US3238688A - Reinforcement grid for concrete - Google Patents

Description

March 8, 1966 H. SCHOCH ETAL REINFORCEMENT GRID FOR CONCRETE 2 Sheets-Sheet 1 Filed Aug. 8, 1963 March 8, 1966 H. scHocH ET AL 3,238,688

REINFORCEMENT GRID FOR CONCRETE Filed Aug. 8, 1963 2 Sheets-Sheet 2 United States Patent cc 3,238,688 REINFORCEMENT GRID FOR CONCRETE Hans Schoch, Zurich, Switzerland, and Charles Eduard Hoeke, Overveen, Netherlands, assignors to Ernst Schoch Actiengesellschaft, Basel, Switzerland Filed Aug. 8, 1963, Ser. No. 300,868 Claims priority, application Austria, Aug. 27, 1962, A 6,846/62 7 Claims. (Cl. 52-645) The invention relates to a reinforcement grid for concrete having reinforcement irons which are flexurally stiff and arranged parallel to one another, which are connected with one another by flexible spacers crossing the same. Reinforcement grids of this kind have the advantage that they can be rolled up for transport and accordingly can be provided practically for any dimensions desired, e.g., for the production of road surfaces. When laying the grid there are no difliculties to spread the same evenly or to adapt it to a given cylindrical camber in contrast to reinforcement grids which consist of elements interwelded at the crossing point wherein the spacer elements must have a substantial cross sectional area in view of the welding and accordingly are not, or only badly flexible. Welded grids are accord ingly produced, transported and laid preferably in the form of panels which involve comparatively high expenses.

In spite of the advantages of the flexible grids the same have not been adopted generally in the practice of concrete construction, namely because the reinforcement irons and the flexible spacers shift relative to one another at the crossing point when laying these grids, so that they have to be brought with great effort into the correct position since otherwise large gaps would be formed between the individual reinforcement irons which have to be obviated absolutely for reasons of safety. Sheet metal clamps have been already proposed, the legs of which are to be pressed over the grid elements at the crossing points. Tests with such clamps have, however, shown that they do not sufliciently prevent the slipping of the grid elements.

The invention has the object of providing a reinforcement grid for concrete which obviates the disadvantages stated hereinabove and which moreover can be produced with the simplest possible technical means and minimum expense in work.

With these and other objects in view which will become apparent later from this specification and the accompanying drawings, we provide a reinforcement grid for concrete comprising in combination: flexurally stiff reinforcement irons arranged parallel to one another, flexible spacers crossing said reinforcement irons and having loops wherein said reinforcement irons are held, each of said loops being closed at least at one point by a fixed connection.

These and other features of our said invention will be clearly understood from the following description of some embodiments thereof given by way of example with reference to the accompanying drawings, in which:

FIGURES 1-3 show three different embodiments of the holding of the reinforcement irons in section transversely of said reinforcement irons.

FIGURES 4, 5 and 6 diagrammatically show in perspective view, how a further embodiment is produced.

According to FIGURE 1 the flexible spacers consist of two parts 1:: and 1b, which are connected with one another at the points 2a and 2b preferably by welding and which between these welding points 2 are constructed as eyelet-shaped loops, through which the reinforcement irons 3 pass. These reinforcement irons '3 may con- Patented Mar. 8, 1966 sist of simple steel bars or alternatively of two steel wires intertwined with one another the diameter of which may lie between 1, 8 and 5 millimetres. Such twin wires are known to have a particularly good adhesion in the concrete.

The spacer parts 1a, 1b, may consist preferably of strip iron, but may alternatively consist of wires particulaly of those having a non-circular profile.

In the embodiment according to FIG. 2 the spacer 1a is continuous, with bulges provided at intervals and for the formation of the eyelet-shape loops short pieces 4 of the same or of a similar material bulging in the opposite direction are arranged in appropriate distances which are connected at both ends with the continuous spacer 1a with the formation of eyelets, which take in the reinforcement irons 3. g

In the embodiment according to FIG. 3 only one spacer element 5.is used which at appropriate distances has loops 7 formed by bulges for taking in the reinforcement irons 3, the two points 6, 6', leading to the loop being interwelded or otherwise fixedly connected with one another.

The aforesaid embodiments fulfill in an excellent manner the requirements of such reinforcement grids or bays.

As reinforcement bars, hard steel bars are to be used which, however, lend themselves to welding with difiiculty only, or whose welding points would involve reduction of their strength properties; according a tensile strength of 12 tons per square centimetre only can be fully utilised.

The spacers may be connected with one another for the formation of eyelets or loops at the points concerned by welding, preferably spot welding, by riveting, foldingover, cementing or 'by tying knots, in which case they are secured against slipping relative to the steel bars only by mechanical pressure. A deterioration of the properties of the material of the steel bars by the heating involved when welding the spacers to one another is thereby obviated since the cross sectional area of the steel bars amounts to a multiple of that of the spacers and since, moreover, the intermediate air layer which is always present hinders the transmission of heat whereby a temperature increase of about 500 C. which would affect the strength proper-ties thereof cannot occur in the material of the steel bar. As flexible spacers cold-rolled or cold-drawn strip irons, round wires, profiled wires or intertwined or twisted wires or the like may be used. It is essential to attain an accurate spacing of the steel bars.

