GB731269A - A weighing device for measuring mass flow - Google Patents

Abstract

731,269. Automatic feed weighers. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Aug. 12, 1953 [May 12, 1952], No. 12037/52. Class 143. Apparatus for measuring the mass flow of viscous liquid, e.g. of heavy fuel oil to a burner, comprises a tank 1 mounted on a counterbalanced weighbeam 2, a valve 7 supplying the tank which automatically is closed when the beam 2 is overbalanced by the tank 1 being filled up, a platform 9 which is raised to remove an additional counterweight 8 loading the weighbeam after balance has once more been restored by liquid flowing from the tank through a pipe 4 by siphoning or other action, a time device, e.g. stopwatch, which is started on balance being obtained and is stopped by the beam returning to balanced position after liquid has flowed from the tank of weight equal to that of the removed counterweight 8. The platform 9 is then again lowered to add the counterweight 8 on the beam and the valve 7 re-opened and the cycle of operations repeated, the watch being reset to zero each time balance is achieved with the counterweight 8 on the beam. The sequence of operations is controlled by mercury cup switch contacts 38, 41 co-acting with contact members depending from the weighbeam in series with a mercury coupling switch 40, two pairs of switch contacts 34, 35 alternately closed when the supply valve 7 is raised and lowered to open and close it, two pairs of contacts 37, 36 alternately closed when the platform 9 is raised or lowered, the interconnection of the switches energizing relays 42-48 resetting the watch, starting it and stopping it, and energizing solenoids 27, 28 and 29, 30 which operate the valve 7 and platform 9. The switch 37 stops the watch but is not closed when the platform 9 is raised to remove the counterweight 8 as the weighbeam overbalances first. The valve 7 and platform are operated by cams 13, 15 on camshafts carrying at each end a pair of oppositely extending arms 17, 18 and 23, 24, each pair on a camshaft being at right angles and alternately engaged by driving pegs 22, 26 on driving members 19, 25 which can be axially slid on a constantly rotating drive shaft 20 to engage one or other of the pegs with the corresponding pair of extension arms 17, 18. The camshafts are thus rotated by a quarter turn each time and the cams, being elliptical, raise and lower the valve and platform. The driving members are axially displaced alternately by the solenoids 27, 28 and 29, 30, when energized, through pivoted levers 192, 252. The platform 9 may have a boss 10 locatingly engaging a recess 11 on the underside of the counterweight 8, the latter forming a scale pan to which additional weights may be added. An indicator lamp may be lit during the watch resetting operation.