Page 69 - Wire Rope News & Sling Technology - June 2019
P. 69

                                                              such as compression of a core cable by rolling.
                                                               On the other hand, if it is desired that the denticulation
                                                              be reduced, it is possible to use a core cable with smoothed
                                                              outer strands or a smooth core strand. The aforementioned
                                                              compression of an outer strand layer on an elastic substrate
                                                              made of plastic in accordance with the invention can also be
                                                              realized in a wire cable with a core that consists exclusively
                                                              of a plastic strand: here too, the wire cable can be hammered
                                                              after the stranding of the strand layer, and thus the strand
                                                              layer can be compressed and smoothed. The wire cable re-
                                                              ceives a higher space factor and becomes resistant to surface
                                                              wear, especially when running over rollers.
                                                               As a rule, standard strands with a core wire and only one
                                                              wire  layer  or  parallel-lay strands are  used  for  the  outer
         Figure  20: Schematically  shows  a  wire rope and a  cross-section  of
         hammers having a tapering inlet.                     strand layer, since  they have no wire  intersections.  How-
                                                              ever, it is also possible to use strands with a readily deform-
         plastic. Under these conditions, very strong deformation of   able core, e.g., a core of soft iron or plastic.
         the outer strands is possible. If the outer strands constitute   As has already been hinted, it is advantageous to use pref-
         a large portion of the cable diameter, reductions of the di-  erably four hammers for the hammering, which are moved to-
         ameter of the wire cable of more than 10% can be achieved.   wards the wire cable from different sides and essentially com-
         A 5% reduction of the diameter can probably be achieved in   pletely surround it with adapted curvatures at the instant of
         most cases.                                          their simultaneous impact. In addition, the hammers should
           Deformation of the core cable or the core strand, the latter   have an axial extent of at least twice the cable diameter and
         to a lesser extent, continues similarly towards the inside to   preferably should have an expanded, tapering inlet.
         a diminished extent but in the opposite way: Here, the out-  If there should be a need for it, after it has been hammered,
         er wires remain essentially unchanged on the outside and   a wire cable of the invention could additionally be subjected
         are deformed on the inside, including the remaining strand   to a surface treatment or coated or provided with a sheath.
         cross section, such that the deformation more or less contin-  The wire cable can also serve as the core cable for the pro-
         ues further into the interior of the cable.          duction of a wire cable, which then has, for example, an ad-
           Essentially no notches occur at intersecting wires of the   ditional counterwound strand layer on the smooth surface.
         core cable or the core strand, on the one hand, and of the   Looking at figures 19 and 20, a core cable 1, which consists
         outer strands, on the other hand. The plastic intermediate   of a central core strand 2 (1+6) and six strands 3 (1+6), is
         layer does not really act as direct cushioning between these   surrounded by a thermoplastic 4. During the stranding pro-
         wires, but rather the conditions are comparable to a confined   cess on the core cable 1, an outer strand layer 5 that consists
         liquid, in which the pressure is exerted towards all sides, so   of six strands 6 (1+6) is pressed into the plastic 4, which has
         that no significantly increased forces at all arise between the   been softened by heating.
         intersecting wires.                                   During this treatment, the outer strands 6 were strongly
           In accordance with the invention, it is possible to produce   deformed. However, on their underside, the wire cross-sec-
         wire cables with an extraordinarily high metal cross section   tional sections 8 that lie in the plastic 4, i.e., that lie below
         that have no internal damage and, in addition, have a very   the dot-dash line 7, are largely preserved in their original
         smooth surface. It is also possible to produce a wire cable   form. The core cable  1 was also somewhat deformed and
         with great structural stability due to close denticulation of   compressed, but this occurred to only a slight extent in this
         the outer strand layer with the core cable or the core strand   case and is not shown in the drawing. Figure 20 shows the
         by the elastic intermediate  plastic layer and at  the same   wire rope and hammers 10 in a cross-section along the axial
         time greater compression than is possible by other methods,   extension of the wire rope. WRN

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