EP2011957B1 - Ladder with permanent summit platform - Google Patents

Description

The invention relates to ladders with permanent top platform, whether they are one or more planes, sliding or not.

Improving the safety of staff working at height from a ladder has led regulators and ladders manufacturers to provide at the top of the ladder, on the one hand, a platform to put their feet on a ladder. surface larger and more stable than that of a bar, and, secondly and above the platform, a guard adapted to retain the user but also to limit its movement over the platform to reduce the effects on the stability of the scale. Other means, outside the scope of the invention, are also provided to improve the stability of the ladder against its support, wall or pole.

The invention relates more particularly to ladders in which the platform, articulated on the last bar, is connected by connecting rods to the guard rail, articulated to the tops of the two uprights of the ladder, so that the movements of deployment or folding of the platform communicate movements similar to the bodyguard.

In the description and the claims that follow the expression "back" designates the part of the ladder that faces the user when it is in support, while the expression "before" designates the part that is behind the user. ladder.

In the current ladders of this type, after the ladder has been placed against a support, wall or post, and other stabilizers have been put in place, the user climbs up the ladder and, when he reaches near the top, it activates the means of unlocking the platform, then controls its deployment. At the end of the movement, the platform protrudes forward from the uprights while the guard rail protrudes rearward of these amounts to retain the user after he has reached the platform.

Connecting rods between the platform and the guard rail extending vertically between the rear edge thereof and the rail of the guard rail, delimit with the amounts of the ladder a passage area. This is substantially vertical and tubular and has a cross section which is sometimes less than the transverse size of the user wearing the belt various tools and equipment necessary for the work he must perform. As a result, to reach his working position in which his feet are on the platform, the user must contort during the passage of his torso at the guard rail, ie perform movements which, what whatever the height, can generate destabilizing efforts and generating discomfort. To remedy this, the user must reduce the clutter of objects attached to his belt and, even see, bring them from the ground by pulling the rope, after settling on the platform, thus increasing the time of setting in place of the site.

The document FR-A-2892146 describes a scale having all the features of the preamble of claim 1.

The object of the invention is to provide an arrangement for this disadvantage.

• de première part, une plateforme rabattable, articulée sur un barreau avec possibilité de déploiement vers l'avant en direction de la zone d'appui,
• de deuxième part, un garde corps supérieur articulé à l'extrémité supérieure des montants portant les barreaux, de manière que sa lisse puisse être en saillie sur l'arrière, et
• de troisième part, des bielles de liaison entre plateforme et lisse transmettant à cette dernière les mouvements de déploiement ou de rabattement communiqués à la première.

The invention relates more particularly to a scale according to the wording of claim 1 comprising:

• first, a folding platform, articulated on a bar with possibility of deployment forward towards the support zone,
• secondly, an upper guard hinged to the upper end of the amounts carrying the bars, so that its smooth can be projecting on the rear, and
• thirdly, link connecting rods between platform and smooth transmitting to it the deployment or folding movements communicated to the first.

• une position de maintien sécurisé du garde corps, dans laquelle elle est calée à l'extrémité arrière de la branche latérale correspondante de la lisse,
• et une position d'effacement temporaire, dans laquelle cette extrémité est poussée vers l'avant, près de l'articulation (9) du garde corps (6), en repoussant vers l'avant les bielles et en relevant vers le haut la lisse du garde corps, pour dégager l'accès par le bas à la plateforme (4).

According to the invention, at least the upper end of each of the two connecting rods is slidably mounted on the corresponding lateral branch of the rail of the railing, with the possibility of occupying two positions:

• a secure holding position of the guard rail, in which it is wedged at the rear end of the corresponding lateral branch of the rail,
• and a temporary erasure position, in which this end is pushed forward, near the hinge (9) of the guard (6), pushing forward the rods and raising up the smooth guardrail, to clear the access from below to the platform (4).

