SUPPORT BAR FOR CABLE TRAYS
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- UNEX APARELLAJE ELECTRICO SL
- Filing Date
- 2022-09-13
- Publication Date
- 2026-06-12
Smart Images
Figure MX434826B0
Abstract
Description
SUPPORT BAR FOR CABLE TRAYS DESCRIPTION FIELD OF THE INVENTION The invention relates to cable support devices used to guide electrical cables, fiber optic cables, or other types of cables. In particular, the invention relates to a support bar for cable trays, which is used to support a cable tray and to form a set of support bars that connect to each other to form a support structure for cable trays. More specifically, the invention relates to a support bar for cable trays, of the type consisting of an extruded hollow profile made of polymeric material in the shape of a rail, having a rectangular outer perimeter in cross-section, and comprising a base wall, two side walls facing each other and an open wall, said open wall facing said base wall and comprising a continuous opening extending along the entire length of the support bar, such that said open wall has a flat outer surface extending on both sides of said continuous opening. The side walls form two facing flanges projecting towards the interior of the support bar, each of said flanges presenting a lower face facing the base wall and an upper face, opposite said lower face, forming the flat outer surface of the open wall.The side walls also form two facing projections that project towards the interior of the support bar below the lower face of the flanges, such that said projections do not cover said lower face of said flanges in a direction orthogonal to the base wall. STATE OF THE ART To install cables in a technical space, such as an industrial building, it is common to construct a support bar structure that serves to support cable trays and also to directly fix individual cables or small cable bundles to said support bars. Support bars of the type described above provide great versatility for forming a support bar structure, particularly with regard to the attachment of connecting pieces for connecting two or more support bars together, as well as the attachment of different types of cable trays to the support bars that form the structure. To fix a cable tray, either a connecting piece or a support bracket to the support bar, a support bar is used. 14U0 for cable trays, a small plate is used as a nut, or other similar element, which is placed inside the support bar, below the flanges, and into which a fixing screw is screwed. The plate rests on the underside of the flanges and is laterally confined by the two projections, preventing it from rotating. In many installations, cable trays bear a heavy weight, as they carry a large number of cables and / or cables of large diameter. Therefore, the robustness of the fixings is an important aspect in the design of cable tray support structures. Document ES1220465U (Figs. 5-9) discloses a support bar of the type indicated above. In this document, the support bar is represented as a crossbar of a cable ladder. BRIEF DESCRIPTION OF THE INVENTION The invention aims to provide a support bar for cable trays of the type indicated at the beginning, which ensures greater robustness for fixing a cable tray to it, or other elements of a cable tray support structure, without complicating or increasing the cost of manufacturing said support bar. This purpose is achieved by means of a support bar for cable trays of the type indicated at the beginning, characterized in that it comprises two internal walls that each join the base wall and the projection of one of the side walls, each of said internal walls extending alongside one of said side walls, such that the base wall, the side wall and the internal wall delimit an empty space between them. The internal walls act as a buttress at the level of the projections, thus preventing the side walls from experiencing bending due to the thrust force that the nut-like plate can exert on the projections, for example, when a cable tray that is fixed to the support bar is subjected to lateral stresses, or when a high tightening is carried out by screwing in the screw.This increased rigidity at the top end of the sidewalls significantly improves the security of the attachment. Furthermore, this configuration can be easily achieved in the extrusion process, with very little added material thanks to the void space between the walls. Preferably, the separation distance between each of said projections and said lower face of said flanges, in a direction orthogonal to said base wall, is less than or equal to 5 mm. In preferred embodiments, each of the internal walls comprises a lower section extending from the base wall parallel to the side wall and an upper section which is inclined with respect to said side wall and which opens into a lower part. 14U0 of the protrusion. Thanks to this configuration, the internal walls reduce the internal width of the support bar very little, thus not affecting other fixing elements that may be inserted into the support bar. Preferably, the flanges are formed by a hook-shaped upper portion of the side walls, and the lower face of the flange facing the base wall is formed by a free end of said hook-shaped upper portion. This configuration allows the flanges to be easily produced by extrusion and reduces the amount of polymer material per linear meter of support bar. Furthermore, it allows for slight bending deformation of the end of the flanges, which facilitates seating of the cable tray on the flat outer surface of the open wall of the support bar, as well as seating of the nut-like insert on the lower face of the flanges when the fixing screw screwed into said insert is tightened. Preferably, the lower face of each flange facing the base wall is provided with a groove in the longitudinal direction of the support bar. This groove has the effect of increasing the frictional force between said lower face of the flanges and