HUT62364A - Steel mat unit for producing reinforced concrete products and method and apparatus for producing same - Google Patents

Abstract

The invention relates to an assembly of reinforcing elements for reinforced concrete products, this assembly comprising a plurality of spaced-apart rigid transverse reinforcing elements (12) and at least two longitudinal flexible elements (14) joined to the transverse reinforcing elements in order to keep them spaced apart at chosen intervals. An assembly is thus obtained which may be easily packaged. The invention also relates to a method and a device for manufacturing this assembly of reinforcing elements. <IMAGE>

Description

The present invention relates to a steel mesh element for the production of reinforced concrete and to a method and apparatus for producing it.

It is known to use a welded mesh for reinforcing concrete slabs, consisting of two steel mesh superimposed and superimposed at welding points 70482-2244 KH / h.

This type of reinforcement is well suited for concrete products where the applied mechanical forces act in two orthogonal directions, which means that they are bidirectional.

In contrast, this type of reinforcement has the disadvantage that it is poorly applied to concrete products where the mechanical forces to be applied act only in one direction, ie unidirectional, or where the forces have already been applied in another direction by another reinforcement. This is the case for prestressed reinforced concrete, which contains prestressed reinforcement or reinforcements, which have already been applied in one direction. In these special cases, the role of one of the two ironing nets is solely to keep the other net at a given distance. It follows that one of the two reinforcing nets is superfluous in terms of the mechanical strength of the reinforced concrete product.

Another disadvantage of classically welded nets is that they are extremely space-consuming in transportation, handling and storage. This defect occurs either in sheet form or in coiled form in the welded mesh. In the latter case, the stiffness and thickness of the reinforcements placed along the length of the roll do not allow for optimization of volume or placement.

In addition, classically welded nets are usually prefabricated in the factory with extremely heavy equipment, in predetermined dimensions, which does not allow the user to optimize the amount of steel, and also requires on-site cutting and many operations, tab is required for the same user location. It follows that there is a loss of material and a loss of human labor.

Finally, a further disadvantage of classically welded nets is that they are often not smooth enough and, in view of the stiffness of the irons connecting the reinforcements, it is necessary to make compressed anchors when inserting the net.

It is an object of the present invention to provide a steel mesh element which eliminates the aforementioned deficiencies and which can be used generally as a distribution reinforcement for conventional reinforced concrete walls.

It is another object of the present invention to provide a steel mesh element which is extremely well suited for reinforced concrete elements in which the mechanical forces to be applied act only in one direction or where the mechanical forces have already been applied in one direction by other reinforcements.

It is therefore an object of the present invention to provide a steel mesh element particularly suited for prestressed concrete products. It is also an object of the present invention to provide a steel mesh element which is not too bulky during transport, handling or storage, which is easy to cut during placement and has a smooth surface.

According to the present invention, this object is solved by one web having a plurality of rigid transverse steel inserts spaced apart, while the other web comprises at least two longitudinal elastic members spaced apart according to a selected spacing. are connected to transverse steel inserts of the front mesh.

• * · «

Preferably, the transverse steel inserts are generally straight steel bars held in parallel by resilient members, which allows the steel mesh element to be disposed in coil form.

This steel mesh element is expanded in the form of a mesh formed of steel inserts and elastic fasteners attached to each of the incisions. The width of the mesh is determined by the length of the steel inserts, while the length of the mesh is adjustable for use, it is sufficient to cut only the elastic members to the desired length. The distance between the steel inserts and the distance between them the gradation may be constant or variable depending on the mechanical forces to be applied.

The steel mesh element thus has many advantages over conventional welded meshes.

In the case of transverse reinforcements consisting of steel inserts, the structure can be stored in a roll form. This roll facilitates transportation and takes up less space than the welded mesh with the same amount of useful ironing. In fact, the flexible elements take up less space than the steel elements they are replacing and also have a much lower weight. They also allow the net to be wound onto a small diameter drum. Such a placement facilitates storage and handling at the point of use.

