EP0086771B1 - Welded wire mesh - Google Patents

Description

The invention relates to a lattice mat made of longitudinal and transverse wires welded together, in which at least some transverse wires protrude beyond the longitudinal edge wires and are bent back in the form of loops. Lattice mats of this type are known for example from DE-B-23 50 866. The purpose of the loop-shaped design of the transverse wire end parts is an improved force transmission from the transverse wires of one mat into the transverse wires of an adjacent mat in a surface reinforcement for a reinforced concrete structure made up of a plurality of lattice mats laid next to one another.

Since mesh mats for concrete reinforcements in large quantities and in a considerable number of different types have to be manufactured and kept in stock and, moreover, the ratio of the steel weight of the mesh panels to the volume required for their transport is very unfavorable, in order to reduce the storage and transport costs to ensure that the mats are stacked in a space-saving manner.

It has therefore long been common to stack lattice mats on top of one another with the aid of special devices in such a way that one mat in each case, in which it emerges from the lattice welding machine, is placed on the mat stack, whereas the next succeeding mat is put on before being put down the mat stack is turned through 180 ° about its longitudinal axis. By this measure, two immediately successive mats can be arranged by themselves when placed on the stack so that, for example, their longitudinal wires come to lie parallel to each other in the same horizontal plane and the cross wires of the upper of these two mats with the cross wires of the next mat placed on them also come to lie parallel to each other in the same horizontal plane. The total height of the mat stack is reduced to half the value that would result if all mats were placed on the stack in the same position.

Prerequisite that the mats in the desired manner, i.e. H. Arranging two adjacent mats with longitudinal or transverse wire coulters lying in pairs on the same plane is a straight course of the longitudinal and transverse wires, because only with straight wires is the probability that two wires remain vertically one above the other without sliding against each other, even then extremely is low if both the top and bottom wires are connected to other wires to form a mat.

In the known mats of the type specified at the outset, the transverse wire end parts of which are bent back in loop form to the longitudinal wires in the plane of the mat, stacking in the manner described is not possible because the loops hinder arranging the transverse wires of two mats lying one above the other in a common plane.

The invention is now concerned with the task of forming mesh mats of the type specified in the introduction so that they can be stacked in a space-saving manner in the same way and with the same devices as are used for mesh mats with straight straight longitudinal and transverse wires.

The solution to this problem according to the invention is that at each mat edge at least the curved parts of the loops formed by the transverse wire ends from the plane of the transverse wires are angled or curved so far towards the plane of the longitudinal wires that the tips of the loops between these two planes lie. The tip of a loop is to be understood in each case that point at which the tangent to the axis of the curved transverse wire end part runs parallel to the longitudinal wire axes.

As will be explained in more detail below with reference to the drawings, it is achieved in this way that the angled or curved loop parts do not prevent the space-saving interlocking of the longitudinal or transverse wire coulters of adjacent mats when alternately placing unused mats and turned by 180 ° about their longitudinal axis on a stack hinder.

• Figur 1 eine Draufsicht auf eine erfindungsgemäße Gittermatte,
• Figur 2 einen Querschnitt durch den einen Randbereich dreier übereinander gestapelter, alternierend gewendeter und nicht gewendeter Matten nach Figur 1,
• Figur 3 eine Draufsicht zu Figur 2 und
• Figur 4 Radialschnitte durch die übereinanderliegenden, schlaufenförmig gebogenen Querdrahtendteile dieser Matten längs der Linien I - M bis VII - M in Figur 3.

The invention will now be explained in more detail with reference to the drawings using an exemplary embodiment. Show it

• FIG. 1 shows a plan view of a grid mat according to the invention,
• FIG. 2 shows a cross section through the one edge region of three mats according to FIG. 1 stacked one above the other, alternately turned and not turned,
• Figure 3 is a plan view of Figure 2 and
• FIG. 4 radial sections through the superimposed, loop-shaped transverse wire end parts of these mats along the lines I-M to VII-M in FIG. 3.

FIG. 1 shows a grid mat made of longitudinal and transverse wires L and Q welded to one another at their crossing points, in which the transverse wire end parts protrude beyond the longitudinal edge wires and are bent back in the form of loops S to the longitudinal edge wires and are welded to them. According to an older proposal by the patentee, the two outermost longitudinal wires have a smaller center distance from each other than the other longitudinal wires, in order to shorten the required covering width of adjacent mats in the event of a load-bearing joint. The loops S are, according to the invention, a short distance outside the longitudinal longitudinal wires parallel to these straight lines G from the plane of the transverse wires in FIG Angled towards the plane of the longitudinal wires.

This angling of the loops S can be clearly seen in FIG. 2, in which the one edge region of three mats stacked on top of one another to save space is shown, the longitudinal wires, transverse wires and loops of which can be distinguished from one another by indices 1, 2 and 3 added to the reference numerals L, Q and S. . FIGS. 2 and 3 show a cross wire Q1 welded to an edge longitudinal wire L1 of the lower mat, a cross wire Q2 welded to an edge longitudinal wire L2 of the middle mat, and finally a cross wire Q3 welded to an edge longitudinal wire L3 of the upper mat.