After deploying the platform and before engaging under the bodyguard to access this platform, the user confirms, if necessary, the position of the rods against the amounts of the scale, so as to enlarge transversely and vertically the access to the platform, to allow it to pass unhindered. After installation on the platform, the user pushes the rods to the rear end of the guard, until their upper ends are keyed to the guard rail. It is encouraged to perform this movement by the position of the rail of the guard rail, which with the rods, pivoted forward and then close to its articulation on the uprights, is raised relative to the normal position more horizontal.

Thus, the mobility of the upper ends of the connecting rods do not affect the safety and, on the contrary, improves it by facilitating the passage under the guard without the user having to contort on the ascent or descent.

Advantageously, each of the two lateral branches of the rail U-shaped guard is articulated on the amount of the ladder via a piece which carries it outside the interval between amounts giving to the interval between branches of this smooth a larger transverse dimension that that between amounts, while each rod, articulated in the lower part inside the platform, comprises an upper part flaring outward to its sliding joint on the side branch of the beam.

This arrangement increases the transverse dimension of the access area to the platform and further improves the passage of the user.

In one embodiment of the invention, the wedging means of each connecting rod on the rail of the railing comprise, on the one hand, at least one notched corner, disposed under the branch of the U-shaped rail and close to the rail. The soul of this smooth, and, secondly, the head of the corresponding connecting rod, arranged to be able to wedge in the notch of the notched corner.

In a preferred embodiment, each arm of the limb comprises, in the vicinity of its articulation, another notched corner ensuring the temporary setting of the connecting rod in the erasing position, the thickness of this wedge, in its part ensuring the wedging , being greater than the functional clearance between the big end and the rail, to cause the upward straightening of the rail.

• de donner à la tête de bielle un jeu fonctionnel lui permettant de coulisser aisément sur la lisse, sans risque de coincement entre les deux coins crantés, même quand l'une des bielles occupe une position décalée par rapport à l'autre,
• et, par le redressement de la lisse vers le haut, d'améliorer le passage de l'utilisateur qui n'a plus à se plier vers l'avant pour mieux passer sous la branche arrière de cette lisse.

This arrangement allows:

• to give the connecting rod head a functional clearance allowing it to slide easily on the rail, without risk of jamming between the two notched corners, even when one of the connecting rods occupies a position offset from the other,
• and, by the straightening of the rail up, to improve the passage of the user who no longer has to bend forward to better pass under the rear branch of this smooth.

• Figures 1 et 2 sont des vues en prespective de la partie supérieure de l'échelle quand la plateforme est déployée et que ses bielles de liaison avec le garde corps sont respectivement, en position d'accès à la plateforme et en position sécurisée de travail ;
• Figure 3 est une vue partielle, en perspective et à échelle agrandie, montrant une forme d'exécution des moyens de calage de chaque bielle sur la lisse du garde corps ;
• Figures 4 et 5, sont des vues de coté en coupe de l'ensemble de la plateforme lorsqu'elle est en position de travail et en position repliée ;
• Figure 6 est une vue de coté avec coupe partielle montrant à échelle agrandie une forme d'exécution du tirant de retenue de la plateforme ;
• Figure 7 est un vue partielle de coté en coupe de la plateforme montrant une forme de réalisation de ses moyens de calage en position d'utilisation ;
• Figure 8 est une vue partielle en coupe suivant VIII-VIII de figure 7 ;
• Figure 9 est une vue partielle en coupe d'une forme d'exécution des moyens de calage avant des bielles sur le garde corps ;
• Figures 10 et 11 sont des vues partielles en perspective avec coupe partielle de la plateforme d'une autre forme d'exécution de l'invention, respectivement, quand la lisse est en position de maintien sécurisé et quand elle est en position d'effacement temporaire ;
• Figure 12 est une vue partielle en perspective et à échelle agrandie montrant une forme d'exécution du collier glissant et blocable.

Other features and advantages will emerge from the description which follows with reference to the attached schematic drawing showing an embodiment of the ladder with its platform.