If, moreover, also any slipping of the steel bars transversely of the spacers is to be obviated safely, the spacers may be provided at least at their loops with a safety means against slipping.

According to a further embodiment illustrated in FIGS. 4, 5, 6 thin wires 11 are used as spacers, for example having a diatmeter of 0.3 millimetre which at any point where a reinforcement iron 13 has to be engaged are bent into two U-bends making transition into one another whose legs lie close to one another. The two U-bends are then, as shown in FIG. 5, bent over the super-imposed reinforcement irons 13, and eventually their ends are intertwined in the manner illustrated in FIG. 6.

Instead of intertwining, however, any other fixing connection e.g. by folding, welding, soldering or cementing may be used. In this manner not only the spacing of the reinforcement irons 13 is secured by the Wires 11 but the loops strongly contacting the reinforcement irons 13 sit on the reinforcement irons with such a strong friction that also on the latter any slipping of the loops in the axial direction is not possible at all or only to such a small extent that this does not matter. For the formation of the double U-bends, the bending and the intertwining or other connecting of the U-bend with one another and for the formation of the loops fully automatic mechanical device can be easily constructed so that the production of such reinforcement grids can be carried out in practice fully automatically.

While we have herein described and illustrated in the accompanying drawings what may be considered typical and particularly useful embodiments of our said invention, we wish it to be understood that we do not limit ourselves to the particular details and dimensions described or illustrated; for obvious modifications will occur to a person skilled in the art.

What we claim as our invention and desire to secure by Letters Patent, is:

1. A reinforcement grid for concrete comprising flexurally stiff reinforcement irons arranged in spaced parallel relation to one another, and flexible spaced members crossing said reinforcement irons and having loops wherein said reinforcement irons are held, each one of said loops being formed by two U-shaped portions formed adjacent each other in said spacer members and initially extending parallel thereto before saidtwo U-shaped portions are bent around said reinforcement iron from opposite sides and are connected with each other to form said loop which tightly engages said reinforcement iron.

2. A reinforcement grid for concrete comprising flexuarlly stiff reinforcement irons arranged in spaced parallel relation to one another, and flexible spacer members crossing said reinforcement irons and having loops wherein said reinforcement irons are held, each one of said loops being formed by two U-shaped portions formed adjacent each other in said. spacer members and initially portions are bent around said reinforcement iron from opposite sides and are connected with each other by twisting to form said loop which tightly engages said reinforcement iron.

3. A reinforcement grid for concrete comprising flexurally stiff reinforcement irons arranged in spaced parallel relation to another, and flexible spacer members crossing said reinforcement irons and having loops wherein said reinforcement irons are held, each one of said loops being formed by two U-shaped portions formed adjacent each other in said spacer members and initially extending parallel thereto before said two. U-shaped portions are bent around saidreinforcement iron from opposite sides and are connected with each other by welding to form said loop which tightly engages said reinforcement iron. 4. A reinforcement grid as claimed in claim 1, in which said U-shaped portions after having been wound around said reinforcement iron are soldered together.

5. A reinforcement grid as claimed in claim 1, in which said U-shaped' portions after having been wound around said reinforcement iron are cemented together.

6. A reinforcement grid as claimed in claim 1, wherein said spacer members consist of thin wires.

7. A reinforcement grid as claimed in claim 1, wherein said reinforcement irons consist of hard steel which is weld resistant.

References Cited by the Examiner UNITED STATES PATENTS r RICHARD W. COOKE, Jr., Primary Examiner.

FRANK L. ABBOTT, Examiner.

M. O. WARNECKE, Assistant Examiner.

Claims (1)

1. A REINFORCEMENT GRID FOR CONCRETE COMPRISING FLEXURALLY STIFF REINFORCEMENT IRONS ARRANGED IN SPACED PARALLEL RELATION TO ONE ANOTHER, AND FLEXIBLE SPACED MEMBERS CROSSING SAID REINFORCEMENT IRONS AND HAVING LOOPS WHEREIN SAID REINFORCEMENT IRONS ARE HELD, EACH ONE OF SAID LOOPS BEING FORMED BY TWO U-SHAPED PORTIONS FORMED ADJACENT EACH OTHER IN SAID SPACER MEMBERS AND INITIALLY EXTENDING PARALLEL THERETO BEFORE SAID TWO U-SHAPED PORTIONS ARE BENT AROUND SAID REINFORCEMENT IRON FROM OPPOSITE SIDES AND ARE CONNECTED WITH EACH OTHER TO FORM SAID LOOP WHICH TIGHTLY ENGAGES SAID REINFORCEMENT IRON.

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