Abstract:
The invention relates to a switching device, in particular fused interrupters, including a housing and a cover arranged thereon, wherein in the housing at least one pair of contacts is provided for receiving respectively one contact blade of a safety device or the like, wherein each contact is electrically connected to an input or output contact element, and one contact of each contact pair has a base section as an input contact which projects from the housing on the underside thereof, including an adapter arranged on the bottom side of the switching device which has two contact gaps per base section for alternative contacting and which is provided for attaching to conductor rails.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a National Stage of International Application No. PCT/EP2007/054100 filed Apr. 26, 2007, claiming priority based on German Patent Application No. 10 2006 022 374.8, filed May 12, 2006, the contents of all of which are incorporated herein by reference in their entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a switching device, in particular a fuse switch disconnector, comprising a housing and a lid arranged thereon, in which at least one pair of contacts is provided in the housing for receiving respectively one contact blade of a fuse unit, wherein each contact is electrically connected to an input or output contact element. 
     2. Related Art 
     Switching devices, in particular fuse switch disconnectors, comprise a housing having a lid, which is preferably pivotably hinged thereto. Depending on the number of poles, contacts having input and output contact elements respectively for receiving fuse units are located in the housing. Here, the fuse units are preferably pivotably arranged along with the lid so that the fuse units are removed from the associated contacts when opening the lid. Such a switching device is known from DE 297 21 440, for example. The housing having the contacts for contacting the contact blades of the fuse units is preferably arranged on busbars by means of an adapter. Here, cylindrical contact elements, which are on one side in electrical contact with respectively one connecting bar, which in turn may be brought into electrical contact with one of the busbars, serve to establish an electrical contact between the input contact elements and the associated busbar. The output contact element serves to mount an end of the line. 
     In such switching devices it is necessary to pay attention to a preset connection direction, i.e., when the switching device is attached to the busbars, which are horizontally arranged and extend in parallel on top of each other, the output contacts are regularly located at the lower side. It is not possible to change the connection direction of the switching device with regard to the output contacts thereof. 
     Switching devices of said kind are known as mounting devices and busbar devices. Mounting devices are mounted on a mounting plate or are also snapped onto a mounting rail. In addition, the switching device has separate input and output contacts, to which electrical lines are clamped. Switching devices in the form of busbar devices, as described above, are attached to busbars and conductor rails respectively and therefore exclusively have connection points and output contacts respectively for the output lines. Here, the input supply (feeding) is carried out by means of the previously described contacting of the busbars. 
     Depending on the concept of the control cubicle and the country-specific standard, output lines leading downwards, but also output lines leading upwards are required. Therefore, in the known switching devices different kinds of housings are required, depending on whether the output contacts are to be accessible from below or from above. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is based on the object to provide a switching device, in particular a fuse switch disconnector, in which the connection direction of the output contacts can be changed. 
     According to the invention, said object is achieved in that one contact of each contact pair comprises as input contact a base section, which is led downwards from the housing through an opening in the bottom of the housing and projects from the housing at the lower surface thereof, comprising an adapter, which is arranged at the lower side of the switching device, has two contact gaps for alternative contacting by the base section and includes a contact rail comprising contacting portions for contacting by the base section in the area of the contact gaps, wherein the adapter is configured to be attached to conductor rails. 
     One embodiment is characterized in that the pairs of openings located at the top of the adapter are aligned with respect to the contacts so that the housing rotated by 180° can be attached to the adapter in case of concurrent contacting between the base section and one of the contacting portions of the contact rail. 
     Another embodiment is characterized in that the base section is formed as plug-in contact. 
     Another embodiment is characterized in that the base section is formed by spring-elastic arms. 
     Another embodiment is characterized in that the base section is formed by at least one plug-in tongue. 
     Another embodiment is characterized in that the housing comprises two pairs of holders, which are alternatively provided as lid support for pivotally supporting the lid. 
     Another embodiment is characterized in that the holders are formed as hinge pins for receiving an arm, at the end of which a slot or the like is provided and which is attached to the lid. 
     Another embodiment is characterized in that the contacts are formed symmetrically to a central line of the housing. 
     Another embodiment is characterized in that an adapter part is provided, which comprises at its top pairs of openings located symmetrically to each other for electrically contacting contact regions, which are a component part of a contact rail arranged in the adapter. 
     Another embodiment is characterized in that each contact rail defines an arm extending substantially parallel to the axis of the adapter, at which the contact regions are formed. 
