Sealed cabinet for electrical apparatus

The invention relates to an electrical or electronic switchgear cabinet having walls formed by panels or plates secured to the elongated elements arranged at the corners of the cabinet and assembled at their ends to constitute a support framework, the set said angular elements being constituted by identical tubular sections arranged in the same way and having two orthogonal faces, facing inwardly of the cabinet and provided with rows of holes for fixing support bars of the switchgear housed inside the cabinet, whose continuity of sealing at the level of the angular junctions of the panels is ensured by the corresponding profile, which are attached spaced edges of the panels with the interposition of a seal.

Such a cabinet is known for example from DE-U-83 35 383. The profile according to DE-U-8 335 383 has a square section having two legs, one of which is an extension of one of the faces of the section provided with perforations and the other is the extension of the other of the faces of the section provided with perforations, but with an end portion bent at right angles.

The imperatives of standardization and mass production required the use of a limited number of elements allowing the production of different size cabinets and meet the mounting needs of the equipment and juxtaposition in electrical switchboards. The cabinet consists of a frame or frame carried by an assembly of standard profiles and panels generally sheet metal fixed to said framework. The size of these cabinets is often important to a few meters in height, and the elastic seals inserted between elements in their assembly are often insufficient to overcome the machining imperfections or local deformations occurring during assembly. It has already been proposed to separate the support function and the sealing functions of the sections constituting the framework, by providing on the profiled extensions which cooperate with the joints. These profiles are complicated and often asymmetrical forms, which complicates the assembly and may result in incorrect assembly origin.

The present invention aims to allow the realization of a cabinet using a standard profile ensures both the function of support and an improved seal at the junctions.

The profile of the cabinet of the present invention is constituted by an angle section whose both sides are arranged within the cabinet to form said two orthogonal fixing faces, the longitudinal edge of each side, opposite to the edge of the angle, being folded at right angles inwards along a truncated contour against which fold is attached the edge of the conjugate panel and the section having an external partition joining said edges of the corner and sealing of the angular junction forming a prism whose base is an isosceles right triangle, the section having a symmetry plane corresponding to the plane bisecting the angle.

The diagonal outer wall defining the internal sealed zone to the cabinet of the unsealed outer area. The panels are applied against the outer edges of the profile with the interposition of a seal, advantageously formed by a resilient bead interposed between the panel and the edge of the profile. The angled fold the edge of the section runs parallel to the panel adjacent small distance from the latter and forms a protective shield of the joint, especially against water spray from the outside. The panels have flanged edges which cover the recesses of the profile so as to provide additional protection by having a real access to the labyrinth seal. The folded edges of the panels contribute of course to their rigidity and aesthetics of the cabinet. The screen role profiled folds is particularly useful when these sections are arranged in the top rails. The roof of dripping water is then collected by the gutter formed by the downturn. This gutter function is essential when the panel is arranged adjacent door, so as to avoid at the opening of the door a water accumulated flow inwardly of the enclosure. In this arrangement it is advantageous to postpone the joint towards the end of the withdrawal to prevent the formation of a channel of water accumulation between the panel and the decline of the profile.

The panels can be fixed by any suitable means directly on the profiles or the folds of these, a preferred fastener making use of an intermediate piece itself contiguous and attached to the diagonal wall. This intermediate piece is common to the two angular panels, which are fixed by simple screws engaging in threaded holes in the adapter. The adapter can be arranged, or wear the hinge of a mobile panel constituting a door. The profiles are assembled to one another by corner pieces in form of tripod. These corner pieces arranged at the eight corners of the cabinet are like profiles, symmetrical identical parts avoiding any assembly errors. The assembly is particularly simple and ensures ease of installation combined with modularity and optimum rigidity. Several frames can be joined together and joined to each other to form cabinets of multiple sizes, the intermediate panel being of course removed so append against the profiles of two adjacent frames with each other with interposition of a gasket similar seal to that used for the panels. The outer contour truncated profiles contributes to the rigidity of these assemblies, which comprise bolts or connecting profiles splints. Such extensions are possible on all sides of the cabinet while keeping a perfect seal and retention of the panels forming the walls.

The profiles can be partially nested in pairs, which facilitates storage and transportation.

