GB752001A - Automatic liquid metering device - Google Patents

Abstract

752,001. Fluid-pressure servomotor-control systems. ATOMA OFFICINE MECCANICHE. March 30, 1954, No. 9339/54. Class 135. An automatic weight metering device for liquids comprises a pneumatic control system operated in response to the pointer position of a tare allowance weighing machine, valve control gear for compressed air and liquid valves with a detent actuated by a bellows and a pneumatic circuit with a relay whereby the bellows is operated according to the pointer position to hold the liquid valve fully open, then partially closed, and finally closed on completion of the metering operation. Compressed air at 12<SP>A</SP>, Fig. 1, acts on a bellows device to deflect a pointer 3 through a predetermined angle corresponding to the weight of liquid to be metered and opens a valve 1 so that air from the bellows device and via the reducer 2 inflates a bellows 4 to open a valve 17 allowing high pressure air from the device via conduit 34 to inflate a bellows 14 to unlatch a lever 6 which is then raised against a spring to open a liquid valve 13, the metered weight of liquid in a container 11 then zeroizing the pointer to close the valve 1 and allow the lever to move down and effect discontinuation of liquid delivery. On lifting the lever 6 about the spindle 37, Fig. 4, until a finger 51 abuts the top of a stop 47, a cam 42 rotates and allows a valve 16 to open and pass air to the bellows device. In this device the bellows is expanded to deflect the pointer and open a valve to pass air via pipes 7<SP>A</SP>, 23a to the parts 2, 1 and 4. The valve 1 is a vane formed by the pointer and moving between opposed orifices. Inflation of the bellows 14 slides a carrier 48 along rods 49, 50 against a spring 58 to move stop 47 from the lever 6 so that the lever may be further raised to engage finger 51 under a catch 52 and rotate a cam 41 allowing the liquid valve 13 to open. On the weight of liquid zeroising the pointer and closing valve 1, both bellows 4, 14 are deflated, the catch 52 releases the lever which then moves to engage the' other side of stop 47. In this position valve 16 remains open but valve 13 only allows a very small flow of liquid which eventually moves the pointer to reopen the valve 1 so that both bellows are re-inflated and stop 47 moved to release the lever and close both valves 13, 16. The liquid may be dispensed without automatic control by using lever 8.