GB1285900A - Arrangements for marking elongated articles - Google Patents

Abstract

1285900 Automatic speed control WESTERN ELECTRIC CO Inc 18 Nov 1969 [26 Nov 1968] 56378/69 Heading G3R An elongated article is marked by a driven rotatable mechanism. The speeds of the article and the mechanism are synchronized by generating a first signal representing the difference between the speeds of the driving devices for the article and for the mechanism and a second signal representing the difference in the speeds of the driving device of the marking mechanism and of a control member moved by the article. The two signals are combined to provide an analog control signal which acts on the device driving the marking mechanism. The system is intended to provide an accurate means of printing footage markings on jacketed cable during reeling. As shown, cable 11 is advanced by a capstan 13 towards a reel 14. Rollers 22, 23 guide the cable past a printing wheel 18 which is rotatably driven by a motor 27 at a tangential speed which is regulated to that of the cable. If the motor 27 is of the A.C. type, it may be controlled using an eddy current clutch and brake. If a D. C. motor is used, the armature current and field excitation may be controlled. The speed of the wheel 18 is controlled by a regulator 30 which receives a first input from a comparator 31. This comparator is in turn fed by tachogenerators 23, 24 coupled respectively to the capstan 13 and the drive of the wheel 18. A second input to the regulator is provided by a digital counter and D/A converter 32 which receives, counts and compares pulse trains from a transducer39 coupled to a control wheel 36 frictionally driven by the cable 11, and from a second transducer 41 coupled to the drive of wheel 18. The analog output of the converter 32 is amplified and, in the regulator 30, over-rides the input from the comparator 31 in the formation of the control signal which determines the driving speed of the printing wheel 18. Preferably the wheels 18, 36 have equal circumferences of, say, two feet, but slight differences can be compensated by the addition of an appropriate number of counts to one of the circuits of counter-converter 32. During operation, wheels 18, 36 drive footage counter 21, 38 respectively to provide a visual indication of the amount of cable reeled as well as a check on the synchronizing system.