     Another embodiment is characterized in that the input contact formed as base section is attached to or inserted into the contact rail when the housing is attached to the adapter. 
     Another embodiment is characterized in that each contact rail comprises predetermined regions for contacting by the input contact. 
     Another embodiment is characterized in that the predetermined regions are rounded. 
     Another embodiment is characterized in that the predetermined regions comprise slots. 
     Another embodiment is characterized in that the plug-in contact is connected to the base section via a shoulder portion. 
     Another embodiment is characterized in that the receiving region of the plug-in contact is formed in parallel and offset with respect to the base section for contacting the blade of the associated fuse unit. 
     The invention provides a switching device, in which the connection direction can be made both downwards and upwards so that different types of housings are not required and the desired connection situation can be conceived correspondingly on the premises at any time. 
     In particular, the switching device according to the invention enables the output contacts to be adjustable in a state either facing downwards or upwards by corresponding positioning of the housing. In the switching device according to the invention a contact, namely the input contact, is formed so as to comprise a base section projecting beyond the lower surface of the housing and serving as plug-in contact so that the housing in a first position and a second position rotated by 180° with respect to the first position, depending on where the output contacts are to be located, can be attached to the adapter element, thereby establishing an electrical contact between the plug-in contact and the associated contact rail element in the adapter. 
     In a preferred embodiment the housing is provided with two pairs of holders for supporting the lid so that in each case, depending on the positioning of the housing of the switching device, the lid can be hinged and pivotally mounted to the housing respectively in the proper position. 
     According to a preferred embodiment, the adapter is provided with one contact rail per pole, each comprising two alternative contact regions so as to be contactable by the plug-in contact of the associated pole in the housing. In the area of said contact regions the adapter opens towards the housing of the switching device to enable the plug-in contact to be put therethrough. 
     In a first embodiment the plug-in contact is provided with spring-elastic contact arms, which are attached to, for example, a tapered region at the contact rail of the adapter. In another embodiment the plug-in contact is fitted with at least one, preferably several, plug-in tongue(s) in the area of the base section, which can be plugged in corresponding gap-shaped openings of the contact rail in the adapter. 
     In order to explain further features, preferred embodiments of the switching device according to the invention will be described below in conjunction with the drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of the switching device according to the invention to show the arrangement of the contacts clearly, 
         FIG. 2  is a view of the switching device according to  FIG. 1  along with an adapter, 
         FIG. 3   a  is a detailed view of the input and output contacts as well as the associated contact rail extending in the adapter, 
         FIG. 3   b  is an illustration in accordance with  FIG. 3   a , in which the plug-in contact is attached to the contact rail, 
         FIG. 4  is an illustration in accordance with  FIG. 2 , in which the housing is rotated by 180° with regard to  FIG. 2 , and 
         FIG. 5  is an illustration of the input and output contacts and the associated contact rail to illustrate an embodiment modified with regard to  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The switching device according to the invention will be explained in further detail below by means of the drawings. 
       FIG. 1  shows the switching device comprising a housing  1  and a lid  2  preferably pivotally hinged to the housing  1 . As is known from DE 297 21 440, the lid  2  serves to receive one or more fuse unit(s). Such fuse units comprise contact blades for contacting the contacts to be described below in the housing  1 . In  FIG. 2  said fuse unit is designated by  3  and the contact blades are indicated by  4  and  5 . 
     As can be seen from  FIGS. 1 and 2 , the lid  2  is pivotally mounted to the holders  8  by swivel feet  7 , wherein the holders  8  are preferably provided in the form of receiving pins or the like. Two pairs of such holders  8 ,  8 ′ are located at the inside of the housing  1 , which serve to mount the lid either to the pair of holders  8  or the pair of holders  8 ′, depending on how the housing is arranged with regard to the associated adapter  18  still to be described. The housing  1  is usually located in vertical direction so that the lid  2  is arranged in such a way that the lid can be pivotally opened “upwards”. 
     In a three-pole switching device three pairs of contacts  10 ,  11  are located in the housing, which are provided opposite to each other and serve to receive the contact blades  4 ,  5  of the respective fuse unit  3  when the lid  2  is moved in a direction towards the housing  1  and closed. 
