GB738353A - Improvements in and relating to belt load weighing apparatus - Google Patents

Abstract

738,353. Electric indicating systems. HARTSHORN, S. D. Aug. 17, 1953, No. 22584/53. Class 40 (1). The load carried by a travelling belt is measuring by a resistance strain gauge supporting a pivotal carriage having rollers over which the belt passes. As shown, the upper run of the conveyer belt 10 passes over rollers 21, 20 carried on a rockable carriage 19 pivoted at 17 to brackets 18 carried by longitudinal frame members 15. The carriage 19 is also supported by a strain-sensitive device 26 on a cross-frame member 25. The strainsensitive device may alternatively be arranged to be tensioned by the conveyer load. The carriage 19 may also carry troughing rollers 29 and its pivotal axis 17 is arranged, by using various brackets 18, in line with the centre of gravity of the load. The carriage may also be counterbalanced by weights at its righthand end corresponding to the belt tare. The lower run of the belt drives a tachometer generator through a pulley 36. Circuitry. The load-sensing device 26 carries strain gauges 50, 51, Fig. 3, arranged in opposite arms of a bridge fed from the belt driven tachogenerator 35. Zero adjustment of the bridge is effected through an adjustable resistor 41. The bridge output may be fed to a watt-hour meter for integrating the load over a period or may be indicated and recorded by means of an automatically-balanced potentiometer. Two weighing stations may be used, separated by a point at which the belt is loaded, the difference between the two loadings being indicated or recorded by connecting the respective bridge outputs differentially to the meter.