RACKING BEAM AND METHOD FOR ITS MANUFACTURING

Abstract

 A beam for shelving units comprises a strut (3) which is elongate in a longitudinal direction and two brackets (5a, 5b) which are provided for attaching the beam (1) to uprights of the shelving unit. The brackets are disposed close to the ends of the strut and fixed thereto by welding. The surface of the beam (1) is protected overall by a primary protection layer which affects almost the entire surface thereof, both internally and externally, and by a secondary protective layer which affects only a limited welding area which surrounds and includes the location at which the ends (3a, 3b) of the strut (3) are close to the respective brackets (5a, 5b).Advantageously, the primary protective layer is made by galvanizing, which is removed in order to expose the welding zone, which is then protected by a layer of varnish as a secondary protective layer.

Description

Field of the invention

[0001] The present invention relates to the field of shelving units.

[0002] The invention has been developed with particular regard to a beam for industrial shelving units, such as, for example, even if in a non-limiting manner, pallet-carrying shelving units and the like. The invention is also directed towards a method for constructing such a beam for industrial units.

Technological background

[0003] Shelving units and more specifically shelving units for industrial use are constructed by fixing vertical uprights and horizontal beams to each other. The beams are formed by an elongate strut, at the ends of which there are fixed two attachment brackets which serve to fix the beams to the uprights of the shelving unit. The attachment brackets may have hooks, which are intended to be inserted in corresponding slots in the uprights, and holes, through which the beams are intended to be bolted to the uprights. The beams can be constructed by joining together two half-shells of sheet metal or other construction methods for a hollow bar with a generally rectangular cross-section which is often provided with longitudinal reinforcement channels and/or channels for coupling other components of the shelving unit.

[0004] Often, the beams are made from steels which are suitable for cold-forming and which have good weldability properties, such as, for example, the steel S275JR which is pickled. The steels of this type allow the brackets to be readily welded to the ends of the strut which forms a beam but require surface protection in order to prevent the oxidation thereof. To this end, after the attachment brackets have been welded to the strut of the beams, the entire assembly is transferred to a varnishing installation, for example, of the spray or powder-coating type, in order to obtain the surface protection.

[0005] In order to reduce the varnishing times and costs for the beams, it has been proposed to make the struts and the attachment brackets from galvanized steel. The galvanizing protects the steel beneath from oxidisation but it forms a surface layer which does not allow efficient and durable welds to be produced between the strut and the attachment brackets which therefore have to be bolted to the strut.

Statement of invention

[0006] The object of the present invention is to solve the problems of the prior art by providing a welded beam for shelving units, for example, for industrial use, which is simple, rapid and economical to produce. Another object is to provide a beam which has good resistance to oxidation and which is at the same time reliable over time and sufficiently resistant also to be used in the construction of shelving units which are critical from the point of view of anti-seismic safety. Another object of the invention is to provide a method for constructing a beam for industrial shelving units which is simple, rapid, economical and reliable.

[0007] In order to achieve these objects and other objects which will become evident from the following detailed description, the invention relates to a beam for shelving units and a method for the construction thereof having the features indicated in the appended claims.

[0008] According to a first aspect, a beam for shelving units, preferably but in a non-limiting manner for constructing shelving units for industrial use, is described. The beam comprises a strut which is elongate in a longitudinal direction. The beam further comprises two brackets which are provided for attaching the beam to the uprights of the shelving unit in accordance with techniques and methods known in the sector.

[0009] The brackets are disposed close to the ends of the strut and can be fixed thereto by means of welding. The surface of the beam is protected by a protection layer. Almost the entire surface of the beam can be protected by a primary protective layer, for example, a galvanization, or other similar processing. The primary protective layer may affect practically the entire external surface and internal surface of the beam except for in a limited welding area which surrounds and includes the location at which the ends of the strut are close and welded to the respective brackets. In the welding area, the external surface of the beam is protected by a secondary protective layer. The main advantage of this solution involves the primary protective layer being able to be made at the time of manufacture of the strut and the brackets while the secondary protective layer - which has a much more limited extent - can be made readily and rapidly after the strut has been fixed to the brackets which is advantageously carried out in this case by welding. The beam has a resistance equal to the resistance of known welded beams but the construction thereof is much faster, simpler and more economical.

