wherein the connection modules  1  of the two groups are in a mirror symmetrical arrangement with respect to the axis of symmetry  9 . The terminal cages  2  of the two groups are, therefore, oriented opposite one another. 
     In comparison to a single-part production of a series connection device (not shown), in which a distance between two adjacent connection modules (not shown) is determined by a width of the adjacent terminal cages (not shown), in particular of their narrow walls, the series connection arrangement  100  according to the invention allows a very tight placement of the terminal cages  2  on the bus bar  3 , because the production of the bus bar  3  and the production of the terminal cages  2  occur independently of one another. The distance A 1  between adjacent 2 terminal cages can therefore be selected to be very small. It can be selected to be smaller than the sum of the widths B of the narrow walls  223 ,  222  of the adjacent terminal cages  2 . 
     In the series connection device  100  of  FIG. 4 c   , four connection modules  1  oriented in the same direction are arranged grouped with respect to one another at the smallest possible distance apart A 1 . The distance A 1  is smaller than the sum of the widths B of the narrow walls  2222 ,  223  of the adjacent terminal cages  2 . In addition, the series connection device  100  has a connection module  1  oriented in the opposite direction, which is farther apart from the four grouped connection modules  1 . 
     The series connection device  100  of  FIG. 4 d    has two connection modules  1  in a mirror symmetrical arrangement with respect to the axis of symmetry  9 , which are arranged a large distance apart from one another. 
       FIG. 5 a    shows the series connection device  100  of  FIG. 4 c   , and in  FIG. 5 b   , the series connection devices  100  of  FIG. 4 b   , each with housing  12 . Both series connection devices  100  have snap-in mounting feet  101 , by means of which they can be arranged on a hat-shaped mounting rail (not shown), as is known in the art. As a result, several such series connection devices  100  can be arranged in a row next to one another on the same mounting rail. 
     While in accordance with the provisions of the Patent Statutes the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that changes may be made without deviating from the invention described above.