GB1329469A - Apparatus for controlling the blending of two flowable sub- stances - Google Patents

Abstract

1329469 Dispensing liquids WILLIAM STOREY & PARTNERS Ltd 11 Sept 1970 43646/70 Heading A4T [Also in Division B1] Two substances flowing along respective conduits 10A, 10B for blending at 14 cause transducers 16A, 16B to produce a number of pulses corresponding to the quantity of A and B passed, which pulses are counted in respective units 25A, 25B and totalled in an adder 52, the proportion of the minor component (say B) in the blend being controlled by interrupting the supply of B after a given number of pulses have been received by the unit 25B, and re-starting the supply of B only after a further number of pulses have been received in the adder 52, the ratio of the given number to the further number being the proportion of B in the blend. The desired blend, say 75%A-25%B, is set on a manual selector 30 which renders a unit 22B controlling supply of B sensitive to signals from a source 34, and a unit 22A controlling supply of A insensitive to such signals. The source 34 is itself rendered sensitive to signals from the counter 25B but not 25A. After the counter 25B has received the given number of pulses, corresponding to the delivery, in this case, of “ gallon of B, it passes a signal actuating the source 34 to send a signal to the unit 22B to stop delivery of B. The selector 30 also renders the unit 22B but not 22A sensitive to signals from the adder 52 which sends a signal to the unit 22B to re-start the supply of B, when it has received the further number of pulses corresponding to a combined delivery of A plus B of one gallon. The intermittent supply of B with continuous supply of A proceeds in this manner until a total quantity of A plus B previously set on a selector 62 has been dispensed, when a signal from the selector 62 causes the units 22A, 22B to stop the supply of A and B. The ratio of the rate of delivery of A to that of B is controlled by a unit 40 in dependence on the setting of the selector 30, to be less than the A to B ratio in the blend. The adder 52 controls a quantity dispensed display 56. The counters 25A, 25B each incorporate means which multiply the pulses by a cost factor settable on a price selector 28, and pass the resultant pulses via a currency counter to an adder 42 which passes the total cost to a display 46. The counters 25A, 25B are binary counters including serially connected bi-stable multi-vibrator stages, and are reset by a switch 26 which also causes the supply of A, B to start at the beginning of a dispensing operation. The reset switch may be on a support for the delivery nozzle and may be operated by lifting the nozzle before dispensing fuel. The substances A, B may be grades of petrol. The displays 46, 56 and the reset may be in a separate kiosk when the apparatus is a self service dispenser. The apparatus may operate electrically or electronically or by gas or liquid fluidics.