An Improved Automatic Yarn Piecing Apparatus for Ring Spinning Frame

摘要

1,186,946. Piecing yarns. TOYO BOSEKI K.K. and HOWA KOGYO K.K. 18 March, 1968 [19 Aug., 1967], No. 13104/68. Heading D1D. Apparatus moving along a ring-spinning frame to repair yarn breaks by uniting yarn extending from the affected spindle with that issuing from the delivery rollers of the corresponding drafting rollers, comprises a device to grip the end extending from the spindle and having a nip roller, means for leading the end through a space between the nip-roller and the delivery roller to the gripping device, means for shifting the device towards the delivery rollers until the nip roller engages the lower delivery roller, means for breaking- off the excess yarn held in the gripping device and means for releasing the yarn after the breaking operation. In a preferred form, the yarn to be united is a supplementary length wrapped around the affected package and taken from the reserve cop, and means are provided for threading the yarn through the traveller before it is taken-up by the gripping device. General description of the device. The various piecing elements are on a carriage, Fig. 3, supported by wheels 7, 8 on a rail (6, Fig. 2A not shown) below the spindle-rail, one of the wheels being driven. For transferring the carriage from one spinning machine to another, it has a trolley, or lower wheels one of which is driven. When a detector 10, 32 finds a broken yarn, the motor driving the carriage is stopped, a brake 57 is applied, and the elements are brought into register with the affected spindle by members 53, 70. A device 28 brakes and may take over the drive of the affected spindle; a "nipper" moves down a guide 21 to transport the end of a supplementary yarn, held in reserve at 22 and taken from a cop at 113, and present it to a "winding- device" which has moved downwardly along guides 21, 26 to the ring-rail, the movements of which it is caused to follow. The winding device has means to position and re-thread the traveller and to transfer the yarn to the affected package. The yarn now extends between the package and the reserve in the space between a "gripper" and the drafting rollers. The gripper is advanced to bring the yarn into contact with the sliver and break off the excess length of yarn. The various elements are controlled by program-cams on a rotated shaft, the sequence of which is described (Fig. 20 not shown). The success of the piecing operation is checked by the detector; if a number of unsuccessful operations are detected, the apparatus is stopped and an alarm given. The application of the gripper is described. in relation to the apparatus of Specification 908507 where the yarn end to be united with the sliver is unwound from the bobbin. The detector is photo-electric and keeps the carriage moving as long as vibrations of an unbroken yarn are detected, extraneous vibrations, arising from reflections from fly or machine parts, being filtered out. A receiver 10, Fig. 4, is in circuit; with a transducer and filter 35, a shaper 36, a Counter 37, a memorydevice 38, a gate-circuit 39 and a relay 43. Connected to 39 are a detector for the presence of a spindle 40 that is in circuit with a shaper 41 and a delay timer 42. When no signal is received at 10 and a signal is received at 40, a pulse is generated to actuate the relay and stop the carriage and actuate the piecing- elements. So that the success of the piecing operation can be checked, the carriage having begun to travel again, the light source and receiver (31, 32, Fig. 6B not shown) are displaced to face back to the position where the operation has taken place. They are accordingly on a bracket, moved, against the tension of a restoring-spring, by a wire actuated by one of the program-cams. When a given number of failures is counted, the carriage is stopped and an alarm actuated. Carriage braking and registering Fig. 7. When a break is detected, the carriage is braked as an electro-magnet is energized to lower a brake 57 on to a rail 59 on the spinning-machine. The position of the carriage is approximated to that of the affected spindle when a second electromagnet 61 is energized to rock a shaft carrying a fork 70 and cause it to engage one of a series of pins 11 on the spinning-machine. The distance of the pins is a multiple of that of the spindles. The fork can move along the shaft 67 between a stop 69 and a cushioning-spring 71. Precise registration of the carriage is effected by a second fork having a number of flared recesses 54 which is raised by rack and pinion when a reversible motor 73 is energized. The number of the recesses corresponds to the spacing of the pins 11. Spindle braking and controlling. So that the supplementary yarn can be wound on the spindle, the latter is braked, and its drive may be taken over by, a friction-pulley 83, Fig. 10A, which is moved forward to engage a supplementary pulley (14, Fig. 2A, not shown). on the spindle below the