• Figures 1 and 2 are views in the prespective view of the upper part of the ladder when the platform is deployed and that its connection rods with the guardrail are, respectively, in the position of access to the platform and in a secure working position;
• Figure 3 is a partial view, in perspective and on an enlarged scale, showing an embodiment of the wedging means of each connecting rod on the rail of the railing;
• Figures 4 and 5 , are sectional side views of the entire platform when in the working position and in the folded position;
• Figure 6 is a side view with partial section showing on an enlarged scale a form of execution of the retaining tie of the platform;
• Figure 7 is a partial sectional side view of the platform showing an embodiment of its wedging means in use position;
• Figure 8 is a partial sectional view along VIII-VIII of figure 7 ;
• Figure 9 is a partial sectional view of an embodiment of the wedging means before connecting rods on the guard rail;
• Figures 10 and 11 are partial perspective views in partial sectional view of the platform of another embodiment of the invention, respectively, when the beam is in the secure holding position and when it is in the temporary erasure position;
• Figure 12 is a partial view in perspective and on an enlarged scale showing an embodiment of sliding and lockable collar.

In known manner, the ladder element constituting a scale on a plane or forming one of the planes of a ladder sliding at least two planes, is formed by two amounts bearing the reference numeral 2 and connected by bars 3 The amounts may be metallic or of composite material.

At its upper end, the ladder element is equipped with a folding platform 4 connected by connecting rods 5 to a railing 6.

The platform 4 comprises a wall 4a which, intended to receive the feet of the user, is bordered on three of its sides by side walls 4b and 4c before. It is inserted between the uprights 2 and is articulated on a bar 3, for example by tabs 4d, bent in round. It can occupy a working position in which it protrudes forward, as shown in Figures 1 and 2 , or a folded position in which it is inserted between the uprights, as shown in FIG. figure 5 .

The guard comprises a tubular smooth 7 folded U and having two lateral branches 7a and a transverse core 7b. The end of each branch 7a is connected to a hinge part 8 which, in the embodiment shown is L-shaped and comprises, on the one hand, a vertical flange 8a, coming against the inner face of the corresponding upright 2 and by which it is articulated on an axis 9, and, on the other hand, a wing 8b, connected to the rail and extending outwardly by deporting the branch of this rail. With this, the interval E1 between the branches of the smooth and greater than that E2 between the uprights 2 and E3 between the rods 5, which increases the space for the passage of the user.

The hinge parts 8 are also used for fixing a section of rail 7c, closing the U of the rail and protecting the user from any fall between the ladder and its support.

Each of the two connecting rods 5 is articulated at its lower part 5a on an axis projecting transversely to the inside of the platform 4 and from the rear and upper edge of its side wall 4b.

The upper part 5b of the rod is connected to a collar 12 which is slidably mounted on the corresponding branch of the beam. In this form of execution, each collar 12 is connected to its connecting rod 5 by a transverse articulation 13 passing through, as shown in FIG. figure 3 , the wings of the rider and the cap 14 disposed at the end of the tubular connecting rod 5.

In the embodiment shown, this plug is part of the means ensuring the locking of the connecting rod 5, in its locking position of the bodyguard 6, means which also include, under each arm branch and near its core 7b, a notched corner back 15. The figure 3 shows that the wedge 15 to a thickness D which increases in going towards the soul of the smooth and towards the notch 15a of the plug 14.

In this embodiment, each arm branch 7a also has, in the vicinity of its articulation part 8, another wedging means and, for example, another notched wedge 25 with notches 25a intended to provide the temporary wedging of the rod 5 in the erasing position. As shown in figure 9 , the thickness S1 of this wedge, in its portion 25a providing the wedging, is greater than the functional clearance S2 between the connecting rod head 14 and the arm, to cause the upward straightening of the arm.

As the Figures 1 and 2 when the scale is observed from the rear, the upper parts 5b of the rods 5 flare upwardly and in particular towards the hinge 13, in order to have a spacing close to that E1 favoring the passage of the user when he / she gains access to the platform. This arrangement is added to the temporary lifting of the bodyguard to facilitate the passage.

