Abstract:
An assembly includes an electrical switching device and terminal-side accessories. The housing includes a front side and oppositely situated terminal sides that respectively include supply-side cable terminals and load-side cable terminals. The housing also includes first recesses disposed on a terminal side and a first snap cam A protective cover forms a first of the terminal-side accessories and includes first mouldings configured to engage the first recesses of the housing and a first hook configured to join the first snap cam. A cable clamp block forms a second of the terminal-side accessories. The cable clamp block includes a back wall with second mouldings configured to engage the recesses of the housing and a locking hook configured to join the snap cam. The cable clamp block also includes a front wall with second recesses configured to engage the first mouldings and a second snap cam configured to engage the first hook.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2011/064910, filed on Aug. 30, 2011, and claims benefit to German Patent Application No. DE 20 2010 012 329.1, filed on Sep. 8, 2010. The International Application was published in German on Mar. 15, 2012 as WO 2012/031946 A1 under PCT Article 21 (2). 
     
    
     FIELD 
       [0002]    The invention relates to an electrical switching device for application in the low voltage range, particularly an electromagnetic switching device, with a switching device housing made of insulating material, with supply- and load-side cable terminals, accessible at oppositely situated terminal sides of the switching device housing, and accessories which can be joined at least indirectly to the switching device at the terminal sides if needed. 
       BACKGROUND 
       [0003]    Document DE 90 11 899 U1 as nearest prior art discloses an electromagnetic switching device and terminal-side accessories. A cable clamp block in a moulded case is provided as an accessory which can be joined in a form-fitting fashion with the supply- or the load-side terminal side of the switching device housing. To this end, the terminal sides of the switching device housing each show two groove-like guide and retaining recesses with undercut sections running perpendicular to the front side of the switching device housing, which can be brought into engagement and joined with the cable clamp block by means of two matching guide and retaining mouldings. As a further accessory, a protective cover made of moulded material is provided for protection against contact with current-carrying parts. The protective cover consists of two lateral protective walls, a front protective wall joining them and intermediate separating ribs connected to it. The protective cover can optionally be mounted directly to the terminal side of the switching device housing or to the cable clamp block. For fastening to the switching device housing, the protective cover is provided with guide and retaining mouldings on one front face which match the guide and retaining mouldings of the cable clamp block in position and shape and can be brought into engagement and joined with the guide and retaining recesses of the switching device housing. For fastening the protective cover to the cable clamp block, it has two lateral guide and retaining rails running perpendicular to the front side which can be brought into engagement and joined with matching guide and retaining recesses on the protective cover. The protective cover can be locked in a defined position by means of a locking hook formed in the protective cover. For adjusting the length of the protective cover to particular requirements, the protective cover exhibits parting lines running crosswise to the longitudinal direction of the cables. 
         [0004]    By contrast, in the circuit breaker according to document DE 295 05 046 U1, a cable clamp block is screwed to the switching device housing. In attaching a protective cover to the cable clamp block, pairs of ledges provided on it, terminal-side grooves and outward-pointing L-shaped indentations cooperate with corresponding pairs of slots constructed on the front face of the protective cover and clamp ribs on the face and lateral, inward pointing retaining webs. Direct assembly of the protective cover to the switching device housing is not provided for. 
       SUMMARY 
       [0005]    In an embodiment, the present invention provides an assembly including an electrical switching device having an electrical switching device housing made of moulded material and terminal-side accessories. The switching device housing includes a front side and oppositely situated terminal sides that respectively include supply-side cable terminals and load-side cable terminals. The switching device housing includes first groove-shaped, undercut guide and retaining recesses disposed on a terminal side running perpendicular to the front side of the housing and at least one first snap cam with a first locking surface facing away from the front side. A protective cover forms a first of the terminal-side accessories and includes two lateral protective walls and a front-side protective wall connecting the lateral protective walls. The protective cover also includes a front face that faces the switching device. The front face includes first guide and retaining mouldings configured to be brought into undercut engagement and joined in form-fitting fashion to the first guide and retaining recesses of the switching device housing, and at least one elastically installed first locking hook with a second locking surface facing the front-side protective wall. The first locking hook is configured to be joined to the at least one first snap cam. A cable clamp block forms a second of the terminal-side accessories. The cable clamp block including a back wall that faces the switching