Abstract:
The invention relates to a circuit breaker device comprising a bottom switch part ( 2 ) that can be brought into electrical contact with bus bars, a top switch part ( 1 ) which can be placed onto the bottom switch part ( 2 ) and is provided with at least one fuse link, switch module, contactor or similar, and a terminal module ( 3 ) for especially at least one outgoing feeder ( 42 ). The bottom switch part ( 2 ) is provided with contact elements ( 5, 6, 7 ) that are in electrical contact with the bus bars ( 9, 10, 11 ) and can be contacted in a contact-proof manner by means of plug-in contacts ( 17, 18, 19 ) of the top switch part ( 1 ) via one respective access slot ( 12, 13, 14 ) located in a top area of the bottom switch part ( 2 ). The terminal module ( 3 ) is pivotally mounted ( 50 ) on the side of the top switch part ( 1 ) of bottom switch part ( 2 ) and is provided with electrical contacts ( 38, 39, 40 ) that can be laterally inserted into the top switch part ( 1 ) and are allocated to each outgoing feeder ( 42 ).

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a circuit-breaking device and to a safety switch or motor protection switch. 
   Circuit-breaking devices are used as safety switches, motor protection switches and are in general used with a so-called adapter part placed upon current busbars as a completely separate element. The adapter part serves to be clamped onto the current busbars, and as a carrier module for the different circuit-breaking devices. 
   Adapters or current bus bar adapters, wherein the adapter part serves to be clamped on the current busbars including a carrier module for the different circuit-breaking device are known from EP 0 762 581. The current linkage between the current bus bars and the circuit breaking devices is accomplished by electrically connecting contact parts with the respective circuit-breaking devices by means of connection lines. 
   A drawback of the known systems resides in that the adapters have to be affixed on the current busbars as additional components and provided with connection lines or connection contacts, and that the circuit-breaking devices have to be mounted on the adapters as separate elements and have to be electrically connected with the connection lines or the connection contacts. If a circuit-breaking device is exchanged or dismounted, it is required that the outgoing conductors are removed from the respective circuit-breaking device and are reconnected subsequently. In addition, the circuit-breaking device is to be detached with respect to the adapter part prior to the disassembly, and the new circuit-breaking device is to be mounted after the exchange. If required, the current buses even have to be switched to be currentless. 
   The invention is based on the object to provide a circuit-breaking device which is easy to affix onto current busbars and which may be exchanged without the removal of outgoing conductors. 
   According to the invention this object is achieved by the features defined in patent claim  1 . Additional embodiments of the invention are defined in the dependent claims. 
   BRIEF SUMMARY OF THE INVENTION 
   The invention provides for a circuit-breaking device which, for example, consists of three components representing one integrated unit and which can be placed upon and interlocked with current busbars in an easy and fast manner. In a preferred embodiment a pivoted connection module is provided on the lower switch part, which may be unlocked from the operating position with mechanical means, e.g. a screwdriver, be unlocked from operating position, be pivoted back subsequently and, as result of its pivoting movement, brings locking or latching mechanism mechanically clutched with the connection module into a released position so as to allow an exchange of the circuit breaker in form of an upper switch part. Upon exchanging the circuit breaker or the upper switch part respectively, the unit may be reassembled in a reversed manner, and upon pivoting the connection module in a manner opposite to the opening movement the upper switch part, the lower switch part and the connection module are interlocked. The interlocking of the circuit-breaking device with respect to the current busbars is preferably accomplished in a conventional manner. Here it is not necessary that the current buses be made currentless or outgoing conductors be disconnected. 
   The circuit-breaking device according to the invention, preferably a three-pole circuit-breaking device, can advantageously be conceived to be narrow-sized. The outgoing conductors are affixed in the connection module in a touch-safe manner such that the connection module has contacts facing in the direction of the upper switch part and engaging into the upper switch part. Upon opening the connection module by laterally pivoting it away from the upper switch part the current flow toward the consumer connected to the outgoing conductors is interrupted and the contacts of the connection module facing toward the upper switch part are likewise currentless. 