wharve, on which meanwhile the driving-tape slips. The pulley 83 is on a slide 87 which is projected when a lever 95 is rocked about, a shaft 93 under the control of a program-cam, either by energizing an electro-magnet or by the engagement of a cam, with a roller 111. The pulley having stopped, the spindle may be rotated to drive the spindle in winding-direction by a motor 97. "The nipper" comprises a tube 23, Fig. 11, which is raised along a vertical guide 21 as a chain 27 is driven in one direction, and allowed to fall by gravity as the chain is driven in the other direction. The nipper grips the supplementary yarn, as it descends and presents the end to the winding device, and releases the yarn as it ascends, so that the nipper is free to slide over the yarn. The tube includes a yarn grip between one end 116 of a pivoted L-lever and a surface 122, one arm of the L being under the pressure of a spring 121 and the other of a retractable wire 124 controlled by a cam. The wire is retracted to close the grip while the nipper descends and is projected to open the grip while the nipper ascends. To avoid undue tension in the yarn when it is presented to the winding device, a reserve length is established at 22 by causing the yarn to take a zig-zag path over fixed and movable guides; as the nipper descends the reserve is released to relieve the tension, by moving the movable guides to straight the yarn path by a lever under the control of a program-cam (Figs. 12A, 12B not shown). The "winding-means" comprises a platform rising and falling under the control of a chain 27 as described in the case of the nipper. So that the platform can follow the traversemovement of the ring-rail, during its descent, the platform rests on a stop on the chain; as the stop descends, the platform comes to rest on the ring-rail while the stop continues to descend to a predetermined point. So that the nipper can follow the movements of the platform, there is a distance-member between the two. The platform, Fig. 14, carries five devices for threading the yarn through the traveller and attaching it to the spindle (a) a nozzle 155 which, under the control of an electromagnetically operated valve, ejects air tangentially of the inside of the ring, (b) a traveller stopper 151 which is advanced to the position shown by a spring 158 when a wire 152 is relaxed, (c) a nozzle 159, Fig. 15, comprising a tube with a mouth 163a, and a slit 163b, and a tube 165, the mouth and slit being initially disposed as shown. When air is blown through tube 165, the yarn presented by the nipper is sucked into the mouth, and when the tube is rotated to bring the slit uppermost, the yarn is released from the tube to be blown by air from nozzle 55 on to the package. The yarn may be moistened, and the package rotated as described above, to assist this operation. Rotation of the tube is effected by a spring 167 when a strap 168 is relaxed by a wire 170, (d) a presser foot 174 which is normally retracted, but is advanced by a spring 181 when a wire 180 is relaxed; during the advance the foot is turned through 90‹ by the pin-and slot arrangement shown to bring a suitable curved part of the foot beneath the upper flange of the ring, (e) a nozzle" 148 which emits a jet of air under the control of an electromagnetically-operated valve. Air is first blown out of nozzle 155, whereby the traveller is blown around the ring; the nozzle 159 is operated to take the end from the nipper, for air from nozzle 155 to attach it to the package; the stopper 151 is advanced to stop the traveller; the foot 174 is advanced to grip the yarn, which now lies across the upper flange of the ring, between it and the ring; stopper 151 being retracted, air is blown from nozzle 148 to move the traveller around the ring, to ride over an inclined end of the foot and re-thread it, and finally tube 163 is rotated to bring the slit uppermost and release the yarn. The "gripper" means, Fig. 18A, is disposed at the level of the lower delivery roller 215a of the drafting-set. It comprises two cooperating parts, (i) a roller 198 on a cradle at the end of a rack 188, a gripping surface being formed on the upper face of the cradle 193, and (ii) a gripper 204 on the end of a rod 201 in a fixed bracket 186, which can slide forwardly, against the force of a spring 202, when a stop 205 on the end of the rack engages the rear end of the rod. When the nipper 23 is raised after presenting the yarn to the winding device, the yarn between it and the package lies between the gripping member 204 and the roller 198. As the rack is advanced (through gearing actuated by one of the programme-cams), the roller first engages the yarn and then moves beyond the member 204 so that the yarn is gripped between the member and the upper surface of the cradle 193. As the rack continues to advance its end engages the rod 201 and moves it forward so that part of the yarn is nipped between rollers 198 and 215A, and part is stretched over a c