AU706743B2

AU706743B2 - Scaffolding platform

Info

Publication number: AU706743B2
Application number: AU46263/96A
Authority: AU
Inventors: Gerard Jullien; Andre Peronnier
Original assignee: SGB COMABI
Current assignee: Comabi
Priority date: 1995-01-25
Filing date: 1996-01-24
Publication date: 1999-06-24
Anticipated expiration: 2016-01-24
Also published as: ES2127617T3; EP0805904B1; ATE174651T1; DE69601155T2; AU4626396A; DE69601155D1; FR2729692B1; FR2729692A1; WO1996023116A1; EP0805904A1; CA2210952A1

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

f WO 96/23116 1 PCT/FR96/00119 SCAFFOLDING PLATFORM The present invention relates to a scaffolding platform, more particularly although not exclusively, a scaffolding platform of the aluminum/wood type.

Two major types of platform forming work surfaces for workers are known in the field of scaffolding, and these are: steel platforms and aluminum/wood platforms.

Steel platforms generally consist of a sheet of metal which has been perforated to make it less slippery, and bent or formed by rollers to obtain rigid decking which at its ends has hooks for positioning the platform on the tubular structure of the scaffolding. The invention does not relate to this first type of platform.

Aluminum/wood platforms, to which the present invention does relate, generally consist of a rectangular frame in aluminum, and decking in plywood inserted in the aluminum frame. The frame usually consists of two longitudinal bearers which may be 3 m, 2.5 m or 2 m long, and two end crossmembers. The longitudinal members and the crossmembers often consist of extruded hollow sections in aluminum. The sections which form the longitudinal members have longitudinal slots in which the longitudinal edges of the plywood decking, which itself has very good mechanical strength, are fitted. The end crossmembers carry hooks which can be used to position the platform on the tubular steel structure of the scaffolding, the hooks generally being welded or bolted on.

To join the longitudinal members and the end crossmembers of the aluminum frame together, a known solution consists in welding each end crossmember against the longitudinal members, generally at 900. The welds connect the two vertical flanks of the crossmember to a side wall of the longitudinal members. Joining aluminum sections together by welding, using a TIG or MIG process is a lengthy and expensive operation which it is difficult to automate, one of its effects being that it reduces the mechanina1 nath of th aUm. approximately 50% in the region of the weld. What is 2 more, the welded regions, which have been metallurgically changed, are the sources of cracks.

Another type of aluminum/wood platform has a beam in the form of a ladder consisting of longitudinal members of clinched rungs supporting the plywood decking.

The hooks are generally arranged longitudinally in line with the longitudinal members. In this case, clinching the rungs to the longitudinal members requires aluminum grades with a very high percentage elongation, therefore a low mechanical strength, which has to be compensated for by increasing the number of rungs. The fact that there are no end crossmembers in this type of scaffolding platform means that some hook configurations are impossible.

In all the cases explained hereinabove, the cross section of the aluminum longitudinal members is designed in such a way that it gives the platform strength in bending. It is therefore necessary for this cross section to be tall enough, and for the walls of the section to be thick enough to obtain a second moment of area which leads to the desired mechanical strength. This can result in two drawbacks: On the one hand, the aluminum longitudinal members are heavy, and their cost is therefore high.

On the other hand, given that the cross section of the sections of which the longitudinal members are formed is very tall, the scaffolding platforms placed one upon another need a tall space for storage and the cost of transporting them is therefore high because a smaller number of platforms will fit into a given volume.

Furthermore, not all of these platforms are designed to take toe boards arranged above a longitudinal edge of a platform. Thus the toe boards often remain fastened to the tubular steel structure of the scaffolding, more particularly to the standards. In some cases, however, attachments are welded to the longitudinal members or the end crossmembers to take these toe boards.

Such arrangements are obviously still expensive, and increase the width taken up by the platforms. When 3 several platforms are juxtaposed to form a continuous work surface, there is inevitably a gap formed between two adjacent platforms, as a result of the presence of the supports for the toe boards.

