GB1039315A - Tower crane - Google Patents

Abstract

1,039,315. Self-erecting tower cranes RICHIER. March 20, 1964 [March 22, 1963], No. 12005/64. Heading B8B. A tower crane comprises a platform 1, with shoes or wheels for bearing either on the ground (as shown) or on rails, on which is mounted a slewing platform 3 carrying a telescopic tower 12, 13 supporting a telescopic luffing jib 6, 14 on a frame 5. The platform 3 mounts a load winch (not shown) and a two-drum winch (not shown) for erecting the tower 12, 13 and for luffing the jib 6, 14. The collapsed crane (Fig. 1) is towed on road wheels by a tractor 8 to an erection site and the shoes or wheels on platform 1 unfolded to contact the ground or rails and the road wheels removed. The two-drum is started and the first drum engaged to wind a cable (not shown) which through a link 9 erects the tower 13, combining a rotational movement about a horizontal axis perpendicular to the tower 13 and a translation of that axis along platform 3 into the position shown in Fig. 3. At the same time a link 10 causes a balance weight box 2 pivoted to platform 3 to move from its horizontal retracted position (Fig. 1) to its vertical working position (Fig. 3). The tower 13 is pinned to the platform 3 and continued operation of the first drum causes the extension of the inner tower member 12. During this extension fixed abutments (not shown) on the inner tower member 12 lift the frame 5 to which the jib 6, 14 is pivoted at 7 and thus extend the jib. The completion of this phase is shown in Fig. 4. The first drum is then disengaged and the second drum engaged to lift the extended jib 6, 14 to the working position (Fig. 6). Instead of a winch hydraulic or screw jacks or a rack system may be used. The jib may carry a trolley or crab and the frame 5 carrying the jib may be mounted on a system of articulated links instead of sliding on the tower.