     In the embodiment shown in  FIGS. 1 and 2  an output contact is provided in the form of the contact  10  and an input contact  11  is provided in the form of a plug-in contact, as is to be explained in further detail below. The plug-in contact  11  comprises a base section  12  led downwards from the housing  1  through an opening  17  in the bottom  1   b  of the housing and protruding over a preset distance with respect to the lower surface  1   a  of the housing. In the illustrated embodiment the output contact  10  is substantially and preferably L-shaped, mounted opposite the bottom  1   b  of the housing by screwing means  13  and in addition supports a clamping screw  14  for clamping a line end or the like thereto on the arm  10   a  extending parallel to the plane of the housing. The plug-in contact  11  is mounted to the bottom of the housing  1  by means of an arm  11   a  projecting perpendicularly to the base section  12  and by means of screwing means. 
     In the embodiment shown in  FIGS. 1 and 2  the plug-in contact  11  is formed so that the base section  12  is arranged to be offset in parallel with respect to the receiving portion  11   b  thereof for contacting the blade of the associated fuse unit  3  by forming a shoulder portion  11   c  between the portion  11   b  and the contact portion  12 . In detail, reference is explicitly made to  FIG. 1 . 
     The shoulder portion  11   c  bears on the bottom  1   b  of the housing  1 . In the bottom  1   b  of the housing there is located an opening  17 , through which the base section  12  of the plug-in contact  11  is led. Furthermore, screwing means  16  are provided in the bottom  1   b  of the housing, which serve to enable the housing  1  to be mounted to the underlying adapter  18 . 
     As results from  FIGS. 1 and 2 , the contact blades  4 ,  5  enter the contacts  10 ,  11  associated with the receiving regions  10   b ,  11   b  upon closing the lid  2 , whereby an electrical connection is established between the input contact in the form of a plug-in contact  11  and the output contact  10 . 
     The switching device according to the invention is attached to the adapter  18 , wherein the base section  12  of the plug-in contact  11  engages predetermined regions or contacting portions  21 ,  22  of a contact rail  20  via one of respectively one pair of openings  18   a ,  18   b , and, so that the electrical contact between the base section  12  and the contact rail  20  is established, which is done when attaching the housing  1  to the adapter  18 . 
     In the embodiment shown in  FIGS. 1 and 2  the contact rail  20  is provided with two defined contact portions  21 ,  22 , as will be explained in detail below. When the housing  1  according to  FIGS. 1 and 2  is attached to the adapter  18 , the base section  12  contacts the region  22  of the contact rail  20 , which itself can be brought into electrical connection with one of the busbar and conductor rail respectively denoted by  24 ,  28 ,  29 . 
     The adapter  18  further comprises feet  25 ,  26 ,  27  for partially engaging under the associated busbars  24 ,  28 ,  29  in order to enable the adapter  18  to be attached to the busbars  24 ,  28 ,  29 , as is known per se. 
       FIG. 3   a  shows a first embodiment of the contacts  10 ,  11  used in accordance with the invention and the contact rails  20  of the adapter  18 . Each contact  10 ,  11  is provided with contact arms  30 ,  31  and  32 ,  33  respectively in a manner known per se, which are biased in a clamping position by a lock washer  35  and  36  respectively, as is also known per se. The contact arms  30 ,  31  and  32 ,  33  respectively extend substantially parallel to each other and support insertion regions widening upwards. The arms  30 ,  31  and  32 ,  33  respectively are engaged behind by respectively one lock washer  35  and  36  respectively. 
     At the lower surface of the plug-in contact  11  there is located the base section  12 , which in this embodiment and in accordance with the upper contact portion is formed with the parts  32 ,  33 ,  36  and also comprises a lock washer  38 . 
     The contact rail  20  comprises widthwise shortened regions  21 ,  22 , which are preferably conical or chamfered and round respectively, in order to enable easy attachment of the plug-in contact  11  with the base section  12  thereof. For this purpose, the arms  39 ,  40  of the base section  12  are also bent laterally, whereby attaching the arms  39 ,  40  to the portion  21  and  22  respectively is eased. 
     The contact rail  20  comprises a tongue  42  bent downwards and ending in an arc  43  arched downwards. The arc  43  is for contacting the associated conductor rail, as can be seen from  FIG. 2 . 
       FIG. 3   a  shows a view according to  FIG. 3   a , wherein, however, the plug-in contact  11  is attached to the contact rail  20  and the guiding arms  39 ,  40  widening downwards are slid over the portion  22 . Therefore, the plug-in contact  11  is in electrical connection with the contact rail  20 . 
