| 摘要 |
1474517 Automatic control of flow DRESSER EUROPE SA 3 May 1974 [3 May 1973] 21138/73 Heading G3R [Also in Division G4] In a blending and dispensing pump having liquid fuel lines 1, 2 which carry low and high octane fuel to a mixing valve 3 and outlet 4, each line has a respective generator 5, 6 producing a pulse for each unit (e.g. À005 gallons) of fuel dispensed and the generators are connected to the inputs 10, 12 of an up-down counter 11, one connection being via a pulse rate adjuster 8 and the counter output being used as an error signal to control the valve 3 via a servomechanism 14 to reduce the error signal to zero. As shown the adjuster 8 is a divider having a divide ratio set by a unit 7 when the desired blend is selected. This unit also delivers a unit price signal to a display 17 and to a multiplier 20. The pulse trains from the generators 5, 6 are combined at 19 to give a signal indicative of the total fuel volume dispensed, this being displayed at 15 via a cumulative counter 18. The volume signal is also fed to the multiplier 20 and multiplied by the unit price signal to feed a total dispensed price display 16 via a counter 21. The displays are of electromechanical or seven-segment solid state type. A more complex alternative embodiment is described in which a frequency multiplier (23), Fig. 2 (not shown) is used instead of a divider, and the volume and price of fuel dispensed are stored as a continuously recycled and updated binary data word. The word also contains information of remaining credit if fuel is to be dispensed to a preset price, and signals are derived to slow down and stop the pump motors as credit is nearly and then totally exhausted (see Division G4). |