In addition, the positioning of the steel mesh element becomes easier after it is sufficient to unwind the mesh, because the elastic elements do not exhibit any resistance to unwinding. After unscrewing the steel mesh element, the flexibility of the fasteners allows the reinforcements to be flush with the force of gravity, which reduces or eliminates fastenings.

- 5 thus saves a great deal of manual power.

In addition, the geometry of the net (length, width, spacing between transverse reinforcements) can be perfectly adapted to the application and mechanical forces. This allows us to optimize the amount of steel used and reduce losses.

Another advantage of the invention is that the longitudinal elastic members are much less expensive than the steel inserts they replace.

Finally, the steel mesh element of the present invention can be manufactured with a simpler apparatus than conventional welded mesh.

The steel mesh element according to the invention can also be implemented with non-linear elements, when in the unrolled state the element appears in a non-mesh form. In this case, the element is not stored in the form of a coil, but in the form of a bellows, in which the longitudinal steel inserts are brought together.

The elastic members used to manufacture the steel mesh element of the present invention may be iron wire, twine, tape, metal or plastic tape or the like.

In a preferred embodiment of the invention, the elastic member comprises at least one plastic tape, preferably polypropylene. Preferably, each resilient member consists of two strips which are spot-welded on both sides of the steel insert, for example one strip is sticky and the other strip is sticky or precise.

The present invention also relates to a method for producing a steel mesh element, the method comprising:

- unwrapping elements of equal length from a container so that they can be parallel to each other at the connecting station.

• · ♦ ·· · ·

- the steel inserts are placed transversely to the flexible members at the connecting station,

- connecting a steel insert to the flexible elements,

- moving the elastic members forward by a division which carries with it the steel insert previously bonded thereto, and

- we will start this operation again for the other steel inserts.

The connection will, of course, depend on the nature of the elastic elements used and may include knotting, gluing, ultrasonic welding, heated blades, stapling, etc.

In the case where each resilient member is a strip of two plastics, an upper strip fed from an upper unwinding drum and a lower strip fed from a lower unwinding drum, the two strips are welded to each other on both sides of the steel insert to be joined.

The welding is preferably carried out by means of ultrasonic devices which are located at the connection points.

After connecting a steel insert, for example. welding, it is sufficient to advance the mesh by one pitch by unwinding the elastic members so that the value of the pitch can be controlled. Subsequently, the formed mesh can be simply wound onto a reel.

The invention also relates to an apparatus for producing the aforementioned steel mesh element. The essence of this is that it comprises elements for transporting a connecting station and elastic members of equal length and conveying them parallel to the connecting station, preferably a winding drum, and steel inserts transverse to each other in the connecting member. * * * ♦ · • ·. · * * ♦ ··· ♦ ··· ♦ ··

- In 7 recesses, the distributor for the flexible elements and the means for advancing the flexible elements by a split, preferably tweezers, to carry with them the previously inserted steel insert.

Preferably, the coupling station is provided with a coupling head corresponding to the elastic members to be connected to the steel inserts.

Preferably, each resilient member comprises at least one web of plastic, preferably polypropylene, and each connecting head is provided with a welding device, e.g. equipped with ultrasonic welding equipment.

In a preferred embodiment of the present invention, where each elastic member comprises two plastic tapes, the feed means comprise two unwinding drums for each elastic member, which can receive the lower and upper web. This allows the two strips to be stacked on top of each other before welding to encircle the steel insert before joining. The welding is then performed on both sides of the steel insert for a specified length.

According to a further feature of the present invention, each winding drum is provided with a brake which includes a lever and is provided with a baffle disc around which the belt is wound such that the brake is released when the belt is subjected to tensile force and locked when the tensile force is released.

Preferably, the apparatus comprises four pairs of unwinding drums, which allow four elastic members to be joined, each of which is formed by superimposing two tapes.

Preferably, the conveying means comprise horizontal, movable clamps which can grasp the flexible members in front of the connecting station to move the entire steel mesh element in one increment.

Preferably, the apparatus has a fixed stop and an adjustable stop which is associated with each of the tweezers to control the transmission split between the two successive steel inserts.