The middle mat is turned by 180 ° with respect to the lower and the upper mat, which is why the loops S1 and S3 of the lower and upper mat formed by the end parts of the cross wires Q1 and Q3 around the straight line G which is shown in FIG Cross wire level obliquely upwards, but the loops S2 of the middle mat appear angled obliquely downwards.

The straight longitudinal wires L1 of the lower and L2 of the middle mats lie, as can be clearly seen in the sectional illustration according to FIG. 2, next to one another in a common horizontal plane. Even the straight parts of the transverse wires Q2 of the middle mat and Q3 of the upper mat lie, as can be seen particularly clearly in the top view according to FIG. 3, next to one another in a common horizontal plane.

The radial sections IM to VII-M, for example relating to the center point M of the curvature of the loop S3 through the three loop-forming transverse wires Q1, Q2 and Q3, which are shown in FIG. 4, show that the space-saving interlocking described above meshes as a result of the bending of the loops the longitudinal and transverse wire coulters of adjacent mats are not hindered. In particular, the radial sections I-M and VII-M show that the cross sections of the cross wires Q2 and Q3 lie at the beginning and at the end of each loop in a common horizontal plane, whereas according to the Ra-. Dial-cut IV-M lie one above the other in the area of the loop tips. In the radial section IV-M, the cross section through the cross wire Q3 corresponds exactly to a section through the loop tip and is therefore denoted by K.

The straight lines G, around which the loops S are angled, are preferably at a distance a from the adjacent longitudinal edge wire of the mat, as indicated in FIG. 2 on the lower mat, which is somewhat larger than the longitudinal wire diameter D. The cross wires Q then run a straight line a beyond the longitudinal edge wire and only the subsequent curved part of the loop is angled. As shown above all in Figure 2, this measure creates a sufficiently large free space in the stack, limited by the cross wires Q2 and Q3 upwards and by the cross wire Q1 downwards, in which the loop S1 of the cross wire Q1 and the with this cross wire welded line wire L1 a line wire L2 of the neighboring mat can find space.

In the illustrated embodiment, the longitudinal and transverse wires of the grid mat have the same diameter. In this case, as the radial section IV-M in FIG. 3 shows for the upper mat, the cross section K through the loop tips should be the plane EL defined by the axes of the longitudinal wires L3 and the plane EQ defined by the axes of the straight sections of the transverse wires Q3 tangent at points P1, P2 diametrically opposite in cross section K.

If the longitudinal wires, as is very often the case, have larger diameters than the transverse wires, then an unobstructed, space-saving stacking of the mats is always possible if the cross sections K through the loop tips in the radial section IV-M of FIG. 4 are in any position between the two planes Take EL and EQ, whereby you may touch one of these levels, but preferably lie in the middle of these two levels.

To produce mats according to the invention, straight cross wires can be fed to a grid welding machine, the end parts of which protrude beyond the longitudinal longitudinal wires are formed into loops in a subsequent operation after welding the longitudinal and transverse wires, which are then angled or curved in a further operation in the manner already described .

On the other hand, the grid welding machine can also be supplied with preformed cross wires which are already provided with loops and which, after welding to the longitudinal wires, merely have to be angled or curved.

Finally, the grid welding machine can also be fully formed, i.e. H. cross wires already provided with angled or curved loops, which only have to be welded to the longitudinal wires.

Claims (4)

1. Grid mat comprising longitudinal and transverse wires (L, Q) welded to one another, in which at least some of the transverse wires (Q) project beyond the- edge longitudinal wires (L) and are bent back to the edge longitudinal wires in the form of loops (S), characterized in that at each mat edge at least the curved parts of said loops (S) formed by the ends of said transverse wires are angled or curved out of the plane (EQ) of the transverse wires (Q) in the direction of the plane (EL) of the longitudinal wires (L) such that the crests of said loops lie between these two planes.

2. Grid mat according to claim 1, characterized in that said loops (S) or their arched portions, respectively, are bent out of the plane of the transverse wires (Q) about a straight line (G) running parallel to the longitudinal wires (L), said straight lines being spaced from said edge longitudinal wires a distance (a) somewhat greater than the diameter (D) of the longitudinal wires.

3. Grid mat according to claim 1 or 2, in which said longitudinal and transverse wires have the same diameter, characterized in that the cross-sections (K) through said loop crests are tangent upon the plane (EL) defined by the axes of the longitudinal wires and upon the plane (EQ) defined by the axes of the straight portions of the transverse wires, at points (P1, P2) located diametrically opposite one another on said cross- section.

4. Grid mat according to claim 1 or 2, in which the longitudinal wires have a larger diameter than the transverse wires, characterized in that the cross-sections (K) through the loop crests are positioned in the middle between the plane (EL) defined by the axes of the longitudinal wires and the plane (EQ) defined by the axes of the straight portions of the transverse wires.

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