GB1198232A - Hoist Mechanism for Bucket - Google Patents

Abstract

1,198,232. Winding arrangements. RUSTONBUCYRUS Ltd. 20 Feb., 1969 [4 March, 1968], No. 9126/69. Heading B8B. [Also in Divisions E1-E2] A hoist mechanism-for the bucket 13 of a dragline excavator comprises two independently driven drums 14, 15, a pair of cables 16, 17 and 18, 19 extending from each drum, and a suspension arrangement which together with the torque/speed characteristics of the drum drive motors, results in an equal sharing of the load of the bucket 13 by the drums. The bucket is supported by a suspension bar 23 which at one end has a rigid beam 27 and at the other end has a pivoted equalizer beam 25, one cable from each of the drums being coupled to opposite ends of each of the beams 27, 25. Any difference in the torque of the drums 14, 15 is balanced out in the cables 16, 18 due to their connection to the pivoted beam 25, but results in a difference in force in the Gales 17, 19 attached to the rigid beam 27. The motors driving the drums 14, 15 produce low torque at high speed, and therefore, any difference in torque between the two drums will result in the higher torque drum slowing down while the lower torque drum speeds up until the torques are equal, whereupon the two hoist drums are kept substantially in step at all times. The beams 25, 27 are each connected to the suspension bar through universal joints 26. A block 29 for the bucket dump rope 30 is mounted on the suspension bar 23, the rope extending between an arch 31 on the bucket, and the drag rope 34.