Patent GB-1228418-A (GB)
IPC: G01F11/04
Filed: 1968-06-19
Abstract: 1,228,418. Dispensing measured quantities of liquids. WHARNCLIFFE FABRICATORS & ENGS. Ltd. 20 Aug., 1969 [19 June, 1968], No. 29143/68. Heading B8N. [Also in Division F2] A device for dispensing measured quantities of liquids containing gas in solution and for controlling the amount of froth comprises a piston 4 reciprocable in a cylinder 5, and valve means 12 for directing liquid alternately from chambers 1 and 2 to an outlet via one or the other of two flow paths. One of the paths includes a constriction which causes cavitation and thus causes the liquid to be dispensed in a relatively "frothy" stage. Liquid is dispensed from the other path in a relatively "flat" state. The valve means includes an end cap 6 and a rotatable head 61 which can be positively located in five different positions by a spring urged ball 92 engaging in respective recesses 96. The head carries therewith a valve disc 66 which is spring urged into engagement with the end cap 6. The device includes a bar mounting 81, (Fig. 14), a nozzle mounting 74, detachable nozzle 17 and a liquid conditioner 75 which serves to define in part the two flow paths. The conditioner includes a closed ended tubular portion 76 and flanges 79. The portion 76 includes bores 78 which, when liquid flows therethrough, cause cavitation, so that the liquid dispensed is relatively frothy. The flanges include non-axially aligned apertures 80 through which liquid flows in a relatively flat state. Liquid from a supply source flows into valve chamber 64 via a passage 13. The arrangement of bores 85-87, which are in constant communication with the chamber 64, and arcuate recesses 88-90 in the disc 66 and the superposed arrangement of the bores 10, 11 communicating constantly with chambers 1, 2 respectively, outlet passages 14, 15 and recesses 82-84 in the end cap 6 are illustrated in Fig. 16. The position A of handle 44 defines a non- flow condition. When moved to position B liquid flows from chamber 64 via bore 87, recesses 84 and bore 10 into the chamber 1. The piston is moved to the right and discharges the liquid in the chamber 2 in a relatively "frothy" state via a passage (not shown), and bore 11, recesses 83, 89 and 82, and the outlet passages 15 and bores 78 to the outlet 16. Movement of the handle to position C will break communication between bore 11 and passage 15 but will effect communication between the bore 11 and the outlet passage 14 via recesses 83, 88. Liquid will flow from chamber 64 to the chamber 1 via bore 86. To supply liquid to chamber 2 and dispense liquid from the chamber 1 the handle is moved to positions D, E. Dripping is prevented after a measured quantity has been dispensed by a nose 77 on the conditioner 75. Bleed valves 97 are provided for removal of gas from the chambers 1, 2. Alternatively the liquid conditioner 75 may be omitted and the valve means in this case includes the constriction which causes cavitation. Also only one outlet passage is necessary. As illustrated in Fig. 11 bores 53-55 constantly communicate with a source of supply and the movable valve disc also includes a recess 52. A stationary valve member (i.e. end cap) includes different size bores 10a, 10c and 11a, 11c communicating respectively with the chambers 1 and 2. When the handle is in position A no liquid flows. In position B bore 55 is aligned with bore 10a and recess 52 effects communication between bore 11c and a part of bore 16a or as shown recesses 101. Cavitation is caused and the liquid dispensed is relatively frothy. When the handle is moved to position C bores 54, 55 are aligned with bores 10a, 10c respectively and recess 52 effects communication between bore 11a and bore 16a. A pin (not shown) is biased by liquid during flow into chambers 1, 2 to engage one of a pair of slots in the valve means which allows movement of the handle between positions B, C or D, E but does not allow movement of the handle to position A. When flow stops the pin is disengaged from the slot by gravity or a spring. Other forms of devices include adjustable bellows type measuring chambers, a flexible diaphragm dividing a spherical measuring chamber, and a piston cylinder arrangement wherein the piston is stationary and the cylinder comprised by two cups moves relative to the piston. The stroke of the cylinder is variable. The valve means may be actuated electrically. A simplified form of the valve means of Fig. 16 is illustrated in Fig. 9.