Patent GB-917052-A (GB)
Title: Method and apparatus for collecting linear material into í¡í¡
IPC: B65H54/74
Filed: 1961-03-30
Abstract: 917,052. Control of several A.C. motors. OWENS-CORNING FIBERGLAS CORPORATION. March 30, 1961 [April 4, 1960], No. 11811/61. Class 38 (3). [Also in Groups IX, XXIII and XXXV] A machine for winding filamentary material on to spools (see Group IX) includes means ensuring a constant take-up velocity of said material. In Fig. 21 an indexible rotary head 48 carries three individual variable-speed motors 53, 55, 57, the rotor 82, Fig. 4, of each motor turning an individual collet 56, as it is moved to a winding position by the head 48, on which collet a yarn takeup spool 72 can be mounted. As the size of a yarn package on a spool increases in diameter the speed of the take-up spool is progressively reduced to maintain a constant take-up velocity of the material. This is achieved by using a constant-speed electric motor 491, Fig. 21, to drive a three-phase generator 498 through a variable eddy current clutch 494, the frequency of the generator 498 being variable with its speed and being utilized to drive the motors 53, 55, 57. Rotating with the alternator 498 is a tachometer generator 518 which is coupled through rectifier 520 to a differential amplifier 526. An energizing coil 522 for the eddy current clutch 494 is supplied with direct current through a thyratron electronic control 524 energized with alternating current by supply lines L1 and L2. The thyratron 524 is connected to the amplifier 526. The control circuit for the tachometer generator 518 includes supply lines L3 and L4. This circuit includes fixed and adjustable resistances 528 and 530, respectively, and a potentiometer 532 varying the voltage to the amplifier 526. The setting of the potentiometer 532 is varied by a rack-and-pinion 534, 533 actuated by hydraulic means 440 coupled to a programming unit 510 that includes a package timer 512 which is adjustable and determines the duration of winding of the strand packages. The differential amplifier 526 summates the voltage from the thyratron control 524 with the reference voltage supplied through the potentiometer 532 constituting the input for the control 524. The control 524 regulates the current to the coil 522 to vary the speed of the alternator 498. To obtain a proper summated voltage to the control 524, the tachometer generator 518 feeds in a negative potential and the potentiometer 532 feeds in a positive potential. A transformer 542 has an output proportional to the line voltage of the alternator 488, this sample output voltage is rectified and filtered by a second voltage summating means or differential amplifier 544. The rectified sample voltage is compared with a reference voltage of the proper magnitude supplied by a second potentiometer 562, driven by the hydraulic means 440, and the differential is used to control the direct current output of an electronic exciter 546 for the alternator 498, the direct current output controlling the output voltage of the alternator 498. The movable components of the potentiometers 532 and 562 are reset at the start of each winding operation. The flow of oil to the hydraulic means 440 is metered by the programming unit 510 and the potentiometers are thereby driven to vary the excitation of the eddy current clutch 496 and the output voltage of the alternator 498. The drive speed control provided by the eddy current clutch and its controls is correlated with the voltage output of the alternator 498 provided by the electronic exciter 546 so that the speed of the collet driving motor at the winding station may be progressively reduced as the strand packages increase in size.