GB863307A - Improvements relating to cranes, grab cranes and the like - Google Patents

Abstract

863,307. Winch controls. PRIESTMAN BROS. Ltd. Nov. 27, 1957 [Nov. 27, 1956; July 29, 1957], Nos. 36283/56 and 23974/57. Class 78 (5). [Also in Group XXIV] A winch drum on a crane, especially a grab crane, is driven in opposite directions by two clutches controlled by movement in opposite directions of a single lever which also controls a brake on the drum. In the form shown, the drum 1. Fig. 1, is mounted on bearings 2 on a shaft 3 driven from a wheel 4, and may be driven through an epicyclic gear train 46, 45, 47, of which the sun-wheel 46 is keyed to the shaft 3, by applying a braking force to the planet carrier 49. This rotates the drum in the opposite direction to the shaft and at a reduced rate. Alternatively, the drum may be clutched directly to the shaft by braking a drum 57, Fig. 3, loose on the shaft 3 and connected by a link 70 and bell-crank 69, 67, pivoted at 68 to the driving wheel, to a band 59 whose end 65 is attached to the driving wheel. Braking the drum 57 causes the band 59 to tighten on a drum 60 attached to the rope drum 1, and hence to clutch the drum 1 to the driving wheel 4. A brake drum 42 is also attached to the drum 1. In a modification, Figs. 4, 5, allowing both clutches to be located at the same end of the rope drum, the rotating band 101 is attached to the planet carrier 83 instead of to the wheel 4, and the bell-crank 97, 99 has one arm on each side of the planet carrier. Braking the drum 95 causes the planet carrier to be locked to the annulus and hence the whole epicyclic train is locked solid and the drive is transmitted direct from shaft 3 to the rope drum. In either embodiment the clutches are controlled by a single lever 10, Fig. 5, pivoted at 11 so that movement to position 10a tightens the band 90 and movement to position 10b tightens the band 81 on to the planet carrier. In either end position the lever 10 is locked by a gravity biased arm 20 engaging a lug 23 on the lever. Depression of the brake pedal 25, also pivoted at 11, causes a link 30 to be rotated about its pivot 21 so that a pin 31 lifts the arm 20, allowing the lever 10 to return to its central position. Specification 834,487 is referred to.