The Mechanical Handling and Storing of Material

THE AUTOMATIC WEIGHING OF MATERIAL 721 The Integrator.—-This consists of an aluminium disc, around the periphery of which are mounted rollers Y free to revolve. These have their axes tangential to the edge of the disc and form practically a continuous annular roller. The disc x is fixed to a spindle and can revolve in bearings on the frame z. This frame is mounted with a bearing at either end, so that it can rotate around an axis coincident with the plane of the disc and at right angles to the axis of the disc. On one end of this frame z is an arm, the extremity of which is connected by a link to the long end of the weigh-beam. Thus any movement of the beam, caused by an increase of the load on the belt, tilts the frame through an angle, the sine of which is proportional to the vertical movement of the float and again proportional to the load on the suspended portion of the conveyor. Four pulleys u u, Q Q guide a small endless belt w round the disc, and touching the rollers thereon at two points diametrically opposite. Pressure rollers v keep the belt and disc rollers in contact. A weighted take-up pulley t assures an even tension in the belt, and compensates for any stretch. The two pulleys u u are geared together and are driven by mitre gear from a bend or jockey pulley under the return belt. The belt driving the integrator thus travels at a speed proportional to that of the conveyor. Fig. 1035. Diagram of Integrator of Merrick Weightometer. So long as the axes of the rollers y are parallel to the direction of the integrator belt, the motion of the latter will only affect them to the extent of revolving the rollers on their own axes. This condition corresponds with a zero position of the beam, that is, when there is no load on the conveyor. If, however, the beam is deflected by the loading of the belt, the frame z and disc x will be correspondingly tilted ; this will incline the axes of the rollers y with respect to the integrator belt, then besides rotating them the belt will push the rollers sideways across its face at the rate proportional to their inclination. As the rollers y cannot slide on the disc x, they will rotate around its axis ; consequently the speed of rotation of the disc is proportional to the deflection of the beam, the movement of the float, or the load on the conveyor. 1 he amount of this motion is thus a measure of the weight of material carried by the conveyor during the period of observation. Thus the revolution counter mounted on the disc shaft will record and totalise the weight carried in any units for which the mechanism is ■designed. A glance at the disc when the conveyor is running empty will determine whether the ■dead weight of the idlers, etc., plus the weight of the belt or buckets, is correctly balanced, so that the net weight of the material is recorded. Should the dial remain stationary, or move backward and forward between two constant limits of travel, the .adjustment is correct. Should the dial make a plus or minus gain it is not, and the proper balancing is obtained by means of a weight on the steelyard. This weight 46