Patent Publication Number: US-7914333-B2

Title: Plug-in adapter

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the US National Stage of International Application No. PCT/EP2005/051096 filed Mar. 10, 2005 and claims the benefit thereof. The International Application claims the benefits of German application No. 102004016380.4 DE filed Apr. 2, 2004, both of the applications are incorporated by reference herein in their entirety. 
     FIELD OF INVENTION 
     The invention relates to a plug-in adaptor for establishing an electrical connection between contacts of a plug, which is fixed to the end of a cable, and contact surfaces of a patch panel, which are formed on the edge of a printed circuit board. 
     BACKGROUND OF INVENTION 
     To connect an electronic unit with a cable, to the end of which a plug is connected, to a printed circuit board, various contacting devices are known. If different types of plugs or the individual leads of the cable are to be connected directly, a corresponding multiway-design of connector is required on the printed circuit board. 
     When connecting a telecommunication system to the public telephone network it may be necessary, depending on local conditions, to form the connection by means of a type RJ-45 or by a screw terminal where the individual leads of the connecting cable are connected directly to the contact surfaces of the printed circuit board. In this case, an RJ-45 and a screw terminal must be provided on the printed circuit board. Moreover, it is often the case that with an ISDN communication system the connection between an SO port (digital exchange connection) and an external SO bus has to be reconfigured on site. To do so, two of the four connecting leads have to be crossed. The crossing takes place by means of a multiway connector provided on the printed circuit board or by manually reconfiguring the relevant contacting devices on site. The embodiment of the printed circuit board as a multiway connector of which only a certain part is actually used for the connection is expensive. The manual reconfiguring of the system on site can lead to faults. 
     SUMMARY OF INVENTION 
     An object of the invention is to create a plug-in adapter by means of which it is possible to connect plugs of various types to contact surfaces that are lead out to a patch panel on the edge of a printed circuit board. 
     This object is achieved by means of a plug-in adapter with the technical features of the claims. For advantageous embodiments of the invention, refer to the dependent claims. 
     According to the invention, a plug-in adapter comprising a base body, in which a first receiving chamber for the insertable reception of a plug and a second receiving chamber for the insertable reception of a patch panel are formed, is plugged into the patch panel of a printed circuit board. Contact bodies are provided in each receiving chamber. Corresponding contact bodies in the receiving chambers are electrically connected by connecting elements arranged in the base body. Depending on the design of the first receiving chamber, the patch panel of a printed circuit board can be connected to cable connectors of different types. By a corresponding design of the plug-in adapter, the connection can take place corresponding to a predetermined contact assignment, i.e. even where the connecting leads are crossed. Plug-in adapters in a type with crossed connecting leads can be color coded, so that the contact assignment can be clearly seen on the outside. 
     In a preferred embodiment, the plug-in adapter consists of two parts that can be manufactured using an injection molding tool that is of comparatively simple construction. In this case, the base body of the plug-in adapter consists of a first part in which the first receiving chamber is formed and a second part in which the second receiving chamber is formed. When correctly used, both parts are held in contact by locking means. With this design, the connecting elements are also formed in two parts and consist in each case of a first and second intermediate contact piece, with corresponding pieces being held in contact by the locking connection when mated. 
     A favorable construction with regard to the connecting technique is characterized in that the plug-in opening of the first and of the second receiving chamber are each arranged on opposite side surfaces of the rectangular plug-in adapter. 
     In a preferred embodiment, the first receiving chamber is formed to be RJ-compatible. The second receiving chamber has a rectangular inner space formed for the insertable reception of the patch panel and has fork-shaped contact springs arranged side by side and aligned in the insertion direction. 
     In a further embodiment of the invention, it is preferred if grooves are formed in the inner wall surfaces that face the plane of the patch panel. The contact springs are arranged in these grooves. Each groove forms a compartment for a leg of a contact spring. This prevents contact between adjacent contact springs when the patch panel is plugged in. 