a nut-like insert placed inside the support bar and into which a fixing screw is screwed, which is used to fix a cable tray, a connecting piece, or a support bracket to the support bar. Thanks to this, when the installer places the nut-like insert, it slides along the support bar much less than in the prior art. The installer can thus place the insert more easily without losing its position. By gently tightening the fixing screw, the insert does not accidentally move, but can be easily moved by the installer to adjust its position.Furthermore, since this striation is in the longitudinal direction of the support bar, it can be easily formed by extrusion together with the profile that constitutes the support bar. Embodiments are possible in which the striation on the lower face of the flange facing the base wall is discontinuous. However, preferably said striation is continuous and extends the entire length of the support bar. This striation can be formed directly in the extrusion die used to form the support bar, and allows the effect described above to be achieved at any position along said support bar. Preferably, said groove on the lower face of the flange facing the base wall is formed by a plurality of parallel ribs that have a pointed section at their end opposite said lower face of the flange and that extend in the longitudinal direction of said support bar. This configuration has the effect of increasing the friction force, since the surface of the insert bears with greater pressure on the sharp edges formed by the pointed shape of the ribs. More preferably, these ribs have a section IVIA / a / ZUZZ / UI 14U0 triangular. This shape provides the aforementioned effect and is easy to obtain by extrusion. Preferably, the flat outer surface of the open wall is provided with a groove in the longitudinal direction of said support bar. The groove has the effect of significantly increasing the frictional force between the flat outer surface of the open wall of the support bar and the surface of the cable tray placed on said support bar. This same effect also occurs when a connecting piece is placed against said flat outer surface of the open wall of the support bar, to connect two support bars together, or when a support bracket is placed to support a cable tray. Thanks to this effect, when the installer places, for example, a cable tray on the support bar, the cable tray slides on the support bar much less than in the prior art.The installer can thus more easily arrange all the mounting elements without losing the correct position of the cable tray. By lightly tightening the fixing screw, the cable tray cannot be accidentally moved, but can be easily moved by the installer to adjust its position. The same advantage is achieved when attaching a connecting piece or a support bracket to the support bar. Furthermore, since this ridge runs in the longitudinal direction of the support bar, it can be easily extruded together with the profile that constitutes the support bar. Another advantageous effect of this ridge running in the longitudinal direction of the support bar is that it effectively reduces cable slippage, in the longitudinal direction of the cables, when these cables extend transversely to the support bar, resting on the flat outer surface of the open wall.When these cables are fixed with tightening means against said open wall, the anti-slip effect provided by the striation allows the cables to be retained in the longitudinal direction with less tightening. Embodiments are possible in which the striation on the flat outer surface of the open wall is discontinuous. However, preferably said striation is continuous and extends the entire length of the support bar. Preferably, said striation is formed by a plurality of parallel ribs, which have a pointed cross-section at their end opposite the flat outer surface and which extend in the longitudinal direction of the support bar. More preferably, said ribs of the striation have a triangular cross-section. The advantages are analogous to those described above for the striation on the underside of the flanges. In preferred embodiments, the base wall is provided with through holes evenly distributed along the support bar and facing the continuous opening of the open wall. This configuration provides greater versatility for attaching elements to the support bar. In particular, it allows a fixing screw to be passed through one of the through holes. IVIA / a / ZUZZ / UI 14U0 Preferably, the support bar is made of an electrically insulating polymeric material, such as PVC (polyvinyl chloride), with a surface resistivity greater than 100 ΜΩ (surface resistivity measured according to EN 62631-3-2:2016). The invention also comprises other detailed features shown in the following detailed description of an embodiment of the invention and in the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and characteristics of the invention can be appreciated from the following description in which, without limiting the scope of the main claim, a preferred embodiment of the invention is set forth with reference to the figures. Figs. 1 and 2 are respectively a top front perspective view and a bottom front perspective view of the support bar. Fig. 3, 4, 5, and 6 are respectively a front view, a top view, a side view, and a bottom view of the support bar. Fig. 7 is an enlarged view showing the top of one of the side walls of the support bar. Figs. 8 to 13 show an assembly consisting of the support bar and a cable tray fixed to it by means of a screw and a small plate in the form of a nut. Figs. 8, 9, 10 and 11 are respectively a top perspective view, a bottom perspective view, a side view and a front view of the assembly. Fig. 12 is an exploded perspective view showing the support bar, the fixing screw and the nut-like plate. Fig. 13 is an enlarged front view of the assembly, showing the position of the screw and insert inside the support bar. DETAILED DESCRIPTION OF