Patent Publication Number: US-11021891-B2

Title: Tool for barbed wire

Description:
FIELD OF THE INVENTION 
     The present invention relates to barbed wire, in particular to means for loosening or removing a set of barbs from barbed wire. 
     BACKGROUND ART 
     Barbed wire is used to discourage animals or people from passing through or over a fence line. The barbs can be formed by a variety of methods. Most commonly, a pair of barbs is formed by twisting a short length of wire about the main strand and leaving the two ends of the twist jutting in opposite directions. A set of four barbs can be formed by co-locating two twists and leaving each of the four ends jutting in different directions. Barbed wire is commonly made from one main strand, or two main strands twisted about each other. Two-strand wire is preferred for preventing the barbs from rotating about, or sliding along, the main wire when contacted by an animal. When formed around two strands, the twists have an asymmetrical cross-section, thereby resisting rotation, and the twisted main strands also resist sliding of the barbs. 
     A variant on the above called traditional twist barbed wire is made by a process wherein the short lengths of wire forming the barbs are first inserted between the two main strands before being twisted there around. The sets of barbs on traditional twist barbed wire have an even greater resistance to movement. 
     One problem with barbed wire is the difficulty in handling and tying off the ends, for example to a post or to another wire. To avoid interference from the sets of barbs, wire tensioners are usually rigged with normal, un-barbed, fencing wire which is then attached to the barbed wire. Furthermore, repairs to breaks in the barbed wire are often required. 
     Another problem with barbed wire arises with steel fence posts which have notches, rather than through holes, to retain wire. Each notch is provided with a pivotal clip. The installation procedure is to run the barbed wire alongside the fence posts and then tension the barbed wire. Then the tensioned barbed wire is engaged with the same notch on each post by raising the clip, inserting the wire into the notch, and lowering the clip to thereby permanently interconnect the wire and post. However, for some posts the location of a set of barbs will be exactly opposite the notch with which the barbed wire is intended to be engaged. Under these circumstances it is necessary to remove this particular set of barbs in order to enable the wire to be engaged with the intended notch. This problem particularly arises with so-called exclusion fencing. 
     The sets of barbs interfere with these activities and it is common to first remove them with a pair of pliers or side cutters. However, removal can be a cumbersome process with hand tools, and especially when working with a free end that is not under tension. Also, the use of hand tools such as side cutters can risk inadvertently nicking, kinking, or otherwise damaging the main strands which is relevant since the wire will be re-installed under high tension. 
     Genesis of the Invention 
     The genesis of the present invention is a desire to provide a tool for loosening or removing a set of barbs from barbed wire that overcomes or at least ameliorates some of the deficiencies of the prior art. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention there is disclosed a tool for loosening or removing a set of barbs from barbed wire, said barbed wire comprising at least one strand of wire and a plurality of spaced apart sets of barbs wound thereon, said strand(s) constituting a wire axis, each of said sets of barbs comprising at least one pair of barbs extending in substantially opposite directions from a wire helix wound around said strand(s); said tool having first and second portions each engageable with said barbed wire, each of said portions having an opposed levering element that is radially offset from said axis for applying leverage to said helix, wherein with said first and second portions engaged with said barbed wire: said first and second portions are rotatable relative to each other about said wire axis, and, whereby said relative portion rotation in a first direction abuts each of said levering elements against a corresponding one of said pair of barbs to unwind or unfurl said helix. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Some embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
         FIG. 1  is a perspective view of the barb removal tool of a first embodiment when engaged with a length of barbed wire, 
         FIG. 2  is a partial longitudinal section of the barb removal tool of  FIG. 1  illustrating the unwinding mechanism set against a pair of barbs within the central region of the tool, 
         FIG. 3  is an exploded perspective view of the barb removal tool of  FIGS. 1 and 2  illustrating the means for inter-connection of parts, 
         FIG. 4  is a perspective view of the barb removal tool of a second embodiment when engaged with a length of barbed wire, 
         FIG. 5  is a partial longitudinal section of the barb removal tool of  FIG. 4  illustrating the unwinding mechanism set against a pair of barbs within the central region of the tool, 
         FIG. 6  is an exploded perspective view of the barb removal tool of  FIGS. 4 and 5  illustrating the means for inter-connection of parts, 
         FIG. 7  is a longitudinal section of the barb removal tool of  FIGS. 4 to 6  illustrating the configuration of the unwinding mechanism and the inter-connection of parts, 
         FIG. 8  is an exploded perspective view of the barb removal tool of a third embodiment illustrating the means for inter-connection of parts, 
         FIG. 9  is a perspective view of a still further embodiment illustrating scalloped end portions, and 
         FIG. 10  is a perspective view of an end portion of the device of  FIG. 9  having a modified levering element. 
