Patent GB-649082-A (GB)
Title: Improvements in fluid measuring and dispensing apparatus
IPC: B67D7/30
Filed: 1945-05-05
Abstract: 649,082. Dispensing measured quantities of liquids. S.A.T.A.M. SOC. ANON POUR TOUS APPAREILLAGES MECANIQUES. May 5, 1945, No. 11493. Convention date, Oct. 20, 1943. [Class 116] In apparatus for dispensing measured quantities of liquid of the kind in which the dispensing operation is in two stages, one in which liquid is dispensed at normal rates of flow and a second in which completion of the delivery is by dribble flow terminated by mechanism controlled by the indicator of a flow-meter, the initiatiation of dribble flow is brought about either manually by throttling the flow at the nozzle or automatically by a predetermining device. As shown in Fig. 1 a flowmeter 1 in the delivering line 2 drives a predetermi n i n g device 6 and indicator 7. A main valve 3 is provided in the delivery line above the nozzle 5, the nozzle being such as that described 'in Specification 637,156, '[Group XXIX], and having main and auxiliary valves, the auxiliary valve remaining open after the main valve has been closed to throttle the delivery and closing automatically upon cessation of delivery or reduction of the rate of delivery to a very small value. A first byepass is connected around the main valve 3, formed by a gauged opening 32 in a diaphragm 30 fast with the main valve closure member, a conduit 38, a pilot valve 34 and the hollow stem 33 of the main valve 3. A spring acting on the rear face of the diaphragm 30 urges the valve 3 to the closed position. The opening and closing of the valve 34 is controlled by the cam 62 and the indicator 7. The valve is, however, maintained open by the stem of the main valve while the latter is open. A second byepass formed by the orifice 32 and conduits 48 and 46 is disposed around the main valve, a second pilot valve 44, the opening and closing of which is controlled by the predetermining device 6 controlling the flow through this byepass. A third byepass formed by conduits 48 and 54 is also disposed around the main valve, a three-way cock 49 enabling either the second or third byepass to be closed. With the second byepass closed delivery is commenced by opening the nozzle. A very small flow through the third byepass causes the indicator 7 and cam 62 to revolve slightly, opening the valve 34. The resulting increase in flow causes sufficient pressure drop across the diaphragm 30 to cause the main valve to open. Delivery continues at full rate until the operator partially closes the nozzle reducing the flow below that necessary to maintain the valve 3 open whereupon it closes, dribble flow continuing via the first byepass until cut off by the cam 62 allowing the valve 34 to close at a point corresponding to an exact number of units of quantity delivered. The slight flow through the third byepass is insufficient to keep the auxiliary nozzle valve open and it closes almost simultaneously with the valve 34. With the third byepass closed by the cock 49, delivery takes place, after opening the nozzle, through the second byepass, the valve 44 having been opened by the setting of the predetermining device 6 to the required quantity. This causes the cam 62 to rotate, opening the valve 34 whereupon the flow increases and the main valve opens. Delivery continues until the pilot valve 34 is closed by the predetermining device whereupon the main valve 3 closes, the flow through the first byepass being insufficient to maintain it open. Delivery is cut off as before when the valve 34 closes. In a modification two indicators 7 and predetermining devices 6 are provided, one for price and one for volume and the first and second byepasses are each split into two branches each with a valve 34 or 44, one valve 34 being controlled by a volume indicator and the other by a price indicator and one valve 44 being controlled by a volume predetermining device and the other by a price predetermining device. The cock 49 is replaced by a four-way cock enabling either the third byepass or one of the branches of the second byepass to be open, and a three-way cock is included in the first byepass enabling either of its branches to be open. Among other possibilities this apparatus permits the quantity delivered to be approximately predetermined by the volume predetermining device, the delivery being terminated by the price indicator at a quantity, corresponding to an exact number of price units, slightly greater than the predetermined amount, to avoid the necessity of giving small change to a purchaser. The four-way and threeway cock in the second and first byepasses of this apparatus may be combined in one multi-way cock, as shown in Fig. 3, The plug 50 of the cock can be manipulated to open any desired combination of byepasses. In a further modification, Fig. 4, a second valve 4 similar to the main valve 3 is disposed in the pipe line below the valve 3 and has a permanently open byepass 43 round it. The conduit 48 of the second and third byepasses opens in the valve box 31 upstream of the diaphragm 30 and the downstream side of the diaphragm in valve 4 communicates via a check valve 53 with the conduit 48. The flow through conduit 48 does not affect the valve 3 and the second and third byepasses can be made larger. The first byepass is also larger as the flow through it has alone to be sufficient to open valve 3. The rate of flow at certain stages of a dispensing operation is thus increased. At the beginning of an operation, valve 3 opens first, allowing valve 4 to open. Near the end of the operation valve 4 first closes and then valve 3. The apparatus of Fig. 4 may be duplicated to give control by price and volume. Any of the apparatus may be hand operated, both nozzle valves being manually controlled. In the apparatus of Fig. 1, branch 54 and cock 49 can be omitted, but for hand and semi-automatic working it is then necessary to set the predetermining device to a value greater than the quantity it is desired to dispense. Specifications 637,155, 649,081 and 649,087 also are referred to.