In the case where the apparatus is used to produce a steel mesh element consisting of straight transverse steel inserts, it also comprises a receiving drum on which the mesh thus formed is wound.

The invention will be described in more detail with reference to the drawings, which are exemplary of the invention. their embodiment.

Figure 1 is a plan view of the steel mesh element.

Figure 2 is a schematic side view of the apparatus of the invention.

Figure 3 is a schematic sectional view showing the connection of the transverse steel insert with an elastic member consisting of two plastic straps superimposed.

Figure 4 is a side view of a detail of the apparatus of Figure 2.

Figures 5A-5D show successive phases of operation of the apparatus of Figure 4.

Figure 6 shows a tape unwinding drum forming part of the apparatus of Figure 2.

Figure 7 shows a detail of the apparatus of Figure 2 on a larger scale.

Figure 8 schematically shows a steel mesh element in which the steel inserts are not straight.

• · «« • · * • · · · 'V · · ♦♦ · * ···· ««

Figure 9 is a schematic view of another steel mesh element in which the transverse steel inserts are non-linear and have a closed contour.

Figure 1 illustrates the steel mesh element according to the invention, which is designated 10 in its entirety. This element consists of rigid transverse steel inserts 12 spaced apart. The steel inserts in the embodiment shown consist of steel bars of equal length, which are arranged parallel to each other. The steel mesh element 10 comprises longitudinally resilient elements 14, in the embodiment shown four. Each of the steel inserts 12 is thus connected to four resilient elements 14 by four knots 16.

In the exemplary embodiment, each of the 12 steel inserts is a steel bar having a diameter of 4 or 5 mm and a length of 2.40 m. The distance or spacing i between two successive steel inserts 12 can be adjusted in steps of 50-50 mm at intervals of 100-450 mm.

In the example, the elastic members 14 are parallel to each other and the distance between two consecutive members 14 is 60 cm.

In the illustrated embodiment, each elastic member 14 consists of two strips of plastic, 10 mm wide and welded at points, as will be described below.

Figure 2 is a schematic diagram of the equipment used to produce the steel mesh element of the present invention. This apparatus comprises a connecting station 18 consisting of a fixed rack 20 forming a horizontal table 22 with which four heads 24 cooperate. These ensure that the steel inserts 12 are connected to the elastic members. In the example, each is an elastic 14 element (of which the · * * «« · · · · · · · · · · ·

In Fig. 2, only one apparent strip is formed by combining two strips, namely an upper strip 14A and a lower strip 14B. These tapes are derived from an upper winding 26A and a lower winding 26B carried by an upper winding drum 2ΘΑ and a lower winding drum 28B. The apparatus thus comprises four upper winding drums 28A and four lower winding drums 28B.

The apparatus further comprises a distributor 30 consisting of a movable rack 32 with wheels, which has an inclined table 36, which forms a magazine and is used for displaying transverse steel inserts 12. The latter are introduced individually into the space delimited by the four pairs of strips 14A, 14B, just in front of the heads 24, relative to the direction of travel of the strips indicated by an arrow F.

In the example, the strips 14A, 14B are made of plastic, namely polypropylene, and the four heads 24 are welded to secure the four pairs of strips 14A, 14B to both sides of the transverse steel insert 12, as shown in Figure 3.

The principle of the apparatus of Fig. 2 can also be applied to other resilient elements, whereby the heads 24 need not necessarily be welding heads.

The four pairs of strips 14A and 14B move step by step in the direction of arrow F as soon as a transverse steel insert 12 is placed on the table 22 below the head 24 by means of the devices described below. The heads 24 then move vertically to secure the four pairs of strips that engage the respective steel insert 12 together. In this way, a net is obtained which can be wound on the receiving drum 136 (see Figure 2).

As shown in Fig. 3, the upper strip 14A is wound around the steel insert 12 and is welded to the bottom 14B in a spot-like manner. ♦ ···· «·········» ·

11 for the sections 38 and 40 located on either side of the steel insert 12. By way of example, sections 38 and 40 may have a length of 1 mm and 10 mm. In this way, for 10 mm wide strips, two welding sections are obtained, each corresponding to a square of 10 mm side length.