To sum up, the problems raised by the current scaffolding platforms of the aluminum/wood type are: connecting the end crossmembers to the longitudinal members, the height of the longitudinal members in relation to their cross section and therefore the weight of these elements, their cost and the volume they occupy in storage, attaching the toe board, and the overall cost of the platform as a result both of the amount of aluminum needed and of the assembly time.

The invention aims to solve these various problems and thus eliminate the drawbacks explained above, by providing a scaffolding platform of the aluminum/wood type which is lightweight and economical to manufacture while at the same time affording high mechanical strength and taking up a small space in storage.

Thus the subject of the present invention is essentially a scaffolding platform, especially of the aluminum/wood type, consisting of a rectangular frame, especially of aluminum, and of decking, especially of plywood, inserted in the frame, this frame itself consisting of two longitudinal members and two end crossmembers in the form of extruded sections, especially of aluminum, the platform being noteworthy in that the longitudinal members of the frame have at least one longitudinal slot or a longitudinal passage which accommodates a reinforcing means of the steel rod type and/or means of attaching the end crossmembers which are pressed against the ends of the longitudinal members.

According to a preferred embodiment of the invention, the sections forming the longitudinal members of the frame of the scaffolding platform have a more or less triangular transverse section, the tip of the triangular cross section pointing downward, these sections having a longitudinal slot or a longitudinal passage in the region of the lower vertex of its triang- 4 ular cross section and designed to accommodate the reinforcing means of the steel rod type, while the base of said triangular cross section, opposite its vertex, forms part of the surface of the decking of the scaffolding platform.

The longitudinal members thus have an optimum cross section, the choice of a triangular cross section with the vertex pointing downward, combined with a steel rod in particular making it possible to reduce the mass of aluminum contained in the longitudinal member. This is because in bending, each longitudinal member behaves like a beam, the upper part of its cross section working in compression and the lower part of its cross section working in tension. In so far as the loadings or stresses need to remain below fixed limits (approximately 13 kg/mm 2 for aluminum, this gives a theoretical requirement for a certain amount of aluminum. The configuration proposed, with a triangular cross section, makes it possible to reduce as far as possible the amount of aluminum working in tension, replacing it with a continuous steel rod which can easily work with stresses of 36 kg/mm 2 or more in tension.

By thus transferring the loadings to a steel rod, which can withstand them, it is also possible to reduce the height of the cross section of the aluminum section of which the longitudinal member is made, and therefore reduce the volume occupied by the scaffolding platforms in storage.

Another benefit of the arrangement proposed here is that it makes the aluminum frame of the scaffolding platform easier to assemble. In this respect, according to a first advantageous possibility, the continuous steel rod accommodated in the longitudinal slot or the longitudinal passage of the section forming the longitudinal member has threaded ends designed to pass right through the end crossmembers pressed against the ends of the longitudinal members and to take tightening nuts. Thus simply by combining two steel rods with the two longitudinal members respectively, means for joining the 5 crossmembers to the longitudinal members to form the frame of the scaffolding platform become available, the rods thus locking the frame of the scaffolding platform while at the same time reinforcing the sections that form the longitudinal members. The benefit of this arrangement, which has the steel rods fulfilling a dual function, is that it does away with the welded connections and their drawbacks, as well as with any attached joining pieces. Furthermore, when the hooks of the platform are longitudinally in line with the longitudinal members, the steel rods, which have nuts on their threaded ends, can also be used to attach the hooks, this giving them a third function. This last arrangement is therefore particularly beneficial: two rods equipped with nuts associated respectively with the two longitudinal members allow the scaffolding platform, including its hooks, to be assembled completely, with an extremely simple overall structure: the longitudinal members are formed by cutting aluminum sections to the desired length with no further operation required, while the crossmembers simply require the piercing of holes for the passage of the ends of the steel rods. From the industrial production viewpoint, all that is required for completely assembling the scaffolding platform is very simple tooling (wrenches). Of course, a tightening force with an appropriate value will need to be predetermined and checked during assembly.

