The present invention relates to a wire fastening means for fences comprising two or more wires or lines arranged one above the other, which are attached to and extend between spaced-apart posts, said wire fastening means comprising a plate-shaped member which is adapted to be arranged with its rear side against an individual post, and wire fixing means for holding each individual wire in a fixed position on the front side of the plate member. Background of the Invention

Different types of fences are used in many situa¬ tions, for example for fencing in industrial estates. The posts used are usually made of metal and have a tubu¬ lar or some other thin-walled cross-section. In a common type of fence, the lower part of the fence consists of a wire netting up to a height of about 2 m, while the upper part thereof, between about 2 and 2.5 m, supports one or more single wires, preferably barbed wires, so as to render climbing of the fence difficult. Each such wire has earlier been separately attached by means of a clasp which is screwed or riveted to the post. Since the wires are not only subjected to downward forces but also to upward forces in connection with such posts as are posi¬ tioned lower than neighbouring posts, use is made of loop-shaped clasps which are connected to a post by means of a screw or rivet which is passed through holes in the two free ends thereof, after first being arranged about a wire that is to be fixed. There is thus no possibility of premounting the clasps, but the entire mounting work must be carried out in the field. This is of course time-con¬ suming work, especially since the height above the ground is so great that the person carrying out the building of the fence must have some sort of ladder or platform to stand on to be able to attach the upper wires. As the work proceeds, the person building the fence must thus

carry along the platform and repeatedly get up on to and climb down the same. It is also time-consuming to attach the wires by boring, for each wire, a hole in the post and screwing or riveting the wires by means of a clasp and a screw or rivet for each wire. Moreover, it is impractical to use such small fixing means as screws, rivets and clasps when building the fence in the field, especially when working in cold weather which requires the use of protective gloves. US 928,807 discloses a wire fastening means of the type mentioned by way of introduction. This fastening means is adapted to be attached to concrete posts as an edge lining along the entire height of the post. This wire fastening means comprises a plate member and a curv- ed portion which is adapted to extend over the upper end of the pos . The fastening means is screwed to the post by means of four through bolts with nuts, and the plate member is formed with punched tongues, an individual wire being adapted to be located between the plate member and the tongue whose free end is then folded inwards to pro¬ vide the holding of the wire. Such holding tongues tend to be bent outwards when applying excessive forces to the wires. To increase the holding power, it would certainly be possible to manufacture the fastening means from a thicker plate, but this is contrary to the wish to keep the cost and the weight as low as possible. If the thick¬ ness of the plate member is decreased, the number of bolts holding the same screwed to the post must, on the other hand, increase correspondingly, and this, too, increases the manufacturing cost.

US 1,437,057 discloses a further wire fastening means, which, like US 928,807, comprises a plate member with a great number of punched tongues for holding wires. However, this wire fastening means is intended to be mounted on metal posts of T-shaped cross-section and therefore comprises U-shaped edge portions to be able to enclose the longitudinal side edges of the web of

the metal section. Such a construction is, in practice, restricted to be mounted on posts of T-shaped or H-shaped cross-section, since the dimensions that would be requir¬ ed to permit its enclosing and being fixed in a similar manner on, for instance, a tube of box-shaped cross-sec¬ tion would make it too heavy and expensive to manufac¬ ture. The wire fixing means in the form of punched tongues also suffer from the drawbacks which have been described above. Summary of the Invention

An object of the present invention is to provide a wire fastening means for fastening wires on posts, which, inter alia owing to the use of a thin material thickness, is inexpensive to manufacture, by means of which the fas- tening is quick and easy to carry out and which results in reliable holding of the wires. At least this object is achieved by a wire fastening means according to claim 1 and by the preferred embodiments of the wire fastening means stated in claims 2-7. A further object of the invention is to simplify and reduce the cost of erecting such fences as comprise a wire netting arranged in the lower part and two or more wires or lines arranged above the netting. These objects are achieved by means of a fence according to any one of claims 8-10.

