FR2930573A1 - Reusable device for adjusting concrete formwork board during e.g. curing of concrete, has arms respectively provided with U-shaped iron sections having soldered ends, where position maintenance of arms is ensured by threaded screw - Google Patents

Abstract

The device has a male arm (1) and a female arm (2) made of iron and respectively provided with U-shaped iron sections (3, 4) with soldered ends. Position maintenance of the arms is ensured by a threaded screw (5) that is introduced in a hole (8) traversing the arms, where the screw is maintained through a nut (6). The arms exert pressure on concrete formwork boards (A, A') via the iron sections, where the pressure opposes pressure exerted by a clamp (C) to ensure stability of a formwork structure and to suppress sinking risk of the structure.

Description

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The present invention relates to a device for wedging the formwork planks during casting and setting concrete. For some types of formwork, the establishment and maintenance of wooden planks is usually carried out on the one hand using clamps, pressing on the outer part of the planks according to the formwork; and on the other hand using calibrated wooden spacers - width of the formwork to be made - nailed to the planks and putting pressure on the inner part of the planks according to the formwork. The force exerted by the clamp on the planks is antagonistic to that of the spacers which locally allows the structure not to collapse. The successive installation of the device clamps and spacers calibrated along the wooden beams - every 50 to 80 centimeters - then ensures the maintenance of the overall structure during casting and setting concrete. So far, it is up to the user to make himself beforehand its spacers. Calibration of the spacers, according to the width of the formwork to be made, must be carried out in a precise manner so as to guarantee no risk of sagging of the formwork structure during pouring and setting of concrete, sagging due to divergences width along the planks and vibratory forces put into play during the casting. In addition, the use of each of the spacers is unique: in fact, the casting is carried out initially up to the height of the spacers placed in the enclosure of the formwork, the concrete takes a first time thus putting pressure on the inside the planks according to the formwork, it then replaces the spacers that can be removed to pour the concrete to the desired height, without taking any risk of sagging the structure of the formwork. The damage caused by their removal and the deposition of concrete make them unusable a second time. Since the spacers are made of wood, the tool then possesses the disadvantages incumbent on the material, which may be non-exhaustive: dilations and shrinkages subjected to variations in temperature and humidity, acting on the stability of the structure, bulky storage slats, risk of injury and loss of time related to the calibration and cutting phase. The device according to the invention makes it possible to remedy the manufacture of the spacers. It comprises two iron u in which are placed the planks, the distance between these u can be adjusted according to the width of the formwork by the two telescopic iron arms constituting the device, each u being connected to an arm. The maintenance of the distance between the u - and moreover between the planks - is ensured by a through hole -2-

the two arms from one side into which is inserted a locking pin. Several through holes placed on the two arms are provided to meet the standard dimensions of formwork width to achieve. In addition, unlike the wooden spacers, the device is placed outside the cavity where the concrete will be poured, at the upper edge of the planks.

This then makes it possible to carry out the pouring of concrete in one go and to easily remove the device after setting the concrete for later use. Compared to the current technique, the device according to the invention offers a saving of time and safety by eliminating the redundant tasks related to the phase of manufacture of the spacers and allowing a single concrete pouring.

The accompanying drawings illustrate the invention: FIG. 1 represents the device of the invention according to its male side. Figure 2 shows the device of the invention according to its female side. Figure 3 shows in section, the device in its entirety as it is set up to ensure the maintenance of the planks. In these drawings, the formwork planks are indicated by (A) and (A '), the material (agglos, bricks, blocks, etc.) on which the concrete casting by (B) is carried out, the clamp by (VS). With reference to these drawings, the device comprises two iron arms (1) and (2) each provided with iron (3) and (4), welded at their ends. Holding the two arms (1) and (2) in position relative to one another is ensured by the presence of a threaded screw (5) inserted into the holes (8) passing through the two arms (1). and (2) and held with the nut (6) welded to the female arm (2). The plug (7) is placed at the end of the screw (5) and forms a rigid whole with it to allow easy clamping manipulation.

According to Figure 3, the clamp (C) presses the planks (A) and (A ') against the material (B). The planks (A) and (A ') then exert pressure on one face of each of the two u (3) and (4). Maintaining the separation of the two arms (1) and (2) under the pressure of the clamp (C) is then ensured by the presence of the threaded screw (5) which opposes a counter pressure of the same value as that of the clamp.

By way of non-limiting example, the bad (1) and female (2) arms are 175 mm long. The wrong arm (1) has an inner square section of 20 x 20mm2 while the female arm (2) has an inner square section of 25 x 25mm2. The dimensions of u (3) and -3-

(4) are 35mm by 35mm and offer a 29mm pass between their two opposite sides for the passage of planks. The arms (1) and (2) and the u (3) and (4) are made of iron 2mm thick. The diameter of the screw (5) must be sufficient to withstand the shear force exerted by the clamp (C) thereon. The length of the screw (5) must be sufficient to pass right through the female arm (2). The diameter of the nut (6) depends on the choice of the diameter of the screw (5). The diameter of the hole (8) is to be 1 mm greater than that of the diameter of the screw (5) to allow its passage through the male arm (1) and the female arm (2). All components of the device receive an anti-corrosion treatment to ensure their use over time. The device according to the invention is particularly intended for the realization of concrete formwork.

Claims (5)

Claims 1) Reusable device for wedging formwork planks (A) and (A ') characterized in that it consists of a male arm (1) and a female arm (2), both of iron and each provided with an u (3) and (4) iron welded at their end 2) Device according to claim 1 characterized in that the screw (5) provided with a socket (7) referred to the nut (6), passing through the hole (8), the arm (1) and the arm (2) makes it possible to exert pressure on the planks (A) and (A ') via the iron u (3) and (4) which is antagonistic to the pressure exerted by the clamp (C) then ensuring locally the stability of the structure of the formwork and eliminating the risk of collapse thereof. 3) Device according to claims 1 or 2 characterized in that the presence of through hole (8) is effected at various locations along the length of the arms (1) and (2) depending on whether the spacing of the two u (3) and (4) correspond to standard widths of the material (B). 4) Device according to the preceding claims characterized in that all the components have received an anti-corrosive treatment 5) Device according to any one of the preceding claims characterized in that the plug (7) can receive a non-slip cladding.