     It is favorable if the contact springs are embodied with respect to material and shape so that in the inserted position the patch panel is held between the legs of the contact springs by spring force. In this way, the plug-in adapter is secured to the printed circuit board by friction force. 
     In order to achieve a particularly stable attachment of the plug-in adapter to the printed circuit board, it is advantageous to form the webs between the grooves in such a way that the web surfaces that face towards the printed surface board are tapered when viewed in the insertion direction. 
     A particularly preferred embodiment of the invention is characterized in that the first receiving chamber is formed as four-pole, plug-in socket, with two adjacent contact tongues being crossed over to connect with corresponding contact springs in the second receiving chamber. 
     Preferably, both parts of the base body are manufactured using injection molding technology by the injection molding of flame-resistant polymer material. 
     For mass production, it can also be favorable if the base body is manufactured in a single work operation from plastic using a suitably formed injection molding tool, with each connecting element also consisting of a single-piece stamped-bent part. 
     To achieve particularly reliable contact, it is advantageous if the contact springs are coated with a corrosion-resistant metal coating, particularly with a gold alloy. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention is explained in the following by means of examples with reference to the accompanying drawings, in which; 
         FIG. 1  shows a general perspective view of a printed circuit board with a patch panel that can alternatively be connected to leads of a cable by means of a screw terminal by or to a plug fitted to the end of the cable by means of the plug-in adapter according to the invention. 
         FIG. 2  shows a perspective view of a first form of embodiment of the plug-in adapter according to the invention, viewed in the direction of the first receiving chamber. 
         FIG. 3  shows a perspective view of the first form of embodiment viewed in the direction of the second receiving chamber. 
         FIG. 4  shows a perspective view of the first form of embodiment showing the first part lifted off from the second part, in an oblique view from below in the direction of the intermediate contacts of the first part. 
         FIG. 5  shows a perspective view of the first form of embodiment also showing the first part lifted off from the second part, in an oblique view from above in the direction of the intermediate contacts of the second part. 
         FIG. 6  shows a second embodiment of the plug-in adapter in accordance with the invention showing a sectional view along line A-A in  FIG. 1 . 
         FIG. 7  shows a circuit diagram of the contact assignment of a four-pole, plug-in adapter according to the invention, with two adjacent connecting leads being crossed. 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
       FIG. 1  shows a perspective view of a printed circuit board  14  on the edge  18  of which a patch panel is formed. Contact tracks lead into the patch panel  23  and terminate there in contact surfaces  15  lying parallel to each other. The patch panel  23  is limited at the sides by recesses  16  and terminates at the front flush with the circuit board edge  17 . To connect a cable  27 , to the end of which a plug  28  is fitted, to the printed circuit board  14 , the plug  28  of the cable  27  is plugged into a first receiving chamber  3  ( FIG. 2 ) and the patch panel  23  is plugged into a second receiving chamber  4  ( FIG. 1 ) of the plug-in adapter  1  according to the invention. Both receiving chambers  3  and  4  are located on opposite side surfaces of the rectangular plug-in adapter  1 . The electrical connection between the contacts  30  of the plug  28  and the contact surfaces  15  of the printed circuit board  14  is by means of connecting elements that are arranged in the base body of the plug-in adapter  1 . Further details of the design of the connecting elements are given in the following. If the individual leads  29  of a cable  27  are to be connected to the patch panel  23  of the printed circuit board  14 , this can be achieved in the conventional manner by means of a screw terminal  24 . A screw terminal  24  of this kind is shown in  FIG. 1  by a broken line. The screw terminal  24  also has a receiving chamber into which the patch panel  23  is inserted as shown by the arrow  22 . The patch panel  23  can thus be connected either by means of a plug-in connection (plug-adapter  1  and plug  28 ) or directly by means of the terminal connection (screw terminal  24  and leads  29 ) to the cable  27 . A first form of embodiment of the plug-in adapter  1  according to the invention is shown in more detail in a four-pole type in  FIGS. 2 to 5 . The plug-in adapter  1  consists of two parts, a first part  9  and a second part  10 . Both parts  9  and  10  form a rectangular base body  2 .  FIG. 2  is a perspective view in the direction of the first receiving chamber  3 , arranged according to IEC 603-7 , i.e. to provide a contact with contacts  30  of the plug  28 , the contact body consists of 4 parallel contact tongues  6  that extend in an approximately diagonal direction into the receiving chamber  3 . 