Let us now move to Figure 4. The table 36 forms a curved inclined plane extending from the upper end 42 to the lower end 44. The latter 44 ends are lower than the upper 42 ends. Above the table 36 is a conductor 46, the lower surface of which is also curved and faces a portion of the table 36. The table 36 and the conductor 46 thus form a suitable space for the adjacent transverse steel inserts 12. A horizontal bar 50 is placed in front of the conduit 46 to prevent two intersecting steel inserts 12 from passing through. The table 36 and the wire 46 form a magazine in which the steel inserts 12 are placed side by side and parallel to each other and horizontally. This magazine practically touches the vertical at its lower part adjacent to the end 44. Underneath the magazine thus formed are four pull-out drawers 52, which are capable of moving in a horizontal direction. The drawers 52 move in sync. The drawers 52 are provided with a corresponding groove 54 which, when the drawers 52 are in the rear position (see Figure 4), receive a steel insert 12. The drawers 52 are movable synchronously and are adapted to move a steel insert 12 into a horizontal space 56 bounded by an upper panel 58 and a lower panel 60. The space 56 ends at 62 stops.

The operation of the portion of the apparatus shown in Figure 4 will now be described with reference to Figures 5A-5D. Advanced. **. ί.!

During movement, as indicated by the arrow in the figures, the drawers 52 carry a steel insert 12 and close the 36 tables and 46. the output end of the wire formed storage. During this movement, the steel insert 12 is guided between the plates 58 and 60.

The steel insert 12 then reaches the stop 62 (see Fig. 5B) and is locked between the removable stop 62 and the drawer 52 in position with the straps 14A, 14B. The heads 24 are then moved synchronously vertically downward (Fig. 5B) to form a connection between the four pairs of strips 14A, 14B around the steel insert 12.

When this operation is complete, the heads 24 are moved vertically upward and the drawers 52 are moved horizontally backward (see Fig. 5C) to return to their initial position (Fig. 5D) where they can receive an additional 12 steel inserts to resume the previous cycle.

Turning now to Figure 6. Each winding drum, such as the winding drum 28A, which is capable of receiving the winding 26A, comprises two side panels which are mounted on a cylindrical hub 64 and which is coaxial with the axis of the winding drum 66. Each winding drum, such as the winding drum 28A, is associated with a brake 68 consisting of a lever 70, one end 72 of which is pivotally mounted about an axis 74 and the other end 76 carries a rotatable baffle 78. The ribbon 14A is wound onto it, which then passes through a deflector disk 80 which is pivotally mounted on the fixed shaft 82. The lever 70 has an intermediate curved portion 84 which can be frictional on the hub 64 to control the rotation of the unwinding drum. When the baffle 78 and lever 70 are in the lower position shown in Figure 6, the lever * * ··· · · * · · · ··· · ι ·

- an arcuate portion 84 formed by the brake, resting on the hub 64 and braking the rotation of the web.

When the tape 14A is subjected to a tensile force, it raises the baffle 78 and the lever 70, which releases the brake and releases the tape reel.

When the desired tape length is pulled from the roll, the deflector 78 and lever 70 are lowered again and the tape roll is again braked. The belt tension remains the same after each pulling operation.

In the illustrated embodiment, the apparatus comprises four winding drums 28A and four winding drums 288. The four lower strips 148 extend to the welding site as they pass under the table 36 (FIG. 2), i.e. under the steel insert 12 to be secured, while the four upper strips 14A arrive above the steel insert 12. The belts are guided and guided through the eight 80 guide wheels.

As shown in Figure 7, both the steel inserts 12 and the four strips 14A and 14B are located at the coupling station 18. The four heads 24 are then moved synchronously vertically downward to ensure that the four pairs of strips 14A, 14B are welded together. To this end, the lower part of each head 24 is provided with an impression 86 which has the same shape as the steel insert 12 so that each head 24 can surround the steel insert 12 and the strips 14A, 14B can be welded on both sides of the steel insert 12. previously mentioned in relation to Figure 3.