   Both the upper switch part and the lower switch part comprise separate housings. The upper switch part has opening slots or openings in the surface of the housing facing upwardly for plug contacts to be plugged into the same, which project from the upper switch part out of the housing in a downward direction. This means that the lower switch part is touch-safe when the upper switch part is withdrawn, as the contact elements are covered by the housing. 
   In a preferred embodiment the circuit-breaking device according to the invention may be exchanged such that upon unlocking the connection module with a screwdriver or the like with respect to the upper switch part the connection module can be pivoted away from the upper switch part. By the pivoting movement of the connection module a mechanical locking means mechanically clutched with the connection module is unlocked with respect to the upper switch part, which allows the withdrawal of the upper switch part from the lower switch part. 
   In another embodiment the upper switch part is provided with lateral openings through which an electrical contact towards contact counter-tongues located inside the housing is possible by means of contact tongues or the like. All upper parts of the switch comprise corresponding contact openings at the same height and with the same width, so that it is possible to electrically connect two or more of such upper parts of the switch with each other so that, for example, a motor protection switch/contactor combination is possible with the use of two of such circuit-breaking devices lying parallel to each other. The lateral circuit-breaking device contacting also allows a combination as a motor starter combination. 

   
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
     Below, a preferred embodiment of the circuit-breaking device according to the invention will be described in order to explain additional features and advantages, wherein 
       FIG. 1  shows a lateral view of a circuit-breaking device with a partially cut open representation of the lower switch part, 
       FIG. 2  shows a perspective view of the circuit-breaking device of  FIG. 1 , 
       FIG. 3  shows a view substantially in correspondence with  FIG. 1 , with current busbars, wherein the connection module is laterally cut open, 
       FIG. 4  shows two circuit-breaking devices for explaining a combination formed of two of such units, 
       FIG. 5  shows schematic views of different combination units on the basis of the circuit-breaking device according to the invention, 
       FIG. 6  shows a perspective view of the circuit-breaking device in correspondence with  FIG. 2 , 
       FIG. 7  shows a schematic, partially cut open view of a circuit-breaking device, 
       FIG. 8  shows a view of an upper switch part for illustrating the mounting of the contacts in correspondence with  FIG. 1  or  FIG. 6 , and 
       FIG. 9  shows a detailed view in correspondence with  FIG. 8 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a lateral view of the circuit-breaking device according to the invention formed of an upper switch part  1 , a lower switch part  2  and a connection module  3 .  FIG. 2  shows a schematic perspective view of the circuit-breaking device according to  FIG. 1 , and  FIG. 3  shows a view in correspondence with  FIG. 1  together with the current busbars, wherein the lower switch part  2  in  FIG. 1 , and also in  FIG. 2  and  FIG. 3 , is laterally cut open. 
   Both the upper switch part  1  and the lower switch part  2  each comprise a separate housing designated with  1   a  and  2   a , each of them including contacts, fuse links or contactors, respectively, or the like in a touch-safe manner, which are located inside respective the switch parts. 
   As is shown in  FIGS. 1 to 3 , an arrangement of contact elements  5 ,  6 ,  7  is provided in the lower switch part  2 , which project over the lower surface of the housing  2   a  as to obtain an electrical contact with the current busbars  9 ,  10 ,  11  as soon as the circuit-breaking device is placed upon the busbars  9 ,  10 ,  11 . For their attachment on the busbars  9 ,  10 ,  11  each lower switch part  2  comprises correspondingly designed feet  15   a ,  15   b ,  15   c  known per se, as well as at least one locking tongue or locking means  16  ensuring an attachment of the circuit-breaking device at least with respect to busbar  11 . Thus, the switch is permanently and safely held with respect to the current busbars  9 ,  10 ,  11 . 
   According to  FIG. 2  the lower switch part  2  is provided with slots or openings  12 ,  13 ,  14  on its upper surface or side respectively, which serve to allow corresponding contact tongues or plug contacts  17 ,  18 ,  19  ( FIG. 1 ) projecting from the lower surface of the lower switch part  1  downwardly to be brought into an electrical contact with the contact elements  5 ,  6 ,  7  (see  FIG. 1 ) via the openings  12 ,  13 ,  14  ( FIG. 2 ). 
