EP0805904B1 - Scaffolding platform - Google Patents

Abstract

An aluminium/wood scaffolding platform consisting of an aluminium framework (1) and a plywood floor (2) fitted into the framework (1). The framework itself consists of two side members (3) and two end cross members (4) in the form of extruded aluminium profile members. The side profile members (3) with a preferably triangular cross-section comprise a longitudinal groove (11) for receiving a steel reinforcing rod (16) which is also used to attach the cross members (4) engaging the ends of the side members (3), as well as to attach hooks (5). In addition, a corner piece (20) is provided at each joint between a cross member (14) and a side member (3).

Description

The present invention relates to a tray scaffolding, more specifically but not exclusively a scaffolding platform of the type produced in aluminum and wood.

In the area of scaffolding, there are two known large types of trays, constituting surfaces of work for the personnel, namely: the trays in steel, and aluminum and wooden shelves.

The steel plates are generally made up a perforated sheet to be less slippery, and folded or formed by burnishing to obtain a rigid floor, carrying at its ends positioning hooks of the platform on the tubular structure of the scaffolding. This first type of tray is not affected by the invention.

The trays made of aluminum and wood, which are concerned with the present invention, are generally consist of a rectangular frame in aluminum, and a plywood floor, fitting in the aluminum frame. The frame is usually consisting of two supporting beams, which may have a length of 3 m, 2.5 m or 2 m, and two crosspieces end. The beams and crosspieces are commonly constituted by extruded hollow profiles, in aluminum. The profiles which constitute the side members have longitudinal grooves, in which are placed the longitudinal edges of the floor in plywood, which itself has very good mechanical resistance. The end cross members carry hooks used to position the tray on the tubular steel structure of the scaffolding, hooks are generally welded or bolted.

To assemble the beams and crosspieces end of the aluminum frame, a known solution consists of welding each end cross member against side rails, generally 90 °. The welds connect the two vertical sides of the crosspiece to a side wall stringers. The assembly by welding of profiles in aluminum, by a TIG or MIG type process, constitutes a long and expensive operation, hardly robotizable, one of the effects of which is to reduce the mechanical resistance of aluminum of approximately 50% in the weld area. In addition the welded areas, metallurgically transformed, are sources of cracks.

Another kind of tray made of aluminum and made of wood has a ladder beam made up of crimped beams and bars, supporting the floor in plywood. The hooks are usually placed in the extension of the side members. In this case, the crimping bars on the beams requires qualities aluminum with a very high elongation percentage, therefore low mechanical resistance, to be compensated by a multiplication of the number of bars. Failure to have end crosspieces, in this kind of scaffolding platform, prohibits certain provisions of hooks.

By document FR-A-2573115, we also know a scaffolding platform made of aluminum and wood, provided with a rectangular frame consisting of two rails and two crosspieces, assembled together and at floor, at the corners of the frame, using oriented rivets vertically or transversely. These rivets ensure only a stiffening in the region of the angles, and does not have a strengthening effect on the length of the stringers; in addition, they require a special shape for the ends of the ties, and they make virtually non-removable assembly.

Document FR-A-2527251 describes another tray scaffolding, made of aluminum and wood, the frame includes two tubular beams that connect several sleepers, extreme or intermediate. The ends of the sleepers, located between the side members, can be assembled to the side members by means of screws which extend transversely through these beams tubular. Such a screw connection is removable, but the screws do not provide any reinforcement function here, in particularly in the longitudinal direction. Otherwise, this document does not provide a solution for sleepers which would be pressed against the ends stringers.

In all the cases described above, the section aluminum beams must be studied in such a way so that it provides resistance to bending of the tray. It is therefore necessary that this section be high enough, and that the profile walls are thick, to obtain an inertia leading to the mechanical strength desired. This translates possibly by two drawbacks:

On the one hand, the weight of the aluminum beams is important, and therefore their cost is high. On the other hand, given the significant height of the section of the profiles forming the side members, the height of storage of scaffolding trays placed one on top of the other others is important, and therefore the transport cost is increased, since in a volume given the number of trays is lower.

