Cable tray on ladder

Abstract

Ladder-style cable tray, of the type made up of two elongated, C-shaped beams (1) arranged parallel to and facing each other, on whose lower horizontal arms (2) a plurality of crossbars (3) are established, characterized in that the crossbars (3) are made up of U-shaped profiles arranged inverted with respect to the lower horizontal arms (2), where each crossbar (3) is made up of a middle arm affected at its ends by indentations (6) of inverted truncated pyramidal configuration; indentations (6) open at their free end which define constricted openings (4), so that the smaller and lower base of each inverted truncated pyramidal indentation (6) determines a support and fixing surface on the upper face of the lower horizontal arms (2) of the beams (1), by means of joining means.

Description

Cable tray on ladder TECHNICAL SECTOR The present invention relates to a ladder-style cable tray, of the type made up of two "C" profiles facing each other and connected by a series of intermediate crossbars on which the cables are fixed by means of clamps, ties or other conventional fastening elements. The object of the invention is to provide a cable tray whose crossbar of novel configuration allows simultaneously offering a highly stable support surface for fixing the cables and a high load capacity within the tray. BACKGROUND OF THE INVENTION In the practical application of the invention, ladder cable trays are known, that is, devices for the distribution of cables based on two elongated "C" profiles facing each other, which are linked from a series of intermediate crossbars of "U" section with a constricted mouth, provided with alignments of longitudinal slashed holes on the middle branch of the "U", for the passage of the cable fixing clamps. In this type of cable tray, the crossbars can be installed in two ways: • The crossbeams are placed with their opening facing downwards, under the lower horizontal branch of the "C" profiles so that they are only attached to them at certain points, remaining "hanging", or • The crossbars are arranged with their mouth facing upwards, supported internally, that is, on the upper face of the lower horizontal branch of the "C", so that in addition to being fixed at a point, the ends of the crossbar rest on the "C" profile itself. Obviously in the first case the load-bearing capacity of the crossbars is less than in the second. However, the second arrangement causes the intermediate branch of the "U" of the crossbar to be distanced from the cables to be held, since these will rest perpendicularly on the constricted mouth of the "U" profile, which makes the fixings made more unstable. Thus, from an "operational" point of view the first solution is more interesting, while from the point of view of load capacity, the second solution is better. At the same time, solutions are known where the crossbeams are welded to the branches, generating the welding point as an area that is unprotected against corrosion. To ensure corrosion resistance at that point, a post-galvanizing treatment is usually carried out, which requires an additional cost in the tray manufacturing process. For all these reasons, the use of welding is usually avoided, as it introduces complexity and increases manufacturing costs. EXPLANATION OF THE INVENTION The ladder-style cable tray proposed by the invention fully and satisfactorily solves the problem described above, including a crossbar of novel configuration that provides the advantages of both solutions mentioned in the background in one. To this end, and more specifically, the cable tray of the invention is based on the conventional structure of this type of ladder cable tray, made up of two elongated, C-shaped beams arranged in parallel and facing each other, on whose lower horizontal branches a plurality of crossbars are established, in which each crossbar is materialized in a U-shaped profile with a constricted opening, and whose middle branch is optionally affected by an alignment of slashed holes for the passage of cable fixing clamps to stabilize the cables. The crossbeam, unlike conventional crossbeams, is designed to always adopt the same position, specifically in the shape of an inverted "U" with respect to the lower horizontal branches of the stringers, so that the support and stabilization surface of the cables is optimal. Now, in accordance with the essence of the invention, it is provided that inverted truncated pyramidal indentations are included at the ends of the middle branch of the crossbeam. These indentations are open at their free end and define the constricted openings, such that the smaller, lower base of each inverted truncated pyramidal indentation provides a support and fixing surface on the upper face of the lower horizontal branches of the stringers. From this structure, the smaller and lower base of each embossing defines a wide contact and fixing surface on the upper face of the lower horizontal branches of the stringers on which it rests, increasing the load-bearing capacity, and defining a wide surface for mechanical fixing by means of joining, such as: screws, rivets or clinching. It should also be noted that, optionally, the crossbar features defined rounded edges between the inverted truncated pyramidal indentations and the constricted mouthpiece. Preferably, the height of these rounded edges corresponds to the height of the crossbar profile. Consequently, and as previously stated, the inclusion of the type of crossbar proposed in the present invention allows for a cable tray with a high load capacity due to the presence of the constricted openings and the inverted truncated pyramidal indentations arranged at the ends of each crossbar. BRIEF DESCRIPTION OF THE DRAWINGS To complement the description that follows and to aid in a better understanding of the characteristics of the invention, according to a preferred embodiment thereof, a set of drawings is included as an integral part of said description, in which, for illustrative and non-limiting purposes, the following has been represented: Figure 1 shows a perspective view of a ladder-style cable tray according to the object of the present invention. Figure 2 shows an enlarged detail of the set represented in Figure 1. Figure 3 shows a side-top perspective view of a crossbar that participates in the cable tray of the invention. Figure 4 shows, finally, a view in a lower-side perspective of the crossbar in Figure 3. PREFERRED EMBODIMENT OF THE INVENTION In view of the figures described, and especially figures 1 and 2, it can be observed how in the ladder cable tray of the invention there are two elongated, parallel and opposing "C" configuration beams (1) whose lower horizontal branches (2) determine means for the mechanical fixing of crossbeams (3). As is also conventional, and as can be seen in figure 4, the crossbars (3) are materialized in inverted "U" profiles, so that each crossbar (3) is made up of a middle branch that is affected by an alignment of slashed holes (5) for the passage of fixing flanges for the cables to be stabilized. According to the essence of the invention, it has been provided that in correspondence with the ends of the crossbeams (3) there are recesses (6) that define constricted openings (4), so that the smaller and lower base of each recess (6), of inverted truncated pyramidal configuration open at its free end, determines a support and fixing surface on the upper face of the lower horizontal branches (2) of the stringers (1) by means of joining. Between each indentation (6) and the constricted opening (4) rounded edges (7) are defined, which improves the transmission of forces between the crossbar and the lower horizontal branches (2) of the stringer (1). As previously stated and according to Figure 3, each embossing (6) has a height corresponding to the height of the crossbar profile itself, while the smaller base of the embossing (6) has a width corresponding to the width defined between the ends of the constricted mouth (4) of the crossbar profile (3), and a length corresponding to the length of the lower horizontal branches (2) of the stringers (1) on which they rest, as shown in Figure 2. Consequently, the smaller base of said embossing (6) defines an optimal contact surface for the mechanical fixing of the crossbar (3) to the upper face of the lower horizontal branches (2) of the stringer (1) by means of screws, rivets or clinching. According to the detail in figure 2, this arrangement allows not only the crossbar to rest on the stringer (1) increasing its load capacity, but also the middle branch of the crossbar (3) on which the slit holes (5) for fixing the cables by means of ties are located is arranged superiorly, thus offering better stability in fixing the cables.