device and a front wall that faces away from the switching device. The back wall includes second guide and retaining mouldings having a matching position and shape as the first guide and retaining mouldings. The second guide and retaining mouldings are configured to be brought into undercut engagement and joined in form-fitting fashion with the first guide and retaining recesses of the switching device housing. The back wall also includes at least one elastically installed third locking hook with a third locking surface facing the front side and configured to be joined to the at least one first snap cam. The front wall includes second guide and retaining recesses having a matching position and shape as the first guide and retaining recesses. The second guide and retaining recesses are configured to be brought into undercut engagement and joined in form-fitting fashion with the first guide and retaining mouldings. The front wall also includes at least one second snap cam having a matching position and shape as the first snap cam and configured to be brought into engagement with the first locking hook. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following: 
           [0007]      FIG. 1  shows a switching device on a terminal side with and without terminal-side accessories on the opposite terminal side; 
           [0008]      FIG. 2  shows the switching device with cable clamp block; 
           [0009]      FIG. 3  shows the switching device with cable clamp block and finger guard caps; 
           [0010]      FIG. 4  shows the switching device with cable clamp block and protective cover; 
           [0011]      FIG. 5  shows the switching device with protective cover in partial cutaway view; 
           [0012]      FIG. 6  shows a detail from  FIG. 5 ; 
           [0013]      FIG. 7  shows the protective cover in partial device-side perspective; 
           [0014]      FIG. 8  shows a detail from  FIG. 7 ; 
           [0015]      FIG. 9  shows the cable clamp block in partial device-side perspective; 
           [0016]      FIG. 10  shows a detail from  FIG. 9  and 
           [0017]      FIG. 11  shows a finger guard cap in device-side perspective. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    In an embodiment, the present invention provides a simplified construction, with respect to manufacture and handling, of a switching device with terminal-side accessories. 
         [0019]    Beginning with a switching device and terminal-side accessories of the type initially mentioned, the task is solved according to the invention by the features of the independent claim, while advantageous further developments of the invention are to be inferred from the dependent claims. 
         [0020]    By means of guide and retaining recesses and snap cams formed on the switching device housing, by means of first guide and retaining mouldings and locking hooks formed on a protective cover, by means of second guide and retaining mouldings, resembling the first guide and retaining mouldings, formed on a cable clamp block as well as third locking hooks resembling the first locking hooks, on the one hand, and second guide and retaining recesses resembling the first guide and retaining recesses as well as second snap cams resembling the first snap cams, on the other hand, the combination of the switching device with the terminal-side accessories is accomplished simply and in accordance with the respective requirements. The switching device can be equipped on one terminal side or both terminal sides with a protective cover only, with a cable clamp block only, with a cable clamp block together with a protective cover, or without any of these accessories. For accomplishing the various combinations mentioned, only similar type connecting elements are provided, and no special instructions have to be followed. 
         [0021]    For fitting to different cable diameters it is advantageous to mount the protective cover at different distances from the front face, to which end a suitable second locking hook is provided, in addition to at least one locking hook, and offset with respect to it. 
         [0022]    Suited to this purpose are paired guide and retaining recesses and guide and retaining mouldings and snap cams, as well as locking hooks. 
         [0023]    It is advantageous to position a locking hook on a spring shackle elastically spaced away from the front protective wall. 
         [0024]    For easy and secure mounting of the terminal-side accessories, it is advantageous and appropriate if the guide and retaining recesses open toward the front face, and if the guide and retaining recesses as well as the guide and retaining mouldings are constructed at least partially with an L-shaped cross-section. 
         [0025]    A further advantage with regard to matching to the respective conditions occurs with hat-shaped finger guard caps, which can be inserted into clamping bars next to the entrance openings for the cable terminals on the cable clamp block and can be retained by the second, and if necessary by additional snap cams. Another advantage here is the grid-like, pierceable if necessary, cover surface of the finger guard caps. 
         [0026]    For better separation of the connecting cables it is appropriate to provide the protective cover with separating ribs. For suitable matching to the connection conditions, for example to the length of the cable lugs connected to the connecting cables, it is also appropriate to make it possible to cut the protective cover to length by means of at least one parting line. 
         [0027]    An advantageous feature consists of equipping the cable clamp block with breakout openings which, in case of need, allow access to auxiliary conductor connections for connecting auxiliary conductors, particularly for control or status signals. 