The figure 6 shows an embodiment of the means used to maintain the front end of the platform when in use position. These means comprise near each of the uprights 2, a telescopic tie rod 16 composed of a tubular upper element 16a articulated on the hinge axis 9 and a lower element 16b. The latter is formed by a folded wire to form an upper loop 18 associated with a damping element and a lower attachment 19. The loop 18 is slidably mounted in the tubular upper element 16a, with guiding and stopping on the damping element by fingers 17, while the fastener 19 surrounds an axis 20 disposed on the upper front edge of the corresponding side wall 4b of the platform 4 and projecting inside the platform.

As shown in figure 6 when the platform 4 is in the deployed position, the loop 18 of each tie rod is supported on the stops 17 so that by the tubular section 16a this tensioner transmits the load that it receives from the platform 4 to the articulation 9 and the amount 2 correspondents.

In the folded position, the telescopic tie rods 16 occupy a very small footprint which facilitates the folding of the components of the ladder and contribute to reducing the size of it when it is brought into storage position.

The figure 4 shows that the axis of articulation of the connecting rod feet is arranged so that, when the platform is fully deployed in the working position with the rods 5 set on the rail, it is in front of a value S3 of the plane P containing the axes of articulation, respectively, 13 of the rods 5 on the guard and the platform 4 on its bar 3 by ensuring the self-locking of this platform.

For safety, the platform 4 is equipped with a means locking it in the deployed position and preventing its folding against the amounts without voluntary human intervention. In the embodiment shown in detail in Figures 7 and 8 these means are constituted by an elastically deformable strip 22 cooperating with the field 2a of one of the uprights 2. This strip is fixed against one of the side walls 4b of the platform 4 by rivets 23 and in such a way that at the end of deployment of the platform, its elastically deformable portion 22a, hitherto constrained in the gap S4 formed between the wall 4b and the inner face of the upright 2, escapes from this interval and elastically resumes its shape, just before its free end comes into abutment against the face 2a of the amount.

To unlock the platform 4 when the user has left and no longer bears on it, it is sufficient that it presses the fexible portion of the strip 22 to bring it back to the level of the interval S4, before cause the platform to fold down, in the direction of arrow 30 to the figure 7 .

Finally, to improve the safety of the user when he is standing on the platform, the two rods 5 are provided with a sub-smooth rear including two hooks 26 for a chain 27, which is unhooked at least on one side to allow access to the platform. Similarly, the upper elements 16a of the telescopic tie rods 16 are provided with a cross member 28, forming a smooth front.

The figure 5 shows that the arrangement according to the invention does not interfere with the folding of the elements against the amounts and, for some of them, between these amounts. It is in this configuration of the platform that the ladder is placed in a bearing position against a wall or a post and possibly stabilized by support legs and / or links clinging to fixed points.

When the user climbs the ladder after being put in place against a support, before he can use it and work at height, he must first deploy the platform 4 to bring it from its folded position, shown figure 5 , at his unfolded working position, shown figure 4 . Deployment is done communicating to the platform a pivoting movement around the bar 3 in the direction of the arrow 31 of figure 5 .

When the platform is substantially horizontal, the user verifies that the rods 5 are in the forward erasing position and access to the platform, as shown in FIG. figure 1 and, failing this, brings them into this position by sliding the jumpers 12 on the branches 7a of the rail 7. In this position the connecting rods 5 are close to the posts 2 and resting on the front blocks formed by the wedges 25, and in a configuration where their length causes the raising up of the rail 7 of the railing. Thus the guard much less gene the passage of the person accessing the platform through the smooth.

After installation on the platform and before any work, the user must bring back the connecting rods in their locked position of the platform, shown figures 2 and 4 , in which position the connecting rod head or its plug 14 is engaged in the notch 15a of the wedge 15. It is warned to have to carry out this action by the position of the rod 7 which is inclined upwards with respect to the position substantially horizontal that it must have in the working position and the need to close the undertray 27 supported, midway between the floor and the rail 7, by the connecting rods 5. At the end of this movement the workstation is totally secure.

Of course, it is necessary to proceed in the opposite way to leave the platform.

