EP1857612A1

EP1857612A1 - Protective provision for wide slab building methods

Info

Publication number: EP1857612A1
Application number: EP06076070A
Authority: EP
Inventors: Petrus Johannes Lambertus De Leeuw
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-05-18
Filing date: 2006-05-18
Publication date: 2007-11-21

Abstract

The invention relates to a safety precaution in the form of a railing (4, 5) to be displaced simultaneously with the wide slab (1), in which the construction workers (8) are optimally protected against falling to an underlying level, in which the wide slabs (1) will simultaneously be centered exactly between the bearing walls (6) owing to the special embodiment of the railing (4, 5) having single-sidedly slanted locators (7) with guiding plates (12).

Description

The invention relates to a safety precaution serving as fall protection, comprising temporarily mounting a catching structure along the edge or edges of a wide slab to be placed, or prefab concrete slabs in general in rough structures, in which the wide slab is part of a floor structure, spanning the space between two spaced-apart bearing walls, beams or columns.
In building houses and offices one often employs wide slab floors for making concrete flooring. The wide slabs are supplied by truck and with the help of a crane, the slabs, connected to one another, are laid on a temporary supporting structure, consisting of struts with binders. In order to get the slabs on the proper location, before laying them down, they are guided by two persons, who are at said wide slab. Up to now, this work is practically always done without consideration of the statutory safety regulat-ions. After all, when working at heights near open floor edges, these floor edges should be protected or, if this is technically not possible, persons should be working while attached to a cable. Working while attached to a cable is an option, which is only acceptable in exceptional situations, because in such a situation the method is highly unreliable. Furthermore, attachment to a cable is cumbersome to the user, which is an additional disadvantage to proper functioning.
In practice, a method is known in which the slabs are provided with temporary guard rails on the truck, whereupon the slabs are hoisted in. The workers on the floor then demount the railing from the preceding wide slab and put this in a special chest, which is suspended below the crane hook, for returning it to the truck, in order to be installed anew. Needless to say, that this method is very cumbersome and strongly extends the operational time of the crane, and thus, for economic reasons this method is not used.
In another method, which did not come beyond the experimental stage either, safety nets are employed, which are suspended across of below the binders. This method too, is very laborious, and furthermore has the disadvantage, that connecting rods situated high in the structure could cause serious injury if a person would fall, by the net springing back. In the procedure of laying down the wide slabs, while hanging from the crane, the persons standing on the floor direct the slabs to the correct location. On command, the crane operator pays out the cable, thus locating the slabs onto the binders. This is foremost a question of proper timing because a horizontal movement of the wide slab as a result of its great mass will lead to an incorrect positioning. Here, experience and good cooperation between the crane operator and the people on the floor are extremely important.
The invention aims to remove above-mentioned difficulties and to provide a temporary safety precaution along the edge or edges of a rectangular wide slab, sufficiently protecting the falling curve of an employee and can be incorporated in the laying procedure of the wide slabs in an economically sound way.
To this end, the safety precaution is embodied as a temporary catching structure and can be moved together with a next wide slab to be laid down, characterized in that said catching structure is positioned along at least one edge of a previously positioned wide slab and can subsequently be elevated with the edge or edges of the next wide slab to be laid, and be displaced together to the next laying position of the next wide slab concerned.
The advantage is that the construction workers on the floor to be laid need not demount a catching structure and then mount it again on the next wide slab width time after time, which takes much time and thus is economically not feasible. Further, the safety precaution according to the invention is characterized in that said catching structure consists of a railing provided with engaging members for bearing on the foremost longitudinal edge of said next wide slab during displacement.
The advantage is that with one and the same movement of the crane, the railing together with the wide slab will end up at the correct position.
Then, the safety precaution according to the invention is characterized in that said railing is also mounted on one or both head ends of the wide slab, the railings at the head ends of the wide slab being telescoping.
The advantage is that a lateral or head guard of the slab edge arises and that it is automatically elongated by the width of the wide slab.
Further, the safety precaution according to the invention is developed further, characterized in that the plane of the railing encloses an angle β with the almost horizontal plane of the wide slab, said angle β being between 60 and 180 degrees.
The advantage is that for the position of the railing, its height can be adapted to the falling curve X more easily.
Then, the safety precaution according to the invention is developed further, characterized in that said catching structure is also provided with single-sidedly slanted locators for centering the next wide slab exactly between bearing walls or beams concerned.
The advantage is that on lowering them between the bearing walls or beams, the wide slabs will be centered without any additional effort, allowing the operation to go faster and more accurately.
Hereinafter, the invention is explained further by way of a preferred embodiment, illustrated in the drawing, in which:

figure 1 shows a perspective view of a partly laid wide slab floor having a safety precaution, in the form of a railing, according to a preferred embodiment of the invention;
figure 2 shows the falling curve X to be guarded by the safety precaution according to the invention;
figures 3A - 3D show side views of stepwise laying of the successive wide slabs together with the safety precaution, in the form of a railing, always along the edges of the preceding and following wide slab, according to view III of figure 1;
figures 4A - 4F show possible vertical cross-sections and positions of the railing having engaging members of the safety precaution according to the invention;
figures 5A - 5C are side views of the single-sidedly slanted locators fastened to the catching structure consisting of a railing for centering the wide slab to be laid between the bearing walls, beams or columns.

