GB867726A - Integrating conveyor scale - Google Patents

Abstract

867,726. Electric weighing machines. TOLEDO SCALE CORPORATION. Nov. 26, 1958, No. 38206/58. Class 40 (1). [Also in Group XVIII] An integrating conveyer weighing machine comprises a strain gauge device for determining the loading on a continuously moving conveyer belt, feeding the signal to a ball and disc multiplier together with a speed proportional to the belt speed, and supplying their product to a counter which indicates total weight carried by the belt. As shown (Fig. I), an endless belt 3 rests on weighing rollers 2, 4 associated with the loaded and unloaded parts of the belt. The rollers are suspended by equal arms about a fulcrum 6, the difference in weight producing a displacement of an extension 9 attached to a strain gauge cell 8 connected in a balancing bridge circuit (Fig. II). The bridge unbalance current drives a motor 10 which rebalances the circuit by moving the slider 34 of a potentiometer 36, the extent of movement being indicated by a pointer 41, simultaneously moving a rod 11 attached to the ball housing 14 of the ball and disc multiplier 12. The belt speed is sensed by a pulley 103 and fed via selsyn link 19, 21 to the disc 13 of device 12, the rotation of output cylinder 16, which is proportional to the product of instantaneous weight and speed of the belt, being fed to a counter 27 through a differential 24 which removes a constant deliberately introduced into the output from the strain gauge cell 8 to prevent the ball housing 14 from being located at the centre of disc 13. Mechanical construction.-The weighing beam assembly is supported by two vertical rods 48 (Figs. III, IV), attached to the frame 7, and comprises twisters 51 joined by a shaft 52 and rotatable about knife edges 51. The shaft 52 carries an adaptor 53 supporting a lever 55 on which a counterweight 56 is adjustably supported to counterbalance the dead weight of the system, and an extension 9 attaches the shaft to the load cell 8, which may incorporate an overload guarding mechanism 61. Rods 70 attached to one side of twisters 51 support plates 73 and brackets 77, carrying between them the upper roller 2. Rods 72 attached to the other side of twisters 51 support plates 88 and brackets 92, carrying between them the lower roller 4.