Patent GB-923556-A (GB)
Title: Improvements in, or relating to, speed control of ring spinning frames
IPC: D01H1/30
Filed: 1960-09-07
Abstract: 923,556. Variable-speed drives for ring spinning frames. ERCOLE MARELLI & C. S.p.A. Sept. 7, 1960 [Sept. 12, 1959], No. 30828/60. Class 120 (2). [Also in Group XXXVII] A mechanism for varying the rate of rotation of the driving motor of a ring spinning frame in accordance with the progressive upward shift a and the layering stroke c of the ring rail 6 thereof, is characterized by two devices 15, 16, 17 and 151, 16<SP>1</SP>, 171 of which each is adapted, independently of the other, to vary electrical currents as a function of the change of position of the ring rail 6, due to its basic stroke, and by two further devices 18, 19 and 18<SP>1</SP>, 19<SP>1</SP>, one for each of the first mentioned devices, which are adapted, to vary as a function of the change of position of the ring rail due to its layering stroke c, the corresponding currents as already modified by the two devices 15, 16, 17 and 15<SP>1</SP>, 16<SP>1</SP>, 17<SP>1</SP>. The two further devices may be transformer primary windings 18, 18<SP>1</SP> associated with displaceable magnetic cores 19, 19<SP>1</SP>, the secondary windings 20, 20<SP>1</SP> of the transformers being connected to an amplifier causing a motor driving the spindle 1 to rotate at a rate corresponding to the resultant of the sum of the electrical outputs of the secondary windings 20, 201. As the ring rail 6 performs its layering strokes c it carries with it a rod 7 on which is frictionally mounted a sleeve 8 carrying the cores 19, 19<SP>1</SP> of the two transformers. The sleeve 8 moves between two stops 9, 10 so that even though the rod 7 is continually raised by the upward shift, the sleeve 8 can only oscillate between the stops 9 and 10. When the ring rail 6 is at its uppermost position 6<SP>1</SP> of a layering stroke the core 19<SP>1</SP> will be fully in the upper transformer 18<SP>1</SP>, 20<SP>1</SP> to cause this transformer to be predominant and give a speed rotation to the spindle 1 appropriate to the diameter of the winding at the top of the conical layer. When the ring rail 6 is at its lowermost position 6<SP>11</SP> of a layering stroke the core 19 will be fully in the lower transformer 18, 20 to cause this transformer to be predominant and give a speed rotation to the spindle 1 appropriate to the increased diameter of the winding at the bottom of the conical layer. As the upward shift a of the ring rail 6 progresses the speed of the driving motor must also be adjusted to keep the tension in the reducing length of thread between the traveller 4 and the draw rollers constant. For this purpose the transformer primary 18 includes a series resistance 17 which is variable in accordance with the position of a movable lever 16 controlled by a cam 15. The cam 15 is frictionally supported by a sleeve 11 on a stationary rod 12 and it is only moved upwardly when an abutment 14 on the rod 7 forces it to do so. The cam 15 thus moves in synchronism with the upward shift a of the ring rail 6. A similar arrangement 11<SP>1</SP>, 15<SP>1</SP>, 16<SP>1</SP>, 17<SP>1</SP> is associated with the primary winding 18<SP>1</SP> of the second transformer. The magnetic cores 19, 19<SP>1</SP> may be linked to the sleeve 8 through intermediate members adapted to shift the phase of movement of the magnetic cores 19, 19<SP>1</SP> relatively to the movement of the sleeve 8.