| 摘要 |
929,711. Automatic speed control. M. C. PFISTER. Oct. 29, 1959 [Nov. 27, 1958], No. 36720/59. Class 38 (4). [Also in Groups XXII, XXIII, XL (b) and XL (c)] A steel billet on a conveyer is brought to rest in a predetermined position by a photo-electric device which measures the distance of the billet from the position and adjusts accordingly the reference voltage of a Ward-Leonard unit controlling the conveyer speed. Devices 44 and 45 derive signals indicative of the billet position and the predetermined position, and the difference therebetween drives a servomotor 53 coupled to the tapping of potentiometer 51. The voltage tapped off is indicative of the desired speed for the existing billet position and the difference between it and the voltage of a tachometer 50 coupled to the conveyer motor 49 drives a servomotor 52. Servomotor 52 varies the excitation of a generator 48 supplying the motor 49. The billet is thus reduced to rest gradually as it approaches the predetermined position. |
