Abstract:
An attachment part for a mechanical connection of a rear wall to a first and a second side wall, a base wall and a ceiling wall of a cabinet includes a plurality of resilient tongues each integrally formed on the attachment part and each having a latching lug, wherein the attachment part can be attached to an inside of the rear wall at each one of four corners of the rear wall at a right angle with the rear wall, and wherein the first and the second side wall, the base wall and the ceiling wall are each firmly latchable to the latching lugs.

Description:
This is a U.S. National Phase Application under 35 U.S.C. §171 of International Application No. PCT/EP2008/005967 filed on Jul. 21, 2008, which claims priority to German Application No. DE 10 2007 034 514.5, filed on Jul. 24, 2007. The International Application was published in German on Jan. 29, 2009 as WO 2009/012964 under PCT Article 21 (2). 
     The invention relates to an attachment part for a cabinet, in particular an electrical switchgear cabinet. 
     BACKGROUND 
     Switchgear cabinets for electrical service distribution panels of this type have a rear wall, two side walls, a base wall and a ceiling wall, which walls are welded to one another at their edges. A door is fitted to one of the vertical free edges and the interior of the switchgear cabinet is accessible by means of said door. 
     The disadvantage of this structural solution is that the switchgear cabinet itself can no longer be dismantled but has to be produced in the factory, this being unfavorable in terms of storage and transportation. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention is to provide an attachment part for a cabinet, in particular an electrical switchgear cabinet, of the type mentioned in the introduction with which the cabinet can be dismantled for transportation purposes and furthermore can be easily assembled. 
     According to the invention, in each case an elongate attachment part can accordingly be attached to the inside of the rear wall at the four corners of said rear wall in a manner oriented at right angles to said rear wall, with resilient tongues with latching lugs being integrally formed on said attachment part, it being possible for the side walls, the base wall and the ceiling wall to be firmly latched to said latching lugs. 
     A significant portion of the assembly work is carried out by fixing the attachment parts to the rear wall; in order to add to and finish the cabinet, in particular the switchgear cabinet, it is only necessary to firmly latch the side walls, the base wall and the ceiling wall to the attachment part. A significant advantage is that the switchgear cabinet is composed of components which can be releasably connected to one another. Therefore, storage can be improved because the space requirement is lower. In addition, the outlay on assembly is lower than, for example, those switchgear cabinets which are welded together. 
     One advantageous refinement of the invention has the effect that the attachment part has an L shape which is formed at right angles to the longitudinal extent in cross section, and in that the tongues are integrally formed on the outer faces of the limbs at right angles to the outer faces by way of the latching lugs. 
     In order that the required and convertible space can be reduced, the outer faces of the limbs in each case have a groove which runs in the longitudinal direction of the attachment part; the tongues are then integrally formed on one of the side walls of the groove parallel to this side wall. 
     A further embodiment of the invention is provides an electrical switchgear cabinet in which the attachment part can be employed. 
     The side walls, the base wall and the ceiling wall accordingly have, at their side edges which adjoin the attachment parts, inwardly bent edges which can latch in behind the latching lugs on the tongues. As a result, assembly of the side walls, the base wall and the ceiling wall is considerably simplified by said walls being fitted to the attachment parts from the outside and being pushed behind the latching lugs by way of their bent edges, with tools not being required for this purpose. 
     In a further advantageous embodiment, second bent edges which form an L shape are provided on the bent edges, said second bent edges forming, with the bent edges, an approximately U-shaped side wall groove, into which two grooves an outer corner part of which the length corresponds to the length of the attachment part can be inserted in the direction of its longitudinal extent and that of the component can be inserted in the direction of the rear wall, with strip-like projections being provided on the outer corner part, said strip-like projections fitting into the side wall grooves for bracing the side walls, the base wall and the ceiling wall. 
     An advantageous refinement of the electrical switchgear cabinet has the effect that soft-elastic seal lips or sealing lips are fitted to the outer corner part, said seal lips or sealing lips being arranged at the limb ends and projecting in the direction of the limbs. In this case, the sealing lips bear against the side walls, against the ceiling wall and the base wall, as a result of which protection in accordance with IP 54 is achieved. 
     Further advantageous refinements of the invention can be found in the further dependent claims. 
     The invention, further advantageous refinements and improvements as well as further advantages will be explained and described in greater detail with reference to the drawings which schematically illustrate one exemplary embodiment of the invention in different working steps. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  shows an internal view into a completely assembled switchgear cabinet, 
         FIG. 2  shows the association of an attachment part to the rear wall before fixing, 
         FIG. 3  shows the arrangement according to  FIG. 2  after the attachment part is fixed to the rear wall, 
         FIG. 4  shows a perspective view of the upper part of a switchgear cabinet according to the invention, with only the two upper attachment parts being fixed to the rear wall, 
         FIG. 5  shows a perspective view of a corner region of a switchgear cabinet with a latched-on side wall and a latched-on ceiling wall and an outer corner part before insertion into the corresponding grooves, and 
         FIG. 6  shows a cross-sectional view according to section line VI-VI of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made to  FIG. 1 . 
