Fluessigkeitszapfvorrichtung

摘要

1,179,618. Dispensing fluids. VEEDER INDUSTRIES Inc. 15 Dec., 1967 [28 Dec., 1966], No. 57073/67. Heading A4T. [Also in Division B1] In an apparatus in which two fluids (e.g. grades of petrol) are mixed in a predetermined ratio by a proportioning valve controlled by a meter in each flow line through a device which adjusts the valve in a pre-determined flow ratio, there is a compensating device which initially moves the valve past the position providing the pre-determined ratio in order to compensate automatically for the time taken by the valve to reach the adjusted position. The outputs of meters 20, 22 (Fig. 1) are summed by differential 28 and transmitted to subtracting differential 16, a speedchange mechanism 32 reducing the speed of shaft 33 so that it will rotate at the same speed on the subtracting differential input shaft 26 when the flow rates are in the desired ratio, maintaining the blend control shaft 18 stationary. The output of summing differential 28 is also applied to a variator 34 and register 36 to compute and register the cost of the blend dispensed. If a blend different from that of the previous delivery be selected, the shaft 18 will rotate (see Fig. 2) actuating valve operating shaft 56 through bevel gear 42 and carrier ring 52 of differential gear 44. Shaft 18 also causes, through worm 72, axial displacement of rack 74 to move along splined shaft 90 a friction wheel 88 which is in peripheral contact with friction disc 96, the latter being driven e.g. by a constant speed motor or by the output shaft 30 of the summing differential 28. A supplementary input to the valve actuating shaft 56 proportional to the angular displacement of shaft 18 is thus given by shaft 90 through the gear train 98, 100, 102, 106, 52, 54. Valve 14 is therefore moved past its adjusted position. As this occurs, subtracting differential 16 will rotate blend control shaft 18 in the opposite angular direction returning wheel 88 to the centre of disc 96 where it ceases to rotate so that the supplementary input to shaft 56 is reduced to zero. By suitable dimensioning of the mechanical elements the supplementary input may be arranged to compensate, without hunting, for the incorrect blend initially supplied due to the time-lag in the valve reaching the adjusted position (see Fig. 3, not shown).