THE INVENTION Figs. 1 to 7 show a preferred embodiment of the support bar for cable trays according to the invention. The support bar 1 is an extruded hollow profile made of polymeric material, preferably an electrically insulating material, such as a thermoplastic such as PVC or a thermosetting resin. As can be seen in Figs. 1 to 3, the profile has a rail shape, with a rectangular outer perimeter in cross-section, and comprises a base wall 2, two side walls 3 facing each other and an open wall 4 facing the base wall 2. The open wall 4 comprises a continuous opening 5 extending the entire length of the support bar 1, such that said open wall 4 has a flat outer surface 6 extending on both sides of said continuous opening 5. The side walls 3 form at their upper end two facing flanges 9 projecting towards the interior of the support bar 1. Each of the flanges 9 has a lower face facing the base wall 2.The flanges 9 are formed by a hook-shaped upper portion 12 of the side walls. The lower face of the flange 9, facing the base wall 2, is formed by a free end of said hook-shaped upper portion 12. The flat outer surface 6 extending on both sides of the continuous opening 5 is formed by a flat upper face of the flanges 9, opposite the lower face of said flanges 9. This flat outer surface 6 is provided, on both sides of the continuous opening 5, with a groove 7 in the longitudinal direction of the support bar 1. The groove 7 is continuous, extends in the longitudinal direction of the support bar 1 along its entire length and is formed by a plurality of parallel ribs 8 which have a pointed shape in section at their end opposite the flat outer surface 6. More specifically, in the embodiment shown in the figures, there are eight ribs 8, they have a triangular section and are equal to each other. The groove 7 is formed directly in the nozzle of the extruder with which the profile is formed. The lower face of the flanges 9, facing the base wall 2, is provided with a groove 10 in the longitudinal direction of the support bar 1. The groove 10 is continuous, extends in the longitudinal direction of the support bar 1 along its entire length and is formed by a plurality of parallel ribs 11 which have a pointed shape in section at their end opposite the lower face of the flanges 9. More specifically, in the embodiment shown in the figures, there are three ribs 11, they have a triangular section and are equal to each other. The groove 10 is also formed directly in the nozzle of the extruder with which the profile is formed. The side walls 3 form two facing projections 13 which project towards the interior of the support bar 1 below the lower face of the flanges 9, and such that said projections 13 do not cover said lower face of said flanges 9 in a direction orthogonal to said base wall 2. The projections 13 are formed directly in the nozzle of the extruder with which the profile is formed. As will be seen later, this configuration of the flanges 9 and the projections 13 allows a nut-like plate to rest on the lower face of the flanges 9 and be confined laterally by the two projections 13. Preferably, the projections 13 are continuous and extend along the entire length of the support bar 1. The separation distance between each of the two projections 13 and the lower face of the flanges 9, in a direction orthogonal to the base wall 2, is less than or equal to 5 mm.In the embodiment shown in the figures, this distance is 3 mm. The outer perimeter of the support bar 1 is a 50 x 50 mm square. The support bar 1 comprises two internal walls 15 each connecting the base wall 2 and the shoulder 13. Each internal wall 15 extends alongside the corresponding side wall 3 and comprises a lower section 17 extending from the base wall 2 parallel to the side wall 3 and an upper section 18 inclined relative to the side wall 3 and opening into a lower portion of the corresponding shoulder 13. The base wall 2, the side wall 3 and the internal wall 15 delimit between them an empty space 16. Preferably, the side walls 15 are continuous and extend along the entire length of the support bar 1. They are formed directly in the nozzle of the extruder with which the profile is formed. The base wall 2 is provided with through holes 14 evenly distributed along the support bar 1. The through holes 14 are oblong in a transverse direction of the support bar 1, and face the continuous opening 5 of the open wall 4. In other embodiments, the through holes 14 may have different shapes. For example, they may be oblong holes in a longitudinal direction of the support bar 1. Figs. 8 to 13 show an assembly consisting of the support bar 1 and a cable tray 19 fixed thereto. The cable tray 19 rests, by the flat underside of its back wall, on the flat outer surface 6, provided with the groove 7, of the open wall 4 of the support bar 1. In the assembly shown in the figures, the cable tray 19 is fixed to the support bar 1 by means of a screw 20 and a small plate 21 with a threaded hole that acts as a nut. In the embodiment shown, the small plate 21 has a rectangular shape and a thickness of 6 mm. The screw 20 and the small plate 21 can be metallic or, preferably, can be made of a polymeric material with high mechanical strength. As can be seen in greater detail in Fig. 13, the plate 21 rests on a main face against the lower face of the flanges 9, provided with the groove 10, and is confined laterally between the projections 13 so that it cannot rotate.The screw 20 is screwed into the plate 21 and rests with its head on the flat upper face of the bottom wall of the cable tray, thus fixing the cable tray 19 by pressure against the support bar 1. The splines 7 and 10 limit the sliding of the cable tray 19 and the plate 21, respectively, even if a strong tightening with the screw 20 has not yet been carried out. The inner walls 15 act as a buttress and prevent the side walls 3 from experiencing a bending due to the force exerted by the plate 21 on the projections 13.