     A switchgear cabinet  10  comprises two side walls  11  and  12  and also a base wall  13 , a ceiling wall  14  and a rear wall  15 , with the switchgear cabinet being substantially completely assembled. By way of example, crossbars in the form of a top-hat rail for latching on electrical installation equipment are to be installed in the switchgear cabinet. Said crossbars and a front door, for closing the switchgear cabinet, are not illustrated because they are not important to the invention. 
     Reference will now be made to  FIG. 2   
       FIG. 2  shows a perspective view of a corner region of a switchgear cabinet, with only part of the rear wall  15  being shown. The rear wall has, at its edges, bent edges  16 ,  17  which are bent inward in an L-shaped manner and of which the free limbs  18 ,  19  run parallel to the inner face of the side wall. A cutout  20  is provided in the region of the corner of the bent edges  16 ,  17  and the limbs  18 ,  19 , and therefore the free limbs  18 ,  19  end at a distance D in front of the corner edge. The free limbs  18 ,  19  adjoin bars  21  and  22  which run at right angles to the side wall, with the cutout  20  also comprising the bars  21  and  22 , and therefore in each case a strip-like protrusion  23 ,  24  is formed in the region of the corners, the height of said protrusion, measured from the inner face of the side wall, preferably being less than half the height of the bars  21  and  22 . 
     An attachment part  25  is attached to the inner face in the region of the corner of the cutout  20 , with the attachment part  25  being mounted on the inner face of the rear wall  15  by way of its end face (not visible), and with the peripheral contour of the attachment part  25  being installed at right angles to the longitudinal extent of the cutout  20 . Attachment is performed by means of an attachment screw  26  which passes through a passage hole  27  in the rear wall  15  and is screwed into the end face of the attachment part  25 . 
     The attachment part  25  has, in cross section, an approximate L shape with two limbs  28  and  29  which run at right angles to one another, with in each case a U-shaped groove  30 ,  31  which runs in the longitudinal direction of the attachment part  25  being provided on the outer faces of the limbs  28 ,  29 . The groove base  32  of the two grooves  30 ,  31  runs, like the groove base  33 , in the direction of the longitudinal extent of the limbs  28  and  29 . The groove base  32  and the groove base  33  run, like the limbs  28 ,  29 , at right angles to one another. Three further cutouts  36 ,  37 ,  38  and also  39 ,  40  and  41 , in which cutouts in each case a resilient tongue  42 ,  43  and  44  and also  45 ,  46  and  47  is arranged, which tongues each protrude at right angles to the groove base  32  and  33  respectively, are arranged on the side walls  34 ,  35  of the grooves  31  and  30  which are placed at the free ends of the limbs  28 ,  29 . The tongues  42 ,  43 ,  44  on the limb  29  accordingly project in the opposite direction to the limb  28 , and the tongues  45 ,  46  and  47  project in the opposite direction to the limb  29 , and are in each case integrally formed on the groove base  32 ,  33  at right angles to said groove base. Latching lugs  42   a ,  43   a ,  44   a  and  45   a ,  46   a ,  47   a , which project into the associated groove  30 ,  31  in order to provide latching, are integrally formed at the end of the tongues  42 ,  43 ,  44  and  45 ,  46 ,  47 . Slots  80 ,  81  into which the protrusions  23  and  24  engage in the assembled state in order to guide the attachment part  25 , as shown in  FIG. 3 , are made on the end face of the attachment part  25  which adjoins the rear wall  15 . 
       FIG. 3  shows the arrangement of the attachment part  25  on the rear wall in an illustration which is slightly enlarged compared to  FIG. 2 . 
       FIG. 4  shows the upper section of a switchgear cabinet in a further assembly step with the rear wall  15 , the side walls  11  and  12  and also the ceiling wall  14 . The attachment parts  25 ,  25   a  are fixed to the rear wall  15  at the illustrated and visible corners, with the limbs  28 ,  28   a  facing one another. 
     At the edges which adjoin the attachment parts  25 ,  25   a  and run horizontally at the upper and lower ends, the side walls  11 ,  12  and the ceiling wall  14  have second bent edges  50  which are bent in the direction of the inner face, see  FIG. 6 , with the bar  51 , which is directly adjacent to the inner face of the side wall  11 , of the second bent edge  50  forming an angle α of less than 90° with the inner face, as a result of which a latching-in lug  52  is formed between the bar  51  and a further bar  53  which runs parallel to the inner face of the side wall  11 . A limb  54  which is at right angles to the bar  53  and of which the end edge lies approximately in the plane of the side wall  11  is located at the free end of the bar  53 . The second bent edges  50  are formed in such a way that they fit into the grooves  30 ,  31 . 
