Patent GB-1246583-A (GB)
Title: Variable count and slubbing apparatus and method
IPC: D01H5/36
Filed: 1969-02-28
Abstract: 1,246,583. Varying draft, fancy yarn. ELECTRO-MATIC CORP. 28 Feb., 1969 [1 March, 1968], No. 10926/69. Heading DID. [Also in Divisions H2 and G3] A spinning frame has front rolls 11 which are driven at a predetermined speed for delivering yarn to the spindle of the frame, and rear rolls 13 for feeding roving into the drafting zones. The rear rolls are controlled independently of the front rolls, and are driven by the motor 15 at an effectively randomly varying rate so that the count of the strand is varied in a like manner. The speed of the motor is controlled by unit 19 receiving a random drive signal 20 from integrator 21. Signals 22, 23, are applied to the unit 21, the signal 22 being interrupted and produced by integrator 25 which receives signals from generators 26, 27, and mechanical randomizer 29. The signal 23 is generated by integrator 30 receiving signals from generators 31, 32. The mechanical randomizer 29 comprises a pilot motor driving a number of cam discs each operating a plurality of micro-switches for developing intermittent voltage signals, Fig. 3 (not shown). The signal generators 21, 27, 31, 32, each comprise a unijunction transistor associated with a flip-flop circuit including a pair of transistors, the time intervals between successive changes in conductive state being determined independently by a pair of potentiometers. The collector circuits of the flip-flop transistors provide inverse signals, such as the signals A, A', Fig. 4 (not shown). Each of the signals integrators 25, 30, comprise a pair of transistors forming and AND gate to combine the signals A and B, for example. In the presence of both signals, a signal is passed through an intergrating transistor, potentiometer, and screening diode to form a component of the signal 22. The integrated signals derived from the combination of other pairs of signals from the generators 26, 27, are combined and then gated by the intermittent signal from the unit 29 to appear as the signal 22. The integrator 30 combines the signals D, E, and D', E', to produce a continuous signal 23 upon which the signal 22 is superimposed, Fig. 5 (not shown). The signal generators and integrators are duplicated to produce four signals along separate channels for application to the unit 21. The signal selected by the positioning of a switch is applied to an amplifier and integrator using a signal transistor to provide a drive signal for a motor controller. Ten units 21 are used together with a corresponding number of controllers, each associated with a motor 15, Fig. 6 (not shown). The signal 20 is compared with a signal from tachometer generator 18 to control two trigger transistors each associated with a controlled rectifier which is included in a bridge network for supplying the armature of the motor 15. When the motor overspeeds, the armature supply is stopped, and a unijunction transistor provides pulses to trigger a further controlled rectifier which completes a rheostatic braking circuit, Figs. 7, 7A, 8 (not shown). The signal 22 may be suppressed, and the signal 23 made to alternate between predetermined levels according to a set programme. A patterned variation of yarn characteristics is then produced.