Patent Publication Number: US-7586052-B2

Title: Electromechanical switching device

Description:
PRIORITY STATEMENT 
   This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/EP2006/060479 which has an International filing date of Mar. 6, 2006, which designated the United States of America and which claims priority on European Patent Application number EP05005046 filed Mar. 8, 2005, the entire contents of which are hereby incorporated herein by reference. 
   FIELD 
   At least one embodiment of invention generally relates to an electromechanical mechanical switching device, to a switching device arrangement and/or to an electrical connecting module. 
   BACKGROUND 
   In electromechanical switching devices, for example motor circuit breakers, contactors, overload relays and other apparatuses for switching, protection and starting of motors and installations, the connecting terminals for the main current paths are permanently integrated in the switching devices. When a switching device is replaced, it is therefore always necessary to detach the wiring lines to the individual connecting terminals of the switching device. When the switching device is reconnected to the wiring lines, it is therefore possible for wiring faults to occur. 
   European patent application EP 1 124 286 A1 discloses an electrical conductor being fixed in a terminal strip with the aid of quick-release connections, with the terminal strip being detachably connected to the housing of an electrical device. A system in which a connecting apparatus for an electrical conductor is likewise detachably connected to the device housing is also known from U.S. Pat. No. 6,411,500 B1. The connection of the conductors is admittedly simplified in these solutions. However, it is no longer possible to easily remove the switching device once it has been mounted on a mounting rail. 
   SUMMARY 
   At least one embodiment of the present invention therefore simplifies the replacement of an electromechanical switching device once it has been mounted on a mounting rail. 
   According to at least one embodiment of the invention, an electromechanical switching device is provided which has a switching device base body and a connecting module which can be connected to the switching device base body and has at least one connecting terminal for a main current path of the switching device. One fundamental idea of at least one embodiment of the present invention is to use a modular design instead of the integrated configuration previously used for switching devices. In this case, a number of connecting terminals are combined in one or more connecting modules for each switching device, and can be connected to the switching device base body. 
   Thus, the connecting module can be installed individually and independently of the switching device base body. This allows prewiring of the connecting terminals, without the actual switching device. There is no need to install the switching device base body, which contains the normal switching device elements, until later. 
   Furthermore, provision may be made for the mechanical connection of the connecting module and switching device base body to be made with the aid of a locking element. The locking element is in this case designed such that the connection of the connecting module and switching device base body is released when a connection is made between the connecting module and a mounting plate, in order to mount the switching device on a mounting rail. 
   The connection of the connecting module to the switching device base body is preferably detachable, so that it is possible to replace the switching device base body while the connecting terminals are at the same time completely wired. When maintenance is required, this makes it possible to greatly reduce the required time for the replacement work. 
   Furthermore, when a replacement is carried out, wiring faults are precluded since the individual wiring lines need not be detached from the connecting terminals. 
   Since the connecting terminals of the connecting module are connecting terminals for the main circuit, that is to say the main current paths in the switching device, it is particularly advantageous for the electrical connection between the connecting module and the switching device base body to be a plug connection. The high currents flowing in the main circuit as well as the short-circuit currents which occur in the event of a fault can therefore also be transmitted reliably. This embodiment of at least one embodiment of the invention for the first time makes it possible to provide plug-in connecting terminals for the main current paths of a switching device of modular configuration. 
   The locking element is preferably permanently fitted to the connecting module, so that it is always available during installation work. Furthermore, the fitting of the locking element to the connecting module makes it possible to ensure that the locking element is always in the correct installation position. However, it is of course likewise possible for the locking element to be provided on the switching device base body or else as an individual part, which is inserted between the connecting module and the switching device base body for installation. 
   It has been found to be particularly advantageous to use a locking element for a safe mechanical connection, which can nevertheless be disconnected again simply, operating in the form of a lever lock, with operation of the lever releasing the connection between the connecting module and the switching device base body. In this case, the locking element is preferably a two-armed lever, having a locking catch on one of its levers which, when in the locked position, rests on a latching projection on the connecting module or on the switching device base body. 
