GB716110A - Improved means of weighing, and for controlling the supply of material to be weighed - Google Patents

Abstract

716,110. Automatic feed weighers. SMALLPEICE, C. D. P. June 1 1951 [Sept. 22, 1950], No. 23248/50. Class 143 [Also in Group XXIX] A weighing mechanism includes a movable weighing member adapted for receiving the material to be weighed, a pressure regulating means adapted for supplying to a pressure gauge a pressure which increases responsively to the weight of material on the weighing member, and vice versa, and a hopper, for supplying the material, with a delivery valve operable by a fluid pressure device which is connected so as to be energized by the pressure actuating the pressure gauge such that the delivery valve will be moved to stop the flow of material from the hopper when the said pressure reaches a predetermined value. As shown in Fig. 1 the guided pan 21 is supported by a bell-crank 12 which bears against the exhaust valve member 23 of a pressure regulator, similar to that described in Specification 649,281, [Group XXIX], having an inlet valve 15 which controls the admission of compressed air from a port M and which is mounted on a sliding member 16 secured to a diaphragm 17. An annulus 22 on the member 16 is urged against the member 23 by a spring 18 and the interior of the regulator is connected through pipes 19, 29 with a pressure gauge 20 and a thrustor 27 which actuates a sliding cut-off valve 25 beneath the feed hopper 24. In operation, an increase in the weight of material in the pan 21 opens the valve 15 which remains open until the pneumatic pressure exerted on the member 23 is sufficient to return the slide member 16 to normal, whilst a decrease in weight in the pan 21 allows the member 23 to be moved away from the annulus 22 so causing the regulator to exhaust through a port E until the internal pressure is sufficiently reduced to enable the member 23 to return to normal. The pressure in the regulator is thus proportional to the weight of the load, and when this pressure reaches a predetermined value it causes the thrustor piston 26 to overcome spring 28 to close the hopper outlet. The modified arrangement shown in Fig. 2 includes a pair of valves 31, 36, each similar to that described in Specification 659,539, [Group XXIX]. In this arrangement an increase in the weight of material in pan 21 depresses plunger 30 so admitting compressed air from the main M through pipe 32 to the gauge 20, thrustor 27 and a further thrustor 33, the piston 34 of which bears on the underside of the beam 12a. After the pressure has reached a predetermined value sufficient to close valve 25, the material is removed from pan 21, the beam is raised by piston 34, so allowing valve 31 to close and opening the similar valve 36 to allow the air to exhaust through pipes 35, E.