Overall, the production costs are thus greatly reduced, by comparison with the traditional techniques.

As an alternative, in some cases where the strength of the platform and of the longitudinal members does not require the insertion of a continuous steel rod extending from one end crossmember to the other, the longitudinal slot or the longitudinal passage in each longitudinal member can still be put to use for attaching the end crossmembers, by making provision for this slot or this passage to accommodate, at its open ends at the ends of the longitudinal member, attaching pins of a common type, which themselves accommodate fixing screws passing right through the end crossmembers pressed 6 against the ends of the longitudinal members.

If the steel rods or other attachment means are housed in slots which are open to the outside, the layout also allows easy visual examination of the condition of these rods or other attachment means.

In any event, the connections thus made between the longitudinal members and the end crossmembers are mechanical, using screw means, and these if necessary allow components made of different materials to be joined together, for example using aluminum longitudinal members with steel crossmembers, the hooks being of aluminum, or alternatively, combining longitudinal members made of composite materials with aluminum crossmembers.

In an advantageous arrangement, the length of the end crossmembers is determined in such a way that the end faces of each crossmember joined to the longitudinal members more or less correspond to the vertical mid-line of the cross section of these longitudinal members and more particularly to the mid-line of the triangular cross section (as defined earlier) of said longitudinal members. The result of this is that at each joint between a crossmember and a longitudinal member, not only is the end of the crossmember uncovered, but a fraction of the end of the longitudinal member is also free, thus allowing the insertion of a corner piece.

Thus, according to another aspect of the present invention, its subject is a scaffolding platform, especially of the aluminum/wood type, consisting of a rectangular frame, especially of aluminum, and of decking, especially of plywood, inserted in the frame, this frame itself consisting of two longitudinal members and two end crossmembers in the form of extruded sections, especially of aluminum, the platform being noteworthy in that inserted at each joint between a crossmember and a longitudinal member is a corner piece which is engaged on the one hand in the crossmember and on the other hand in the longitudinal member, the corner piece being automatically locked when the crossmember is attached to the longitudinal member. This corner piece, thus locked to 7 the frame of the scaffolding platform with no additional fasteners, can fulfil several functions all by itself, thanks to an appropriate shape: First of all, the corner piece fills in the corner between the two sections forming the longitudinal member and the crossmember respectively, thus preventing the ingress of water or other products inside the sections.

In addition, the corner piece advantageously has, opening onto its upper face, a housing, especially one of cylindrical shape, designed for attaching the end of a toe board which runs along the edge of the scaffolding platform. The toe board can thus be attached directly to the platform, whereas at the present time toe boards are generally attached between the scaffolding standards, which leaves a significant space between the toe board and the platform, and therefore a risk of objects such as tools falling off, a drawback remedied by the invention.

Furthermore, this corner piece, in addition to the crossmember being screwed to the longitudinal member, mechanically locks this crossmember and said longitudinal member together, preventing any twisting.

Finally, by giving the corner piece a rounded external shape, this corner piece, through being present, does away with the sharp edges which are in the region of the corner of the platform and which result from the cutting to length of the sections of which the longitudinal member and the end crossmember are made. The platform thus becomes less angular, and therefore less dangerous.

In addition, as the corner piece sticks out, it affords the aluminum frame consisting of the longitudinal members and crossmembers protection against knocks.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the attached diagrammatic drawing which represents, by way of examples, some embodiments of this scaffolding platform: Figure 1 is an overall view, in perspective, of a scaffolding platform of the aluminum/wood type, in 8 accordance with the present invention; Figure 2 is an exploded perspective view of the region of a corner of this scaffolding platform, in a first embodiment; Figure 3 is a view in longitudinal section passing through the region of this corner, the platform being assembled; Figure 4 is a view in transverse section on IV-IV of Figure 3; Figure 5 is a partial plan view of an alternative form of this scaffolding platform; Figure 6 depicts an alternative form of the cross section of the section of which one of the longitudinal members of such a platform is made; Figure 7 is a perspective view similar. to Figure 2, illustrating another embodiment of this scaffolding platform; Figure 8 is another perspective view of the region of a corner of a scaffolding platform according to the invention, more particularly illustrating the attachment of the toe board; Figure 9 is an exploded perspective view corresponding to part of Figure 8.