This platform arrangement can permanently equip the upper part of any ladder or part of scale, without the implementation on this ladder of additional support devices against a wall or a pole, as well as devices for anchoring and securing.

In the embodiment shown to Figures 10 to 12 the elements identical to those of the previous embodiment will have the same reference numbers, while the modified elements will have a number increased by 100 and the new elements will be referenced from 30.

This embodiment differs from the previous by the locking means of the rods 5 on the branches 107a of the smooth 107 and the general shape of these branches.

Indeed, and as shown by Figures 10 and 11 , each of the lateral branches 107a has the general shape of a V whose tip 30 is disposed at the hinge part 8 and above the hinge 9 of this piece on the corresponding upright 2.

When the collar 32, slidably mounted on the branch 107a, it is formed by folding a stainless steel wire, shaped to present two juxtaposed strands, both in its wings 32a that in its portion 32b surrounding the smooth.

Thanks to this arrangement, on the one hand, the wings 32a have a resilient return capability, which can bring them back into position when they are no longer subjected to a clamping force, and secondly, the collar is supported on the smooth by two generatrices spaced, which transmit well the clamping force on this smooth and ensure the setting of the rod 5 corresponding.

The clamping means are constituted by a threaded knob 33 whose threaded rod 34 is screwed into a nut 35 and passes through the flanges 32a of the collar. It also crosses the head 5a of the connecting rod 5 by constituting axis of articulation of this connecting rod with respect to the collar.

After being pressed against a wall or a post and deployment of the platform 4, the ladder has the configuration shown in FIG. figure 11 . In this position, the collars 32 are not tight and can slide on the branches 107a of the rail of the guard but are in abutment against the gussets 8.

Before entering the platform, the guard rail must be confirmed in the raised position of figure 11 , by pushing the upper part 5a of the rods 5, towards the front and according to the arrow 36, by pivoting about their hinges 10 with the platform. During this pivoting the trajectory of the collars 32 describes a circular arc which, thanks to the V-shape given to the branches 107a, tangents these branches and thus generates on each of the branches 107a an upward force, represented by F at the figure 11 . Under this force F, the arm is straightened by pivoting around the articulation 9, to come into the temporary erase position mounted to the Figure 11 .

When the operator has passed through the beam 107 and is on the platform 4, it pushes the rods 5 back to a position marked by a stop 37, reported or formed under each branch 107a. It then remains to manually actuate the threaded buttons 33, in the tightening direction of the collars 32, to ensure the setting in position of these collars 32 on the branches of the bar.

This embodiment adds human intervention in the process of wedging and shifting of the collars on the rail of the railing, but is not sensitive to mechanical failures of this wedging, as it may be the case by wear in a system automatic calibration.

Claims (11)

1. Ladder with permanent summit platform comprising:

   - firstly, a platform (4) articulated on a bar (3) with possibility of deployment forwards in the direction of the bearing zone,

   - secondly, a top guard rail (6) articulated at the top end of the uprights (2) supporting the bars, so that its stringer (7) can protrude rearwards, and

   - thirdly, connecting rods (5) for connection between platform (4) and guard rail (6) transmitting to the latter the deployment or closing movements communicated to the former,

   characterized in that the top end of each the two connecting rods (5) is mounted slidingly on the corresponding lateral branch (7a) of the stringer (7) of the guard rail, with possibility of occupying two positions:

   • a secure retaining position of the guard rail, in which it is immobilized at the rear end of the corresponding lateral branch (7a) of the stringer;