Further Elucidation of Prior Art

US 1,565,339 discloses a fence post of angular cross-section. The post is formed with recesses in one flange for receiving wires. A disadvantage of such a post is that the loads to which it may be subjected and the fence heights of up to 2-2.5 m that may be involved necessitate a great material thickness of the angular section, approximately at least 5 mm. This makes the post expensive to manufacture and heavy and unwieldy to handle. A result of the great material thickness further is that working, such as boring and milling of recesses, becomes very costly to carry out. In practice, such a

post could not be manufactured at a reasonable cost, let alone be offered for sale at a competitive price.

US 4,266,757 discloses a fastening means which is adapted to be mounted on a fence post. Such fastening means are, however, not intended for mounting of wires on the posts, but for carrying horizontal rods or rails between neighbouring posts. For each post, at least two separate fastening means are thus required. The problem lying behind and the solution thereof thus differ sub- stantially from the present invention. Among other things, the fastening means comprises two bent flange portions throughout its longitudinal extent, but these are intended to face the post and not to be turned out¬ wards, as in the present invention. Thus, the aim of the flange portions is not to function as carrier for the rails, but they just permit the steel wires to be passed through their apertures and be lashed around the post, for holding the fastening means thereon. Instead, sepa¬ rate U-shaped holders for the fence rails are welded to the front of the fastening means. Consequently, this is a very expensive construction, which requires very accurate erecting of the posts, since the distance between two posts must conform almost exactly with the length of the rails. Brief Description of the Accompanying Drawings In the drawings FIG 1 is a perspective view of a fence comprising three barbed wires which are arranged at the top and attached to posts by fastening means according to the present invention,

FIG. 2 is a perspective view of an upper part of a post and a fastening means mounted thereon, FIG. 3 is a perspective view according to Fig. 2, in which the fastening means carries three barbed wires and an upper carrying line of a wire net¬ ting,

FIG. 4 is a perspective view of a first alternative embodiment of a wire fastening means according to the present invention, FIG. 5 is a perspective view of a second alternative embodiment of a wire fastening means according to the present invention, and FIGS 6-9are side views of a portion of a wire fastening means, illustrating a preferred design of a T-shaped groove and a barbed wire shown in cross- section in different positions.

Detailed Description of the Invention

Reference is first made to Fig. 1, which is a per¬ spective view of a section of a fence comprising a wire netting generally designated 1 and arranged in the lower part, and three barbed wires 2 arranged at the top, both the netting and the barbed wires being carried by and tensioned between posts 3 in the form of tubes of square or rectangular cross-section. The wire netting is of a type comprising an upper carrying line 4 and a lower car- rying line 5, between which there are arranged wires, preferably steel wires, in a diamond pattern. The fence shown can in practice have a height of 2.4 m, i.e. the upper barbed wire is located 2.4 m above the ground, while the wire netting can have a height of about 2.0 m. The wire netting 1 is attached to each post by means of three clasps 6 which are shown schematically. More precisely, the lower carrying line 5 is held by one clasp, while two clasps are arranged to hold the wires of the wire netting in the area between the carrying lines. The upper carrying line 4 and the three barbed wires 2 are held by a wire fastening means according to the present invention, generally designated 7, in the upper end portion of each post. In Fig. 1, the upper end portion of the central post and the associated wire fastening means are shown in an enlarged partial view.

