Patent GB-390350-A (GB)
Title: Improvements in and relating to automatic weighing machines
IPC: G01G13/00
Filed: 1932-06-02
Abstract: 390,350. Automatic-feed weighers. HORST, E. C. VON P. VAN DER, Pasoeroean, Java, Dutch East Indies. June 2, 1932, No. 15618. Convention date, July 4, 1931. [Class 143.] In order to permit the operator to observe the accuracy of the net and tare weighings during the normal operations of the machine, the cycle of operations during each weighing is prolonged at the position of equilibrium, during both the descent of the weighing vessel after cut-off of the feed, and its rise after discharge, an external influence (for example the gravitation of the fluid supply, a spring or electrical device) being provided to initiate the removal and replacement of a counterbalancing net weight at the appropriate times. As the weight of fluid entering the weighing vessel 10, Fig. 1, approaches the full charge, the scale beam 8 rocks into the equilibrium position at the same time picking up the net weight 12 and permitting the feed valve 13 to close owing to the descent of its support 14. A connection from the scale beam at the same time rocks a pipe 5 into the position shown by broken lines to direct fluid into the right-hand compartment of a tilting vessel 6. In this position the weighing vessel 10 contains the desired weight and the scale beam remains horizontal sufficiently long for the attendant to observe the accuracy of its state of equilibrium whereafter the fluid accumulated in the right-hand compartment of the tilting vessel 6 causes this vessel to tilt and, by means of a connection 22, switch over the cock 20 of an oil cylinder 19 thereby permitting the piston 18 to descend under the influence of a counterweight 17. The counterweight is carried by one end of a lever 24 the other end of which rises into engagement with the net weight 12 and causes the further-descent of the weighing vessel 10 into the discharging position where the discharge valve 15 is opened by contact with a stationary abutment 16. Towards the end of the discharge the weighing vessel rises under the influence of the tare weight 11 and the valve 15 closes (a residue being retained in the weighing vessel) the net weight 12 however remaining entirely supported in its higher position by the lever 24 which is prevented from turning by the restraint of the oil cylinder 19. The movement of the scale beam also rocks the pipe 5 so as to direct the fluid into the left-hand compartment of the tilting vessel 6. At this stage the scale beam is in the equilibrium position and remains in this position for observation by the attendant until the fluid entering the left-hand compartment of the tilting vessel 6 tilts this vessel and operates the cock 20 so as to release the net weight 12 and continue the cycle of operations The compartments of the tilting vessel 6 empty through spouts 6a, 6b. Weighted levers 28, 33, engaged and relinquished by the weighing receptacle during its movements compensate for the influence of the valves 13, 15 on the weighing operations. The duration of the puase at the position of equilibrium may be adjusted by a valve 4 which regulates the flow of fluid through the pipe 5. The counterweight 17 and lever 24 may be replaced by a spring or a loaded lever supporting the fulrum 9 which is in these modifications mounted on the piston rod of the oil cylinder. Instead of employing the tilting vessel 6, an electrical device with a delay action may be used to operate the cock 20. In a modification, Fig. 5, the pause at the equilibrium position of the scale beam is obtained by employing a system of narrow pipes between the change-over cock 20 and the hydraulic cylinder 19 thus damping the rapidity of action. The change-over cock is connected by rack and pinion gear to a rocker arm 78 and is actuated at the appropriate times by springs 79, 80 when the rack gear is liberated from catches 65, 67 by fingers 69, 70 on the scale beam 8.