GB1361766A - Mobile crane - Google Patents

Abstract

1361766 Mobile jib cranes HARNISCHFEGER CORP 20 Dec 1972 [27 Dec 1971] 58968/72 Heading B8B [Also in Division F2] A mobile crane 10 comprises a vehicle 12 on which a boom 26 is mounted for luffing and slewing, the centre of gravity of the crane 10 describing a non-circular path 45 around the slewing axis 36 as upper crane unit 14 rotates carrying the boom 26 at a constant boom angle. The crane 10 is stabilized by outrigger assembly 16 and is shown on a dock 18 with a ship 20 alongside. The outrigger assembly 16 comprises similar right side and left side sections 44, 46 and is movable from a raised transport position to the lowered supporting position shown. Rigid transfer beam 70 is connected, with a very limited amount of play, to hydraulically operated, telescopic outrigger beams, 50, 54. Front and rear equalizer beams 80, 82 are connected by bearings 114 to the transfer beam 70 and respectively carry floats 84, 86 and 88, 90 through similar bearings 114 giving at least a limited degree of movement. Fig. 5 shows that the bearing 114 connecting the transfer beam 70 to the rear equalizer beam 82 comprises a pair of rigid steel plates 116, 118 spaced by an elastomeric block 121 and preferably bonded thereto. A rod bolt 128 passes through apertures 122, 124, 126 and has nuts 130, 132 on either end prevented from rotation by cotter pins 134, 136 passing through holes in the rod bolt 128 and engaging grooves 138 in the nuts 130, 132. Convex bearings 150, 152 at either end of the rod bolt 128 co-operate with respective concave bearings 146, 148 secured in hollow, cylindrical bearing retainers 140, 142. In practice it is desirable to tighten the nuts 130, 132 so as to compress the elastomeric block 121 and preload the bearing 114 to prevent undue play.