       FIG. 4  shows an illustration according to  FIG. 2 , in which, however, the housing  1  is rotated by 180° with regard to  FIG. 2  so that the plug-in contact  11  in  FIG. 4  is located on the left side of the housing  1 , i.e. close to the lid  2 , in contrast to  FIGS. 1 and 2 . In the embodiment according to  FIG. 4  the lid  2  is attached to and pivotably supported around the holders  8 ′. By arranging the holders  8 ,  8 ′ in pairs it is therefore possible to mount the lid  2  either to the holders  8  or alternatively and according to  FIG. 4  to the holders  8 ′ so that the housing  1  rotated by 180° with respect to  FIGS. 1 and 2  can be provided, whereby the output contacts are located in the direction opposite to the direction of  FIGS. 1 ,  2 . 
     In the embodiment according to  FIGS. 1 and 2  the output contacts are located “at the top”, i.e. in the area where the lid  2  is mounted, whereas in the embodiment according to  FIG. 4  the output contacts  10  are located “at the bottom”, i.e. at the side facing away from the lid  2 . 
     When the housing  1  according to  FIG. 4  is attached to the adapter  18 , the base section  12  contacts the region  21  having the same design as the region  22  according to  FIG. 3   a , wherein openings  18   a ,  18   b  are formed in the adapter  18  both above the region  21  and the region  22  so as to enable the plug-in contact  11  to be inserted correspondingly. 
     The switching device according to the invention comprises respective contacts  10 ,  11  per pole. As can be seen in  FIGS. 2 and 4 , there is provided respectively one contact rail  20  per pole and per conductor rail  24 ,  28 ,  29  respectively. The illustrated embodiment is a three-pole switching device for use on the busbars. 
     From the previous explanation it is obvious that the housing  1  may be attached as desired or required without any problem in a state in which it is rotated by 180° to locate the output contacts once either “at the top” or “at the bottom”. 
     With respect to the embodiment according to  FIG. 3   a ,  FIG. 5  shows a modified embodiment of the contacts  10 ,  11  and the contact rail  20 . In this embodiment the contact  10  is the same as that of the previous embodiment and the plug-in contact  11  differs from that of the previous embodiment in that the base section  12  is formed by at least one, preferably three, plug-in tongues  46 ,  47 ,  48 , each of which may comprise at least one projection  49 ,  50 ,  51  projecting laterally. A pair of slots  53 ,  54  corresponding to the width of the plug-in tongue and plug-in tongues respectively is formed in the contact rail  20  for receiving the plug-in tongue(s). It is possible to turn round the housing  1  according to the previous explanation, i.e. the plug-in contact  11  can either be inserted into the slot  54  or the slot  53 . The slots  53 ,  54  are slightly larger than the thickness of the contact tongues  46 ,  47 ,  48 , wherein, after insertion of the plug-in contact  11 , the projections or ridges  49 ,  50 ,  51  prevent the plug-in contact  11  from being removed unintentionally from the slots  53  and  54  respectively. 
     In the contact rail  20  there may also be provided one respective slot for each plug-in tongue instead of the continuous slots  53 ,  54 . 
     The contact rails  20  are preferably made of a flat copper ribbon to ensure the spring properties required for the contacting of the busbars. In the embodiment according to  FIG. 3   a  the regions  21 ,  22  are bent to a predetermined extent into an approximately U-shape in order to ease sliding the clamping arms  39 ,  40  thereon. 
     Although in the previously described embodiment the holders  8 ,  8 ′ are provided as hinge pins projecting from the inner wall of the housing towards the interior of the housing, another design than the illustrated one may also be used for pivotally supporting the lid  2 . 
     The embodiment of the plug-in contact  11  shown in  FIG. 5  has the advantage that the plug-in tongues are provided without separate spring means, i.e. the lock washer  38  used with respect to  FIGS. 3   a ,  3   b  is omitted and the contact rail  20  merely requires to be formed with slots and pairs of slots  53 ,  54  respectively compared with the formation of the particularly processed narrowed regions  21 ,  22  in the alternative embodiment according to  FIG. 3   a.    
     In the switching device according to the invention the housing  1  is made of a preferably rectangular or square body of plastics comprising a bottom  1   b  of the housing for receiving several, preferably three, contact pairs  10 ,  11  with the previously described input and output contacts. The individual contact pairs  10 ,  11  are formed in chambers isolated from one another by partition walls, as is known per se, so that the individual fuse units are separated from each other by the partition walls when the lid  2  is closed. The housing  1  is open-topped so as to receive the fuse units inserted in the lid  2  while closing the lid  2 . Although not further described in the figures, the lid  2  itself comprises means for fixing the fuse units  3  so that the fuse units  3  come to be located next to each other in parallel and accordingly can be inserted simultaneously into the associated contacts  10 ,  11  with their contact blades  4 ,  5  while closing the lid. 
