EP1057967B1 - Stepstool or stepladder with a mid-articulated platform - Google Patents

Abstract

The step ladder, consisting of a stile (1) with rungs (3) and a prop (5) which deploys to support the stile when in operation and folds against it for storage, has a top platform (7) in two hinged halves (7a) which deploy and fold together with the stile and prop. In the storage position the two halves of the platform are folded together and in line with the stile and prop, while in the deployed position they pivot about a rod (9) along their undersides, so that the platform is locked by the facing edges of the two halves. The two halves of the platform are identical and basically flat, being made from extruded metal alloy, e.g. aluminium.

Description

The invention relates to a stepladder or step provided with a platform articulated in the middle. Such a stool is known from DE 88 07572U.

Stepladders or steps are also known whose upper platform articulated to the stand plane is locked in the horizontal operating position to the plane of climb by means of a hook engaged on the plane of climb, or by means of a lower tie rod, which further allows the tilting of the platform in the folded out of service position. These mechanisms are not rigid, subject to play and low mechanical strength. They require more for stepladders at a certain height lower straps for maintaining the opening of the plans fixed on their uprights.

The object of the invention is to provide a platform of good strength and mechanical rigidity and which does not require lower straps for maintaining the plans and which allows to guarantee the blocking of service of the platform.

It is indeed proposed according to the invention a stepladder or step according to claim 1.

Thus, to ensure the locking of the closure of the platform in the operating position and prevent inadvertent opening, there is provided a low angle of depression on the platform plane (2 to 5 °) or an angle of upper platform section alignment equal to about 175 ° to 178 °.

Advantageously, said platform portions are hinged at the middle portion of the formed platform service plane and at the same height on each of the rise and sill planes. In addition, said platform portions may be identical, substantially flat and extruded from metal alloy, aluminum for example.

They are each articulated on an upright axis or on a connecting rod of the uprights, respectively of the stand plane and the plane of rise, without protruding outwards beyond this rod or the respective plane to prevent the possibility of creation of a couple by the operator may open unexpectedly the platform (folded upwards).

Said articulation rod is advantageously mounted in the lower legs of the half-platforms, formed regularly below them along the width of their edge and with intersecting of one to the other.

• la figure 1 est une vue en perspective partielle d'un marchepied selon l'invention, en position de service ;
• la figure 2 est une vue en coupe transversale médiane partielle du marchepied en position de service ;
• la figure 3 est une vue en coupe transversale médiane partielle du marchepied en position repliée hors service, et
• la figure 4 est une vue en perspective de dessous de la plate-forme seule.

The invention is illustrated below with the aid of an exemplary embodiment and with reference to the appended drawings in which:

• Figure 1 is a partial perspective view of a step according to the invention in the service position;
• Figure 2 is a partial cross sectional view of the step in the operating position;
• Figure 3 is a partial partial cross sectional view of the step in the folded out position, and
• Figure 4 is a perspective view from below of the platform alone.

As represented in FIGS. 1 to 3, the step according to the invention essentially comprises a front climbing plane 1 provided with steps 3, a rear landing gear plane 5 hinged at its upper end to the climbing plane 1, and a platform service 7.

This platform 7 of rectangular format has a width substantially equal to the (identical) distance between the respective amounts 1a; 5a two by two of each of the rise planes 1 and 5, and a length equal to the distance between two lateral uprights 1a, 5a adjacent, open service position and the platform height.

It consists of two identical parts or half-platforms 7a. These are flat, extruded aluminum. They substantially aligned with each other in the service position to form said platform.

The half-platforms are hinged to each other at the median level of the step on the median vertical plane P of the step (FIG. 2) and on the other hand, at each of the landing gear 5 and the climb 1 planes, respectively, by their outer edge end 7b.

The medial joint (see also Figure 4) is achieved by means of a rod 9 extending over the width of the coupled half-platforms 7a. This rod is received in tabs 7c forming a hinge bearing of the rod and arranged regularly over the width and under the edge of each of the half-platforms. The tabs 7c are spaced apart from each other by their own width so as to allow them to intersect with the coupling of the half-platforms.

The rod 9 thus forms the lower hinge axis of the two half-platforms 7a. These abut against each other by their singing before 7d in the open position. In this position, they are substantially in alignment with each other to form the service plan of the platform 7 of the step.