Preferably, the heads 24 are ultrasonic welding heads to provide a local fusion of the materials forming the strips at the point of contact. This fusion, followed by holding the welding head for a period of time after the vibration has ceased, ensures that the four pairs of tapes are welded together.

As shown in FIG. 7, the apparatus includes, inter alia, diverting means comprising horizontally movable clamps 88. Each clip 88 consists of an upper jaw 8ΘΑ and a lower jaw 88B and are capable of grasping a ribbon 14 in front of the anchor station to advance the steel mesh element in the direction of the arrow F by one step. The jaws 88A, 888 of the clamps 88 are converged to each other to clamp each of the strips 14A, 148, and the clamps 88 are then moved synchronously, horizontally, to the left in Fig. 7 with the desired pitch. The displacement of the clamps 88 is limited by a fixed stop 90 located near the heads 24 and by an adjustable stop 92 on the other side. This adjustable stop 92 makes it possible to control the distance between two successive steel inserts 12.

At the start of the welding operation, the clamps 88 are located near the heads 24 and the jaws 88A and 88B are actuated to grip the tapes and hold them firmly in place when the welding operation is completed.

When the welding operation is completed, the welding heads are raised, the stop 62 is depressed (Fig. 4) and the clamps 88 move to the left in Fig. 7 and carry the formed steel mesh element 10 and unwind the ribbons by a split value.

At the start of the next welding operation, the clamps 88 open and are positioned adjacent to the welding heads.

Upon exiting the apparatus, the formed steel mesh element 10 moves first around cylinder 94 and then around another cylinder 96 to eventually be wound onto the receiving drum 136. The latter is driven by the transmission 100 by the engine 100. The cylinder 96 is guided vertically by two probes (not shown) which determine the upper and lower positions of the cylinder 96. When in the lower position of the cylinder 96, the motor 100 of the receiving drum 136 starts, which causes the net to be wound until this cylinder 96 is in the upper position.

As the mesh is wound on the receiving drum 136, the drum rotates its axis alternately in progress to prevent the webs from overlapping.

Fig. 8 shows a steel mesh element according to the invention comprising transverse rigid steel inserts 112 other than a straight line and connected by three elastic members 14, for example a belt.

This steel mesh element can be stored in a folded state when folded.

Figure 9 illustrates another embodiment of the invention, which includes steel inserts 212 other than a transverse straight line. In the illustrated embodiment, the steel inserts 212 are folded back to form a closed contour, which is generally rectangular. The steel inserts 212 are joined by three elastic members 14. As in the embodiment shown in the previous figure, this steel mesh element can be stored in a folded state when folded.

The mesh elements of the present invention are particularly applicable to prestressed concrete products, particularly prestressed concrete slabs containing prestressed steel which are arranged parallel to one another. In this case it is sufficient to unwind the net according to the invention so that the rigid transverse steel inserts are perpendicular to the prestressed steels.

direction.

However, the structure can generally be used as a distribution iron for conventionally ironed walls.

Thus, the steel mesh element of the present invention can be used to replace welded rods or nets for reinforcing conventional reinforced concrete slabs which are cast on site or in formwork.

It can also be used as a positive torque steel cap resting on a front plate or as a steel insert in a pressurized plate (unidirectional force effect). It can be used for reinforcing the casings of prefabricated pieces, especially on the front, at the joints.

The steel mesh element of the present invention can be used as transverse spacer reinforcement for pressurized concrete slabs, beams or blind ceilings and as a supporting steel cap.

The invention can be varied in a very spk way, for example by reinforcing steel bars forming transverse steel inserts, rather than being cut and cut from steel wire coils by the machine itself.