   According to the embodiment shown in the figures guides or feet  20  to  25  are provided laterally of the plug contacts  17 ,  18 ,  19 , which are made of an insulation material such as a synthetic material and which may be arranged as integral components on the housing  1 . Said feet  20 ,  21  and so on simultaneously form a lateral protection of the plug contacts  17  to  19 , but basically have a guiding function so as to ensure that the upper switch part  1  be purposefully placed upon the lower switch part  2 . In correspondence therewith the lower switch part  2  includes sparings or recesses  27 ,  28 ,  29  adjusted to and matching with the distance of the feet  20 ,  21  and  22 ,  23  and  24 ,  25  respectively in view of their width, i.e. transversely to the course of the current busbars, so as to ensure that the upper switch part  1  be exactly placed upon the lower switch part  2  and that the plug contacts  17 ,  18 ,  19  be exactly inserted into the corresponding contact slots  12 ,  13 ,  14 . 
   With respect to the upper surface of the housing, the contact elements  5 ,  6 ,  7  with the openings  12 ,  13 ,  14  are downwardly offset inside the lower part  2  of the circuit breaker to an extent that a touch of the contact elements  5 ,  6 ,  7  is safely prevented once the upper switch part  1  is withdrawn from the lower switch part  2 . 
   Moreover, counter-locking elements  30 ,  31  are provided on the upper switch part  1 , e.g. in the form of brackets with locking openings  32 ,  33  facing outwardly, as are shown in  FIG. 1  et seq. and the purpose of which will be described below. 
   The contacts  17 ,  18 ,  19  are connected with corresponding sides of a motor contactor, a safety unit and the like, the other sides or poles of which being electrically connected with contact sockets or contacts respectively, which are located inside contact openings  35 ,  36 ,  37 , wherein said contacts or contact sockets are not illustrated in the figures in more detail. In the embodiment as shown in  FIG. 2  the openings  35 ,  36 ,  37  are preferably provided in a laterally offset or diagonally extending manner. However, they may also be disposed in a row one above the other, and so may the contacts located in the same. 
   Contact tongues  38 ,  39 ,  40  are associated with the contact openings  35 ,  36 ,  37 , project laterally from the connection module  3  in the direction towards the upper switch part  1  and are formed or arranged on the connection module in correspondence with the arrangement of the openings  35 ,  36 ,  37 . According to a preferred embodiment each connection module  3  comprises one spring-type terminal  34  per outgoing conductor  42 . In this respect reference is made to  FIG. 3 . Inside the connection module  3  the contact tongues  38 ,  39   40  are connected with a spring clip, a spring-type terminal  34  or another means for a permanent reception of connection cables  42 , wherein only one single connection cable  42  is shown in the figures. 
   It can be seen that with current-carrying busbars  9 ,  10 ,  11  the contacts  5 ,  6 ,  7  are at least partially energized, but are covered by the housing  2   a  in a touch-safe manner, even if the upper switch part  1  is withdrawn in accordance with  FIG. 1 . The contact tongues  38 ,  39   40  of the connection module  3  are likewise not current-carrying as soon as the connection module  3  adopts the inoperative position shown in  FIGS. 1 to 3 . 
   In the operating state and in the as-delivered state, however, the upper switch part  1  sits tightly on the lower switch part  2 . Moreover, in contrast to the representation of  FIG. 1 , the connection module is pivoted clockwise and is laterally adjacent to the upper switch part  1  and the lower switch part  2  such that the contact tongues  38 ,  39   40  are inserted practically horizontally and in alignment with the upper switch part  1  into the same and are electrically connected with the correlating contact elements in the upper switch part  1 . Thus, in the operating state, the upper switch part  1 , the lower switch part  2  and the connection module  3  form a permanently connected unit. 
   The connection module  3  is moreover provided with a detachable locking or latching means  45 , e.g. in the form of a hook  45  adjustable with a screwdriver or the like, which engages into an associated locking opening  46  in the upper switch part  1  when the connection module  3  adopts its operating position adjacent to the upper switch part  1 . In the embodiment as illustrated, the locking tongue  45  may be moved downwardly with a screwdriver, which may be inserted through an opening  47  formed on the upper side of the connection module, so as to be released from the opening  46  and so as to displace the connection module  3  clockwise into the position as shown in  FIG. 1 to 3  subsequently. 