   In this case, the lever is preferably designed such that the locking catch is pushed out by pushing the lever downwards, in order to change to the open position. The switching device base body according to one further embodiment of the invention is designed for direct mounting on a mounting rail. The mounting rail may, for example, be a so-called top-hat rail, which is used to arrange the switching device in a switchgear cabinet or the like. 
   In the situation where direct mounting on a mounting rail is not intended, the invention provides a switching device arrangement which, in addition to the switching device, has a mounting plate for mounting the switching device on a mounting rail. 
   In this case, the mounting plate preferably has a holding plate and a mounting part which is detachably connected to the holding plate, in which case it has been found to be advantageous for handling of the switching device arrangement on the one hand for the mounting part to have connection elements for forming a detachable mechanical connection to the connecting module, and on the other hand for the holding plate to have connection elements for forming a detachable mechanical connection to the switching device base body. 
   According to one particularly advantageous embodiment of the invention, the connection between the connecting module and the switching device base body is released when the mounting part and the connecting module are connected to one another. In other words, in this case, since there is neither a mechanical nor an electrical connection between the connecting module and the switching device base body any longer, the switching device base body can be removed from the switching device arrangement, without any problems, for example by pulling it out. During this process, the connecting module is still connected to the mounting part of the mounting plate. 
   In consequence, it remains in the mounting position even when the switching device base body has been “withdrawn”. A new switching device base body can be “plugged in” without any problems. The switching device base body can therefore be replaced without any rewiring, and therefore particularly easily and without faults. 
   In order to release the connection between the connecting module and the switching device base body when the connecting module is connected to the mounting part, the mounting part preferably has an operating element, which operates the locking element between the connecting module and the switching device base body. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will be explained in more detail in the following text with reference to the drawings, in which: 
       FIG. 1  shows a switching device base body without a connecting module, 
       FIG. 2  shows a connecting module, 
       FIG. 3  shows the connecting module from  FIG. 2 , with the housing partially removed, 
       FIG. 4  shows variants of a plug contact which can be used in a connecting module, 
       FIGS. 5 to 10  show various installation steps for a switching device arrangement with a switching device and a mounting plate, 
       FIGS. 11 and 12  show installation steps for the switching device arrangement as shown in  FIGS. 5 to 10 , in the form of section illustrations, 
       FIGS. 13 to 15  show various installation steps for a switching device, for direct mounting on a mounting rail, and 
       FIG. 16  shows a switching device arrangement as shown in  FIGS. 13 to 15 , in the form of a section illustration. 
   

   DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS 
   The switching device according to an embodiment of the invention in the simplest case comprises a switching device base body  1 , see  FIG. 1 , and a connecting module  2 , see  FIGS. 2 and 3 . On its front face  3 , the switching device base body  1  has a rotary switch  4  for operating the switching device. Attachment projections in the form of two retaining grooves  6 , which run transversely over the entire rear face, as well as two stop strips  7 , which are used to connect the switching device base body  1  to other mounting elements, are provided on the opposite rear face  5  of the switching device base body  1 , see  FIG. 8  or  10 . A mounting surface  9  which has been introduced and is therefore arranged in a recessed form is located on the upper face  8  of the switching device base body  1 , and guide webs  11 , running in the housing longitudinal direction  10  and having a trapezoidal cross section, are fitted to this mounting surface  9  in order to form dovetail connections. 
   A multiplicity of blow-out openings  12  for the switching chamber of the switching device base body  1  are located between the guide webs  11 . Guide webs  11  and blow-out openings  12  are located in the area of the first section, facing the rear face  5  of the switching device base body  1 , of the mounting surface  9 , while the second section of the mounting surface  9 , adjacent to this first section in the direction of the front face  3  of the switching device base body  1 , has no guide webs. In addition, no blow-out openings  12  are provided in the area of this second section. 
   On its lower face  14 , the connecting module  2  has three terminal contacts  15 , which are located in housing sections  16  that are each separated from one another. Conductor insertion openings  18  are provided on the opposite upper face  17  of the connecting module  2 . The front face  19  of the connecting module  1  is equipped with operating openings  20  for the terminal contacts  15 . 
