Improved rollstand equipment for unwinding and rewinding web material

摘要

1,075,852. Feeding webs. FULLER ELECTRIC Ltd. April 9, 1964 [April 10, 1963], No. 14300/63. Heading B6B. [Also in Division G3] In reel-stand apparatus for winding or unwinding a web, control apparatus is provided to match the peripheral speed of a web-roll core or a web-roll with the linear speed of a running web prior to splicing. The Figure illustrates unwinding apparatus. A replacement web-roll 15 is driven by an electric motor 7. A tachometer 17 driven by the web-roll spindle or the motor 7 provides a voltage output directly proportional to the angular velocity of the web-roll 15. Alternatively, a voltage directly proportional to the angular velocity may be taken from the armature of the motor 7. A tachometer 29 driven by a roller 13 over which the running web 11 passes, provides a voltage directly proportional to the linear velocity of the running web 11. Alternatively, a voltage proportional to the web speed may be taken from the armature of a motor driving a web roller. A motor 6 is used to rotate the reel-stand 1 from the position shown in full line to the splicing position shown in broken line. A suitable detector 16 such as a photo-electric device or an ultrasonic sound beam device stops the rotation of the reelstand in the splicing position. Coupled to the shaft of the reel-stand via gearing 28 is a cam 21. A cam follower 25 which has a rack 24 engaging a pinion 27 moves a contact 23 of a potentiometer, the terminals 18 and 19 of which are supplied with the voltage from tachometer 17 which is directly proportional to the angular velocity of web roll 15. Movement of the contact is directly proportional to the diameter of web roll 15, therefore the voltage difference at the contact 23 is directly proportional to the peripheral velocity of the web-roll 15. This latter voltage together with the voltage from tachometer 29 proportional to the running web speed, is applied to a regulator 30. The regulator controls the field windings of a generator 32 which in turn supplies the electric motor 7 driving the web-roll 15.