   As it is additionally shown in the figures, the connection module  3  according to the embodiment as shown is provided with a locking tooth  48 . In the operating state this locking tooth or the locking rib  48  engages into an outwardly facing recess  32  of a bracket  30  projecting downwardly from the upper switch part  1 , as was described already above. This secures the upper switch part  1  of the circuit-breaking device against a movement away from the lower switch part  2  in the operating state, at least in the region of the connection module  3 , while the connection module  3  itself is locked by the locking means  45  with respect to the upper switch part  1 . As it is shown in  FIGS. 1 and 2 , the connection module  3  is pivotably mounted with respect to the lower switch part  2  along an axis  50  and, according to a preferred embodiment, comprises a downwardly elongated bracket  51 . The bracket  51  has an articulated relationship with a lever  52  controlling a locking flap or locking tooth  53  such that, when pivoting the connection module  3  counter-clockwise, the locking flap  53  is pivoted clockwise about an axis  53   a  and thus releases the upper switch part  1 . In the operating state of the circuit-breaking device the locking flap  53  is engaged by a bracket  31  provided with an outwardly facing opening  33 , as was described above, into which, again, the tooth  53   b  of the locking flap  53  engages when the connection module  3  adopts its operating position. 
   The above-described locking means or latching means consisting of elements  30 ,  32 ,  48 ,  52 ,  53 ,  53   b ,  31  and  33  ensures a fixation and locking of the upper switch part  1  with respect to the lower switch part  2 . 
   It can be seen that the connection module  3  may also be pivotably mounted on the upper switch part, and a locking with respect to the lower switch part  2  may kinematically be accomplished in an opposite manner. 
   According to another embodiment the upper switch part  1  is provided with lateral openings  60 ,  61 ,  62 . Contacts  60   a ,  61   a ,  62   a  ( FIG. 4 ) are provided in said openings or slots  60 ,  61 ,  62  which serve to have an electric contact produced to an adjacent circuit-breaking device. This possible combination may, for example, be desired if—instead of one single circuit-breaking device—a combination of one circuit breaker and one contactor or a so-called reversible contactor combination consisting of a circuit breaker, a contactor and a reversible contactor is desired. With respect to a switch-contactor combination this will hereinafter be explained by means of  FIG. 4 . If, for example, two circuit-breaking devices according to  FIG. 4  are used, both circuit-breaking devices are connected with each other by means of the contacts  60   a ,  61   a ,  62   a  and corresponding contact tongues  64 ,  65  which are brought into an electric contact with the contacts  60   a ,  61   a ,  62   a  of the adjacent circuit-breaking device  70  facing the same. In this case the contacts  17 ,  18 ,  19  with respect to the upper switch part designated with  1  in  FIG. 4  are removed from the underside of the circuit-breaking device, as is suggested in  FIG. 4 , while the circuit-breaking device  70  is provided with corresponding contacts  17 ,  18 ,  19  for contacting the current busbars. 
   In other respects, both elements  1  and  70  respectively, as well as the lower switch part  2  and  72  respectively, preferably have the same configuration. 
   According to a preferred embodiment it is provided that the plug contacts  17 ,  18 ,  19  are arranged to be removable from the underside of the upper switch part  1  and, in correspondence with the use shown in  FIG. 4 , can be used as contact tongues when laterally pushed into the opening  60 ,  61 ,  62 . 
     FIG. 5  shows the use of the circuit-breaking device according to the invention as a motor protection switch or as a contactor. The application of two of such circuit-breaking devices with corresponding electrical connections is used as a switch-contactor combination, while the application of three of such units with a correspondingly modified contacting is used as a reversible contactor combination. 
     FIG. 5  shows in detail as  FIG. 5   a  a representation wherein the circuit-breaking device according to the invention is used as a motor protection switch, i.e. the circuit-breaking device is electrically connected with the current busbars  9 ,  10 ,  11  via the lower switch part and the outgoing conductors  42  are connected with the motor not further illustrated. 