As shown in Figure 1, the invention deals with a scaffolding platform which has a rectangular bearing frame 1 of elongate shape and decking 2. The bearing frame 1 is composed of two longitudinal members 3 consisting of extruded aluminum sections, and two end crossmembers 4 consisting of other extruded aluminum sections. The scaffolding platform also has, at each of its ends, a pair of hooks 5 designed for positioning it on the tubular steel structure (not depicted) of the scaffolding. In the example under consideration, this scaffolding platform is also fitted with a toe board 6 which runs along one of its long sides.

With reference to Figures 2 to 4, each aluminum section forming a longitudinal member 3 of the frame 1 has a more or less triangular, but asymmetric, cross section, the vertex of which triangle points downward.

Figure 5 is a partial plan view of an alternative form of this scaffolding platform; Figure 6 depicts an alternative form of the cross section of the section of which one of the longitudinal members of such a platform is made; Figure 7 is a perspective view similar to Figure 2, illustrating another embodiment of this scaffolding platform; Figure 8 is another perspective view of the region of a corner of a scaffolding platform according to the invention, more particularly illustrating the attachment of the toe board; Figure 9 is an exploded perspective view corresponding to part of Figure 8.

~As shown in Figure 1, the invention deals with a scaffolding platform which has a rectangular bearing frame 1 of elongate shape and decking 2. The bearing frame 1 is composed of two longitudinal members 3 consisting of S 15 extruded aluminium sections, and two end crossmembers 4 consisting of other extruded aluminium sections. The scaffolding platform also has, at each of its ends, a pair of hooks 5 designed for positioning it on the tubular steel structure (not depicted) of the scaffolding. In the example under consideration, this scaffolding platform is also fitted with a toe board 6 which runs along one of its 20 long sides.

With reference to Figures 2 to 4, each aluminium section forming a *longitudinal member 3 of the frame 1 has a more or less triangular, but asymmetric, cross section, the vertex of which triangle points downwards.

9 This section, of tubular overall configuration, .thus has a more or less horizontal upper face 7 (corresponding to the base of the triangular cross section), an outside inclined flank 8 (corresponding to one side of the triangular cross section) and an inside inclined flank 9 (corresponding to another side of the triangular cross section). At its upper part, on the side pointing inward, the section of the longitudinal member 3 forms a longitudinal slot 10 in which a longitudinal edge of the decking 2, made of plywood, is inserted, the upper face 7 of the section thus extending the surface of the decking 2.

At its lower part (corresponding to the vertex of the triangular cross section), the section of the longitudinal member 3 forms a longitudinal slot 11, of more or less circular cross section, open at the bottom.

The tubular configuration of the section of which the longitudinal member 3 is made defines an internal space 12. Two internal longitudinal ribs 13 and 14 attached respectively to the upper part and to the lower part of the section and situated vertically in line with one another project into the internal space 12.

Each aluminum section constituting an end crossmember 4 of the frame 1 has a more or less rectangular transverse section, its configuration also being tubular.

At the two ends of this crossmember section 4, in the vertical walls thereof, there are holes 15 lying opposite each other.

The longitudinal slot 11 of each longitudinal member 3 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. For this, the two ends of each steel rod 16 have a screw thread 17. These threaded ends of the rod 16, which protrude from the corresponding ends of the longitudinal member 3, pass through the holes of the crossmembers 4 which (in the assembled condition see Figure 3) are pressed against the ends of the longitudinal members 3. A nut 18 screwed from the outside onto the screw thread 17 of each end of the rod 16 clamps 10 the crossmember 4 against the corresponding end of a longitudinal member 3.