         [0028]      FIG. 1  through  FIG. 4  show the different and advantageous combinations of a switching device  1 , taking in example the form of a three-pole electromagnetic switching device, with its terminal-side accessories according to the invention.  FIG. 1  shows the switching device  1  enveloped by a switching device housing  10  made of moulded insulating material on its supply-side terminal side  12  without any accessories according to the invention. The connecting cables represented by cable lugs  14  are screwed to the cable terminals  16  of the switching device  1 . A protective cover  2  made of moulded insulating material is mounted in front of the load-side terminal side  13  of the switching device  1 , thereby providing extensive protection from contact with current-carrying metal parts.  FIG. 2  shows the switching device  1  in combination with a cable clamp block  3  mounted in front of the terminal side  13  with case  17  made of moulded insulating material. Here it is possible to connect connecting cables to the cable terminals  16  accessible through access openings  18  in the moulded material case  17 .  FIG. 3  shows similarly to  FIG. 2  a combination of the switching device  1  with the cable clamp block  3 , but this time the access openings  18  are protected against contact by finger guard caps  4 . The finger guard caps  4  are shown in the new condition and can be suitably pierced through their grid-like cover surface  22  for the purpose of feeding cable ends through.  FIG. 4  shows a combination of the switching device  1  with protective cover  2  and cable clamp block  3 . The cable clamp block  3  is mounted in front of the terminal side  13  of the switching device  1 , and the protective cover  2  is mounted in front of the access openings  18  of the cable clamp block. This combination allows the connection of connecting cables through the cable clamp block  3 , as well as an extensive contact protection against current-carrying parts. 
         [0029]    As shown in  FIG. 1 ,  FIG. 5  and  FIG. 6 , one pair of first guide and retaining recesses  24  is shown on each of the terminal sides  12  and  13  of the switching device housing  10 . The groove-shaped guide and retaining recesses  24  run perpendicular to the front face  26  of the switching device  1 , open toward the front face  26  and are constructed, in their area that is remote from the front face  26 , undercut with an L-shaped cross-section. In addition, pairs of first locking cams  28  stand out from the terminal sides  12 ,  13 , having first inclined slides  32  pointing toward the front face  26  and running with a first locking surface  35  parallel to and turned away from the front face  26 . 
         [0030]    As shown in  FIG. 7 , the protective cover  2  consists of two outer lateral protective walls  38  and a front-side protective wall  39  connecting the two. Inner separating ribs  40  parallel to the lateral protective walls  38  stand out from the protective wall  39 , separating the connecting cables according to pole. According to  FIG. 7  and  FIG. 8 , the protective cover  2  exhibits, on its front face  42  to be joined to the terminal side  12  or  13  of the switching device  1 , a pair of batten-shaped first guide and retaining mouldings  44 . On the front face, a pair of first spring shackles  46  is formed from the front-side protective wall  39 . The first spring shackles  46  are elastically bendable parallel to the protective walls  38  and  39 . On each spring shackle respectively are formed a first locking hook  46  and a second locking hook  49 . The locking hooks  48 ,  49  are similarly constructed and point away from the front-side protective wall  39  with second diagonal slides  33  and run with second locking surfaces  36  parallel to the front-side protective wall  39 . The locking hooks  48 ,  49  are positioned one behind the other on each first spring shackle  46  respectively in the direction of the front-side protective wall  39 , whereby the second locking hook  49  is located closer to the front-side protective wall  39 . 
         [0031]    Upon setting the protective cover  2  on the corresponding terminal side  12  or  13  of the switching device  1 , the first guide and retaining mouldings  44  engage in the first guide and retaining recesses  24  of the switching device housing  10  and thereby create an undercut connection. In the process, as shown in  FIG. 5  through  FIG. 8 , the diagonal slides  32  of the first snap cams  28  slide over the diagonal slides  33  of the first locking hooks  48 , whereafter the protective cover  2  is locked in a first position by laying the locking surfaces  35  of the first snap cams  28  on the locking surfaces  36  of the first locking hooks  48 . If a mounting position located farther from the front side  26  compared with  FIG. 5  is desired, then it can be arranged, by the use of greater force on the protective cover  2 , that the diagonal slides  32  of the first snap cams slide farther over the diagonal slides  33  of the second locking hooks  49 , whereafter the protective cover  2  is locked in a second position by laying the locking surfaces  35  of the first snap cams  28  on the locking surfaces  36  of the second locking hooks  49 . The locking surfaces  35 ,  36  can be taken out of engagement, and the protective cover  2  thereby released from the switching element housing  10 , by means of a suitable tool through the first half-openings  52  left free at the junction of the front-side protective wall  39  and first spring shackles  46 . 
         [0032]    As shown in  FIG. 9  and  FIG. 10 , the cable clamp block  3  is equipped with a pair of batten-shaped guide and retaining mouldings  45  on its back wall  54  facing the switching device  1 , which match the first guide and retaining mouldings  44  of the protective cover  2  ( FIG. 7 ) and are partially L-shaped in construction. Furthermore, a pair of second spring shackles  47  is provided on the back wall  54 , each bearing one third locking hook  50 . The third locking hook  50  match in arrangement and shape, particularly with respect to a third diagonal slide  34  and a third locking surface  47 , the second locking hook  49  of the protective cover  2  ( FIG. 8 ). 
