444,018. Control of two motors. SIEMENS - SCHUCKERTWERKE AKT.- GES., Siemensstadt, Berlin. Sept. 6, 1934, No. 25716. Convention date, Sept. 6, 1933. [Class 38 (iii)] [See also Group IX] Travelling to predetermined limits.-In a spinning-mule having at least two driving motors 1, 2 of which the motor 2 constitutes the spinning motor for driving the spindles during both the spinning and backing-off operations, means is provided whereby the motor 2 is electrically reversed for the backing- off operation and at the end of this operation is cut off from the supply mains by a switch, e.g. a relay, controlled by mechanism, e.g. the fallers, moved during backing-off so that the rotation of the motor 2 in the reverse direction is terminated at the commencement of the run-in. The motor 1 mounted on the headstock drives the delivery mechanism and effects the running in and out of the carriage and is controlled by a relay 11. The motor 2 is mounted on the carriage and is permanently coupled directly or through gearing with the tin rollers. It is controlled so as to be switched alternately to run right- and left-handed or to be cut out of circuit by two relays 21, 22. A safety switch 4 is provided in addition to the main switch 3. The relay 11 is operated by closing the spring returned press button switch 5 or the switch 6 in parallel thereto and operated by the carriage, and locks over the self-holding contacts 12. The motor 1 is switched in by the relay 11, a brake lifting magnet 10 being energized and thereby releasing an adjustable brake. The relay 11 also closes through contacts 12 a starting circuit for the motor 2 extending through the switches 14, 15, the exciter winding of relay 21 and the normal contacts 24 of relay 22. The relay 21 operates and energizes the stator of the motor 2 for right-hand running. The rotor is connected through the contacts 26 to resistances 27, 29 which at first are in the rotor circuit so that the spinning motor 2 is gradually accelerated. After a certain time the resistance 29 is cut out by the relay 30 and the motor 2 runs up to desired speed. A contact 25 of the relay 21 arranged to switch in a slow acting relay 33 serves for a switch in the rotor relay 30. The exciter circuit of relay 33 is extended through contacts 31 on the rotor relay 30. After a predetermined time the relay 33 closes its contacts 34 and switches in the relay 30 which locks up over the self-holding contacts 32. The relay 33 then releases since its exciter circuit is interrupted at contacts 31. The spindles then run at full speed until the end of the outward run and the spinning motor 2 continues to run until the desired twist is put in when the switch 14 is operated by the twist wheel and the exciter circuit of relay 21 thereby broken. At the same time the bottom contact 16 of the switch 14 is closed and the relay 22 operates as soon as the relay 21 has fully released and closes its normal contacts 23. By means of the relay 22 the spinning motor 2 is reversed for backing-off and thereby rapidly stops and then runs in the opposite direction, this action being controlled by a resistance 35 brought into circuit by closing the contacts 28 on the relay 22. When backing-off is completed the switch 15 is automatically opened, e.g. by the fallers, and interrupts the exciter circuit of the relay 22. This switch remains open during the inward run and is only again closed for the commencement of the next outward run. The switch 14 is re-set to the position shown at the commencement of the inward run which is effected in known manner by the motor 1. During winding-on which is controlled by the quadrant, the rotor of the motor 2 is switched out and rotates under no load. When the carriage has been fully run in the switch 15 is closed and the next run commences. To stop the mule during working either press button 7 or the switch 8 controlled by the carriage is opened so that the relay circuit for the motor 1 and also the control circuit of the relays 21, 22, 30 and 33 are interrupted. The spinning motor 2 stops rapidly on account of the friction of the spindle bands and the brake control 10 is preferably adjusted to stop the motor 1 in synchronism therewith. The push knob 9 on the head-stock is used for forming the cop bottoms or to permit winding of a few turns on the lower end of the cop-tubes. On pressing the knob of the switch 9, only the forward relay 21 and the spinning motor 2 are switched in for right-hand running. A pole changing device 20 is provided to reverse the rotation of the motor 2 to give right- or lefthand twist. Instead of the speed being regulated by a slow action relay, the switching out of the resistance 29 may be controlled by a stop on the carriage, while one of the resistances 27, 29 may serve for backing-off instead of the resistance 35.