In the embodiment depicted in Figures 2 to 4, the hooks 5 are longitudinally in line with the longitudinal members 3. These hooks 5 have a base pierced with a hole 19 and slipped over the threaded end of the steel rod 16, on the front end of the crossmember 3 [sic].

Thus, tightening the nut 18 at the same time attaches both the crossmember 4 and the hook In contrast, Figures 1 and 5 illustrate an alternative form in which the hooks 5 are offset inward relative to the longitudinal members 3. In this case, the steel rods 16 and the nuts 18 merely join the longitudinal members 3 and the crossmembers 4 together. The hooks 5 here are attached separately to the corresponding end crossmembers 3 [sic], especially by means of bolts (not depicted here).

At each corner of the platform, the end crossmember 4 is interrupted along a vertical plane which more or less corresponds to the mid-line of the triangular cross section of the longitudinal member 3. The internal space 12 of the section forming this longitudinal member 3 thus becomes accessible, and allows the insertion of a corner piece 20, made of a synthetic substance or some other material, clearly visible in 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 crossmember 4. The second tenon 23 is engaged in the internal space 12 of the section forming the longitudinal member 3 and more specifically in that part of this internal space 12 which is delimited by the inclined outer flank 8 and by the two superimposed ribs 13 and 14.

The corner piece is first of all engaged in the housing 24 of the crossmember 4, then introduced into the internal space 12 of the longitudinal member 3 and it is automatically locked when the nut 18 is tightened onto the screw thread 17 of the rod 16.

11 The body 21 of the corner piece 20 has a rounded external face. The upper face of the body 21 has a housing 25, here of cylindrical shape, designed to accommodate a retaining nod 26 attached to the end of the toe board 6 see also Figure i.

The presence of the corner piece 20 provides mechanical locking between the crossmember 4 and the longitudinal member 3. It may be assumed that the forces exerted on the plywood decking 2 inserted in the longitudinal slot 10 of the section of the longitudinal member 3 would tend to cause this section to tilt inward, with respect to an axis of pivoting consisting of the steel rod 16. However, the corner piece 20, the second tenon 23 of which has a profile to mate with that of the longitudinal member 3 prevents this tilting and locks the assembly.

In an alternative form, shown in Figure 6, the aluminum section forming the longitudinal member 3 still has a cross section of triangular appearance, with a vertex pointing downward, but this section has two longitudinal slots. As before, one longitudinal slot 11 of circular cross section is provided at the lower part of the section (vertex of the triangular cross section).

Another longitudinal slot 27 is formed in the upper part of the section of the longitudinal member 3, beneath its upper face 7. By placing in these two slots 11 and 27 steel rods, or another means (as described below) for attaching the end crossmembers 4, it is possible in such cases to avoid undesirable tilting of the longitudinal member 3.

As illustrated in Figure 7, the means of attaching the end crossmembers 4 may also consist of at least one pin 28 inserted into the end of the longitudinal member 3 in the slot 11, which here does not accommodate any continuous steel rod. As before, the crossmember 4 near its ends, has holes 15 situated opposite each other.

A fixing screw 29, inserted from the outside, passes through the holes 15 and is screwed into the pin 28. Of course, if the section of the longitudinal member 3 is 12 one that has two superimposed slots 11 and 27 (Figure then the crossmember 4 can be attached to the longitudinal member 3 by means of two pins 28 and two screws 29 inserted from the outside, passes through the holes and is screwed into the pin 28. Of course, if a section of the longitudinal member 3 is one that has two superimposed slots 11 and 27 (Figure then the crossmember 4 can be attached to the longitudinal member 3 by means of two pins 28 and two screws 29.

Figures 8 and 9, which represent the region of a corner of the scaffolding platform, show in greater detail one embodiment of the corner piece 20 with its body 21, its two tenons 22 and 23, and its housing 25 which accommodates the retaining rod 26 fixed to the end of the toe board 6. Figure 8 clearly shows how the corner piece 20, once fitted, fills in the corner between the two sections S: which respectively form the longitudinal member 3 and the crossmember 4.