[0010] According to a particular aspect, the primary protective layer is a zinc layer which can advantageously be carried out by means of established techniques during the manufacture of the strut and the brackets which, for example, can be produced from a galvanized web. On the other hand, the secondary protective layer may be a layer of varnish which is relatively economical and easy to apply after the welding is made between the strut and the brackets of the beam. The initial, galvanizing provides optimum resistance to oxidation in the majority of the surface of the beam, while the varnishing zone is small and does not require particularly expensive or bulky equipment items for the construction thereof. Since the varnishing extent is limited, it is not necessary to transfer the entire beam to a varnishing installation as for welded beams of the prior art.

[0011] According to another particular aspect, the welding area can extend over a short portion on the strut from each of the ends thereof. The term "short portion" is intended to be understood to be a portion with a length which is far less than the length of the strut and which is sufficient for carrying out a good welding of the end of the strut with respect to the corresponding bracket. Similarly, the welding area on each bracket is a peripheral portion of a more extensive zone devoid of any primary protection, having dimensions slightly greater than the area of the cross-section of the strut.

[0012] There is further described a method for constructing a beam for shelving units of the above-mentioned type. The method may comprise, not necessarily in the precise sequence indicated, a number of main steps, including the step of providing a strut which is protected at the surface by a primary protective layer and the step of removing the primary primary protective layer over a short portion from the ends of the strut so as to expose the material of the strut. Another main step may be the step of providing two brackets which each have at least one planar wall which is protected at the surface by a primary protective layer. The primary protective layer can be removed from the planar wall at least in a zone which is intended to be moved close to a respective end of the strut. Another step may be the step of moving the brackets close to the respective ends of the strut and fixing them to each other by welding in the welding area without the primary protective layer which surrounds and includes the location at which the ends of the strut are close to the respective brackets. Another step may be the step of protecting the welding area with a secondary protective layer. As mentioned above, the primary protective layer may advantageously be produced by means of galvanizing while the secondary protective layer may advantageously be produced by means of varnishing the external surfaces of the beam devoid of galvanizing.

Brief description of the drawings

[0013] Additional features and advantages will be appreciated from the following detailed description of a preferred embodiment with reference to the appended drawings which are given by way of non-limiting example and in which:

• Figure 1 is a perspective view of a beam incorporating aspects of the present invention;
• Figure 2 is a view of a strut which is provided for constructing the beam of Figure 1;
• Figure 3 is a view of an attachment bracket which is intended for constructing the beam of Figure 1;
• Figure 4 is a view of the bracket of Figure 3 provided to be welded to the strut of Figure 2;
• Figure 5 is a view, drawn to an enlarged scale, of the connection zone of the strut of Figure 1 to the bracket of Figure 4, in a first step of the construction method for the beam of Figure 1;
• Figure 6 is a view similar to Figure 5 in a second step of the construction method for the beam of Figure 1; and
• Figure 7 is a view similar to Figures 5 and 6, in a concluding step of the construction method for the beam of Figure 1.

Detailed description

[0014] Now with reference to Figure 1, a beam 1 which is intended for constructing shelving units, for example, for industrial use, comprises an elongate strut 3 at the ends 3a, 3b of which two corresponding brackets 5a, 5b are welded. The brackets 5a, 5b are mutually symmetrical and are formed to fix the beam 1 to the uprights of the shelving unit (which are not illustrated in the Figures). As will be appreciated more clearly below, the strut 3 and the brackets 5a, 5b are made from steel which is galvanized at the surface with the exception of the connection zones for welding between the ends 3a, 3b of the strut and the brackets 5a, 5b, where the surface galvanizing is replaced by a protection varnishing. The protection varnishing may have a colour which is identical or very similar to the colour of the galvanizing of the strut 3 and the brackets 5a, 5b so as to obtain a beam 1 which is aesthetically pleasing.