Claims

1. A ladder-style cable tray, of the type consisting of two elongated, C-shaped beams (1) arranged parallel to and facing each other, on whose lower horizontal arms (2) a plurality of crossbars (3) are established, characterized in that the crossbars (3) are made of U-shaped profiles arranged inverted with respect to the lower horizontal arms (2), where each crossbar (3) consists of a middle arm affected at its ends by inverted truncated pyramidal indentations (6); indentations (6) open at their free end, defining constricted openings (4), such that the smaller and lower base of each inverted truncated pyramidal indentation (6) defines a support and fixing surface on the upper face of the lower horizontal arms (2) of the beams (1), by means of joining means. 2.Ladder-style cable tray, according to claim 1, characterized in that the smaller base of the inverted truncated pyramidal recess (6) has a width corresponding to the width defined between the ends of the constricted opening (4) of the crossbar profile (3), and a length corresponding to the length of the lower horizontal arms (2) of the stringers (1) on which it rests.

3. Ladder-style cable tray, according to claim 1, characterized in that the joining means are screws, rivets, or clinching.

4. Ladder-style cable tray, according to claim 1, characterized in that the middle arm of each crossbar (3) has an alignment of slotted holes (5) for the passage of cable ties to secure the cables to be stabilized. 5.Ladder-style cable tray, according to claim 1, characterized in that the crossbar (3) has rounded edges (7) defined between the inverted truncated pyramidal indentations (6) and the constricted opening (4).