Reference is now made to Fig. 2, in which the inven¬ tive wire fastening means 7 is shown in more detail in a

perspective view, together with an upper end portion of a post 3. The wire fastening means comprises a plate-shaped member 8 which in the shown embodiment is flat and elon¬ gate and has a front side and a rear side, and which along one longitudinal side edge carries a flange 9. At an upper terminal edge of the plate member, there is formed a hook means 10, which is adapted to engage over a terminal edge of a side wall of the post 3. The flange 9 is formed with four T-shaped through grooves or recesses 11 which are composed of a first horizontal groove por¬ tion 12 extending from the outer free edge of the flange towards the plate member, and a second vertical groove portion 13 whose centre connects with the inner end of the horizontal groove portion. An elongate aperture 14 is formed in the lower portion of the plate member and serves to receive a screw or rivet 15 for connecting with the post 3. In a preferred embodiment of the invention, the wire fastening means is made of a flat and thin metal plate, suitably of galvanised sheet metal, which is form- ed with grooves 11 and apertures 14 and is bent along a longitudinal side edge to form the flange 9, and along a terminal edge to form the hook 10. Being so designed, the wire fastening means can be manufactured at a very low cost. Basically, the flange 9 has two functions, on the one hand it serves as a carrier of wires via the recessed grooves 11 and, on the other hand, it serves as rein¬ forcement of the plate member 8, whereby the wire fasten¬ ing means can be made of a very thin plate, but still be sufficiently rigid for its purpose. The wire fastening means can either be mounted in advance before the posts are set up in the intended position, or be mounted after the posts have been set up. In the latter case, mounting can be carried out very quickly and easily by the wire fastening means being hooked onto the upper end of the post by means of the hook 10, and then a hole is bored in the post, such that the wire fastening means can be firm¬ ly connected therewith by means of a single rivet or

screw through the aperture 14. It is preferred that the aperture 14 is positioned as far down as possible on the plate member 8 to make it possible for the person putting up the fence to carry out his work without needing anything to stand on. In practice, the plate member 8 may have a length of about 300-400 mm and a width of about 40 mm. The inventive wire fastening means enables very quick and easy mounting, its upper end portion being firmly fixed by the engagement of the hook 10 with the upper end of the post and its lower end portion being firmly fixed by means of the rivet or screw 15, which prevents the wire fastening means from being moved upwards such that the hook is disengaged. It is prefer¬ red that after mounting of the wire fastening means, the upper end of the post is fitted with a cap 16 of plastic. Reference is now made to Fig. 3, which shows a wire fastening means which is mounted on a post and which car¬ ries three barbed wires 2 and the upper carrying line 4 of a wire netting (not shown). The inventive wire fasten- ing means facilitates the building of the fence to a great extent. The wires need only to be inserted into the grooves 11 in the flange 9 and are thus positioned at a predetermined desired distance from each other, without any measuring operation. If the wires are positioned high up, the person putting up the fence can, standing on the ground, insert them into the grooves by means of an elon¬ gate tool.

Reference is now made to Figs 4 and 5 which illu¬ strate an alternative embodiment of a wire fastening means according to the present invention. In this embodi¬ ment, the vertical groove portion 13 of the groove 11 is designed with parts 17 having an increased cross-sec¬ tional dimension and widening at the top and at the bot¬ tom. This has been done to achieve increased security against pulling out of an individual wire from the groove 11 when applying a horizontally directed force. The groove portion 12 of the groove may suitably have a

cross-sectional dimension that with optimum fit corre¬ sponds to the wire thickness. Also the cental part of the vertical groove portion 13 may have a cross-sectional dimension that corresponds closely to the wire thickness. When applying a horizontally directed force, to the left in Figs 4 and 5, the retaining of the wire is facilitated by the slightly inwardly extending portion of the flange between the groove portion 12 and the widened part 17 of the groove portion 13. Fig. 4 illustrates individual wires which are subjected to differently directed forces. The uppermost wire is subjected to an upwardly directed force and thus is received in the upper widened part of the groove portion 13. The centre wire is subjected to a downwardly directed force and thus is held by the lower widened part of the groove portion. The lowermost wire is subjected to a horizontal force, is held by the lower widened part of the groove portion and is prevented from sliding away from the groove by the inwardly directed portion of the flange. Fig. 5 shows a further alternative embodiment of a wire fastening means according to the present invention, whose flange 9 is bent at its free edge to form a guide or channel 18. When the wires (not shown) are placed in their respective groove 11, a wire or rod 19 is insert- able into the guide 18 and will thus block the grooves and prevent pulling out of the wires. By means of a pair of tongues or the like, the guide 18 can be pressed together or be deformed so as to prevent the wire 19 from being pulled out. Reference is now made to Figs 6-9 illustrating a portion of the flange 9 of a wire fastening means with a preferred design of the T-shaped wire-holding groove 11. A barbed wire 2 is schematically shown in cross-section and conventionally composed of two separate, twisted wire parts or strands. In this embodiment, the width of the vertical groove portion 13 and the horizontal groove por¬ tion 12 is adapted such that it is greater than the