     
    
    
     DETAILED DESCRIPTION 
     According to a first embodiment there is provided a tool  1  for loosening or removing a set  2  of barbs  3  from barbed wire  4 . 
     The tool  1  is provided with a mechanism  5  for unwinding or unfurling a helical twist  6  of wire from the main strand or strands  7 . The mechanism  5  includes two opposing levering elements  8  that can engage with, and apply leverage to, opposite ends of the helix  6 . By applying leverages that oppose the handedness of the twist  6 , the twist  6  can be unwound or unfurled from the main strands  7  at least sufficiently to allow for its removal. For example, a twist  6  of enlarged diameter can be removed by sliding it off an adjacent free end of the barbed wire  4 . 
     The body  14  of the tool  1  includes two end portions  11  separated by a hollow cylindrical spacer  12  that surrounds a central region  13 . The body  14  is configured to internally accommodate the main strand(s)  7  along their axis  15 , and also to accommodate a set  2  of barbs  3  (and the twist  6  therebetween) within the central region  13  where the unwinding mechanism  5  is housed. The tool  1  has an overall shape which is substantially co-axial about the wire axis  15 . 
     Each of the two end portions  11  has a radially extending slot or aperture  16  for receiving the barbed wire  4  into the body  14  of the tool  1 . Each end portion  11  also supports a corresponding levering element  8 , and is counter-rotatable relative to the other end portion  11  about the axis  15  of the barbed wire  14  when so received. 
     The levering elements  8  of the first embodiment are cylindrical prongs  17  that jut inwardly from the corresponding end portions  11  and extend substantially parallel to the wire axis  15  into the central region  13 . The levering elements  8  are each configured to contact the corresponding barbs  3  at positions that are radially offset from the wire axis  15 , so as to enable leverage against the twist  6 . 
     The end portions  11  can thus engage with the barbed wire  4 , be manipulated to set the unwinding mechanism  5  against the barbs  3 , and then be relatively counter-rotated about the wire axis  15  to unwind or unfurl the twist  6 . 
     The cylindrical spacer  12  of the first embodiment is adapted to ensure the smooth and effective operation of the tool  1 . The spacer  12  axially constrains, and also maintains the alignment of, the end portions  11  and the unwinding mechanism  5  supported thereon. The spacer  12  also has a longitudinally extending slot or aperture  18  to enable the barbed wire  4  to enter into the body  14  of the tool  1 . 
     The inter-engagement between the end portions  11  and the spacer  12  of the first embodiment is achieved by means of a pin  21 -and-groove  22  engagement. As seen in  FIG. 3  the ends of the pins  21  are retained in the circular grooves  22  of the end portions  11 . 
     In other embodiments, the spacer  12  engages with the end portion  11  by analogous means such as a snap fitting, an annular tongue-and-groove fitting, a or staple-and-groove fitting (or staple lock). Preferably the spacer  12  rotates relative to each of the end portions  11 , however, it is also possible to have the spacer  12  fixed to one of the end portions  11 . 
     The engagement of the spacer  12  with the end portions  11  is such that the levering elements  8  maintain their radial position about the axis  15  of the wire  4  when the unwinding mechanism  5  is operated by relative counter-rotation of the end portions  11 . 
