A WALL TIE

Abstract: In order to minimise the risk of injuries when using wire wall ties during the building of double walls, the wall tie (1) according to the invention is configured in such a manner that at least its one end is bent to form a closed wire eye (3). Thus the part of the wall tie protruding outwardly from the one wall (6) no longer constitutes any risk of injury in the form of eye injuries or stab wounds, since it no longer ends in a point but, on the contrary, in a rounded-off non-pointed eye, and the holding strength is greater than that with ties with "open" eyes.

Description: A WALL TIE State of the art The invention relates to a wall tie of wire for use in the building of double walls, where the wall tie is secured in each wall for holding the walls together, and where the one or both ends of the tie are bent to form a wire eye. Wall ties of this kind are known for use in the building of double walls of bricks or blocks. They are dimensioned so that they have a suitable building-in length in order for a sufficient securing of the tie to be achieved, and herewith for its ability to absorb tensile strains. Known wall ties are normally configured as a straight piece of wire, which at the ends is bent at an angle of 90°. Because of their shape, they are normally known as Z-ties. During the building of the first wall, the wall tie is built in so that it extends out of the wall for building-in during the subsequent building of the second wall. Consequently, there is a period where the wall tie exists as a piece of wire which protrudes out from the wall which has been built first, where it constitutes a considerable risk of causing injury to people who unintentionally come into contact with the pointed piece of wire which sticks out from the wall. The injuries which can arise hereby are especially eye injuries, but in addition hereto there is also the risk that the ends of the wires can inflict stabbing injuries and the like. There are also known wall ties which are bent over at the ends, so that this risk of causing injury is eliminated. An example of such a tie is that described in GB 2,157,736. In the ends of the tie there is formed an eye which is disposed in the longitudinal direction of the wire. This, however, is a very inappropriate configuration, since it results in a poor securing of the tie in the layer of mortar. When a load is placed on the tie, the eye is exposed to a tensile force which will press the mortar out from under the one half of the eye, whereby the wire eye is almost disengaged, since the remaining part of the mortar will be influenced and pressed out by the uneven tensile strain resulting from the tension in the wire. A second example is the tie described in GB 2,215,356. In this tie, the eye is "open", in that the end of the wire lies around the centre of the eye. The result is that when the tie is exposed to a tensile strain, the mortar is influenced outwards from the centre of the eye, since the tension in the wire gives rise to a resulting, obliquely extending loading of this part of the mortar. Additional tension on the tie results in a complete loosening of the mortar under the remaining part of the eye. This stepwise loosening of the mortar around these known wall ties is particularly unfortunate, since it gives rise to a latent risk that the holding- together of the walls is not maintained. Moreover, this is a concealed defect which can not be observed from the outside. The object of the invention It is the object of the invention to eliminate this risk of industrial injuries with the known wire wall ties, and furthermore to improve the wall tie. According to the invention, this is achieved with a wall tie where the wire eye is formed by a bending of the end of the wire in the formation of a substantially closed eye, and where the wire constitutes the innermost part of the eye. With the configuration of the eye according to the invention, there is achieved a hitherto-unknown high degree of fastening, holding strength, since the tension in the wire will give rise to no moment in the wire which constitutes the eye, but only a pure traction, which will not be able to loosen the mortar. It is hereby ensured that at normal loads the mortar remains intact without any risk of partial loosening of the mortar around the tie. By bending the wire in two operations as disclosed in claim 2, the bending work will be easier to carry out in an automatic bending machine. The drawing In the following, example embodiments of the wall tie according to the invention will be described in more detail with reference to the drawing, where fig. 1 shows a wall tie with a wire eye at the one end, fig. 2 shows a wall tie with a wire eye at each end, and fig. 3 shows the wall tie shown in fig. 1 during the building of a double wall. Description of the example embodiments In fig. 1 there is shown a first example of a wall tie according to the invention. It is made of round metal wire which can be stainless, acid-proof or tin bronze wire. The dimension of the wire can, for example, be between 3 and 4 mm in diameter. The wall tie 1 consists of a straight piece of wire 2 which is bent at the one end in the formation of an angle piece 4, the length of which can be about 50 mm, and which at the other end is bent twice in the formation of an eye 3. The first bend is of 90°, while the second bend is of about 150° and with the wire end lying close to the straight piece 2. The overall length of the wall tie 1 can, for example, be between 120 and 400 mm. In fig. 3 it is shown how such a wall tie 1 is used. During the building of the first wall 6, uppermost in the drawing, the wall tie 1 is built in as prescribed so that the angled end 4 is built into the course. This is effected so that the angle piece 4 receives the prescribed cover layer 9 and building-in length 10. Hereafter, the overlying course can be laid. The end formed with the eye 3 extends out from the wall 6, but because of its rounded shape, the eye 3 does not constitute any risk of injury when touched. When the second wall 7 is built up, the wall tie 1 is built in as indicated in fig. 3. Insulation 11 can be placed in a known manner between the walls 6 and 7 in the final double wall 8. This wall can thus be built up without any risk of injury arising due to pointed ends of wires. Instead of a wall tie 1 with an eye 3, as shown in fig. 2 it can be produced with an eye at each end. This results in a good adhesion in the mortar, which will surround the eye and form an unbroken connection through the eye opening. There is hereby achieved an increased extraction strength, while at the same time the risk of stabbing injuries is eliminated. There is shown a broad eye 3, but eyes of other shapes can naturally be envisaged, merely providing that they are "closed" and extend along the wire so that they do not end in a pointed manner, and moreover that they achieve the greatest possible retaining strength. It naturally lies within the scope of the invention to configure the wall tie with an eye according to the invention in the one end, and provide the other end with known securing means such as threads, which can be self-cutting, wood screw or cinder block threads, so that the tie can be screwed into the one wall. Another possibility is to configure the end with an expansion anchor for fastening in a bore, or the tie can be configured in a corrugated manner so that it can constitute a corrugated anchor for building into the wall.

Claims: CLAIMS 1. Wall tie of wire for use in the building of double walls, where the tie is fastened in each wall for holding the walls together, and where the one or both ends of the tie (1 ) are bent in the formation of wire eyes (3, 4), c h a r a cterised in that the wire eye (3) is formed by bending the end of the wire in the formation of a substantially closed eye (3), and where the wire (2) constitutes the innermost part of the eye. 2. Wall tie according to claim ^characterised in that the wire eye (3) is formed by a first bending of the wire end to around 90°, and a subsequent second bending of around 150° a distance further out along the wire in the formation of the closed eye (3).

Inventors: LAURSEN KNUD, LAURSEN, KNUD
Applicants: LAURSEN KNUD, MIDTJYDSK MURBINDERFABRIK AS, LAURSEN, KNUD, MIDTJYDSK MURBINDERFABRIK A/S
Application year: 2001
Main classification: E04B2
IPC codes: E04B1, E04C2