   In order to mount the connecting module  2  securely on the switching device base body  1 , the terminations of the side parts  21  of the switching device base body  1  are designed to rise in a stepped form from its rear face  5  towards its front face  3 , such that, in the installed state (see  FIG. 6 ), the side contour  22  of the connecting module  2  terminates with the side parts  21  of the switching device base body  1 , and the lower faces  23  of the housing sections  16  for the terminal contacts  15  rest on the second section of the mounting surface  9 , while the lower face  24 , which is not provided with housing sections  16 , of the actual module housing rests on the upper face  25  of the switching device base body  1 . 
   Terminal contacts  15  are arranged in a manner known per se from the prior art in the connecting module  2 , see  FIG. 3 . These are preferably plug contacts, various forms of which are illustrated by way of example in  FIG. 4 . A corresponding number of plug contact pins  27  are provided in the switching device base body  1  and extend in the direction of the rear face  5  of the switching device base body  1 , running in the longitudinal direction  10  in the second section of the mounting surface  9 . The plug contact sockets  28 , which are complementary to the plug contact pins  27 , are located in the corresponding housing sections  16  of the connecting module  2  and are connected to corresponding screw connections  30  via a contact rail  29 . The screw connections  30  can be opened and closed by way of a screwdriver, which can be inserted through the operating openings  20 . 
   On the lower face  31 , which is opposite the upper face  25  of the switching device base body  1 , the switching device base body  1  is designed to be identical to its upper face  25 . In other words, a connecting module  2  can also be connected there. 
   In a first step of the process for fitting the switching device, two connecting modules  2  are mounted on the switching device base body  1 , see  FIG. 5 . For this purpose, the connecting module  1  is simply inserted into the second section of the mounting surface  9  in the installation direction  32 , parallel to the longitudinal direction  10  of the switching device base body  1 . During this process, an electrical plug connection is made on the one hand between the plug contact pins  27 , which project into the second section of the mounting surface  9 , on the switching device base body  1 , and the plug contact sockets  28  in the connecting module  2  on the other hand. At the same time, the housing sections  16  and the actual module housing of the connecting module  2  make contact with the switching device base body  1 , so that the plug connection also ensures a secure mechanical connection. Furthermore, a mechanical connection is ensured between the connecting module  2  and the switching device base body  1  by way of a number of locking elements, whose operation will be explained further below. 
   When using a mounting plate  33  to mount the switching device on a mounting rail, the mounting parts  34  are first of all mounted on a holding plate  35 , as is illustrated in  FIGS. 6 and 7 . The mounting parts  34  are in this case pushed onto the holding plate  35  in the vertical direction  36 , from above and below. For this purpose, the holding plate  35  has side guide flanks  38 , which are used to guide the mounting parts  34 , in the area of its upper and lower ends, on its front face  37  facing the switching device base body  1 . In other words, in the installed state, the side parts  39  of the mounting parts  34  rest on the guide flanks  38 . 
   Spring tongues  40  which are machined out of the housing material of the holding plate  35  are provided between the guide flanks  38 , arranged approximately centrally on the front face  37  of the holding plate  35 , at both ends of the holding plate  35 , to each of whose ends pointing away from the center of the holding plate  35  a latching element  41  with an incline is fitted. When the mounting parts  34  are being mounted on the holding plate  35 , the latching elements  41  latch into latching recesses (not shown) which are provided in a corresponding manner on the mounting parts  34 , and thus ensure a secure connection between the mounting parts  34  and the holding plate  35 . Operating openings  44  are provided on the upper faces  42  of the mounting parts  35  and on the end surfaces  43  of the holding plate  35  in order to release these connections, through which openings  44  a screwdriver or some other operating tool can be inserted in order to deflect the spring tongues  40  to their open position. 
   A dovetail joint groove  46  for attaching the holding plate  35  to a transverse mounting rail is incorporated on the rear face  45 , opposite the front face  37  of the holding plate  35 . In  FIG. 7 , the mounting parts  35  have already been mounted on the holding plate  35 , thus resulting in a complete mounting plate  33 , which is attached to a mounting rail  46 . 