     The spacer  12  is provided with several windows  23 . The windows  23  allow the unwound barb to drop out of the tool. The windows  23  also ensure operator visibility of the unwinding procedure, and accessibility of the central region  13  to hand tools, if required. The windows  23  can also allow for the event of a twist  6  tending to unwind in directions other than a circumferential expansion of the helix. 
     When the unwinding or unfurling is complete, the slots  16 ,  18  in the end portions  11  and spacer  12  can be re-aligned by relative rotation of the end portions  11  to allow the tool  1  to be released from the now de-barbed wire  4  by moving the wire  4  out of the slot  18 . 
     It will be appreciated that the above tool  1  can also be used for sets  2  of barbs  3  made up from more than one pair of barbs  2 , for example where multiple twists  6  of wire about the main strand(s)  7  are co-located to provide, typically, four barbs  3  that jut in mutually orthogonal directions. 
     In a second embodiment of the invention, the inter-engagement between the end portions  11  and the spacer  12  is achieved by means of a rivet  24 -and-groove  22  engagement as illustrated in  FIGS. 4 to 7 . 
     The tool  101  of this second embodiment is also provided with a means of increasing friction with the user&#39;s hands, such as a plurality of indents, protrusions, knurling, or scorings  25  disposed about the circumference of each end portion  11 , for ease of counter-rotation. 
     As illustrated in  FIG. 6 , the slot  16  in the end portion  11  of the tool  101  of the second embodiment is also provided with a curved, J-shaped, or hockey-stick shaped portion  28 . This curved portion  28  permits both easy location of the wire  15  within its proper position in the tool  101  and maintenance of that position when the unwinding mechanism  5  is operated. The curved portions  28  of the tool  1  are preferably made with the same handedness such that the wire  14  engages with each curved portion  28  when the end portions  11  are counter-rotated. In other embodiments, the curved portions  28  on the tool  1  are made with opposite handedness. 
     In a third embodiment of the invention as illustrated in  FIG. 8 , the inter-engagement between each of the end portions  11  and the spacer  12  is achieved by means of an annular rim or ridge  26  formed on the inside of the spacer  12  that engages with a valley or notch  27  formed on the corresponding end portion  11 . The spacer  12  is made from mild steel and the spacer ridge  26  is cold-pressed with a roller. 
     Turning now to  FIGS. 9 and 10 , a still further embodiment of the tool  201  is illustrated in which the end portions  211  are provided with scalloped protrusions  225  which enable the operator&#39;s fingers  202  to better engage with the end portions  211 . This is particularly the case where the operator is wearing gloves, which normally reduce the operator&#39;s usual dexterity somewhat. 
     Illustrated in  FIG. 10  is a substantially cylindrical levering element  208  which is provided with a helical rope thread  218 . It will be apparent to those skilled in the art that the barbs  3  although notionally identical at the time of manufacture, are not necessarily identical at the time of utilising the tool  201 . In particular, the barbs  3  may have been bent or otherwise mis-aligned during transportation or installation of the barbed wire, or during subsequent normal operation of the fence. The thread  218  is intended to engage with the corresponding barb  3  and the movement of the levering element  208  drives the barb  3  so as to be more perpendicular to the longitudinal axis of the element  208 . In this way the inter-engagement between the element  208  and the barb  3  is enhanced and maintained. In particular, the barb  3  lies within the groove of the thread  218  and is driven towards the end portion  211  by the crest of the thread  218 . 
     In other embodiments, the levering element  8 ,  208  can be provided with other modifications including a head, similar to the head of the nail, or a plurality of cylindrical ridges which are co-axial with the longitudinal axis of the levering element, or threads other than the above described and illustrated rope thread. 
     In other embodiments, each of the end portions  11  is provided with a means for easily selecting the proper alignment of the slots  16 ,  18  in the end portions  11  and spacer  12 , such as a ball detent pin between each end portion  11  and the sleeve  12 . 
     The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the fencing arts, can be made thereto without departing from the scope of the present invention. 
     The term “comprising” (and its grammatical variations) as used herein is used in the inclusive sense of “including” or “having” and not in the exclusive sense of “consisting only of”.