GB1213106A - Anti-sway mechanism for suspended loads - Google Patents

Abstract

1,213,106. Preventing swinging of loads in cranes. FRUEHAUF CORP. 30 April, 1969 [23 May, 1968], No. 22124/69. Heading B8B. Swinging of a load 55, Fig. 8 (which may be e.g. a cargo container 21 or a truck trailer 23 with a container 21 on it), is damped by an anti-sway mechanism 25 secured to a lifting platform 27 and comprising arresting ropes 41 wound on drums 51, two of which are mounted on each end of a shaft 29. The ropes 41 extend in opposite directions from each end of the shaft 29 and the ropes 41 from either end of the shaft 29 are connected to opposite sides of the load 55. The arrangement is such that a brake 39 comprising a drum 43 and shoe 45 opposes the pulling of the ropes 41 off the drums 51, whilst no braking occurs when the ropes 41 are rewound by rewind means including independent prewound spring motors 57 engaged with each of the drums 51 take up slack in the ropes 41, internal unidirectional clutches (not shown) being provided in each drum 51. Fig. 8 shows the load 55 moving with pendulum motion in a lateral direction. The ropes 41 are pulled off both the lower drums 51, turning the shaft 29 and causing work to be done on the brake 39. Concurrently the upper drums 51 are overrunning and their ropes 41 are being rewound on to them by the spring drums 57. Other unwanted load motions are similarly damped. When used on a low lift crane, e.g. as shown in Fig. 1, the brake may be permanently engaged, Fig. 4 (not shown), or for high lift cranes the brake may be disengaged for lowering by hydraulic cylinder, solenoid or mechanical means. Sway of a point load, or one suspended from a single cable, may be arrested by running all the ropes 41 to the load hook. A simpler unit with only one drum 51 at each end of the shaft 29 may be used under certain conditions (not shown).