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

INVENTOR’S CORNER
         35 acts on the rotating bed 20 predominantly, and in this
         case only, through the counterweight support frame.
           A counterweight movement system is connected between
         the rotating bed 20 and the counterweight unit 35 so as to
         be able to move the counterweight unit 35 toward and away
         from the boom. The counterweight unit 35 is moveable be-
         tween a position where the counterweight unit is in front
         of the rearmost fixed portion of the rotating bed, such that
         the tail swing of the crane is dictated by the rearmost fixed
         portion of the rotating bed (as seen in figures 21 and 22),
         and a position where the counterweight unit dictates the tail
         swing of the crane (as seen in figures 23, 24 and 26). Prefer-
         ably the counterweight unit 35 can be moved to a point so
         that the center of gravity of the counterweight unit is near
         to, and preferably even in front of, the rear tipping fulcrum
         16 of the crane, as seen in figure 21.               Figure 26: Partial side elevation view of the crane.
           The counterweight movement system in the crane 10 com-
         prises a counterweight unit movement device made up of a   ment device has two spaced apart identical assemblies, and
         drive motor 40 and a drum on the rear of the counterweight   thus the drive motor 40 drives two drums 42, best seen in
         support frame 32. Preferably the counterweight unit move-
                                                              figure 24. Each assembly of the counterweight unit move-
                                                              ment device further includes a flexible tension member that
                                                              passes around a driven pulley and idler pulley 41 (best seen
                                                              in figure 24). The driven pulleys are provided by drums 42.
                                                              The flexible tension member may be a wire rope 44 as shown,
                                                              or a chain. Of course if a chain is used, the driven pulley will
                                                              be a chain drive. Both ends of each flexible tension member
                                                              are connect to the counterweight tray 33 as seen in figure 26,
                                                              so that the counterweight unit 35 can be pulled both toward
                                                              and away from the boom. Preferably this is accomplished by
                                                              having an eye 43 on both ends of the wire rope 44 and holes
                                                              in a connector 45 on the counterweight tray 33, with pins
                                                              through the eyes and the connector 45. Thus, in the crane
                                                              10, the counterweight  unit movement device is connected
                                                              between the counterweight support frame 32 and the coun-
         Figure 25: Partial rear elevation view of the crane.
                                                              terweight unit 35. WRNWRN



                                                       Adolf Bleichert & Co. celebrated its 50th
                                                       Anniversary in 1924. By the time of this occasion,
                                                       the company had constructed 3,000 miles
                                                       of wire ropeways at landmark points around
                                                       the globe, and designed and built the world’s
                                                       record-holding systems: Longest and highest
                                                       elevation (Argentina); Length of system over
                                                       water (New Caledonia); Steepest (Tanzania);
                                                       Highest capacity (France); Northernmost
                                                       (Norway); and, Southernmost (Chile).

                                                       Adolf Bleichert & Co.’s Wire Rope Systems:
                                                       Written by the great-great grandson of the
                                                       company’s founder, this book includes over 100
                                                       pictures and detailed engineering drawings that
                                                       explore the legendary company’s history.


                                                                       Available at Amazon for your
                                                                       Kindle or in paperback.


                                                                       ‘Like’ it on Facebook.



                                                            Wire Rope News & Sling Technology   December 2019  69
   64   65   66   67   68   69   70   71   72   73   74