GB816046A - Apparatus for delivering a predetermined quantity of a liquid - Google Patents

Abstract

816,046. Fluid-pressure servomotor-control systems; liquid meters. CIBA Ltd. Sept. 2, 1955 [Sept. 3, 1954], No. 25351/55. Classes 69 (1) and 135. Apparatus for automatically delivering a predetermined quantity of a flowing liquid comprises a fluid pressure operated liquid supply valve 14, a rotary liquid meter 15, and a fluid pressure control mechanism which is mechanically coupled to the meter 15 and is adapted when the predetermined quantity of fluid has been delivered through the meter to cause a change in the fluid pressure acting on a pressureresponsive valve controlling the valve 14. The valve 14 and the meter 15 are arranged in a pipe 12 and the meter 15 is connected to a counter wheel 24 through a reduction gear 16, a slidable coupling 17, and a toothed wheel clutch 19, 20 the parts of which are normally kept in engagement by a spring 21. The clutch parts 19, 20 are disengaged when fluid pressure is applied to a bellows 22 fixed at its upper end to a base 22a. A spring (not shown) then returns the wheel 24 to its zero position, a pin 25 on the wheel serving as a stop. The wheel 24 enables the quantity of liquid delivered at any time to be read off on a scale. Coaxial with the wheel 24 is a wheel 26 settable by a knob 27 and bearing a nozzle 28 supplied. with compressed air from a pipe 30 via a throttle 31 and a pipe 32. The nozzle 28 is normally closed by a resilient flapper 39 which is moved slightly away from the nozzle 28 to vent the pipe 32 when engaged by the stop 25 after the predetermined quantity of liquid has passed through the meter. The venting of the pipe 32 puts a diaphragm-operated valve 33 into the exhaust position so that the control conduit 38 of the diaphragm-operated valve 14 is also exhausted and the valve 14 closes. At the same time a diaphragm-operated valve 41 opens due to the conduit 38 being vented. The bellows 22 may then be operated to separate the clutch parts 19, 20 by operating a push-button valve 40. Although the wheel 26 is set and the nozzle 28 is closed, the valve 14 is not opened until a push-button valve 35 is temporarily closed. The pressure in the conduit 32 then causes a disc 37 to block a second nozzle 36 after which the valve 35 may be released, the valve 33 remaining in the pressure supply position shown. The operation may be interrupted at any time by opening a push-button valve 34. In a modification, the pin 25 co-operates with an indicating arm movable with respect to the wheel 26. The fluid pressure control mechanism may be arranged so that the nozzle 28 is normally open and is closed after the passage of a predetermined quantity of liquid.