Figure 9 gives details of the means of attaching one of the hooks 5, when these 15 are offset from the longitudinal members 3, these attachment means comprising a bolt 30 engaged through holes 31 in the crossmember 4.

As goes without saying, and as is clear from the foregoing, the invention is not restricted merely to the embodiments of this scaffolding platform which have been described hereinabove by way of examples; on the contrary, it 20 encompasses all alternative forms thereof which follow the same principle.

Thus, especially, it would not be departing from the scope of the present invention if the cross section of the sections forming the longitudinal members were to be modified, it being possible for the triangular cross section to be replaced with a trapezoidal cross section, or alternatively with a rectangular cross section, so long as these sections still have at least one longitudinal slot or a longitudinal passage or channel to accommodate a continuous steel rod or pins for attaching the end crossmembers. By the same token, changes in materials may be envisaged for some components, without this in any way departing from the main inventive idea. Finally, it will be noted that the characteristics relating to the corner pieces, especially the use of these corner pieces for attaching the toe boards, apply independently of the use of the reinforcing rods housed in the longitudinal members.

Claims

1. Scaffolding platform, of the type made of aluminium and wood, consisting of a rectangular frame especially of aluminium, and of decking, especially of plywood, inserted in the frame, this frame itself consisting of two longitudinal members and two end crossmembers in the form of extruded sections, especially of aluminium, wherein the sections forming the longitudinal members of the frame have at least one longitudinal slot or a longitudinal passage which accommodates a continuous steel rod running along the entire length of the longitudinal member and acting as a reinforcing means and as a means of attaching the end crossmembers, said steel rod having threaded ends designed to pass right through the end crossmembers pressed against the ends of the longitudinal members and to take tightening nuts. S2. Scaffolding platform according to claim 1, wherein the sections forming the longitudinal members of the frame have a more or less triangular transverse section, the tip of the triangular cross section pointing downward, these sections S. having a longitudinal slot or a longitudinal passage in the region of the lower vertex of its triangular cross section and designed to accommodate the steel rod, while the base of said triangular cross section, opposite its vertex, forms part of the surface of the decking of the scaffolding platform.

3. Scaffolding platform according to claim 1 or 2, having hooks longitudinally in line with the longitudinal members, wherein the steel rods which carry nuts at their threaded ends also attach the hooks.

4. Scaffolding platform according to any one of claims 1 to 3, wherein the length of the end crossmembers is determined in such a way that the end faces of each crossmember joined to the longitudinal members more or less correspond to the vertical mid-line of the cross section of these longitudinal members and more particularly to the mid-line of the triangular cross section of said longitudinal members. 14 Scaffolding platform according to claim 4, wherein inserted at each joint between a crossmember and a longitudinal member is a corner piece which is engaged on the one hand in the crossmember and on the other hand in the longitudinal member, the corner piece filling in the corner between the two sections which respectively form the longitudinal member and the crossmember.

6. Scaffolding platform according to claim 5, wherein the section forming each longitudinal member has two internal longitudinal ribs delimiting part of the internal space of this section in which space a tenon of the corner piece is engaged.

7. Scaffolding platform according to claim 5 or 6, wherein the corner piece has, opening onto the upper face, a housing, especially one of cylindrical :°:shape, designed for attaching the end of a toe board which runs along the edge o. of this scaffolding platform.

8. Scaffolding platform according to any one of claims 5 to 7, wherein the corner piece has a rounded external shape. o DATED this 20th day of April, 1999. SGB COMABI WATERMARK PATENT TRADEMARK ATTORNEYS 4TH FLOOR, "DURACK CENTRE" 263 ADELAIDE TERRACE PERTH W.A. 6000 AUSTRALIA MCQ:MSE:JAH DOC 26 AU4626396.WPC