EP0491634B1 - Connecting arrangement for seaffold platforms - Google Patents

Description

The present invention relates to a scaffolding comprising load-bearing structures, constituted by prefabricated frames and to which scaffolding floors are fixed. The device which is the subject of the invention maintains the scaffolding floors in position without additional means, while allowing the dismantling and mounting of these floors on an erected support structure.

The scaffolding currently used generally consists, on the one hand, of a load-bearing metal structure formed by prefabricated elements (frames, rails, posts, diagonals) or by assemblies of tubes and assembly collars, and on the other share, self-supporting floors or horizontal planks. The connection of the floors with the supporting structure must ensure the resumption of the vertical forces due to the load supported by the floors, the maintenance in position of the floors when they are subjected to a vertical force due to the wind, and the transmission of the horizontal forces in the structure.

Scaffolding floors are generally fitted, at their ends, with hooks positioned on the horizontal crosspieces of the supporting structure. Vertical immobilization upwards of the floors is generally ensured either by a locking device integrated into the hooks or the floor, or by the lower cross member of an upper frame of the supporting structure, coming to block the hooks in the upper cross member of a lower frame of the same structure. The latter solution imposes a very precise assembly order, the floor must be placed on the lower frames before the installation of the upper frames, and it excludes in particular the dismantling or adding of the floors once the structure is assembled.

This is illustrated by Figure 1 of the accompanying schematic drawing, which partially shows a scaffolding structure of a type currently very common. This structure consists of closed frames comprising in particular an upper cross member 1 and a lower cross member 2, joined by tubular posts 3,4. The upper cross member 1, belonging for example to a lower frame 5, has a "U" section with wings facing upwards. The lower cross member 2 belonging for example to an upper frame 6 is generally constituted by a tube of rectangular section; it can also be constituted by a square section tube, or by a "U" profile whose wings are turned downwards. The hooks 7 of a floor 8 rest on a wing of the upper cross member 1 of the lower frame 5, and are blocked because the width of the lower cross member 2 of the upper frame 6 is equal to, or at least substantially equal to, the width of the upper cross member 1, thus preventing the hooks 7 from being released upwards. It should be noted that the lower ends of the tubular posts 4 of the upper frame 6 are engaged in the upper ends of the tubular posts 3 of the lower frame 5; pins 9 cross horizontally the nested parts of the posts 3 and 4, and provide the connection between the lower 5 and upper frames 6. It is understood that the hooks 7 are thus trapped between the crosspieces 1 and 2, in other words that the floor 8 is itself trapped between the lower 5 and upper 6 frames, and that it is not possible to remove or add such a floor 8 to the erected structure, without at least partially dismantling this structure.

With regard to the "U" shape of the cross member, with two wings facing upwards, and the presence at the ends of the floors of hooks facing downwards, resting on the wings of the cross member, reference is made to the documents. DE-A-2724932 and FR-A-2307099.

The invention aims to allow the removal and addition of scaffolding floors without dismantling the supporting structure, in particular to be able to move and reuse one of the floors depending on the work to be done, while ensuring good immobilization of the floors.

To this end, the subject of the present invention is a scaffolding comprising load-bearing structures constituted by prefabricated frames and to which scaffolding floors are fixed, equipped at their ends with hooks turned downwards and intended to cooperate with upper horizontal crosspieces of frames belonging to the supporting structure, the scaffolding being characterized in that lower horizontal crosspieces of frames belonging to the same supporting structure limit the upward movement of the hooks supported on the upper crosspieces, in that the upper crosspieces of the frames have on their sides notches formed in correspondence with the positions of the hooks of the floors to be fixed and provided for receiving these hooks, and in that the lower crosspieces of the frames, of width less than that of the upper crosspieces, comprise laterally projecting parts located in correspondence with the positions of the notches of the upper crossmembers, so that a hook engaged in a notch of an upper crossmember is surmounted by a projecting part of a lower crossmember which limits its direct movement upwards, but can be disengaged from the notch and from the corresponding projecting part by a displacement comprising a lateral component.

