JIB CRANE Russian patent published in 1997 - IPC

FIELD: manufacture of hoisting-and-conveying machinery. SUBSTANCE: jib crane has two column supports fixed on truck body and trailer and two column heads mounted alternately on the supports. Top part of each head is made in the form of open rectangle. Crane jib is mounted on the column head with the aid of bearing unit including case with hollow rectangle secured on the case through cantilever. The hollow rectangle is inserted into the open rectangle and retained in the working position by means of pin. Hollow axle of the bearing unit caries worm gear engaged with worm secured on the case. The jib is slewed in the horizontal plane and fixed in the required position by revolving the worm with the use of handle. Rope with load hook secured to its end is reeved through rope pulley mounted on the jib to be fixed in different points of the jib and through another pulley bloc. Further on it is passed through the hollow axle and reeved between two rope blocks. The other end of the rope is secured on drum with brake in the form of safe handle seated on one end of the brake shaft. The other end of the brake shaft is splined. EFFECT: enhanced safety and reliability of jib crane operation. 5 cl, 4 dwg