GB1155410A - Apparatus for Aligning Crane Loads or the like - Google Patents

Abstract

1,155,410. Self-levelling lifting devices. W. A. M. POMPE. 23 Sept., 1966 [14 May, 1966; 12 Aug., 1966], No. 42711/66. Heading B8H. When a load having a centre of gravity to the left of a pivot 8, Fig. 1, is raised by a selflevelling lifting beam 1 the beam will turn anticlockwise and an upper spring 26 will be compressed by an arm 24b. After a short time-delay, fluid will be pumped from a ram 10 by the weight of the load into the left-hand side of a ram 9, thus moving trolleys 4a ,4b, from which the load is suspended, to the right to effect a balance. As the load is raised a spring 18 is tensioned. This acts as an energy accumulator for returning the device to its original condition after the load has been set down. As shown in Fig. 2 a beam 41 is suspended from a pivot 48 by rams 44, 45. If the centre of gravity of the load is to the left of the pivot 48 the beam will rotate anticlockwise and an arm 52 will turn clockwise moving a regulating slide 56 downwards. This allows fluid to flow from the ram 45 to a tank thus causing extension of the ram. As a result, the pivot 48 moves upwards and to the left until equilibrium is reached. Springs 59 store the energy for returning the device to its original condition. Fig. 3 shows an arrangement in which a beam 11 is supported by a pair of rams 2, 3 and a chain 14 which passes round a sprocket 15. If fluid is forced out from one of the rams the piston-rod will descend and the sprocket 15 will be rotated by the chain 14. This will cause sprockets 17 to rotate and drive trolleys 10, which connect the beam to the rams 2, 3, to either the right or the left by means of chains 18. The flow of fluid from rams 2, 3, Fig. 3b, is controlled by valves 27 which are opened when floats 29 move downwards. A flow of fluid occurs between float chambers 35, 36 through a pipe 39 when the beam is tilted.