Page 68 - Wire Rope News & Sling Technology - June 2019
P. 68

INVENTOR’S CORNER
         continued from previous page                         nel 30 is open engagement of segment teeth 50, such that a
         keeping the pieces nominally engaged, for example by keep-  cable easily can be added or removed.
         ing gear segments 41 nominally engaged with one another.
         This allows for substantially easy and seamless alignment   Method for producing a wire cable
         of  the  segments and pieces  when  one  wedge piece  is  piv-  Pat. 10,260,198 U.S. class D07B 1/068 Int. class D07B 5/00
         oted, without requiring gear teeth to “catch” on their own.   Inventor: Roland Verreet, Aachen, DE.
         One useful means for nominally engaging segments 41 is by   Assignee:  CASAR  DRAHTSEILWERK  SAAR  GMBH,
         means of some kind of tension-inducing tether, for example   Kirkel, DE.
                                                               A method for  producing  a  wire  cable  with  a core  cable
                                                              or core strand, the method including the steps of: prior to
                                                              stranding an outer strand layer, applying an intermediate
                                                              layer of a plastic material to the core cable or core strand;
                                                              pressing  the outer  layer into  the plastic material during
                                                              stranding; and, hammering the wire cable, after the outer
                                                              strand layer has been stranded, to increase the space fac-
                                                              tor of the wire cable, wherein the hammering step includes
                                                              hammering with  hammers that are moved from different
                                                              sides toward the wire cable and essentially completely sur-
                                                              round the wire cable with adapted curvatures at the instant
                                                              of their simultaneous impact.
                                                               The objective of the invention is to prevent wire damage
                                                              caused by hammering to the greatest possible extent. In ac-
                                                              cordance  with  the  invention,  this  objective  is  achieved  by
                                                              applying an intermediate layer of a plastic material to the
                                                              core cable or core strand before the outer layer of strands is






         Figure 17: Perspective view of a timed gripper system in a closed position.

         by means of an elastomer. In the figures, a tension bolt 80
         extends up from the upper surface of wedge 20, by attaching
         to a bolt opening 82. An elastomer, such as an O-ring 60,
         then can be stretched across two opposing tension bolts, the
         elastomer’s stretching capacity defining the limit to which
         wedges pieces 20 can be rotated away from one another via
         a pivot point 22. Figures 17 and 18 illustrate an embodiment
         where an elastomer 60 limits the cable surface aperture of
         the wedge pieces in the gripper assembly. In figure 17 the
         wedge pieces are in close proximity, the inner concave sur-  Figure 19: Cross-sectional drawing showing an embodiment of the
         faces 32 together defining a channel for receiving a cable or   wire cable.
         wire rope. In figure 18, wedge pieces 20 are rotated away
         from one another via pivot point 22, and the central chan-  stranded and by pressing the outer layer of strands into the
                                                              plastic during the stranding process.
                                                               It was found that the support of the outer strands on the
                                                              elastic plastic does not impair the hammering and the de-
                                                              sired deformations. In a hammer works in which hammers
                                                              adapted to the curvature of the surface of the cable strike
                                                              simultaneously from different sides and essentially com-
                                                              pletely surround the surface of the cable at the instant of
                                                              their simultaneous striking of the surface of the cable on an
                                                              axial length of at least twice the cable diameter, the plastic
                                                              apparently does  not  have  enough  time or  space  to  escape
                                                              from under the blow. The cavities between the outer layer of
                                                              strands and the core cable or core strand are preferably filled
                                                              with the plastic as far as the wedge-shaped spaces between
                                                              the wires bounding these cavities.
                                                               Deformation of the outer strands occurs, more or less ex-
                                                              cluding those cross-sectional regions of the wire on the un-
                                                              derside that are surrounded by the plastic and receive the
                                                              counterpressure of the plastic everywhere perpendicular to
                                                              their surface; they are thus not exposed to any deforming
                                                              forces here. Directed forces, which deform the wires, occur
         Figure 18: Perspective view of a timed gripper system in an open position.  on the upper side of these wires, which is not surrounded by

         68     Wire Rope News & Sling Technology   June 2019
   63   64   65   66   67   68   69   70   71   72   73