In addition, it is advantageous to provide a slight upper depression so as to lock the platform opening (upper alignment angle half-platforms 7a equal to about 175 ° to 178 °). Thus, any approximation of the stand and climb planes can not induce an upward force on the half-platforms in order to fold them.

The locking of the opening of the medial joint can be achieved by an attached insert (not shown) such as a hook connecting the two half-platforms or a leg of a half-platform turned against the other half-platform to lock.

The external articulation of the half-platforms is carried out using a rod 11 connecting the uprights 1a; 5a two by two each of the planes of rise and crutch. This rod is mounted through and free to rotate at low backlash along the outer edge end 7b of each of the half-platforms. The outer edge 7b is rounded without protruding outside the plane, so that the operator can not leverage on this edge to inadvertently fold the platform.

The closed off position of the step with its folded platform is shown in Figure 3. In this position, the plans of Mount 1 and stand 5 are folded substantially in alignment with each other and likewise the half-platforms 7a are folded upwards.

To reach this position, it is sufficient to manually raise the platform 7 in the middle on the underside, with one hand, while the stand and climb plans are pushed towards each other by the other hand. . As soon as the half-platforms 7a have begun a slight rotation, the closing is carried out automatically by bringing the planes 1, 5 back to each other.

Conversely, the opening is obtained automatically by pulling one of the planes 1 or 5 spaced from the other, the opening of the platform 7 being developed simultaneously with that of the plans 1, 5. It is sufficient to slightly exceed aligning the half-platforms 7a and reaching said locking recess, so that the service position is reached.

It will be noted that the crutch and climbing planes are doubly articulated, first at the upper level as the standard running boards, and secondly at the platform following an articulated triangle isosceles (in vertical cross section) whose vertices are respectively the upper articulation of the planes and the articulations of the platform, itself articulated in the middle, with the plans of crutch and rise, respectively. It follows a good rigidity of connection of the steps of the step that allows him to support heavy loads safely.

Claims (7)

1. A stepladder or pair of steps comprising a stile (1) and a prop (5) hinged together at the upper level, and an upper service platform (7), said platform (7) consisting of two parts (7a) hinged, on the one hand, opposingly to one another and, on the other hand, each respectively to the stile (1) and to the prop (5), in such a way that, when out of use, the two platform parts (7a) are folded one towards the other, substantially in alignment with the stile (1) and prop (5) brought towards one another, and that when in use they are opened out substantially flat and locked in place relative to one another, characterised in that the platform parts (7a) are hinged to one another by a lower rod (9) extending under their edge and held axially over their width, a closing stop being provided when in use by their narrow front edges (7d), which narrow edges (7d) are applied against one another above said hinge rod (9), and in that, to ensure that the platform is locked closed when in use and to prevent untimely opening, there is provided a slight hollow angle in the plane of the platform of 2 to 5° or an upper alignment angle of the parts of the platform equal to approximately 175° to 178°, said hinge rod (9) being mounted in lower brackets (7c) of the half-platforms, formed regularly under each one thereof over the width of their edges, in criss-cross arrangement for coupling together of the half-platforms.
2. A stepladder or pair of steps according to claim 1, characterised in that said platform parts (7a) are hinged together at the level of the median part of the platform service plane (7) formed.
3. A stepladder or pair of steps according to one of the preceding claims, characterised in that said platform parts (7a) are hinged at the same height to each of the stile (1) and the prop (5).
4. A stepladder or pair of steps according to one of the preceding claims, characterised in that said platform parts (7a) are identical.
5. A stepladder or pair of steps according to one of the preceding claims, characterised in that the platform parts (7a) are substantially planar, formed by extrusion of a metal alloy.
6. A stepladder or pair of steps according to one of the preceding claims, characterised in that said platform parts (7a) are each hinged to an upright axis or to a rod (11) connecting the uprights, respectively, of the prop (5) and of the stile (1), without projecting outwards beyond said rod or the stile or prop respectively in order to prevent the untimely generation of torque by the operator which might open the platform, folding it upwards.
7. A stepladder or pair of steps according to one of the preceding claims, characterised in that the prop (5) and stile (1) are doubly hinged, firstly at the upper level like conventional steps and secondly at the level of the platform, forming in cross-section an articulated isosceles triangle, the apices of which are respectively the upper hinge of the planes (1, 5) and the lower points of which are the hinges (11) of the platform (7), which is itself hinged together in the middle with the prop (5) and stile (1) respectively.

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