Figure 1 illustrates a perspective view of a partly laid wide slab floor, comprising wide slabs 1 on the temporary supports, consisting of beams 2 and struts 3. Along the edges, where one could fall from the building, a safety precaution in the form of a temporary railing 4, 5 has been mounted. The wide slabs 1 should be centered between, in this case, the bearing walls 6 with the single-sidedly slanted locators 7, as indicated in detail in figures 5A through 5C. The construction workers 8 should pull the wide slabs 1 against one another during the displacement and laying procedure, indicated in the figures 3A through 3D. A scaffold 9, partly illustrated, is positioned at the rear side. In a subsequent stage, the wide slabs 1 are provided with a layer of concrete, so that a reinforced or prestressed concrete floor is created by the reinforcement or prestress present in the wide slabs 1. The foremost railing 4 can be taken up by the next wide slab 1 to be laid and together with that wide slab 1 be displaced to the next position time after time. The lateral railing 5 can at the same time be displaced with it and be provided with a telescoping railing 10.
Figure 2 illustrates the falling curve X for construction workers 8 which is to be guared according to the rules and regulations. The safety precaution in the form of a railing 4, 5 should always extend up to the falling curve X indicated.
Figures 3A through 3D show in side view stepwise laying and simultaneous displacement of the railings 4, 5. In order to effect this, engaging members 11 are mounted at the railings 4 and 5, as cleary seen in figures 4A through 4F and thus can be manufactured or constructed in different shapes, depending on the vertical railing profile. Railing 4, 5 can have various shapes or vertical profiles, as can be seen.
In figures 4A through 4C, an open railing 4, 5 of e.g. tubular sections has been made for the angle β situated between the values of 60 to 100 degrees.
In figure 4D, the railing 4 for angles β situated between 100 and 180 degrees is provided with a gauze netting.
Figures 4E and 4F illustrate a suitable plurally bent vertical railing 4 so as to avoid further existing obstacles in rough construction during laying of the wide slab 1.
In figures 5A through 5C, the single-sidedly slanted locators 7 are shown fastened to the railing 4. The single-sidedly slanted locators 7 locate the railing 4 with the wide slab 1 between the indicated bearing walls 6. After that, on lowering, the wide slab 1 will slide exactly into the centered position between the bearing walls 6.
Finally, it should be clearly stated, that preferred embodiments of the invention have been described above and that obviously further modifications and the like are possible, without departing the scope of the present patent.

Claims

Safety precaution serving as fall protection, comprising temporarily mounting a catching structure along the edge or edges of a wide slab (1) to be laid, or prefab concrete slabs in general in rough structures, in which the wide slab (1) is part of a floor structure, spanning the space between two spaced-apart bearing walls (6), beams or columns, characterized in that said catching structure is positioned along at least one edge of a previously positioned wide slab (1) and subsequently can be elevated with the next wide slab (1) to be laid and be displaced together to the next laying position of the next wide slab concerned.
Safety precaution according to claim 1, characterized in that said catching structure consists of a railing (4, 14, 24) provided with engaging members (11) for bearing on the foremost longitudinal edge of said next wide slab (1) during displacement.
Safety precaution according to claim 2, characterized in that said railing (5) is also mounted on one or both head extremities of the wide slab (1).
Safety precaution according to claim 3, characterized in that the railing (5, 10) is telescopic at the head extremities of the wide slab (1).
Safety precaution according to claim 1, characterized in that said catching structure comprises a horizontally projecting platform (14) having engaging members (11) for bearing on the edge or edges of said next wide slab (1) for the purpose of displacement.
Safety precaution according to claims 2-4, characterized in that the plane of the railing (4) encloses an angle β with the almost horizontal plane of the wide slab (1), said angle β being between 60 and 100 degrees.
Safety precaution according to claims 2-4, characterized in that the plane of the railing (14) encloses an angle β with the almost horizontal plane of the wide slab (1), said angle β being between 100 and 180 degrees.
Safety precaution according to claims 2-4, characterized in that the plane of the railing (24) has a plurally bent vertical course, in which the heigth of the engaging members (11) H is variable, said height H being approximately 0.50 m.
Safety precaution according to claim 1, characterized in that said catching structure is also provided with single-sidedly slanted locators (7) having guiding plates (12) for accurately centering the wide slab (1) to be laid between the bearing walls (6), beams or columns concerned.