Patent GB-350313-A (GB)
Title: Improvements in or relating to winding control systems
IPC: B65H23/195
Filed: 1930-07-29
Abstract: 350,313. Winding webs. SHEPHERD, G. R., 2, Norfolk Street, Strand, London.-(Westinghouse Electric & Manufacturing Co. ; East Pittsburg, U.S.A.) July 29, 1930, No. 22823. [Class 100 (i).] To control the winding of a web which is passed from a roll 1 through a stack of calendering rolls 5 .. 12, the web is pressed against a core 14 by a plurality of rollers 13, 15 driven by separate motors 18, 19. The calender rolls are operated from a shaft 17 which is driven by two motors 16, 57, of which the latter is supplied by a generator 56 on the shaft 58 of the supply roll 1. The generator 56 is driven by the unwinding of the web and serves to tension the web between the supply roll and the caldender rolls. The motors 18, 19 are arranged in parallel circuit across supply lines 45, 51 supplied with current from a booster generator 37 which is driven by a motor 38 operated from a three-phase set of mains 79. The generator 37 is in series with a generator 23 which is mounted on the shaft 17 of the calender roll 12. The motors 18, 19 are compound wound, and have separately excited field coils 26, 33 supplied with current from mains 27, 28 and controlled by resistances 29, 34. The armatures 24, 31 are in series with field-coils 25, 32, across which adjustable resistances 30, 35 are shunted. The motors have drooping characteristic speed-torque curves and in order to wind the roll tightly are set so that the torque of the motor 19 is greater than that of the motor 18. In a modification the field-coils 25, 32 are arranged in series across the lines 45, 51. At the commencement of operation of the machine the web is threaded through the calender rolls by the intermittent operation of the motor 16 which is controlled by an electromagnetic switch 105 which is energized from the mains 27, 28 when a pushbutton 98 is pressed and is de-energized by a stop-switch 100. A few turns of the threaded material are wound upon the core 14, and the booster generator 37 is operated by the motor 38 to take up slack in the web. The motor 38 is also controlled by an electromagnetic switch 87, and a similar switch 43 controlled by a closing switch 80 and a stop switch 84. The switch 43 also closes the circuit to the motors 18, 19. After the slack is taken up, the motor 16 is thrown in permanently, and the whole machine is driven continuously. In order to maintain the tension of the web constant, the generator 56 is arranged in series with the motor 57, and a rheostat 66 is provided to cause the resistance of the circuit containing the field-coil 62 of the generator 56 to be increased automatically, when the current is increased in the circuit containing the armatures of the generator 56 and motor 57 due to the increased speed of the armature 60. The armature 60 is in circuit with a solenoid 72 which together with a solenoid 73 controls the movement of an armature connected to a lever 69 which reduces the pressure between carbon discs 66 and so increases the resistance in the field circuit when the current in the armature circuit increases. The armature of the solenoid is controlled by a spring and a dashpot. As the speed of the calender rolls increases, the generator 23 accelerates and the increase in current will cause the motors 18, 19 to accelerate correspondingly so that the web will be wound as fast as it is delivered from the rolls.