       FIG. 3  is a view of the plug-in adapter  1  in the direction of the second receiving chamber  4 . The second receiving chamber  4  is formed in the second part  10  of the base body and has an approximately rectangular inner space. The inner surfaces of the inner space facing towards the printed circuit board are provided with grooves  8 . The grooves  8  lie parallel to each other and extend in the insertion direction  22 . Groove webs  11  forming a type of comb in the inner space can be seen between the grooves  8 . Pairs of opposing grooves  8  each form a receiving space for a contact spring  7 . The contact springs  7  are forked-shaped. Opposing grooves  8  each form a compartment for a leg  32  of a contact spring  7 . 
       FIGS. 4 and 5  are perspective views showing the first form of embodiment of the plug-in adapter  1  according to the invention, with both parts  9  and  10  being shown lifted off. As can be seen from  FIG. 4 , the contact bodies in the first receiving chamber  3  each continue to a top intermediate contact piece  19 . Similarly, the contact springs  7  in the second receiving chamber  4  are formed to the bottom intermediate contact piece  20 . If the top part  9  is now placed on the bottom part  10  in the direction of the arrow  25 , the locking elements  12  engage in the corresponding locking openings  13  of the top part  9 , with corresponding intermediate contacts  19  or  20  being held in contact. 
       FIG. 6  is a section view along line A-A in  FIG. 1  of a second embodiment of the plug-in adapter  1  according to the invention. This embodiment of the plug-in adapter  1  is single-piece construction. It consists of a base body  2  produced in a single piece by injection molding. The connecting elements  5  are also single-piece and manufactured from a single piece of material as a bent-stamped part. A connecting section  26  of each connecting element  5  is furthermore embedded in polymer material. The connecting section  26  that connects the contact tongues  6  in the first receiving chamber  3  with the contact springs  7  in the second receiving chamber  4  [lacuna]. In this embodiment also, the contact springs  7  are located in grooves. 
     As shown above, opposing surfaces of groove webs  31  can also be tapered when viewed in the insertion direction  32 , to improve the mechanical retention. 
       FIG. 7  shows a circuit diagram of a third embodiment of the invention that is particularly preferred for use when connecting a telecommunication device. The illustration is a schematic view of a plug-in connector  1 , the receiving chamber  4  at the plug end of which is formed to receive a four-pole RJ-compatible plug. As already shown in the introduction, problems frequently occur when connecting a telecommunications system, in that the printed circuit board connection not only has to be designed alternatively as a plug-in or screw terminal but also must be able to be configured both for an external SO and an internal SO terminal, i.e. the adjacent leads have to be crossed. In this embodiment, this problem is solved in that in the plug-in adapter  1  according to the invention two adjacent connecting elements  5  are formed crossed over. As can be seen in the circuit diagram in  FIG. 7 , the contact tongues  61  of the first receiving chamber  4  are not connected to the corresponding contact tongues  61 ′ of the patch panel  23  of the printed circuit board  14  but instead to the contact surface  51 ′; equally, the contact tongue  51  is not connected to the corresponding contact surface  51 ′ but instead crossed over to connect to the contact surface  61 ′. It is particularly advantageous in this case if on the plug adapter  1  it can be clearly seen on the outside, for example by color coding, whether the connecting elements  5  are crossed or not crossed.