Furthermore, not all of these trays are provided to support plinths, arranged over an edge longitudinal of a plate. Thus the baseboards remain the most often attached to the tubular steel structure scaffolding, especially at posts. In some cases, however, patches are welded on the beams or on the crosspieces end, to support these baseboards. Such provisions are obviously expensive, and increase the overall width of the trays. When juxtaposing several trays to form a continuous work surface, play due to the presence of supporting parts for baseboards inevitably appear between two adjacent shelves.

In summary, the problems posed by the trays scaffolding made of aluminum and wood are: the connection of the end crosspieces with the spars, the height of the spars in relation to their section and therefore the weight of these elements, their cost and their storage volume, fixing the plinth, and the overall cost of the resulting shelf as well the amount of aluminum needed only time assembly.

The invention aims to resolve these various problems, and thus eliminate the disadvantages exposed higher, providing a scaffolding platform of the type made of aluminum and wood which is light and economical manufacturing, while offering resistance high mechanical and small footprint of storage.

To this end, the present invention has essentially for a scaffolding platform, type made of aluminum and wood, consisting of a frame rectangular including aluminum and a floor including plywood, fitting into the frame, this frame itself consisting of two beams and two end crosspieces in the form of extruded profiles especially aluminum, the tray being remarkable in this that the frame rails have at least one groove longitudinal or a longitudinal duct receiving a rod continuous steel, extending over the entire length of the spar and serving as a means of reinforcement as well as means for fixing the end crosspieces, said rod made of steel with threaded ends, provided for cross right through the end crosspieces, applied against the ends of the side members, and for receive tightening nuts.

According to a preferred embodiment of the invention, the profiles constituting the side members of the scaffolding tray frame have a section transverse substantially triangular, the tip of the triangular section being directed downwards, these profiles with a longitudinal groove or a longitudinal duct located in the tip region lower of its triangular section, and able to receive the steel rod, while the base of said section triangular, opposite its point, partially forms the scaffolding platform floor surface.

The beams thus have an optimal section, the choice of a triangular section with point downwards, combined with a steel rod, making it possible in particular to reduce the aluminum mass of the beam. Indeed, each spar behaves in flexion in the manner of a beam, the upper part of its section working in compression and the lower part of its section working in traction. Insofar as the forces or stresses must remain below fixed limits (approximately 13 kg / mm ² ) for aluminum, a certain amount of aluminum is in principle necessary. The proposed configuration, with triangular section, makes it possible to reduce as much as possible the amount of aluminum working in traction, by replacing it with a continuous steel rod which can easily work with stresses of 36 kg / mm ² or more in traction.

By thus transferring the forces on a rod in steel, which can accept them, we also get a reduction of the section height in aluminum constituting the spar, and therefore a reduction in the storage volume of the trays scaffolding.

Another advantage of the provision proposed here is to facilitate the assembly of the aluminum frame of the scaffolding platform, thanks to the steel rods whose ends are threaded and receive the nuts of Tightening. So, by simply combining two rods in steel respectively to the two beams, we have means of assembling the sleepers with the side members for constitute the framework of the scaffolding plate, the rods then ensuring the blocking of the tray frame scaffolding, while reinforcing the profiles forming the stringers. The interest of this provision, which brings into play a double role to steel rods, is to remove the welded or riveted connections and their disadvantages, as well as all assembly parts reported. In addition, if the hooks of the are located in the extension of the side members, the steel rods carrying at their threaded ends nuts can also secure the hooks, this which gives them a third function. This last layout is therefore particularly interesting: two rods fitted with nuts, respectively associated with the two side members, allow the complete assembly of the scaffolding platform, including its hooks, with a extremely simple overall structure: the side members consist of cutting aluminum profiles, to the desired length, without any other operation, while that the sleepers only require the drilling of holes for the passage of the ends of the rods in steel. From the point of view of industrial production, a very simple tools (tightening wrenches) are sufficient to completely assemble the scaffolding platform. Good understood, a tightening force of suitable value must be predetermined, and be checked during assembly. In overall, the production costs are thus greatly reduced compared to manufacturing traditional.

If the steel rods or other fastening means are housed in grooves, open to the outside, the arrangement also allows an easy visual examination of the condition of these rods or other fixing means.

In all cases, this is achieved between the side rails and end cross members mechanical, by screw means, which allow the case necessary to assemble components of materials together separate, for example by combining longitudinal members aluminum with steel sleepers, the hooks being aluminum, or by combining beams in composite materials with aluminum sleepers.

