GB1020548A - Weighing apparatus - Google Patents

Abstract

1,020,548. Weighing load on a crane. DAVY UNITED INSTRUMENTS Ltd. Nov. 7,1963 [Nov. 12, 1962], No. 42625/62. Heading G1W. Relates to an apparatus for weighing the load on a crane or hoist. As shown diagramatically Fig. 1 a pulley 13 is suspended from a jib block through a load cell 18 which gives an indication of the sum of the loads in falls B and C, the total load on a hook 17 being carried by four falls ABCD is therefore twice the value measured. Fig. 2 shows a jib top pulley arrangement with the load cells incorporated whereby accurate measurement of load is obtained irrespective of the angle of the jib, the load cells 23, 27 being automatically aligned with the direction of the force due to the load being weighed. A hoist pulley 12 is free to rotate on a shaft 20 rotatable in bearings 21 and the shaft has keyed to it a footstep 22 for the load cell 23. A shaft 24 carried in bearings 25 and with its axis in line with that of the shaft 20 has a footstep 26 for a load cell 27. The two load cells support a loading rig 28 which bridges a pulley 13. This pulley is free to rotate on a shaft 30, whose axis lies below the axis of the shafts 20, 24, and which is secured in a U frame 31 welded to the rig 28. Extending from the frame 31 are two pairs of arms 32 (Fig. 2) and (Fig. 3 not shown) each pair embracing extensions 33,35 respectively of the shafts 20, 24, and joined thereto by rods 34 which, by flexing, permit downward movement of the frame 31 thus influencing the load cells. As the jib angle varies the structure including the load cells and the pulley 13 so swings about the axis of the shafts 20, 24 that the axis of the pulley 13 and the contact between the load cells and their footsteps always lie in a common vertical plane. The use of one load cell instead of two is described (Fig. 4 not shown).