   According to  FIG. 5   b  the circuit-breaking device serves as a contactor, i.e. the outgoing conductors  42  are connected with the non-illustrated consumer in the form of a motor. In  FIG. 5   c , a double combination is used, i.e. two circuit-breaking devices are provided whereof the right one in  FIG. 5   c  acts as a contactor and is designated with  70 , while the preconnected switch acts as a circuit breaker being in electrical contact with the current busbars while the contactor  70  is not in an electrical contact with the current busbars  9 ,  10 ,  11 , but whereof the outgoing conductors  42  lead to the subsequently connected motor or consumer respectively. 
     FIG. 5   d  shows three circuit-breaking devices arranged side by side in the form of a reversible contactor combination, i.e. with a circuit breaker  71 , a contactor  70  and a reversible contactor  73  which comprises the outgoing conductors  42  leading to the consumer or motor respectively. Accordingly, the two devices arranged adjacent to each other in  FIG. 5   c  are connected with each other by lateral contacts explained in  FIG. 4 , in which they are shown by the contact tongues  64 ,  65 , namely to ensure the operation of each individual unit. This means, in other words, that three contact tongues are provided between each device, as is explained in connection with  FIG. 4 . Correspondingly, the three circuit-breaking devices according to  FIG. 5   d  are connected with each other by means of such contact tongues. 
   As is shown in the above description, the circuit-breaking device according to the invention may be used as contactor and as reversible contactor or safety switch and preferably is of a narrow construction due to the compact design, wherein several of such circuit-breaking devices can be provided next to each other with a correspondingly differently designed contacting. The outgoing conductors are clamped in a touch-safe manner in a separate connection module  3  being in an operating communication with the circuit-breaking device. 
   For the purpose of exchanging the upper switch part  1  due to a defect or for other reasons the upper switch part  1  can easily be exchanged with respect to the lower switch part  2  upon correspondingly releasing the connection module  3 , whereupon the new upper switch part  1  can again be placed onto the same. 
   The circuit-breaking device according to the invention is constructed such that the electro-mechanical components, in as far as the upper switch part  1  and the lower switch part  2  are concerned, are provided to be lying on top of each other and that the connection module  3  for the outgoing conductors is laterally articulated to be pivotable with respect to the upper switch part  1  and the lower switch part  2 . This ensures that the entire unit including said three components can easily and quickly be clipped onto the current busbars in one go while a common locking mechanism in connection with the clamping feet  15   a ,  15   b ,  15   c  ( FIG. 1 ) is maintained, wherein the locking mechanism, e.g. in the form of the locking teeth  16 , effects a clamping or retaining effect with respect to the current busbars  9 ,  10 ,  11 . Even in this state can the lower switch part  2  and the connection module  3  remain where they are when an exchange of the upper switch part  1  is required, by opening—in accordance with the above description—the connection module  3  with respect to the locking means  45  and with respect to the entire unit, whereupon a second locking unit then allows a removal of the upper switch part  1  with respect to the lower switch part  2  by means of the control rod or the control lever  52 . Once a new upper switch part  1  has been mounted, this mechanical locking mechanism, consisting of the elements  30 ,  32 ,  48 ,  52 ,  53 ,  53   b ,  31 ,  33 , again allows an automatic locking with respect to the lower switch part  2  due to a pivoting movement of the connection module during the pivoting movement thereof clockwise. 
   During the phase of exchanging the upper switch part  1  the busbar system  9 ,  10   11  remains protected against contact by the lower switch part  2  remaining on the same, and there is no need to disconnect the other consumers provided on the busbar system. 
   According to another embodiment the upper switch part  1  is equipped with ventilation channels  80 ,  81 ,  82  which—in a sectional view—are preferably formed semi-circular and communicate with the corresponding ventilation channels of adjacent circuit-breaking devices, and which, with circuit-breaking devices arranged directly next to each other, result in circular ventilation channels extending in horizontal directions, i.e. parallel to the current busbars  9 ,  10 ,  11 , so that the hot air dissipation is ensured on the front side of the circuit-breaking devices, namely on the face where all ventilation channels are lead towards the outside. In addition, one or more ventilation holes may be provided also above each circuit-breaking device, as is shown by reference numeral  84  in  FIG. 2 . 
   The formation of the locking units as described moreover ensures that an unintended removal or an unintended disassembly of the entire circuit-breaking device and a contact with the current-carrying current busbars is prevented. 