   In order to mount the switching device on the mounting plate  33 , attachment elements, which are arranged in pairs above and below the rear-face dovetail groove  46 , are provided on the front face  37  of the holding plate  35  and allow detachable attachment of the holding plate  35  to the corresponding mating contour  6 ,  7  of the rear face  5  of the switching device base body  1 . One attachment element pair  50  is in this case used to support the holding plate  35  on the holding strip  7  on the switching device base body  1 , while the second attachment element pair  51  is in the form of latching hooks which can be deflected in the vertical direction  36 , engaging behind a corresponding mating contour  6  on the rear face  5  of the switching device base body  1  in the installed state. In this case, the end faces of the latching hooks  51  are provided with inclines such that they are deflected in the vertical direction  36  during a movement of the mating contour  6  on the rear face  5  of the switching device base body  1  onto them, and engage in the mating contour  6  on passing over the latching point. 
   On its lower face  52  that is used as the mounting face, the mounting part  34  has holding grooves  53 , with a trapezoidal cross section, and is pushed onto the first section of the mounting surface  9  on the upper face  8  of the switching device base body  1  in the installation direction  32  such that the complementary guide webs  11 , which are arranged there, engage in the holding grooves  53  in order to form an interlocking connection. At the same time, two pins  55  are located on the front face  54 , facing the switching device base body  1 , of the mounting part  34  and project from the front face  54 , and the function of these pins  55  will be explained in detail further below. 
   Latching elements  56  which point in the direction of the switching device, can be deflected in a sprung manner and have latching hooks  57  that point outwards are provided on the side parts  39  of the mounting part  34 , with these latching hooks  57  latching into corresponding latching recesses  58  on the side parts  59  of the connecting module  2  in the installed position, see  FIG. 8 . The switching device arrangement which has been installed completely as shown in  FIG. 8  can now be connected to the corresponding connecting lines  61  in order to form the three main current paths, as is illustrated in  FIG. 9 . Since, as will be explained in more detail further below, the connection between the connecting module  2  and the switching device base body  1  has been released with the connection of the mounting part  34  and connecting module  2 , the switching device base body  1  can now be removed from the switching device arrangement, see  FIG. 10 . 
   The connecting modules  2  with the mounting parts  34  and the holding plate  35  remain in the installed state, and form a so-called permanent wiring. Since the connecting modules  2  can be mounted on the mounting parts  34  even without the switching device base body  1 , it is possible to wire the main current paths in advance, without any switching device base body  1  being installed. By way of example, a switchgear cabinet can be completely wired in advance without a single switching device having already been connected. The switching device base body  1  can then be installed subsequently, for example by a customer. 
   The connection between the connecting module  2  on the one hand and the switching device base body  1  on the other hand is made using two locking elements  62 , which are in the form of two-armed levers, see  FIG. 11 . Each locking element  62  is mounted such that it can pivot by means of a pivoting element  63  in the lower face  14  of the connecting module  2 . In this case, the pivoting element  63  extends out of the essentially flat lower face  64  of the locking element  62 , and is inserted in a pivoting holder  65  in the connecting module  2 . The opposite upper face  66  of the locking element  62  is in the form of a rocker. In other words, the locking element  62  has a fulcrum  67  approximately centrally and approximately in the area of the pivoting element  63 , where the cross section of the locking element  62  is particularly large. 
   The cross section of the locking element  62  tapers from this fulcrum  67  towards its two ends. This results in a two-armed lever, with one lever arm  68  pointing in the direction of the rear face  5  of the switching device base body  1 , while the lever arm  69 , which points in the opposite direction, has a locking catch  70  which projects out of its lower face  64  and, in the locked position (see  FIG. 11 ) rests on a latching projection  71 , which extends from the lower face  14  of the connecting module  2  in the direction of the front face  3  of the switching device base body  1 . The latching projection  71  is not shown in  FIGS. 2 and 3 . 