According to an advantageous arrangement, the length of the end sleepers is determined in such a way that the end faces of each cross member, assembled to stringers, substantially correspond to the median vertical section of these beams, and more particularly at the median of the triangular section (as defined above) of said beams. It results at each junction of a cross and a not only the end of the cross member found clear, but still a fraction of the end of the spar is released, allowing insertion of a corner piece.

At each junction of a cross member and a spar can therefore be inserted a corner piece, engaged with a part in the cross member and on the other hand in the beam, the corner piece is automatically blocked when the cross member is fixed to the beam. This corner piece, thus blocked on the frame of the scaffolding plate without other fixing accessory, can provide alone several functions, thanks to an appropriate form:

First, the corner piece closes the angle of the two sections respectively constituting the beam and the crosses, thus preventing the penetration of water or other products inside the profiles.

In addition, the corner piece has advantageously, opening onto its upper face, a housing, in particular cylindrical in shape, suitable for fixing the end of a plinth along the top scaffolding. The plinth can thus be fixed directly on the set, whereas currently plinths are generally fixed between the posts the scaffolding, which leaves a large gap between the plinth and tray, hence a risk of falling objects such as tools, a disadvantage that is remedied the invention.

Furthermore, this corner piece ensures, in complement of the screwed assembly of the cross member on the longitudinal member, a mechanical block between this cross member and said spar, preventing any torsional movement.

Finally, by providing for the corner piece a rounded outer shape, this corner piece removes by its presence the cutting edges located in the plateau angle region, which result from cutting of the constituent sections of the spar and the cross-member end. The tray is thus made less angular, therefore less dangerous. In addition, the corner piece being in projection provides impact protection of the frame aluminum made up of side rails and crosspieces.

Figure 1 est une vue d'ensemble, en perspective, d'un plateau d'échafaudage du type réalisé en aluminium et en bois, conforme à la présente invention ;

Figure 2 est une vue en perspective éclatée de la région d'un angle de ce plateau d'échafaudage, dans une première forme de réalisation ;

Figure 3 est une vue en coupe longitudinale passant par la région de cet angle, le plateau étant assemblé ;

Figure 4 est une vue en coupe transversale, suivant IV-IV de figure 3 ;

Figure 5 est une vue partielle, en plan par dessus, d'une variante de ce plateau d'échafaudage ;

Figure 6 représente une variante de la section du profilé constituant l'un des longerons d'un tel plateau ;

Figure 7 est une vue en perspective, similaire à la figure 2, illustrant une autre forme d'exécution de ce plateau d'échafaudage ;

Figure 8 est une autre vue en perspective de la région d'un angle d'un plateau d'échafaudage selon l'invention, illustrant plus particulièrement la fixation de la plinthe ;

Figure 9 est une vue en perspective éclatée, correspondant à une partie de la figure 8.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of examples, some embodiments of this scaffolding platform:

Figure 1 is an overall perspective view of a scaffolding plate of the type made of aluminum and wood, according to the present invention;

Figure 2 is an exploded perspective view of the corner region of this scaffolding plate, in a first embodiment;

Figure 3 is a longitudinal sectional view passing through the region of this angle, the plate being assembled;

Figure 4 is a cross-sectional view along line IV-IV of Figure 3;

Figure 5 is a partial view, in plan from above, of a variant of this scaffolding plate;

Figure 6 shows a variant of the section of the profile constituting one of the side members of such a plate;

Figure 7 is a perspective view, similar to Figure 2, illustrating another embodiment of this scaffolding plate;

Figure 8 is another perspective view of the region of an angle of a scaffolding plate according to the invention, more particularly illustrating the fixing of the plinth;

Figure 9 is an exploded perspective view, corresponding to part of Figure 8.

As shown in Figure 1, the invention is interested in a scaffolding platform which includes a rectangular support frame 1, of elongated shape, and a floor 2. The supporting frame 1 consists of two longitudinal members 3, formed by extruded profiles in aluminum, and two end crosspieces 4, made up by other extruded aluminum profiles. The tray of scaffolding still includes, at each of its ends, a pair of hooks 5 provided for its positioning on the tubular steel structure (not shown) of the scaffolding. In the example, this scaffolding tray is still provided with a plinth 6, extending along one of its long sides.