Other advantages and features will become more clearly apparent from the following description of an embodiment of the invention given by way of non-limiting example and represented in the accompanying drawings in which:<ul><li>Figure 1 is a schematic perspective view of a frame of a cabinet according to the invention;</li><li>Figure 2 is a section along the line II-II of Figure 1;</li><li>Figure 3 is a section along the line III-III of Figure 1 ;,</li><li>Figure 4 is a section of the constituent profile of the frame of Figure 1;</li><li>Figure 5 is a view similar to that of Figure 4 illustrating an alternative embodiment;</li><li>Figure 6 illustrates another section of the embodiment.</li></ul>

In the figures, an electrical equipment housing cabinet is formed by the assembly 12 angular elements forming a right parallelepiped rectangle. 10,12,14,16 profiles forming the uprights or vertical angular elements and the profiles 18,20,22,24 of the upper part of the frame, and the sections 26,28,30,32 of the lower portion of the frame are all identical and arranged in the same manner. Referring more particularly to Figures 4 and 5, it is seen that the sections 10-32 have an angle portion 34 whose both sides 36,38 are orthogonal and have longitudinal edges bent at right angles for a 40.42 fold directed towards the inside. 44,46 the edges formed by the folded edges 40,42 are connected by an outer confining wall 48 with the bracket 34 a tubular internal space 50 of triangular section. Both sides 36,38 of the bracket 34 are provided with rows of holes 52 for fixing crosspieces 53 support the electrical equipment housed in the cabinet of a manner well known to specialists. Sleepers 53 are secured to brackets 34 by bolts with nuts are inserted into the profile. The outer wall 48 which extends along the hypotenuse of the triangular section is a solid partition or provided with a limited number of fixing holes whose usefulness will be described later.

The enclosure frame is dressed panels 54,56 respectively on the back and on the front face of the cabinet as well as panels 58,60 on the side faces 62,64 and to the base and top of the wardrobe. These panels are each constituted by a sheet metal plate whose edges 66 are folded at right angles to ensure the rigidity of the panel. The beams 10 to 32 are all disposed in the same manner with the edge 68 of the bracket 34, corresponding to the vertex of the right angle of the triangle, oriented towards the inside of the cabinet. The panels 54-64 cooperate with the edges 44 and 46 of the folded edges or folds 40,42 with the interposition of seals 70 bead-shaped extending around the periphery of the panel. The panels 54 to 64 are fixed to the beams 10 to 32 by screws 72 screwed into the intermediate pieces 74 abutting the outer wall 48. The fixing of the intermediate parts can be performed by any suitable means, for example by gluing or simply by bolts passing through openings in the partition 48. the same intermediate piece 74 serves as an attachment to the two panels forming the corresponding angle of the cabinet. This intermediate piece is in the external template of the section and has a recess 76 of housing flanges 66 of panels 54 to 64. The panels 54 to 64 may of course be achieved in a different way, the screw 72 can for example build on 40.42 folds or directly on the wall 48.

When one of the panels, including the front panel 56 is arranged door, the corresponding intermediate piece 78 is shaped to form a supporting hinge 80 of the door 56. The hinge 80 is in the external template of the profile. The opposite intermediate part disposed on the moving side of the door 56 may be identical to the other, or be devoid of one of the fixing points rendered unnecessary by the presence of the door 56.

With particular reference to Figure 2, one sees that all the seals 70 cooperating with the vertical beams 10 to 16, cooperate with the edges 44,46, formed by the folded edges 40,42. Sealing between two adjacent panels, such as panels 54,60 are carried through the seals 70 and the outer partition 48. The partition 48 constitutes a separation of a sealed inner area wherein lie the 36,38 sides of the bracket 34 on which can be fixed sleepers or other support rails of the apparatus. The outer side of the partition 48 extends a unsealed region serving for fixing to the intermediate parts 74,78 with their accessories, such as the hinge 80 or the screws 72. By concentrating the elastic joints 70 of the edges 44 , 46 sufficient deformation is obtained to compensate for uneven profile or other deformations of the cabinet structure elements. The crushing of joints 70 when tightening the screw 72 limits the interval between the boards 54-64 and 40.42 folds and reduces the risk of water penetration and wetting of joints 70. This risk is further diminished by the edges 66 of the panels 54-64 which cap the ends of 40.42 folds, forming a veritable labyrinth seal limiting the risk of water penetration at joints 70. the shape of the profile also enables to ensure the sealing or with an adhesive joint or clipped onto the folds 40,42, or with an adhesive joint or clipped inside the panels constituting the cladding. The sealing profiles form horizontal struts may be performed in the same manner by cooperating seals 70 with the edges 44,46 but according to a preferred embodiment of the invention shown in Figure 3, the seal 70 above the door 56 or preferably all joints 70, interposed between the vertical panels 54,56,58,60 and 18,20,22,24 horizontal top rails, are slightly offset upwardly so as to cooperate with the edge 84 of 40.42 folds. It is easy to see that this offset avoids any accumulation of water between panels and 40.42 folds may affect the tightness of the cabinet or cause water penetration when opening the door 56. the beams 10 to 32 are assembled at their ends by the cut pieces 86 having three orthogonal feet fitting into the triangular ends of the profiles. These pieces are exactly the same, regardless of their position. The arrangement can of course be achieved in another way, for example by welding.