The direct and complete vertical clearance of a floor is thus prevented by the projecting parts of the lower cross member of the upper frame, located above the notches of the upper cross member of the lower frame in which the hooks are housed. On the other hand, there is the possibility of releasing the hooks from the notches by slightly lifting the floor, then by making a lateral movement of a few centimeters from this floor, also releasing the hooks from the projecting parts; the hooks are then brought into a position where they are no longer surmounted by parts of the lower crossmember of the upper frame, the current width of which is smaller than the width of the upper crossmember of the lower frame, and the floor can finally be released fully up. A floor can therefore be removed by a successively vertical, then lateral and again vertical displacement, and of course by a succession of reverse movements it is possible to set up a floor, this always without separating the upper frames from the lower frames of the load-bearing structure. The presence of a longitudinal plinth of the floor, cooperating with a fixing lug integral with a post of the upper frame is sufficient to laterally block the floor in normal times and thus avoids the possibility of releasing this floor accidentally out of the notches.

If the upper crosspieces of the frames of the supporting structure are formed by profiles having a "U" section, the aforementioned notches, provided for receiving the hooks of the floors to be fixed, are formed on the upper edge of the wings of these section profiles in "U".

As for the projecting parts of the lower crossmembers of the frames, these can result from lugs formed on a fixed flat iron, for example by welding, under each of said lower crossmembers, produced in particular as tubes of square or rectangular section.

In a variant, the lower crosspieces of the frames of the supporting structure are constituted by profiles having an inverted "U" section, with downwardly facing wings which locally include outwardly facing deformations forming said projecting parts, which avoids any patches.

• Figure 2 est une vue en perspective partielle d'un échafaudage conforme à la présente invention ;
• Figure 3 est une vue en coupe verticale d'une extrémité de plancher avec crochet engagé dans une encoche de traverse supérieure de cadre ;
• Figure 4 est une vue en coupe similaire à figure 3, mais montrant le crochet dégagé de l'encoche ;
• Figure 5 est une vue en plan par dessus de l'extrémité d'un plancher, illustrant son blocage latéral ;
• Figure 6 est une vue en élévation, correspondant à figure 5 ;
• Figure 7 est une vue partielle en perspective d'un cadre, représentant une variante de l'invention.

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 nonlimiting examples, an embodiment of this scaffolding, as well as a variant .

• Figure 2 is a partial perspective view of a scaffold according to the present invention;
• Figure 3 is a vertical sectional view of a floor end with hook engaged in a notch of the upper cross member of the frame;
• Figure 4 is a sectional view similar to Figure 3, but showing the hook released from the notch;
• Figure 5 is a plan view from above of the end of a floor, illustrating its lateral locking;
• Figure 6 is an elevational view, corresponding to Figure 5;
• Figure 7 is a partial perspective view of a frame, representing a variant of the invention.

With reference to FIGS. 2 to 6, which represent a first embodiment, the invention uses a support structure of a generally known type consisting of closed frames, comprising in particular an upper cross member 1 and a lower cross member 2, joined by posts tubular 3,4. We consider here more particularly a lower frame 5 and an upper frame 6, superimposed and assembled together by fitting their respective posts 3,4, and a scaffolding floor 8 which must be fixed, by one end, at the level of the junction between the two frames 5,6. The end of the floor 8 is provided, for its fixing, with two hooks 7 facing downwards, the hooks 7 here being obtained from a flat profile folded adequately.

As shown more particularly in Figures 2 to 4, the upper cross member 1 of the lower frame 5 is constituted by a section having a "U" section, with two parallel wings 10, located in vertical planes and facing upwards. Each wing 10 has two notches 11 which are arranged in correspondence with the positions of the hooks 7 of the floor 8 and which open onto the upper edge of this wing 10, the width of the notches 11 being in relation to that of the hooks 7.

The lower cross member 2 of the upper frame 6 is produced in the form of a tube of rectangular section, the width d of which is less than the width D of the upper cross member 1 of the lower frame 5. A flat iron 12 is welded under the face lower of the lower cross member 2. The flat iron 12 has on each of its longitudinal edges two lugs 13, projecting laterally, located in correspondence with the positions of the notches 11 of the upper cross member 1; in line with the lugs 7, the flat iron 12 has locally an increased width, substantially equal to that D of the upper cross member 1. Thus, considering the two superimposed frames 5, 6, each notch 11 of the upper cross member 1 of the lower frame 5 East surmounted by a lug 13 of the lower cross member 2 of the upper frame 6.

With particular reference to FIGS. 2 and 3, when a floor 8 is normally fixed to the support structure, the two hooks 7 fitted to the considered end of the floor 8 are housed respectively in the corresponding notches 11 of the upper cross member 1 of the lower frame 5. The presence of the pins 13 above the notches 11 limits the direct upward movement of the hooks 7, therefore preventing accidental or voluntary release of the floor 8 by a simple vertical movement.