[0015] Each of the two brackets 5a, 5b is made from a sheet metal which is stamped and folded so as to form a structure with an approximately J-shaped formation when viewed from above. In particular, each bracket 5a, 5b comprises a planar wall 7 to which the corresponding end 3a, 3b of the strut 3 is butt-welded. From the planar wall 7, the bracket is bent at 90° in order to form a front wall 9, on which fixing openings and holes 11 are formed. At the opposite side to the planar wall 7, the bracket 5a, 5b has a short edge 13 which is bent at 90° with respect to the front wall 9 and which faces the planar wall 7. The rim of the edge 13 is cut with a shape which forms a number of hooks 15 (four hooks in the non-limiting example of the Figures). The hooks 15 are suitable for being engaged in known manner in corresponding slots which are constructed in the upright of the shelving unit. The brackets 5a, 5b are made from steel with a galvanized surface protection covering.

[0016] As shown more clearly in Figure 2, the strut 3 has a substantially rectangular cross-section with an internal tubular cavity 17 which is defined by a peripheral wall 19. There are formed on the peripheral wall 19 longitudinal channels 21 which are constructed, for example, by means of a known method involving rolling profiling. A protection galvanizing covers the external surface of the peripheral wall 19 with the exception of two short portions 23 at the ends 3a, 3b of the strut 3, at which the steel surface of the strut is exposed without the protection galvanizing. The portion 23 without any galvanizing extends over the entire perimeter of the strut. The length of the portions 23 without any galvanizing is a few tens of millimetres, for example, but in a non-limiting manner, between 5 and 10 mm in the longitudinal direction of the strut 3 from the end 3a, 3b thereof.

[0017] During the manufacturing method for the beam 1, it is advantageous to provide the strut 3 from a metal sheet or from a tubular member made from galvanized steel. The beams can be constructed, for example, by joining two half-shells made from sheet steel which is galvanized at a surface. Alternatively, it is possible to take as a basis a strip of galvanized steel which is bent in order to obtain the strut of the beam. It is also possible to construct the strut by means of drawing, stamping or other known construction methods for a hollow bar, subjecting the strut which is constructed in this manner to surface galvanizing at the production facilities for semi-finished products.

[0018] The strut 3 is subsequently processed in order to eliminate the galvanizing from the peripheral zones 23 at the ends 3a, 3b. These zones can have the zinc removed by means of techniques of the known type, for example, by means of mechanical removal (for example, milling) or chemical removal (for example, pickling).

[0019] Figure 3 illustrates one of the two brackets 5a, 5b which is initially completely galvanized at a surface. As Figure 4 shows, the preparation of the bracket 5a (and the same applies to the other bracket 5b which is not illustrated) provides for the removal of the surface layer of zinc in a substantially rectangular area 25 with dimensions slightly greater than those of the profile of the strut 3. The zinc can be removed from the area 25 in a simple manner with a milling operation over a small depth in the planar wall 7 of the bracket 5a, 5b. The area 25 may be, for example, wider and deeper by approximately from 5 to 10 mm with respect to the width and the depth of the rectangular section of the strut 3. Inside the area 25, the steel of the bracket 5a is exposed while, outside this area, the steel remains protected by the surface galvanizing layer. As Figure 5 shows, this allows the end 3a (or the end 3b) with the short portion 23 of the strut 3 to be moved in the direction of the arrow A near the area 25 of the bracket 5a (or the bracket 5b) which also does not have any zinc in such a manner that, in the contact zone between the two components and in the immediate environment thereof, the steel of the strut 3 and of the bracket 5a is bare and exposed to the exterior.