The cabinet according to the invention is carried out as follows:    The standard profiles 10-32 of appropriate length, are assembled by cubic parts 86 arranged at the corners of the enclosure, taking care to orientate the edge 68 angles inward of the enclosure. The perfect symmetry of the profile avoids any incorrect assembly and it is possible to realize a variety of cabinet, or by cutting the profiles to the application or by providing a stock of profiles of different length, in particular with a modular 25 mm in all three dimensions. Profiles 10-32 assembled, constitute a frame or solid frame for fixing the cladding panels 54-64 and the sleepers 53 or support rails appliances housed inside the enclosure. The panels 54 to 64 of appropriate dimensions are then fixed on the different sides of the cabinet, taking care to interpose gaskets 70 between the sections and the edges of the panels. By screwing the screw 72 on the intermediate pieces 74, previously fixed on the outer walls 48, it is possible to strongly clamp the panels with a crushing of seals 70 bearing against the edges 44,46 or slices 84 folds 40,42 . The door 56 is of course fixed by the hinge 80 carried by the intermediate piece 78, and a lock (not shown) is disposed on the opposite edge of the door 56 in a manner well known to specialists. The apparatus can of course be placed in the cabinet before fixing all or some of the panels 54 to 64. The dismantling of the panels or cabinet is extremely simple and it is possible to join several frames each other both laterally, in depth or height in maintaining the seal and retaining the same exterior panels.

The beams 10 to 32, may be made by any suitable means, for example by extrusion, but in a preferred method, they are obtained by folding a metal strip, for example on an automatic roller burnishing machine. Figure 4 shows an embodiment with six folds, the edges of the folded strip being stapled at the fold 40, which has three stacked sheet thicknesses. This produces rounded edges adapted to cooperate with seals 70 without risk of damage. The opposite fold 42 consists of a single fold and therefore two sheet thicknesses. The symmetry can be maintained by providing an empty space 86 between the folded parts to render such fold 42 or a comparable thickness equal to that of the fold 40 to three thicknesses. Figure 5 illustrates an alternative embodiment in which the thickness of the fold 42 is increased by inserting a wedge 88 replacing the void 86 between the folded edges of the fold 42.

Referring to FIG 6 shows another alternative embodiment wherein the profile has a wing 90 which extends along the edge 68 of the bracket 34, projecting inwardly of the enclosure. The wing 90 has perforations 92 for fixing internal components in the cabinet. The wing 90 extends in the bisecting plane of the angle (Figure 6) and it is constituted by a fold of the sheet as shown in FIG.

The structure according to the invention imparts to profile high stiffness relative to the weight and provides a seal while maintaining the external template of the cabinet allowing easy juxtaposition of several frames.

The nuts of the bolts 10-32 sections are to be introduced inside these profiles and maintained facing the perforation 52 receiving the screw. In Figure 2, there is shown a support 94 common to two nuts 96, 98 facing said two perforations 52 located at the same level on the two wings of the angle. The nut 98 is mounted pivotally and slidably on the support 94 to allow, from the active position, shown in Figure 4, a downward sliding and pivoting to put on the rectangular slice nut permitting withdrawal by the perforation 52.

4 shows a nut 100 mounted in a cage 102 stirrup-shaped. 10-32 the profiled section has on the edge 68 of the perforations 104 and the pitch at the perforations 52 of the sides 36, 38 to allow introduction of the nut 100 within the profile being retained by the caliper 102 which straddles the side. It is seen from FIG nut in place on one side 38 opposite the punch 52 and another nut being inserted to come in front of the perforation 52 of the other side 36. The cage 102 folded steel has a lug 106, which under the tightening force becomes embedded in the profile to ensure electrical continuity. A folded tab 108 fits into the hole 52 to center the nut.