Patent GB-617875-A (GB)
Title: Improved plant for dealing with loose granular and like materials in manufacturing and processing operations
IPC: G01G13/04
Filed: 1945-08-11
Abstract: 617,875. Conveyers. DUNLOP RUBBER CO., Ltd., and WILLSHAW,. H. Aug. 11, 1945, No. 20666. [Class 78 (i)] [Also in Group XVIII] Plant for automatically delivering predetermined weights of loose granular and like materials to a delivery station comprises a single moving conveying agency for transferring the material from a loading station to a delivery station, weighing means at the delivery station, electrical control means associated with the weighing means, changespeed mechanism for varying the speed of the conveying agency, clutch means for actuating the change-speed mechanism, driving means operated by the electrical control means for actuating the clutch and an electromagnetic brake operated by the electrical control means whereby during the progress of a weighing operation the speed of the conveyer system is reduced and stopped as the predetermined weight is approached and reached respectively. The conveyers 7, which are of the chain and flight type, are fed from hoppers 4, Fig. 1 which communicate with dust - extracting apparatus 5. Each conveyer delivers to a weigh hopper 8a of an identical pair of automatic weighing apparatus 8. The outlet is controlled by a gate 8b actuated pneumatically under the action of a solenoid-operated valve 9. Each weigh hopper has associated therewith a pneumatically-operated vibrator mechanism 10 controlled by the valve 9. The outlet from each weigh hopper communicates by way of shoots 12a, 12b with the hopper 13a of a rubber mixing machine 13. Associated with each shoot 12a, 12b is electrically-operated vibrator mechanism 14. Each weighing apparatus is associated with an electric circuit making and breaking means of the roller contact type. The outlet from the mixer 13 is controlled by pneumatically-operated door 13b under control of a solenoid valve 15 which co-operates with a limit switch 16, actuation of which is by contacts 17 associated with a ram 13c of mixer 13. Lifting of the ram 13c is effected by pneumatic means under control of a solenoid valve 18. Switch 16 is in circuit with electric clock 20. Conveying apparatus is driven by an electric motor 21 having, fast and dribble speeds. Rubber is fed to the mixer 13 from an elevator 26. A control panel 27 is situated at the delivery station. Coloured lights are used as indication at every stage of the operation. Press-button switch 38 closes door 13b and tumbler switch 39 controls solenoid valve 18 for moving ram 13c. In operation, carbon black is conveyed from the loading hopper 4 in a chamber 3 to the weigh hopper 8a until almost the required amount is delivered. The red warning light 281 and white light 29 are shown initially. The weighing mechanism then causes the contact through the motor 23a of the clutch mechanism 23 to be started to actuate the clutch mechanism so that the speed changes from fast to dribble and the orange light 291 is illuminated. After the mixer 13 has been loaded with raw rubber or the like, the tumbler switch 39 is operated to complete the circuit through the solenoid valve 18 to lower ram 13c pneumatically and when the latter contacts the switch 16, control clock 20 commences to control the time cycle. To deposit carbon black powder in the mixer 13, the discharge switch 30 is pressed, thus actuating solenoid valve 9 so that the. gate 8b is opened pneumatically and vibrator 10 operates and green light 292 is illuminated. The tumbler switch 31 is also actuated to bring the electrical vibrator mechanism 14 into action. As soon as discharge from hopper 8a is effected, the circuit through the valve 9 is completed so that the gate 8b closes and vibrator 10 is cut out and after a short lag of, say, 10 secs., the driving motor 21 starts, magnetic brake 24 is released and clutch 23 operated so that the conveyer 7 commences to redistribute to the weigh hoppers 8a at full rate, the white light 29 is illuminated and the green light 292 extinguished. When the clock 20 reads zero, electric circuit through valve 15 is completed to open door 13b and red light 38a shows and clock reading returns to its presetting and the tumbler switch 39 lifts ram 13. Press-button 38 is pressed to close door 13b, whereupon the cycle of operation is repeated.