Referring to Figures 2 to 4, each profile made of aluminum, constituting a spar 3 of the frame 1, has a substantially cross section triangular, but asymmetrical, the point of which is turned down. This profile, of general conformation tubular, thus has an upper face 7 substantially horizontal (corresponding to the base of the triangular section), an external inclined side 8 (corresponding to one side of the triangular section), and an inner inclined side 9 (corresponding to another side of the triangular section). At its upper part, on the side facing inwards, the profile of the spar 3 forms a longitudinal groove 10, in which is inserted a longitudinal edge of the floor 2, made in plywood, the upper face 7 of the profile extending thus the surface of the floor 2.

In its lower part (corresponding to the point of the triangular section), the profile of the spar 3 forms a longitudinal groove 11, of section substantially circular, open downwards.

The tubular conformation of the constituent profile of the spar 3 defines an interior space 12. Two internal longitudinal ribs 13 and 14, attached respectively at the upper part and at the part bottom of the profile and located directly below one of the other, protrude into the interior space 12.

Each aluminum profile, constituting a end cross member 4 of frame 1, has a cross section substantially rectangular transverse, its configuration also being tubular. At both ends of this profile cross member 4, in the vertical walls thereof, are provided holes 15 located in correspondence.

The longitudinal groove 11 of each beam 3 receives a continuous steel rod 16, extending over all the length of the beam 3 and serving as a means of reinforcement as well as means of fixing the sleepers end 4. For this purpose, the two ends of each steel rod 16 have a thread 17. These ends threaded from rod 16, protruding from the ends corresponding to the side member 3, pass through the holes 15 of the cross members 4 applied (in assembled state - see figure 3) against the ends of the side members 3. A nut 18, screwed from the outside on the thread 17 of each end of the rod 16, tightens the cross member 4 against the corresponding end of a beam 3.

In the embodiment shown in the figures 2 to 4, the hooks 5 are located in the extension of the side rails 3. These hooks 5 have a pierced base a hole 19, and threaded onto the threaded end of the steel rod 16, in front of the cross-member 3. Thus, the tightening the nut 18 ensures the simultaneous fixing of the cross 4 and hook 5.

On the contrary, Figures 1 and 5 illustrate a variant in which the hooks 5 have, for relative to the side members 3, a position shifted towards the interior. In this case, the steel rods 16 and the nuts 18 only assemble the side members 3 and crosspieces 4. The hooks 5 are fixed here separately on the end crosspieces 3 corresponding, in particular by means of bolts (here not represented).

At each corner of the platform, the end crosspiece 4 is interrupted along a corresponding vertical plane, substantially, at the median of the triangular section of the spar 3. The interior space 12 of the constituent profile this spar 3 is thus made accessible, and allows the introduction of a corner piece 20, in terms of synthetic or other material, clearly visible in the figure 2.

The corner piece 20 has a body 21, and two tenons 22 and 23 arranged at right angles. The first tenon 22 is engaged in a housing 24 at one end of the crosspiece 4. The second tenon 23 is engaged in space interior 12 of the profile constituting the beam 3, and more particularly in the part of this interior space 12 delimited by the external inclined flank 8 and by the two superimposed ribs 13 and 14. The corner piece 20 is first engaged in the housing 24 of the cross 4, then introduced into the interior space 12 of the beam 3, and it is automatically blocked when the nut 18 is tightened on the thread 17 of the rod 16.

The body 21 of the corner piece 20 has a rounded outer face. The upper face of the body 21 has a housing 25, here of cylindrical shape, provided to receive a retaining rod 26 fixed at the end plinth 6 - see also figure 1.

By its presence, the corner piece 20 ensures a mechanical locking between the cross-member 4 and the beam 3. In indeed, we can assume that the forces exerted on the plywood floor 2, inserted in the groove longitudinal 10 of the beam member 3, would have tendency to tilt this profile inward, by relative to a pivot axis formed by the rod in steel 16. However, the corner piece 20 including the second tenon 23 has a profile adapted to that of the spar 3 prevents this tilting and ensures blocking of the assembly.