   The two locking elements  62  for connecting the connecting module  2  and the switching device base body  1  are arranged in the channel-like free sections  73  of the housing sections  16  for the terminal contacts  15  (see  FIGS. 2 and 3 ). During installation, the latching hook  70  “latches” with the latching projection  71  in such a way that it is impossible to “pull” the switching device base body  1  off the connecting module  2  in the installation direction  32 , see  FIG. 11 . At the same time, the plug contact pins  27  are inserted into the holding openings  74  which are provided for this purpose in the housing sections  16 , and make contact with the plug contact sockets  28 . 
   When the mounting part  34 , which is attached to the holding plate  35 , is being mounted on the switching device, the pins  55  which are arranged on the front face  54  of the mounting part  34  slide into the free sections  73  between the housing sections  16 , and act on the locking element  62 , see  FIG. 12 . In this case, the pins  55  are provided with an incline such that, during insertion, the lever arm  66 , which points in the direction of the rear wall  5  of the switching device base body  1 , is pressed down by the pin  55  in the direction of the connecting module  2 . The locking catch  70  on the opposite lever arm  69  is forced out by the lever function, and is moved to its open position. At the same time, the connection is produced between the mounting part  34  and the connecting module  2  via the side latching elements  56 ,  58 . In other words, the connecting module  2  is permanently connected to the mounting part  34  while the switching device base body  1  can be removed from the mounting plate  33  and from the connecting module  2  attached to it, in the installation direction  32 . 
   The mounting parts  34  also have holding grooves  53  on their upper face  42 , so that it is also possible to push the mounting parts  34  onto the guide webs  11  of the switching device base body rotated through 180° (not shown). In this case, the pins  55  engage in empty openings  80 , which are provided for this purpose on the connecting module  2 . This makes it possible for one and the same mounting part  43  to be used for mounting both with and without opening of the connection between the connecting module  2  and the switching device base body  1 . 
   If the intention is to use the switching device according to the invention without a mounting plate  33 , the switching device can be attached directly to a mounting rail  47 , as shown in  FIG. 13 . In this case, the holding groove  6  of the rear face  5  of the switching device base body  1 , and the guide strip  7  which is formed by the first section of the mounting surface  9  projecting beyond the rear face  5  of the switching device base body  1 , provide a corresponding holding contour for the mounting rail  47 . 
   When the connecting modules  2  are connected to the corresponding connecting lines  62  (see  FIG. 14 ), then the switching device base body  1  can be replaced easily and quickly, as in the case of the first exemplary embodiment as well. In this case, all that is necessary is to release the plug contacts and to pull the switching device base body  1  off the mounting rail  47 , see  FIG. 15 . In this case, the locking element  62  can be forced out of its locked position even without a mounting part, specifically with the aid of an operating tool  75 , see  FIG. 16 . 
   For this purpose, an operating opening  76  is provided for each locking element  62  on the upper face  8  of the switching device base body  1 , through which opening  76  an operating tool  75 , for example a screwdriver or the like, can be inserted. The tip of the operating tool  75  is in this case guided directly to the lever arm  69  to be operated, by means of the incline  77  on the operating opening  76 , so that the lever is forced out just by pushing it. 
   Since in this example embodiment as well, the connecting modules  2  can be released from the switching device base body  1 , it is also possible in this case to replace the switching device base body  1  without having to remove the connecting lines  61 . One particularly advantageous feature of the position of the locking element  62  is that the connection can be released from the front, that is to say from the front face  3  of the switching device base body  1 . 
   Each of the figures shows only a single switching device or a single switching device arrangement. It is, of course, also possible to arrange a plurality of switching devices alongside one another in the form of an installation assembly. For this purpose, two side guide webs  78 , which are bisected in the longitudinal direction  10 , are provided alongside the two central guide webs  11  on the mounting surface  9  of the switching device base body  1 . Corresponding side guide grooves  79  with a “bisected cross section” are provided on the lower face  52  of the mounting parts  34 . The web halves which are required for filling the guide grooves  79  are complemented by the side guide webs that are likewise provided there, during installation of an adjacent switching device base body (not shown). 
   It is within the scope of the invention to provide only the feed side or the outgoer side of the switching device with a connecting module according to embodiments of the invention, with the other side in each case being connected in the conventional manner. 
   Example embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.