FR2544775A2 - Spacer device for formwork element - Google Patents

Abstract

Spacer device for concrete wall formwork, making it possible to hold the boards at a constant separation, and to hold them while the concrete is poured. It comprises a rigid steel wire, in one piece, provided with bends at its ends, which form the loops A and A' intended to receive the keys which hold the formwork in the open position, and stop-pieces B and B' placed on the loops and which hold the formwork boards at a predetermined spacing h. The invention may be used advantageously on all types of small-panel formwork known on the market.

Description

Spacer device for formwork element.

The present invention relates to a distance device for shuttering element, in particular for the production of Breton works, and which comprises a metallic piece made in one piece of steel wire, comprising at each end a flat loop intended to receive a key for retaining the formwork elements, and plastic tabs, arranged in a plane perpendicular to the plane of the loops and placed at the front of said loops,
There are already known spacers of this type, in particular those described by the American patents 3 411 742, 3 544 059 and 1 924 630. retainers made by stamping sheet metal, of complicated design and costly manufacturing, This device is similar to the classic twist of iron wire used for generations to prevent the spacing of the formwork boards when the concrete is poured into it.

The second patent cited also describes a spacer comprising on the one hand a twisted wire and on the other hand, locking keys of extremely complicated design. In fact, these keys complementary to the spacer itself made of twisted wire , are made up of several machined metal parts, the manufacturing as well as the installation of which are very expensive,
The last patent cited relates to a spacer made in one piece by means of a bent metal rod. However, due to the shape of the folding, this distance must be achieved by means of a metal rod of relatively large diameter, to be able to withstand the pressures of concrete on the formwork during the casting operation,
Finally, French patent 80 04749 also consists of a steel wire, but of small diameter, and the stop tabs of which are produced by bending the end sections of the steel wire, foresaw the drawback when making automatic machine, not being able to effectively control the positioning of the stop tab in a plane perpendicular to the loop, due to the spring effect of the steel used
The pray additive to this basic patent defines the improvements and improvements proposed to obtain a light distance, resistant, and whose lugs are well perpendicular to the loops, while ensuring dimensional accuracy
For this purpose, the distance device according to the invention is characterized in that the end loops are completely closed, in that the stop tabs are formed by plastic parts of a special profile provided with a notch to be positioned on the inner sides of the end loops.

The present invention and its main advantages will be better understood with reference to the description of a preferred embodiment and of the accompanying drawings in which FIG. 1 represents a perspective view of the distance device according to the invention.

FIG. 2 represents in detail a type of stop tab according to the invention.

Figure 3 shows a schematic view of the distance device in place on a formwork.

With reference to the figures, the distance device, produced by bending from a predetermined length of rigid steel wire, comprises at each of its ends a loop A, respectively A ′, having a substantially rectangular shape, the sides being respectively a, b, c, d, and a 'b' c 'd'. The ends i and i 'are folded 180 around sectors a and a' to overlap the sides d and d '
In the example shown in Figure 1, the dimensions b and b 'can be rounded, However, it should be noted that they can also be rectilinear, the angles preferably being rounded to facilitate folding without breaking the friend steel wire When the distance device is placed on a formwork, the loops A and A 'are in a horizontal position (fig. 3).

The device also comprises two shank legs B and B ', in the form of shims arranged in a plane perpendicular to the plane of the loops A and A'. These stop lugs are constituted by plastic profiles of the impact PVC type, the section of which will be substantially rectangular, and provided with grooves e and e 'in their thickness. On the upper part f of the legs B, as well as on the lower part g, grooves are arranged in order to allow better attachment of said legs in the concrete flush with the formwork.

The fixing of the stop lugs B and B 'on the loops A and A' is done at the level of the superimposed cooked i and d, respectively i 'and d', which are housed in the grooves e and e ', thus ensuring a precise and square positioning of legs B and B '.

These stop lugs can have any geometric shape, in particular an oval or circular profile, provided with grooves to allow fixing on the loops A and A '.

FIG. 3 represents a detailed view of part of a formwork which is assembled by means of spacers as shown in FIG, 1.

The formwork boards 1 and 3 are supported against the stop lugs
B and B 'and are held in place by reinforcing bars 2 or fixing pins, which are placed in the loops A and A'. As shown in this figure, the formwork boards are maintained at a spacing gives h which determines the thickness of the finished concrete wall.

The stop tabs B and B 'come to bear inside the boards and guarantee their constant spacing. On the loops A and A ′ which protrude from the formwork, the reinforcing bars 2 are placed ensuring the rigidity and the retention of the boards 1 and 3, so that they do not move apart when the concrete is poured.

When the setting of the concrete has taken place, we proceed to the formwork removal, by removing the keys 2 from the loops A and A ', which also makes it possible to remove the formwork boards 1 and 3. After this operation, the loops A remain and'A 'perpendicular to the wall and the stop legs B and B' embedded flush with the wall in the concrete mass. It suffices to cut the loops A and A 'as close as possible to the wall, using a pliers of the "bolt cutter" type for this purpose, to release the loops A and A'. Only the locking tabs B and B ', as well as the straight rod of the distance gauge which
initially separated, remain in the concrete.

The industrial production of these spacers will advantageously be done by a succession of bends of a rigid steel wire by means of a
automatic machine provided with a mechanized feed for the placement of bait bars B and B 'on loops A and A'
The embodiment of this distance allows a device with a weight close to 40 grams for a distance of 20 centimeters.

Given the large number of these accessories used to mount a formwork, one will understand the savings made and the convenience of handling these parts. Compared to known spacers, which for some require the production of stamped metal sheet parts leading to a spacer whose average weight is of the order of 150 grams, it will be understood the economy achieved by the use of spacers according to the invention . Its moderate cost price, the simplicity of its installation and the ease with which the user can remove the visible parts, constitute other appreciable advantages of the device according to the invention.

Claims (2)

Claims 1. Spacer device for formwork element, in particular for the production of concrete structures, comprising a metal part made of a single piece of steel wire, comprising at each end a flat loop, intended to receive a key for retaining the formwork elements, and the attached locking tabs> arranged in a plane perpendicular to the plane of the loops and placed at the front of said  loops, characterized in that the end loops are fully closed, in that the stop tabs each consist of a spacer which is extended on the flat loops, and which straddles the inner sides of the flat loops0 2, Device according to claim 1, characterized in that the end loops have a substantially rectangular shape with rounded angles facilitating folding.  3. Device according to claim 1, characterized in that the stop tabs are advantageously made of plastic of the kind PVC resistance shock 135/140 Kg / mm2. 4, Device according to claims 1 and 3, characterized in that the stop tabs are obtained from a profile in the shape of a rectangular parallelepiped provided with a groove to allow the wise setting on the sides of the end loops , and provided with grooves on the upper and lower parts to allow better attachment in concrete. 5. Device according to claim 4, characterized in that the profile of the stop lugs can have a different geometric shape, for example, oral round, or squareS provided with grooves for crimping on the inner sides of the flat loops 6, Device according to claim 1, characterized in that the steel wire has a diameter between 2> 5 millimeters and 3.5 millisneters, and a tensile strength greater than 150 Kg / mm2.