         [0033]    In setting the cable clamp block  3  on the corresponding terminal side  12  or  13  of the switching device  1 , the second guide and retaining mouldings  45  engage in the first guide and retaining recesses  24  of the switching device housing  10  and thereby create an undercut connection. In the process, the diagonal slides  32  of the first snap cams  28  slide over the diagonal slides  34  of the third locking hooks  50 , whereafter the cable clamp block  3  is locked by laying the locking surfaces  35  of the first snap cam  28  on the locking surfaces  37  of the third locking hook  50 . The locking surfaces  35 ,  37  can be taken out of engagement, and the cable clamp block  3  thereby released from the switching element housing  10 , by means of a suitable tool through the second half-openings  53  left free at the junction of the back wall  54  and second spring shackles  47 . 
         [0034]    As shown in  FIG. 2 , the cable clamp block  3  is equipped with a pair of groove-shaped second guide and retaining recesses  25  on its front wall  56  facing away from the switching device  1 , which correspond in arrangement and shape the first guide and retaining recesses  24  of the switching device  1 . Furthermore, a pair of second snap cams  29  is provided on the front wall  56 , which are arranged in front of the two outer access openings  18 . The second snap cams  29  are similar in arrangement and shape to the first snap cams  28  on the switching device  1  ( FIG. 1 ). 
         [0035]    In setting the protective cover  2  on the front wall  56  of the cable clamp block  3 , the first guide and retaining mouldings  44  of the protective cover  2  engage in the second guide and retaining recesses  25  and thereby create an undercut connection. In the process the second snap cams  29  cooperate in the manner already described with the first and second locking hooks  48  and  49  respectively of the protective cover. 
         [0036]    As shown in  FIG. 2  and  FIG. 3 , a pair of L-shaped clamping bars  58  is formed on the front wall  56  of the cable clamp block  3  on either side next to each access opening  18 . Furthermore, an additional snap cam  30  similar to the second snap cam  29  is provided in front of the middle access opening  18 . As shown in  FIGS. 3 and 11 , the finger guard caps  4  are built box-shaped with an open side located opposite the grid-like cover surface  22 , and with elastic sidewalls when the profile is hat-shaped. The finger guard caps  4  can be clamped behind the clamping bars  58  by means of the brim-like circumferential surfaces  60  of the elastic longitudinal sides  62 . At the same time, the finger guard caps  4  are set in their position on the cable clamp block  3  at their respective front transverse side  64  by means of the snap cams  29 ,  30 . The cover surfaces  22  are only pierced to the extent that the ends of the cables to be connected need to pass through, whereby an extensive protection is afforded against dangerous contact with energised parts. 
         [0037]    As shown in  FIG. 7 , the protective cover  2  is provided parallel to its front face  42  with a parting line  68  extending through the sidewalls  38 ,  39 . With the help of the parting line  68 , the protective cover  2  can be shortened so as to suitably match the cables to be connected. 
         [0038]      FIG. 2  shows that the cable clamp block  3  is equipped with breakout openings  70  for auxiliary conductor terminals located behind them on its front wall  56  facing away from the switching device  1 . By breaking away the breakout openings  70 , access to the auxiliary conductor terminals is opened for connecting auxiliary conductors, particularly for control or status signals. One pair of breakout openings  70  per pole is provided next to each second snap cam  29 . By this means, auxiliary conductors can be connected as necessary above and/or below to the auxiliary conductor terminals. 
         [0039]    In the illustrations, only the load-side terminal side  13  of the switching device  1  is shown in combination with the terminal-side accessories  2 ,  3 ,  4 . It is obvious that either the supply-side terminal side  12  alone or both terminal sides  12 ,  13  are or can be combined in the same or a different manner with the terminal-side accessories. 
         [0040]    While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. 
         [0041]    The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B.” Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
           1  Switching device 
           2  Protective cover 
           3  Cable clamp block 
           4  Finger guard cap 
           10  Switching device housing 
           12 ;  13  Terminal side 
           14  Cable lugs 
           16  Cable terminals 
           17  Moulded housing 
           18  Access openings 
           22  Cover surface 
           24 ;  25  Guide and retaining recesses 
           26  Front side 
           28 ;  29 ;  30  Snap cams 
           32 ;  33 ;  34  Diagonal slides 
           35 ;  36 ;  37  Locking surface 
           38 ;  39  Protective walls 
           40  Separating ribs 
           42  Front face 
           44 ;  45  Guide and retaining mouldings 
           46 ;  47  Spring shackles 
           48 ;  49 ;  50  Locking hook 
           52 ;  53  Half-openings 
           54  Back wall 
           56  Front wall 
           58  Clamping bars 
           60  Circumferential surfaces 
           62  Longitudinal sides 
           64  Transverse side 
           68  Parting line 
           70  Breakout openings