Claims
1. Support bar (1) for cable trays, said support bar (1) being a hollow extruded profile of polymeric material in the shape of a rail, having a rectangular outer perimeter in cross-section, and comprising a base wall (2), two opposing side walls (3) and an open wall (4), said open wall (4) facing said base wall (2) and comprising a continuous opening (5) extending the entire length of said support bar (1), such that said open wall (4) has a flat outer surface (6) extending on both sides of said continuous opening (5), said side walls (3) forming two opposing flanges (9) projecting into said support bar (1), each of said flanges (9) having a lower face oriented towards said base wall (2) and an upper face opposite said lower face,forming said flat outer surface (6) of the open wall (4), and said side walls (3) forming two opposing projections (13) that extend into said support bar (1) below said lower face of said flanges (9), and in such a way that said projections (13) do not cover said lower face of said flanges (9) in a direction orthogonal to said base wall (2), characterized in that it comprises two internal walls (15) each joining said base wall (2) and said projection (13) of one of said side walls (3), each of said internal walls (15) extending alongside one of said side walls (3), such that said base wall (2), said side wall (3) and said internal wall (15) delimit from each other an empty space (16). 2.- Support bar (1) according to claim 1, characterized in that the separation distance between each of said protrusions (13) and said lower face of said flanges (9), in a direction orthogonal to said base wall (2), is less than or equal to 5 mm.
3. Support bar (1) according to any of claims 1 or 2, characterized in that each of said internal walls (15) comprises a lower section (17) extending from said base wall (2) parallel to said side wall (3) and an upper section (18) inclined with respect to said side wall (3) and ending in a lower part of said protrusion (13). 4.- Support bar (1) according to any of claims 1 to 3, characterized in that said flanges (9) are formed by a hook-shaped upper part (12) of said side walls (3), and said lower face of the flange (9) facing towards said base wall (2) is formed by a free end of said hook-shaped upper part (12).
5. Support bar (1) according to any of claims 1 to 3, characterized IVIA / a / ZUZZ / UI 14U0 in that said lower face of each flange (9) facing said base wall (2) is provided with a groove (10) in the longitudinal direction of said support bar (1).
6. Support bar (1) according to claim 5, characterized in that said groove (10) on the lower face of said flange (9) facing the base wall (2) is continuous and extends the entire length of said support bar (1). 7.- Support bar (1) according to any of claims 5 or 6, characterized in that said groove (10) on the lower face of said flange (9) facing the base wall (2) is formed by a plurality of parallel ribs (11) which have a pointed shape in section at their end opposite said lower face of the flange (9) and which extend in the longitudinal direction of said support bar (1). 8.- Support bar (1) according to claim 7, characterized in that said ribs (11) of the striation (10) on the lower face of the flange (9) oriented towards the base wall (2) are of triangular section.
9. Support bar (1) according to any of claims 1 to 8, characterized in that said flat outer surface (6) of the open wall (4) is provided with a groove (7) in the longitudinal direction of said support bar (1). 10,- Support bar (1) according to claim 9, characterized in that said striation (7) on the flat outer surface (6) of the open wall (5) is continuous and extends the entire length of said support bar (1).
11. Support bar (1) according to any of claims 9 or 10, characterized in that said ribbing (7) on the flat outer surface (6) of the open wall (5) is formed by a plurality of parallel ribs (8) which have a pointed shape in section at their end opposite said flat outer surface (6) and which extend in the longitudinal direction of said support bar (1). 12,- Support bar (1) according to claim 11, characterized in that said ribs (8) of the ribbing (7) on the flat outer surface (6) of the open wall (5) are of triangular cross-section.
13. - Support bar (1) according to any of claims 1 to 12, characterized in that said base wall (2) is provided with through holes (14) uniformly distributed along said support bar (1) and facing said continuous opening (5) of the open wall (4).