GB937822A - Improvements in and relating to conveyor arrangements - Google Patents

Abstract

937,822. Automatic control systems. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. March 1, 1960 [March 3, 1959], No. 7381/59. Class 38 (4). A conveyer system for delivering loose material at a desired rate includes a first conveyer delivering material at a given rate and a second conveyer controlled to deliver material at a rate corresponding to the difference between the desired rate and the actual delivery rate of the first conveyer. As shown, a conveyer 4 driven at constant speed moves material from a tippler 2 to a shoot 1 at a given rate ascertained by a weighing beam 5. A second conveyer 6 is fed through a vibrator 3, and a weighing device 7 controls the excitation and thereby the speed of a motor 8 driveng the vibrator 3 so as. to maintain the load weight per unit surface of the conveyer constant. The motor 8 and a motor 9 driving the conveyer 6 are supplied from a generator 10 the excitation of which is controlled by an amplidyne 11 having three field windings F1, F2 and F3, energized respectively by a reference voltage, by a signal from the device 5, and by a tachogenerator TG coupled to the motor 9. Windings F2 and F3 oppose the effect of winding F1. If the weight of material provided per time unit by the tippler 2 decreases, the generator 10 supplies a higher voltage to motors 8, 9 so that while the loading of conveyer 6 remains constant the speed of the conveyer and therefore the rate of supply per unit time to the shoot 1 increases until the total rate determined by the reference voltage at winding F1 is obtained.