   Both in  FIG. 1  and  FIG. 2  the lower switch part  2  is shown in a partially cut open view. 
   It can be inferred, for example, from  FIG. 2  that, due to the structure of the housing in the area of slots  12 ,  13 ,  14 , the associated contacts  5 ,  6 ,  7  are closed on the sides and on the top by the housing sections  12   a ,  13   a ,  14   a , i.e. they are designed to be insulated such that the connection contacts  17 ,  18 ,  19  ( FIG. 1 ) may be electrically connected with the contacts  5 ,  6 ,  7  via said slots  12 ,  13 ,  14  while, when the upper switch part  1  is withdrawn, said contacts  5 ,  6 ,  7  are enclosed by the housing sections  12   a ,  13   a ,  14   a  in an insulated manner. The height of these housing sections  12   a ,  13   a ,  14   a  preferably corresponds to the height of a side wall designated with  12   d . The side wall preferably extends over the entire length of the lower switch part  2 , as can be seen in  FIGS. 1 and 2 . 
   Reference will now be made to  FIGS. 6 and 7 . With respect to the preceding figures same parts are designated with the same reference numerals in  FIGS. 6 and 7 . 
     FIG. 6  shows an embodiment modified over  FIG. 1 . In both  FIG. 6  and  FIG. 7  a portion of the lower switch part  2  is illustrated in a cut open view. 
   It can moreover be seen in  FIG. 6  that the side walls  3   a  have approximately the same depth as the upper wall  3   b  of the connection module  3  so that the contact tongues  38 ,  39 ,  40  of the connection module  3  are entirely enclosed by the housing or the walls  3   a ,  3   b  respectively in an insulated manner. 
   In the embodiment according to  FIGS. 6 and 7  the insulation safety of the individual parts is still further improved as compared to the embodiment according to  FIG. 1  as will be described below. With reference to the upper switch part  1  shown in the embodiment according to  FIGS. 6 and 7  a protective collar  20   a ,  22   a ,  24   a  is provided with respect to each contact  17 ,  18 ,  19  instead of the lateral cover brackets  20 ,  21 . The protective collar according to the embodiment as illustrated preferably has an opening surface being at least slightly larger than the surface of the housing sections  12 ,  13 ,  14  which include the slots  12 ,  13 ,  14 . The height of the protective collars  20   a ,  22   a ,  24   a  is selected to be at least as high as the contacts  17 ,  18 ,  19  downwardly projecting from the upper switch part  1 , preferably even higher than the same. Thus, the contacts  17 ,  18 ,  19  are laterally entirely covered by the protective collars  20   a ,  22   a ,  24   a  in an insulated manner so that, when the upper switch part  1  is withdrawn, e.g. for replacing it by a new upper switch part  1 , the danger of touching the area between the housing sections  12   a ,  13   a ,  14   a  or the contacts  17 ,  18 ,  19  with a hand is completely eliminated, even when the busbars are current-carrying. 
   In correspondence with the illustration in  FIGS. 6 and 7  the connection module  3  is preferably elongated with respect to its side walls arranged parallel to each other, whereof only side wall  3   a  is depicted in  FIGS. 6 and 7 , such that the contact tongues  38 ,  39 ,  40  ( FIG. 1 ) are likewise laterally covered. When the device is in operation, this results in the prevention of an access to the contact tongues  38 ,  39   40  even with a slight pivoting counter-clockwise movement of the connection module  3  in  FIG. 1  or  FIG. 6  respectively, i.e. that the safety against contact is very high, even if it can be assumed that already a slight pivoting counter-clockwise movement of the connection module  3  according to  FIG. 1  entails that the contact tongues  38 ,  39 ,  40  would be currentless. This means, in other words, that the side walls  3   a  of the connection module  3  according to the embodiment shown in  FIGS. 6 and 7  have such a length in the direction of the upper switch part that the contact tongues  38 ,  39 ,  40  are laterally covered or that the contact tongues  38 ,  39 ,  40  even lie inside these walls or, respectively, that the side walls  3   a  at least slightly project over the contact tongues  38 ,  39 ,  40  in the direction of the upper switch part  1 . Thus, in the operating state ( FIG. 7 ), the connection module is designed with respect to its housing including the side walls  3   a  such that it covers a lateral subsection designated with  1   c , which comprises the contact openings  35 ,  36 ,  37  and the locking opening  46 , or is placed upon the same. The subsection  1   c  of the housing therefore has a smaller cross-sectional surface than the rest of the housing of the upper switch part  1 , as can be inferred from  FIG. 6 . 
