GB148034A - Improvements in automatic weighing apparatus for powdery granulated, or liquid substances - Google Patents

Abstract

148,034. Leumann, R. June 17, 1919. Addition to 142,678. Automatic-feed weighers. - The swinging of the feed-device induced by the attainment of a predetermined charge of the scale pan, as described in the parent Specification, whereby further feed to the scale pan is at once prevented, is effected through the progressive filling of the scale pan by pneumatic agency. Several forms of apparatus are described. As shown in Fig. 1, the feed-device 3 is secured to the lever 4, 6 and one arm of the lever is weighted so as to be capable of swinging the feed device and of diverging the stream of material. The other arm 6 is under the influence of vacuum, the suction of which tends to move the lever in opposition to the loading upon the other arm of the lever. The suction is secured bv the raising of the piston in the cylinder 9 and by means of the fitting 12 at the end of the suctionpipe 11, the suction holds the feed-device in the charging position. On the predetermined charge having been received in the scale-pan 20, the pan and the weighing-lever 22 with its accessories operate so as to strike the projection 30 against the flap 14 and thereby admit air to the pipe 11. The lever 4, 6 then moves the feed-device about the pivot 2 and away from the projection 30, with the result that the flap 14 again bears against the fitting 12 and seals the pipe 11. Further swinging movement is then arrested. The operation is repeated until the stream of material flowing through the filling-hopper is entirely deflected from the funnel 19 and the scale pan 20 and is led to the distributing-funnel 21. The lever 4 is brought from one position shown in dotted lines to the other 'by hand or by mechanical means. By the descent of the piston 8, air is forced from the conduit 11. After sealing by the fitting 12 against the flap 14, the weight 5 is released, the piston 8 is raised, a vacuum is produced below the piston, and the lever 4, 6 assumes the position of equilibrium shown in full lines. In the arrangement shown in Fig. 2, the destruction of the vacuum in the conduit 12 is secured by the raising of the flap 35 by the electro-magnet 34 which is energized through the projection completing an electrical circuit. Instead of vacuum, compressed air may be used in which case the cylinder 9 is fitted with an air-inlet valve. In a further arrangement, the cylinder is replaced by the trough 38, Fig. 3, and by the bell 42 to which is applied the conduit 11 and the air-outlet valve 43, the method of operation of which is similar to the arrangement shown in Fig. 1. In Fig. 4 the bell is shown provided with the open-ended pipe. Another constructional form is shown in Fig. 5, wherein the one arm 4 of the rocking- lever is loaded by a vessel 53 provided with the inwardly-opening valve 50 and the apertures 51, 52, the latter of which communicates with the open receiver 56, and the former with the conduit 54 and sealing-device. Instead of the valve 43, Fig. 3, the bell 42 may communicate with the vessel 58, Fig. 6, by the pipe 57 and the sealing- pipe 59, the vessel being open to the air, a similar device being also substituted for the valve 50 shown in Fig. 5.