     The lower surface of the housing  1  is merely opened in the area of the plug-in contact  11  and for receiving the screwing means  14 . Except for the openings  18   a ,  18   b  for the regions  21 ,  22  and for the thread holes for the screwing means  16 , the adapter  18  is close-topped. At its lower surface the adapter  18  is fitted with clamping feet  25 ,  26 ,  27 , which are made of an insulating material, in particular plastics, and are able to support the compensation elements  50 ,  51 ,  52  where required to enable the adapter  18  to be used at conductor rails  24 ,  28 ,  29  of different thicknesses. 
     Openings are formed on the lower surface of the adapter  18  so that the arc-shaped contact pieces  43  of the individual contact rails  20  slightly project from the lower surface of the adapter  18  for the purpose of contacting the conductor rails  24 ,  28 ,  29  upon attaching the adapter  18  to said conductor rails  24 ,  28 ,  29 . As shown in the figures, said contact regions can be biased by springs  63 ,  64 . 
     Both the lid  2  and the housing  1  and the housing of the adapter  18  are made of insulating material, in particular plastics. The live parts, as for example the contact rail  20  and the contacts  10 ,  11 , are preferably made of copper material. 
     The arrangement of the contact rails  20  in the adapter  18  is made so that in a three-pole switching device a total of three contact rails  20  are provided next to each other in parallel in the adapter  18  according to the three pairs of contacts  10 ,  11  in the housing  1 . 
     In the illustrated embodiment the contacts  10 ,  11  are provided symmetrically to a centre line, whereas the contact rails  20  are formed parallel to each other, but to be offset in terms of the contact regions  43  in the longitudinal direction of the adapter  18  to be able to respectively contact the individual conductor rails  24 ,  28 ,  29 . The contact regions  21 ,  22  are also located symmetrically to a central axis of symmetry, whereby it is ensured that the housing  1  is attachable to the adapter  18  both in the position shown in  FIG. 2  and the position shown in  FIG. 4 , thereby ensuring a contact between the plug-in contact  11  and the contact rail  20  with the predetermined contact regions  20 ,  21 . 
     Thus, the contact rails  20  located in the adapter  18  parallel to each other definitely may have different lengths, however, the preset contact regions  21 ,  22 , according to the arrangement of the contacts  10 ,  11  in the housing  1 , are located in alignment with each other and are therefore also located mirror symmetrically to an imagined centre line. 
     Unlike the contact rail  20  described in conjunction with  FIGS. 3   a  and  3   b , the contact rail over its length of the arm, which is located above the tongue  42 , including the contact regions  21 ,  22  can be formed continuously with a shape and width corresponding to those of the contact regions  21 ,  22  i.e., that the contact rail over the length of the whole arm is correspondingly formed narrow and rounded, as the regions  21 ,  22  in  FIG. 3   a . If the contact rail  20  has the same shape and configuration, i.e. arc-shaped flattenings when seen in cross section, over the total length including the regions  21 ,  22 , the manufacture of the contact rail  20  might be simplified. 
     The contact rails  20  provided in the adapter  18  extend parallel to each other and towards the axis of the adapter  18 . The arm of the contact rail receiving the contact regions  21 ,  22  extends in the adapter  18  slightly below an upper cover or wall of the adapter  18 , which is denoted by  19 . In said cover or wall  19  the pairs of openings  18   a ,  18   b  are located, the number of which corresponds to the number of poles of the switching device, i.e., respectively one pair of openings  18   a ,  18   b  is located above the respective contact rail  20  to enable the base section  12  to have access to the contact rail  20 , namely both in the position of the housing  1  according to  FIG. 2  and in the position of the housing according to  FIG. 4 . 
     In the illustrated embodiment there is respectively provided one spring means  63 ,  64  between the arm of the contact rail  20 , which extends parallel to the cover or wall  19  of the adapter  18  and includes the contact regions  21 ,  22 , and the tongue  42  and the arc-shaped contact region  43  respectively in order to bias the arc-shaped contact region  43  towards the conductor rails  24 ,  28 ,  29 .