   • and a temporary withdrawal position in which this end is pushed forwards, close to the articulation (9) of the guard rail (6), while pushing the connecting rods (5) towards the front and while lifting up the stringer (7) of the guard rail, in order to clear away the access via the bottom to the platform (4).
2. Ladder with platform according to Claim 1, characterized in that each of the two lateral branches (7a) of the U-shaped stringer (7) is articulated on the upright (2) of the ladder by means of an articulation part (8) which shifts it to the outside of the space (E2) between uprights (2) giving to the space between branches (7a) a larger transverse dimension (E1) than the dimension (E2) between uprights, while each connecting rod (5), articulated in the bottom portion on a spindle (10) protruding inside the platform (4), comprises a vertical bottom portion (5a) extended by a top portion (5b) opening outwards up to its sliding connection (12, 13) on the branch (7a) of the stringer.
3. Ladder with platform according to Claim 1, characterized in that the means for immobilizing each connecting rod (5) in a position of retaining the guard rail (6) comprise, on the one hand, at least one notched wedge (15), attached under the branch (7a) of the stringer and close to its core (7b), and, on the other hand, the head (14) of the corresponding connecting rod (5) arranged so as to be able to be immobilized in the notch (15a) of the notched wedge.
4. Ladder with platform according to the combination of Claims 1 and 3, characterized in that the top end of each connecting rod (5) is articulated on the wings of a U-shaped strap (12) mounted so as to slide on the lateral branch (7a) of the stringer (7) of the guard rail (6).
5. Ladder with platform according to the combination of Claims 1 and 3, characterized in that each branch (7a) of the stringer (7) comprises, close to the articulation part (8), another notched wedge (25) ensuring the temporary immobilization of the connecting rod (5) in the withdrawal position, the thickness (S1) of this wedge (25), in its portion (25a) carrying out the immobilization, being greater than the functional clearance (S2) between the head (14) of the connecting rod and the stringer (7), in order to cause the straightening upwards of the stringer.
6. Ladder with platform according to Claim 1, characterized in that the means for locking the platform (4) in the deployed working position consist of a metal strip (22) of which the body is attached to one of the lateral walls (4b) of the platform (4) and of which the active portion (22a) is elastically deformable and is placed close to the corresponding upright (2) of the ladder, so as to be able to rest against the face (2a) of this upright, when the platform (4) is in the deployed position and, in the space (J) between this upright (2) and the lateral wall (4b) of the platform, when the latter is folded down.
7. Ladder with platform according to Claim 1, characterized in that the articulation spindle (10) of the bottom end of each of the connecting rods (5) on the lateral wall (4b) of the platform (4) is placed in such a way that, when this platform is fully deployed in the working position with the connecting rods immobilized on the stringer, it is in front of the plane P containing the respective articulation spindles (13) of the connecting rods on the guard rail (6) and (3) of the platform (4) on its bar, ensuring the automatic locking of this platform (4).
8. Ladder with platform according to Claim 1, characterized in that the front end of the platform (4) is held in the deployed working position by two telescopic tie-rods (16) each consisting:

   - of a tubular top element (16a), articulated on the articulation spindle (9) of the guard rail (6) on an upright (2),

   - and of a bottom element (16b), mounted slidingly in the first with limitation by a stop (17) of its extension travel, the bottom end of this element being articulated on a spindle (20) placed on the top front edge of the corresponding lateral wall (4b) of the platform (4) and protruding to the inside of this platform.
9. Ladder with platform according to the combination of Claims 1 and 8, characterized in that the bottom element (16b) of each telescopic tie-rod consists of a metal wire folded to form:

   - a top loop (18), by which it is slidingly mounted in the top tubular element (16a), with guidance and stopping on a damping element by through-fingers (17).

   - and a bottom fastener (19) with which it is articulated on the spindle (20).
10. Ladder with platform according to the combination of Claims 1 and 2, characterized in that the top end of each connecting rod (5) is articulated on the wings of a U-shaped collar (32) mounted slidingly on the lateral branches (107a) of the stringer (107), the said collar having an elastic return in the direction of the opening of its wings, while its clamping, ensuring the immobilization of the connecting rod (5) on the branch (107a), depends on the manual screwing of a threaded button (33) of which the stem (34) also forms the articulation spindle of the connecting rod (5) on the collar (32).
11. Ladder with platform according to Claim 10, characterized in that each of the lateral branches (107a) of the stringer (107) has a general shape of a V of which the point (30) is situated substantially above its articulation (9) on the upright (2).

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