Page 56 - Wire Rope News & Sling Technology






Page 56 - Wire Rope News & Sling Technology
P. 56



                             By William Fischer

         Thank you for your interest in our publication
         and this month’s patent submissions for The
         Inventor’s  Corner. Summer  is here,  but as
         I write  this, we  haven’t  seen  the  sun in the
         northeast  for  about  a week  now. Hopefully,
         we  will eventually  be  able  to  enjoy  actually
         getting out of the house. I hope all our readers
         are having a great summer.
         Editor: We’ve had a few nice Spring-like days since this month’s Inventor’s Corner
         was submitted. Of course in our “neck of the woods” here in New Jersey, Winter
         is that unwanted guest that stays longer than expected and Summer checks in
         long before the room is ready!

         Mobile crane having counterweight
         Pat. 8,528,755 U.S. class 212/196 Int. class B66C 23/76
         Inventor: Hitoshi Kurotsu, Akashi, JP.
         Assignee: Kobelco Cranes Co., Ltd., Tokyo, JP.
           This patent provides a mobile crane capable of adjusting a
         counterweight height with no use of a costly hydraulic cylin-
         der. The mobile crane comprises a lower propelling body, a
         upper slewing body, a boom pivotably attached to the upper
         slewing body, a mast which is at the rear of the boom and
         adapted to be raised and lowered so as to raise and lower the
         boom, a counterweight which is at the rear of the upper slew-

                                                              Figure 2: Top plan view of a propelling body of the mobile crane.
                                                              ing body and hung from the mast through a guy line, and a
                                                              counterweight-lifting cylinder attached to the counterweight
                                                              so as to be extended to vertically push up the counterweight
                                                              with respect to a ground surface. The counterweight-lifting
                                                              cylinder has a cylinder body, a piston partitioning an inter-
                                                              nal space of the cylinder body into an upper head-side cylin-
                                                              der chamber and a lower rod-side cylinder chamber, and a
                                                              rod extending from the piston downwardly beyond an lower
                                                              end of the cylinder body. the counterweight-lifting cylinder
                                                              is extended by supply of a hydraulic pressure into the head-
                                                              side cylinder chamber and retracted by supply of a hydraulic
                                                              pressure into the rod-side cylinder chamber.
                                                               Figure 1 shows a mobile crane 1. This mobile crane 1 is a
                                                              counterbalance type crane, having not only upper slewing
                                                              body-rear end counterweights 22, which are one attached to
                                                              an rear end of the upper slewing body 20, but also a coun-
                                                              terweight 50 (extra counterweight) disposed at the rear of
                                                              an after-mentioned upper slewing body 20. Specifically, the
         Figure 1: Overall view of a mobile crane.            mobile crane 1 comprises a lower propelling body 10, a upper

         56     Wire Rope News & Sling Technology   June 2018
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