On the other hand, as illustrated in FIG. 4, each hook 7 can be released voluntarily from the corresponding notch 11 by a slight vertical displacement, followed by a lateral displacement which shifts the hook 7 relative to the lug 13 surmounting this notch 11. Due to the reduced width d of the upper cross member 2, the hook 7 then finds a free space above it, making it possible to move it again upwards, without encountering any obstacle. Thus, the end of the floor 8 can be entirely released. Naturally, the same operation can be carried out simultaneously at the two ends of the floor 8 fixed, by the same device, so that the floor can be removed from the support structure without the need to separate the lower frames 5 and upper 6. It goes without saying that a reverse movement sequence, also comprising a lateral component, makes it possible to engage the hooks 7 in the notches 11 without removing the upper frame 6 from the lower frame 5, therefore to add a floor 8 to a pre-existing supporting structure without dismantling this structure.

With reference to FIGS. 5 and 6, a lateral blocking of the end of the floor 8, fixed to the support structure by the device described above, is ensured by taking advantage of a longitudinal plinth 14 of this floor 8. At its end, the plinth 14 is extended by a short horizontal rod 15, which is engaged in a fixing lug 16 secured to a post 4 of the upper frame 6. Thus, the floor 8 is immobilized laterally in normal times, and it cannot be released . To be able to extract the hooks 7 from the notches 11, it is first necessary to remove the plinth 14.

Finally, FIG. 7 represents a variant, concerning the production of the lower cross member 2 of a frame 6. The lower cross member 2 is formed here by a section having an inverted "U" section, the current width of this cross member 2 being , as before, lower than that of the upper crossmember (not shown). The wings 17 of the profile, facing the bottom, locally contain deformations 18 turned outwards, which form projecting parts producing the equivalent of the lugs 13 of the embodiment described above, the deformations 18 being located in correspondence with the positions of the notches of the crosspiece superior.

Of course, the invention is not limited to the sole embodiments of this scaffolding which have been described above, by way of examples; on the contrary, it embraces all the variant embodiments and applications falling within the scope of the claims. Thus, one would not depart from the framework of the invention by modifications of constructive forms, in particular for the lower cross members of the frame and for the laterally projecting parts of these cross members.

Claims (5)

1. Scaffolding including bearing structures constituted by prefabricated frames, and to which are fixed scaffolding planking (8), the planks (8) being equipped at their ends with hooks (7) turned downwardly and provided to cooperate with upper horizontal cross-members (1) of the frames (5) belonging to the bearing structure, characterised in that lower horizontal cross-members (2) of the frames (6) belonging to the same bearing structure limit the upward movement of the hooks (7) supported on the upper cross-members (1), in that the upper cross-members (1) of the frames (5) have on their sides (10) notches (11) formed to correspond with the positions of the hooks (7) of the planking (8) to be fixed and provided to receive the hooks (7), and in that the lower cross-members (2) of the frames (6), of width (d) less than that (D) of the upper cross-members (1), have laterally projecting portions (13; 18) positioned to correspond with the positions of the notches (11) of the upper cross-members (1), such that a hook (7) engaged in a notch (11) of an upper cross-member (1) is surmounted by a projecting portion (13; 18) of a lower cross-member (2) which limits its direct upward movement, but may be disengaged from the notch (11) and from the corresponding projecting portion (13; 18) by a movement having a lateral component.
2. Scaffolding according to Claim 1, characterised in that the upper cross-members (1) of the frames (5) of the bearing structure are constituted by profiles having a "U"-shaped section, and in that the aforesaid notches (11), provided to receive the hooks (7) of the planks (8) to be fixed, are formed on the upper edges of flanges (10) of these profiles (1) of "U"-shaped section.
3. Scaffolding according to Claim 1 or 2, characterised in that the projecting portions of the lower cross-members (2) of the frames (6) of the bearing structure result from lugs (13) formed on a flat-plate (12) fixed, for example by welding, beneath each of the lower cross-members (2), in particular formed as tubes of square or rectangular section.
4. Scaffolding according to Claim 1 or 2, characterised in that the lower cross-members of the frames (6) of the bearing structure are constituted by profiles (2) having an inverted "U"-shaped section, with downwardly turned flanges (17) which have local outwardly turned deformations (18) forming the projecting portions.
5. Scaffolding according to any one of Claims 1 to 4, characterised in that the lateral clamping of the planking (8), normally preventing its disengagement from the notches (11), is ensured by a longitudinal projecting portion (14) of this planking (8), cooperating with a fixing lug (16) rigid with a post (4) belonging to a frame (6) of the bearing structure.

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