GB1233057A - - Google Patents

Abstract

1,233,057. Winding and reeling. WESTING- HOUSE ELECTRIC CORP. 20 June, 1968 [11 July, 1967], No. 29376/68. Heading B3E. [Also in Division H2] The wind-on mandrel 10 of a strip coiling apparatus is controlled by the circuit shown to ensure that the trailing end of the strip stops at a predetermined angular position, e.g. approximately midway between the points A, B. To do this it is necessary to determine the number of mandrel revolutions required to wind the length of strip D between pinch rollers 22, 24 and the tangential point of contact 42 between strip and coil, which number is dependent on the coil diameter. Accordingly a tachometer pulse generator 47 and counter 50 responsive to the revolutions of the roller 24 periodically relate the distance D to the number of revolutions of the mandrel determined by a tachometer pulse generator 44 and counters 48, 62. The settings of these counters are altered each time a length D of strip has passed through the rollers 22, 24, this occurrence opening a gate 56 to transfer to the counter 48 a count equal to the number of revolutions corresponding to the coil diameter. The counter 48 is preset to a fixed number of pulses corresponding to the angle between the points A and 42. When the trailing end of the strip passes the rollers 22, 24, a gate 58 is opened to apply the output of the tachometer 44 to the counter 48 to count down the last value of the latter plus the fixed number of pulses. The output of counter 48 is fed to a D/A converter and function generator 64 which, via member 38, controls the field 36 of the D.C. generator 32 supplying the motor 28 driving the mandrel 10. As the count of member 48 decreases the output of generator 32 is reduced, the arrangement being such that the mandrel stops just before the count reaches zero with the trailing end ahead of the point A. Should the count reach zero, indicating that the strip end has passed the point A, the counter 48 is reset to rotate the mandrel through an angle slightly less than 360 degrees and so bring the end to rest at its desired position. Passage of the strip end through the rollers 22, 24 is detected by a magnetic amplifier 60 sensing the current taken by the motor 26 driving the roller 24. Alternatively this detection may be made by photo-cells or magnetic sensing devices.