Claims (19)

A steel mesh element for the production of reinforced concrete products comprising two superposed steel meshes, wherein one mesh comprises a plurality of rigid transverse steel inserts (12, 112, 212) spaced apart and the other mesh being at least two longitudinal , the steel inserts (12, 112, 212) comprising a resilient member (14) spaced apart from each other and connected to the transverse steel inserts of the first mesh. Steel mesh element according to Claim 1, characterized in that the transverse steel inserts (12) are generally rectilinear steel bars held parallel to one another by the resilient elements (14), which allow the steel mesh element to be disassembled in roll form. Steel mesh element according to Claim 1, characterized in that the transverse steel inserts (112, 212) are non-linear elements which allow the steel mesh element to be disposed in a bellows shape. 4. Steel mesh element according to any one of claims 1 to 3, characterized in that the elastic elements (14) may consist of iron wire, twine, adhesive tape, metal or plastic tape or the like. 5. Steel mesh element according to one of Claims 1 to 3, characterized in that the elastic element (14) consists of at least one strip (14A, 14B) of plastic, preferably polypropylene. Steel mesh element according to claim 5, characterized in that each elastic element (14) consists of two strips (14A, 14B) which are spot-welded on both sides of the steel insert (12). Steel mesh element according to claim 6, characterized in that one of the strips (14B) is sticky and the other strip (14A) is sticky or precise. 'rt 8. Procedure 1-7. A steel mesh element according to any one of claims 1 to 3, characterized in that: - unwinding elements (14) of equal length from a container so that they are placed parallel to each other at the connecting station (18), - inserting the steel inserts (12) transversely to the resilient members (14) at the connecting station (18), - connecting a steel insert (12) to the elastic members (14), - moving the resilient elements (14) forward by a portion which carries with them the steel insert (12) previously attached thereto, and - we will start this operation again for the other steel inserts. A method according to claim 8, characterized in that each elastic member (14) is formed of two plastic tapes, an upper web (14A) fed from an upper unwinding drum (28A) and a lower web (14B). which is fed from a lower unwinding drum (28B) and the two strips are welded in sections (38, 40) on both sides of the steel insert (12) to be joined. Method according to claim 9, characterized in that the two strips (14A, 14B) are welded by ultrasonic welding. 11. Apparatus according to claims 1-7. Steel mesh element according to any one of claims 1 to 3, characterized in that it is a connecting element - comprising 19 stations (18) as well as elements (14) for transporting equal length elastic members (14) and conveying them parallel to the connecting station (18), preferably a winding drum (2ΘΑ, 28B) and steel inserts (12) transverse to the connecting station (18) comprising a distributor (30) for positioning the resilient members (14) and means for advancing the resilient members (14), preferably tweezers (88), to carry with them the steel insert (12) previously attached thereto. Apparatus according to claim 11, characterized in that the connecting station (18) is provided with a connecting head (24) corresponding to the elastic members to be connected to the steel inserts (12). Apparatus according to claim 12, characterized in that the elastic member (14) consists of at least one strip (14A, 14B) of plastic, preferably polypropylene, and that each connecting head (24) is provided with a welding device, e.g. equipped with ultrasonic welding equipment. Apparatus according to claim 13, characterized in that each elastic member (14) consists of two straps (14A, 14B) of elastic material and that the feeding means for each elastic member (14) comprise two unwinding drums (28A, 28B). ), which can receive two tape coils (26A, 268). Apparatus according to claim 14, characterized in that each winding drum (28A, 28B) is provided with a brake (68) comprising a lever (70) provided with a baffle disc (78) around which the belt (14A) is wound. such that the brake (68) is released when the belt is subjected to traction and latches when the traction force ceases. Apparatus according to claim 15, characterized in that it comprises four pairs of unwinding drums (28A, 288), which allow four elastic members (14) to be joined, each of which is formed by superimposing two straps (14A, 14B). 17. 11-16. Apparatus according to any one of claims 1 to 4, characterized in that the conveying means comprise horizontal, movable clamps (88) which can grip the elastic members (14) in front of the connecting station (18) to move the entire steel mesh element in one increment. Apparatus according to claim 17, characterized in that it has a fixed stop (90) and an adjustable stop (92) associated with each of the clamps (88) so that between two successive steel inserts (12) forwarding sharing can be controlled. 19. Apparatus according to any one of claims 1 to 3, characterized in that the transverse steel inserts (12) are linear and the electric motor (100) driving the receiving drum (136).