[0020] As Figure 6 shows, in the contact zone between the end 3a of the strut and the surface 25 of the bracket 5a without any zinc, there is carried out a weld 27 which runs around the periphery of the end 3a of the strut 3 so as to fix it securely to the wall 7 of the bracket 5a. Preferably, the weld 27 is a weld with a continuous bead, at three sides (upper side and two flanks) of the end 3a of the strut 3, even if it is not excluded that there is carried out a different weld, which is configured and carried out according to techniques which are generally known in the field of components of welded structural work and in particular welded beams which are known and used for shelving units of the industrial type.

[0021] As shown in Figure 7, after the strut 3 has been welded to the brackets 5a, 5b, the weld 27 and the zone in its vicinity without any galvanizing are varnished with a layer of protective varnish 29. The varnish may be of the same type used for the complete varnishing of known welded beams. The limited area which has to be protected by means of varnishing prevents the need to transport the entire beam to a varnishing installation, it being sufficient to provide a small varnishing area or station on the production line.

[0022] From the preceding description, it is evident that the solution of the present invention has a large number of advantages. Since it is not necessary to transport the entire beam to a varnishing booth, the production times can be accelerated. Furthermore, there is a substantial reduction in varnish necessary to protect the finished beam. The provision of components (beams and brackets) which are galvanized beforehand allows the reduction of times and costs for the surface protection of the workpieces, it being possible to carry out semi-finished products at the primary production facility and at the end of the production of the beam. A greater durability over time is thereby ensured, including as a result of the fact that both the surfaces of the beam, both the internal surface and the external surface, are protected by the galvanizing.

[0023] Naturally, the principle of the invention remaining the same, the forms of embodiment and details of construction may be varied widely with respect to those described and illustrated without thereby departing from the scope of the present invention.

Claims

1. A beam for shelving units, comprising

- a strut (3) which is elongate in a longitudinal direction and

- two brackets (5a, 5b) which are provided for attaching the beam (1) to uprights of the shelving unit, disposed close to the ends (3a, 3b) of the strut (3) and fixed thereto by welding (27),

wherein the surface of the beam (1) is protected overall by a protection layer comprising a primary protective layer which affects almost the entire surface of the beam and a secondary protective layer which affects only a limited welding area which surrounds and includes the location at which the ends (3a, 3b) of the strut (3) are close to the respective brackets (5a, 5b).

2. A beam for shelving units according to claim 1, wherein the primary protective layer is a layer of zinc and the secondary protective layer is a layer of varnish.

3. A beam for shelving units according to either one of the preceding claims, wherein the welding area extends over a short portion (23) on the strut (3) from each of the ends (3a, 3b).

4. A beam for shelving units according to any one of the preceding claims, wherein the welding area on each bracket (5a, 5b) is a peripheral portion of a larger area (25) devoid of the primary protection layer, having dimensions slightly greater than the area of the cross-section of the strut (3).

5. A method for constructing a beam for shelving units according to any one of the preceding claims, comprising the steps of:

- providing a strut (3) which is protected at the surface by a primary protective layer;

- providing two brackets (5a, 5b) which each have at least one planar wall (7) which is protected at the surface by a primary protective layer;

- removing the primary protective layer over a short portion (23) from the ends (3a, 3b) of the strut (3) so as to expose the material of the strut (3);

- removing the primary protective layer from the planar wall (7) of each bracket (5a, 5b) at least in an area (25) which is intended to be moved close to a respective end (3a, 3b) of the strut (3);

- moving the brackets (5a, 5b) close to the respective ends (3a, 3b) of the strut (3) and fixing them to each other by welding (27) in the welding area without the primary protective layer which surrounds and includes the location at which the ends (3a, 3b) of the strut (3) are close to the respective brackets (5a, 5b);

- protecting the welding area with a secondary protective layer.

6. A method according to claim 5, wherein the primary protective layer is made by galvanizing.

7. A method according to claim 5 or claim 6, wherein the secondary protective layer is made by varnishing.

Drawing