In a variant, shown in FIG. 6, the aluminum profile constituting the beam 3 has always a triangular section, with point facing downwards, but this profile has two longitudinal grooves. As before, a groove longitudinal 11 of circular section is provided at the lower section of profile (point of section triangular). Another longitudinal groove 27 is formed in the upper part of the profile of the beam 3, under its upper face 7. By placing in these two grooves 11 and 27 of steel rods, or other means (as described below) used for fixing the end crosspieces 4, here we avoid tilting side rail 3.

As illustrated in Figure 7, the means of fixing the end crosspieces 4 can also consist of at least one pin 28, introduced at the end of the beam 3 in the groove 11, which does not here receives no continuous steel rod. As previously, the crosspiece 4 has towards its ends holes 15 located in correspondence. A fixing screw 29, introduced from the outside, passes through the holes 15 and is screwed into the ankle 28. Of course, in the case of a spar profile 3 having two grooves superimposed 11 and 27 (Figure 6), the fixing of the cross member 4 on the beam 3 can be made by means two plugs 28 and two screws 29.

Figures 8 and 9, which represent the region of an angle of the scaffolding plate, show so more precise one embodiment of the corner piece 20, with its body 21, its two tenons 22 and 23, and its housing 25 which receives the retaining rod 26 fixed to the end of the plinth 6. Figure 8 clearly shows how the corner piece 20, put in place, closes the angle of the two sections respectively constituting the beam 3 and cross member 4. Figure 9 shows the detail of the means for fixing one of the hooks 5, when these are offset with respect to the side members 3, these means of fixing comprising a bolt 30 engaged through holes 31 of the cross 4.

Claims (8)

1. Scaffolding platform, of the type made of aluminum and of wood, consisting of a rectangular frame (1), especially of aluminum, and of decking (2), especially of plywood, inserted in the frame (1), this frame (1) itself consisting of two longitudinal members (3) and two end crossmembers (4) in the form of extruded sections, especially of aluminum, characterized in that the sections forming the longitudinal members (3) of the frame (1) have at least one longitudinal slot (11, 27) or a longitudinal passage which accommodates a continuous steel rod (16) running along the entire length of the longitudinal member (3) and acting as a reinforcing means and as a means of attaching the end crossmembers (4), said steel rod (16) having threaded ends (17) designed to pass right through the end crossmembers (4) pressed against the ends of the longitudinal members (3) and to take tightening nuts (18).
2. Scaffolding platform according to claim 1, characterized in that the sections forming the longitudinal members (3) of the frame (1) have a more or less triangular transverse section, the tip of the triangular cross section pointing downward, these sections having a longitudinal slot (11) or a longitudinal passage in the region of the lower vertex of its triangular cross section and designed to accommodate the steel rod (16), while the base (7) of said triangular cross section, opposite its vertex, forms part of the surface of the decking (2) of the scaffolding platform.
3. Scaffolding platform according to claim 1 or 2, having hooks (5) longitudinally in line with the longitudinal members (3), characterized in that the steel rods (16) which carry nuts (18) at their threaded ends (17), also attach the hooks (5).
4. Scaffolding platform according to any one of claims 1 to 3, characterized in that the length of the end crossmembers (4) is determined in such a way that the end faces of each crossmember (4) joined to the longitudinal members (3) more or less correspond to the vertical mid-line of the cross section of these longitudinal members (3) and more particularly to the mid-line of the triangular cross section of said longitudinal members (3).
5. Scaffolding platform according to claim 4, characterized in that inserted at each joint between a crossmember (4) and a longitudinal member (3) is a corner piece (20) which is engaged on the one hand in the crossmember (4) and on the other hand in the longitudinal member (3), the corner piece (20) filling in the corner between the two sections which respectively form the longitudinal member (3) and the crossmember (4).
6. Scaffolding platform according to claim 5, characterized in that the section forming each longitudinal member (3) has two internal longitudinal ribs (13, 14) delimiting part of the internal space (12) of this section in which space a tenon (23) of the corner piece (20) is engaged.
7. Scaffolding platform according to claim 5 or 6, characterized in that the corner piece (20) has, opening onto its upper face, a housing (25), especially one of cylindrical shape, designed for attaching the end (26) of a toe board (6) which runs along the edge of this scaffolding platform.
8. Scaffolding platform according to any one of claims 5 to 7, characterized in that the corner piece (20) has a rounded external shape.

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