     By way of the latching-in lug  52 , the side wall  11  is pushed in direction P 1  toward the attachment part  25  and the side wall  12  is pushed in the opposite direction P 2  toward the attachment part  25   a  until the latching-in lug  52  engages in behind the latching lugs  42   a ,  43   a ,  44   a . The ceiling wall  14  has a second bent edge of identical design to that of the side wall  11  and the corresponding latching-in lug of this second bent edge then engages behind the latching lugs  45   a ,  46   a  and  47   a.    
     Further bent edges are provided at the longitudinal edges, which run at right angles, of the side walls  11 ,  12  and also of the base wall and ceiling wall  14 , limbs (only the limb  55  of the side wall  11  is illustrated) which run at right angles to the rear wall  15  being provided at said bent edges, it being possible for further carrier elements or a front door to be fitted to said limbs if desired. 
     As can be seen in  FIG. 2 , each attachment part has two grooves  30 ,  31  into which the bent edges  50  of the side walls  11  and of the ceiling wall  14  engage (only attachment part  25  can be seen here). A receiving groove  58  (see  FIG. 6 ) into which an outer corner part  60  can be inserted is formed by the bar  51 , the further bar  53  and the limb  54 . The outer corner part  60  is illustrated in  FIG. 5 . Said outer corner part has an L-shaped cross section with a first outer corner part limb  61  and a second outer corner part limb  62 , which limbs run at right angles to one another and which limbs have, on their inner faces, strip projections  63  and  64  which can be inserted into the receiving grooves  58  in arrow direction P 3 . The side wall  11  is braced to the ceiling wall  14 , the ceiling wall  14  is braced to the side wall  12  and, inversely, the side walls  11  and  12  are braced to the base wall by way of this plug-on part  60  or outer corner part  60 . 
     The attachment part  25  and the outer corner part  60  are complemented by a covering cap  65  which has a plate-like shape and a screw which can be screwed through a passage hole  66  and can be screwed to or into a threaded bore  67  in the attachment part  25 , so that the switchgear cabinet as illustrated in  FIG. 1  results when assembly is complete. The fact that bent beam edges  70  and  71 , which are complemented by bent edges  55 , are provided on the base wall in the front region, like on the ceiling wall, is merely noted in passing. 
     As can be seen in  FIGS. 1 to 6 , the attachment parts  25 ,  25   a , like the outer corner parts  60 ,  60   a , have a length which corresponds to the depth of the switchgear cabinet, or to the distance between the front face and the rear wall. 
     The particular advantage of the invention is that, in order to produce the switchgear cabinet according to  FIG. 1 , only attachment work of the attachment parts  25 ,  25   a , latching work of the side walls  11 ,  12  and of the ceiling wall  14  (and also of the base wall of course), insertion of in each case an outer corner part  60 ,  60   a  into the corresponding receiving grooves  58  in the side walls  11 ,  12  and the ceiling wall  14  (like the base wall) is required; the assembly work by attaching the covering caps  65 ,  65   a  to the attachment parts  25 ,  25   a  by means of the screws  67 ,  67   a  is stopped. A further significant advantage of the invention is that the switchgear cabinet can be dismantled, this reducing the space requirement for storage and the space requirement during transportation. 
     At its limb ends  70 ,  71 , the outer corner part  60  has sealing lips  72 ,  73  comprising an elastic material which are placed against the side panels  11 ,  12 , the base wall  15  and the ceiling wall  14 , as a result of which the switchgear cabinet meets the requirements of standard IP 54. 
     The outer corner part  60  and sealing lips  72 ,  73  are produced using a two-component technique. 
     LIST OF REFERENCE SYMBOLS 
     
         
           10  Switchgear cabinet 
           11  Side wall 
           12  Side wall 
           13  Base wall 
           14  Ceiling wall 
           15  Rear wall 
           16  Bent edge 
           17  Bent edge 
           18  Free limb 
           19  Free limb 
           20  Cutout 
           21  Bar 
           22  Bar 
           23  Protrusion 
           24  Protrusion 
           25  Attachment part 
           26  Attachment screw 
           27  Passage hole 
           28  Limb 
           29  Limb 
           30  Groove 
           31  Groove 
           32  Groove base 
           33  Groove base 
           34  Side wall 
           35  Side wall 
           36  Further cutout 
           37  Further cutout 
           38  Further cutout 
           39  Further cutout 
           40  Further cutout 
           41  Further cutout 
           42  Tongues 
           43  Tongues 
           44  Tongues 
           45  Tongues 
           46  Tongues 
           47  Tongues 
           42   a  Latching lug 
           43   a  Latching lug 
           44   a  Latching lug 
           45   a  Latching lug 
           46   a  Latching lug 
           47   a  Latching lug 
           50  Second bent edge 
           51  Bar 
           52  Latching-in lug 
           53  Further bar 
           54  Limb 
           58  Receiving groove 
           60  Outer corner part 
           61  First outer corner part limb 
           62  Second outer corner part limb 
           63  Strip projection 
           64  Strip projection 
           65  Covering cap 
           66  Passage hole 
           67  Threaded bore 
           70  Bent beam edge 
           71  Bent beam edge