smallest cross-sectional dimension of the barbed wire, i.e. greater than the thickness of an individual wire strand, but smaller than the greatest cross-sectional dimension of the barbed wire, i.e. smaller than the total thickness of the wire strands. This implies that the barbed wire can be passed through the groove portions in one way, but not in the other. The barbed wire is mounted by being inserted into the horizontal groove portion 12 and oriented with its greatest cross-sectional dimension substantially horizontal, as shown in Fig. 6. In order to facilitate insertion, the groove portion 12 can suitably diverge outwards, and the inner part of the groove por¬ tion 12 connecting with the vertical groove portion 13 has a width which is somewhat greater than the smallest cross-sectional dimension of the barbed wire. In the transition to the vertical groove portion 13, the barbed wire is turned about 45° as shown in Fig. 7. When mount¬ ing barbed wires high up, such turning can suitably be carried out by means of a turning tool fitted with a handle. In Fig. 8, the barbed wire has been moved down¬ wards through the vertical groove portion 13 and is located in the lower widened part 17. If, for some rea¬ son, the barbed wire should be moved upwards through the vertical groove portion to the position illustrated in Fig. 9, the barbed wire still cannot be removed from the groove, unless actively turned about 45°. This embodiment thus affords improved security against intentional as well as unintentional release. The embodiment is not restricted to precisely barbed wire, but is applicable to all types of wire of substantially elliptic cross-sec¬ tion. In an embodiment in which the fence comprises a wire netting in its lower part, which via a carrying line or loop is fixed in a groove of the wire fastening means, the groove portions of the lowermost groove can suitably be wider than the other grooves which are designed as described above.

Possible Modifications of the Invention

Of course, the invention can be modified in various ways within the scope of the appended claims. For in¬ stance, the wire fastening means can be manufactured from many different materials such as plastic and various metals. It may also be adapted to be supported on posts and to carry wires of different materials and of different cross-section. Furthermore, the wire fastening means need not necessarily be made by bending a plate, but may also be, for example, injection moulded. In this case, it is possible to use flanges of different shape and in dif¬ ferent positions. It is thus not necessary that the flange be positioned at a longitudinal side edge of the wire fastening means. The means for fixing the wires to the wire fastening means can be designed in many different fashions and need not be recessed grooves. Corre¬ spondingly, the hook need not be manufactured exclusively by bending the plate, but may consist of, for example, a separate member which is attached to the plate. Moreover, the plate member need not be planar, but may be e.g. arched so as to facilitate connection with a round post. By using a hook or a hook-shaped member as fixing means in the upper portion of the wire fastening means, the mounting of the wire fastening means on high posts is, as mentioned above, facilitated by the upper end of the wire fastening means being hooked on to the post, whereupon the lower portion may readily be connected by screwing or riveting at a considerably lower height. However, the in¬ vention is not restricted to a wire fastening means with a hook member in its upper end. In case of, for instance, premounting of the wire fastening means before the posts are set up, connection of the upper portion can also be carried out by an optional fixing means, such as screws or rivets. The fixing means for connecting the lower part of the fastening means to the post need, of course, not be precisely a prebored hole, and a rivet or screw insert¬ ed through the hole. It should thus also be conceivable to use self-tapping screws or, in wooden posts, nails.