Apparatus for the manufacture of a roll of coiled, clamped barbed wire

#The present invention relates to a method and apparatus for the manufacture of a roll of coiled barbed strap, and more particularly to such a coiled barbed strap the loops of which, in pairs, are provided with an odd number of clamps of at least three per loop and are axially separable from each other within each roll, such that each strap loop passes around one screw line.

#A prior art method of producing coiled barbed strap is illustrated in FIGS. 1 through 4 of German Pat. No. 23 48 714. According to the thus known method, the barbed strap is coiled, the clamps corresponding to the number of clamps per coil are placed on two adjacent loops and the barbed strap is cut after the last clamp is placed. To this end the barbed strap loops are produced with the aid of a cylindrical winder in the core through continuous coiling of the barbed strap, which is under tension, whereby the winder is continuously displaced in the direction of its longitudinal and rotational axis in accordance with the inclination of the strap loops, so that the winder performs a screw-type movement. Prior to the beginning of this screw-type movement, the beginning end of the tangentially supplied barbed strap is detachably connected to one end of the winder. A rotary table is arranged coaxially to the winder, which table revolves synchronously with the winder but remains still axially. This rotary table supports a plurality of clamping devices, namely five, for example, which corresponds with the number (five) of clamps for every two loops of the barbed strap, so that during the uninterrupted rotation of the winder, each clamping device is activated one for every two rotations, thereby connecting two adjacent loops of the barbed strap by a clamp.

#It is disadvantageous in the known method that the lengths of the strap loops produced by winding the barbed strap onto radial ribs of the winder can vary as a result of failures during production (stamping and edging process) of the barbed strap and/or as a result of nonuniform welding of the cross bars of the winder an that, in some cases, the strap sections, which are crimped to assist in the crease closure of the crimped barbed strap around a support wire, do not rest with sufficient phase-equal precision beneath the clamping devices to allow the clamping to be performed without difficulty.

#FIG. 1 is a curved barbed strap section in top view,

#FIG. 2 is a schematic illustration of an axially spread apart coil with clamps in a plane,

#FIG. 3 is a similar schematic illustration to illustrate the strap cutting process,

#Referring now in detail to the drawings wherein like parts are designated by like reference numerals throughout, there is illustrated in FIG. 1, an originally flat barbed strap 10 provided on its two edges with oval cutouts 11a that leave pointed barbs 11b on coplanar wings 11c. Between the rows of cutouts 11a that oppose each other perpendicularly to the longitudinal direction of the strap, there remains a narrow strap web 13. This strap 10 is creased on one side in the center over its entire length, including in its wing sections, so that a support wire 12 of spring steel can be embedded therein. After the embedding there takes place a crimping of the strap web 13 between two successive wing pairs, so that the support wire 12 is securely surrounded. The thus-formed barbed strap is then formed into a coil by winding, the layout of which is shown in FIG. 2, which shows that a clamping of adjacent winding coils 1 through 9 is provided by means of clamps 14 distributed in equal fifths relative to the periphery of two windings. Any uneven number of divisions is possible.

#As shown in FIGS. 4 and 7, the wire-free, completely flat barbed strap 10' coming from a supply roll (not shown) is guided into a creasing device 22 by a pair of rollers (20) to crease the flat barbed strap 10' so that it can receive the support wire 12 in the crease. The support wire 12 coming from a supply roll (not shown) is introduced at the point 24 from the side and below into the open crease in the barbed strap 10". Rollers 30 of a crimping device 28 effect the crimping of the strap web 13, so that the support wire 12 is securely surrounded. The crimping rollers 30 are driven by means of a regulated direct current drive 32. Two draw-in roller pairs 40 of a draw-in device 38 are driven by intermediate gears by this single drive 32 of the apparatus. The roller pair 20 of the creasing device 22 is not driven; the barbed strap 10' is pulled through the rollers 20 by the draw-in roller pairs 40.

#The finished barbed strap 10 is fed by the draw-in roller pairs 40 to three bending rollers 48, 48', 48" and three following guide rollers 46 of a stationary coiling device 50 and is formed into a coil by these rollers 46 and 48. The rollers 46 and 48 are formed in such a manner that the barbs 11b of the barbed strap 10 pass unhindered through these rollers and the barbed strap 10 with the inserted support wire 12 is rounded in the plane of its wings 11c without deforming them; see FIG. 9. A guide device 118 attached to a plate 145 is provided to guide the wings 11c of the two coils of the barbed strap 10 to be clamped, which guide device 118, according to FIG. 6, includes as exchangeable elements three covers 111, 111a and 116 that guide a front coil of the barbed strap 10 on its wings 11c, three guide elements 112, 112a and 113 that guide a center coil and a guide support 114 that guides a rear coil, which together guarantee a certain curvature of the strap.