     FIG. 7  shows a representation of the circuit-breaking device in the operating position, i.e. in the position in which the upper switch part  1 , the lower switch part  2  and the connection module  3  are permanently connected or interlocked with each other, and in which position the contacts  17 ,  18 ,  19  are inserted into the counter-contacts or counter-contact tongues  5 ,  6 ,  7 . 
     FIG. 8  is a lateral view of an upper switch part  1  which preferably corresponds to the embodiment according to  FIG. 6 . By cutting away the side wall, the mounting of one of the contact elements  18  is depicted.  FIG. 9  is a detailed view for illustrating a preferred embodiment of the mounting of the contacts  17 ,  18 ,  19 , with the view concentrating on contact  18 . As had already been explained above, it may be possible or required with a parallel arrangement of a motor protection switch and a contactor corresponding to  FIG. 5   c  or a reversible contactor combination corresponding to  FIG. 5   d  to remove individual ones of the contacts  17 ,  18 ,  19  from the upper switch part and to produce an electrical connection between the adjacent units via the contacts located in slots  60 ,  61 ,  62  instead. According to a preferred embodiment the contacts  17 ,  18 ,  19  are, for this reason, detachably mounted on the lower switch part  1  wherein, according to the embodiment of  FIG. 8 , when the contacts  17 ,  18 ,  19  are inserted, the same are enclosed by the protective brackets  20 ,  21  and so on or entirely by the pedestals  20   a ,  22   a ,  24   a  so as to ensure an insulated arrangement of these contacts. 
   For facilitating the illustration those reference numerals not referring to the mounting of the contact  18  have been omitted in  FIGS. 8 and 9 . 
   According to a preferred embodiment of the circuit-breaking device in correspondence with  FIG. 9  a substantially vertically extending slot for each contact  17 ,  18 ,  19  is formed on the lower side of the upper switch part, which is designated with reference numeral  90  in  FIG. 9 . Each contact  17 ,  18 ,  19  preferably has two webs  91 ,  92  laterally projecting away to the longitudinal plane of the contacts, whereof at least one of the webs  91  is received in a step-like slot receptacle of the upper switch part, said step-like receptacle being designated with  93 . With this mounting variant of the contact  18  a strip or web  95  is provided on the side opposite the step-like receptacle  93 , which is preferably made of an insulating material, said web  95  being made either of an insulating material or an electrically conducting material and, in the latter case, producing an electrical contact to the contact  18 . If the web or strip  95  is made of an insulating material, the electrical contact to the contact  18  is provided above said contact  18  in a manner not illustrated in more detail. 
   A locking hook  96  serves to fix the contact  18 , wherein said locking hook  96  is attached on a web  97  or, as an integral part of the web  97 , projects away in a downward direction in the manner shown in  FIG. 9 , said web  97  being laterally adjustable. A section  98  forking off from the locking hook  96  is provided on the web  97  which is spaced away from the locking hook  96  by a slot  99 , as can be seen in  FIG. 9 . 
   The slot  99  serves to receive a tool, e.g. a screwdriver, by means of which the web  97  with the locking hook  96  in  FIG. 9  can be displaced away from the contact  18  towards the right, so that the web  92  of the contact  18  may be released with respect to the locking hook  96  and contact  18  may be displaced out of the upper switch part downwardly in the direction of an arrow  100 . Thus, when the upper switch part  1  is placed upon the lower switch part  2 , no contact to the contact  6  is possible, but the contact element  18  is rather plugged into the contact located inside slot  61  so as to produce a bridge to the adjacent module. 
   It is essential that an unlockable locking means is provided for mounting the contacts  17 ,  18 ,  19  which allows the locking and the removal of the contacts  17 ,  18 ,  19  according to need, i.e. of one or more of these contacts, and which ensures the locking of these contacts in case of need.