GB1189521A - Method and Apparatus for Conveying and Twisting a Strand - Google Patents

Abstract

1,189,521. Suction device for textile machine. LEESONA CORP. 9 March, 1967 [14 March, 1966], No. 11121/67. Headings DID and D1F. [Also in Division F2] In a method of transporting the free end of a strand, the end is moved through a predetermined path which twist is inserted into the srand. The strand may be a broken roving issuing from the drafting rollers of a ring- spinning machine, and the means for moving and twisting it may be a nozzle 288, Fig. 2, which may be moved either to rejoin the roving to the other end of the break on the package, or to attach it to a fresh bobbin donned to replace the original package. In both cases the strand is rethreaded automatically through the traveller. The nozzle is one of a number of elements on a carriage patrolling to and fro along the machine which stops and services a position where a break is detected. First form of apparatus The carriage moves by means of rollers 78, 80 running on rails 74, 76 attached respectively to the base and spindle-rail of the frame. One roller is driven by a timing-belt from an airmotor 96, Fig. 1, which allows the carriage to halt when locked by means to be described. The motor is reversible by a solenoid-operated valve 104, controlled as a switch 108 engages end-stops, and can operate at two speeds determined by the condition of a throttle 106. The motor, together with other air-using devices on the carriage, is supplied from an accumulator 94 fed by a compressor driven by a motor taking current by a shoe from a bus-bar within the rail 74. When electric and compressed air points are provided beneathe the carriage, the latter may be connected to them by the means described in Specification 21756/66, 1,189,523. Carriage-braking and registering means. The spindle rail has recesses 129 Fig. 4 corresponding in spacing to the spindles. As the carriage moves along the rail, a roller 133 on the armature of a switch 132 on the carriage falls into successive recesses. When a sensing-feeler closes a switch 380 on failure of a thread, a solenoid 652 {see Fig. 30) is energized to operate the throttle 106 to reduce the speed of the carriage, a solenoid 144 is energized to project a detent 153, and a solenoid 646 is energized or deenergized, according to the position of the reversing-switch 108, to operate a valve 104 to reverse the direction of the carriage. The momentum of the carriage has caused it to over-run the position of the affected spindle, operation of valve 104 causes the carriage to be braked and finally to go into reverse, the detent 153 falling into a recess to arrest its motion while the air-motor stalls. In case the carriage, owing to some defect, proves unable satisfactorily to service a particular position, slidable bars 156, each with an operating tab 160 are provided adjacent each recess. One of thsee bars is operated, to mask the recess concerned, so that the carriage rides past it, by energizing a solenoid 162 for its armature to engage the tab. The bar is moved back by hand when the defect has been rectified. The thread-feeler is of looped form 376, Figs 13 (and 16, not shown) so that it can effectively seek a broken end whichever way it is moving. It is pivoted at 374 and is normally held up by the yarn, and actuates a switch 380 when it falls. To clear the position for doffing, the feeler can be retracted, to which end, it is on a slide 370 controlled by an air cylinder 382 on the carriage. As the feeler will fall between adjacent threads the switch 380 is effective only when the carriage is in register with a spindle position (see Fig. 30). The upper thread guide may also be adapted to serve as a thread-feeler as described in Specification 21758/68. Upper thread-guide moving device. The upper thread guides 40 Fig. 13 can be individually moved upwardly to facilitate doffing. Each has a pin 340 which can be operated by the piston 344 of an air cylinder 346 on the carriage and slung beneath the cylinder 382. Spindle braking device. The spindle receiving attention can be stopped individually by a brake 172, Fig. 2, operated by an air-cylinder 678, Fig. 30 or 1158, Fig. 49 and which engages the upper flange of the wharve 49. Full bobbin cut-off device. This is as described in Specification 21757/68, 1,189,524 and acts by severing the yarn to halt the carriage to service the position. The donning and doffing device, comprises a head 262 Figs. 1 and 2 that can rise and fall vertically and be swung between a spindle and a container for full and empty bobbins around a post 230. The head is carried by a rod 252 that can slide on guides on an arm 250 fast with a rod 232 rotatably housed in the post. The rod can be rotated to swing the head as a sprocket 234 fast with it at one end is rocked by a chain 236 that is connected to an air-cylinder 242. The head can be raised and lowered by the piston of an air-cylinder 256 which bears against the top of the rod 252. The head comprises three pivoted arms 264 that can be closed to grip, and opened to release, a bobbin, as a conical cam 270 is lowered and raised as a bellows 272 is inflated and exhaused. Holders for full and empty bobbins are provided on the carriage. The empty bobbins are in a holder formed between vertical side walls by a curved plate 188; at its forward end the holder has a gate-compartment 190 capable of transferring, when it is swung about vertical pivots, a single bobbin from the front of the supply to the point reached by this doffing-head when it is swung away from the spindles. There are supports 200 for the bobbin in the gate; a detent 212 to control the release of the bobbins into the gate; upper and lower means 202 to guide the bobbins into the gate; and a feeler 216 of a switch 218 to detect exhaustion of the supply. When the gate is retracted, the space reached by the doffing- head lies above a curved guide 222 leading to a store for filled bobbins. End finding and twisting nozzle has a bore into which the yarn is sucked and in which the yarn is twisted by pressure-air entering the bore in a vortical path. The bore is in part 290, Fig. 8, with end portions 292, 294 of reduced diameter. Where the parts 290 and 292 meet, there is a bevel 296 through which downwardly-inclined bores 298 are made to meet the bore tangentially. The part 294 is pressfilled into an enlarged tubular part 306 having a bore 20 flaring downwardly. The outside of the part 306 is threaded to receive a cap 312, Fig. 10, such as to provide an annular space 316 communicating with the bores and which is connected to air under pressure at 318. The nozzle is mounted on an end of a rod 330 movable along a curved guide between an inoperative position and an operative position near the drafting rollers. The rod is moved as a chain connected to it is moved into and out of a storage tube 326 as a sprocket 327 is driven by a motor 328. Limit switches 336, 338 determine the end positions of the nozzle. Beneath the outlet of the drafting-rollers is a suction device 69 to take up the end when a yarn breaks. When the nozzle is brought near the rollers it withdraws the end from the device and gives it twist. So that the nozzle can find the end, it is moved to and fro along the rear rollers by a fork 256<SP>1</SP>, Fig. 13 at one end of a centrally-pivoted arm the other end of which is oscillated by an eccentric pin on a disc 361 driven by a motor 364 on a slide 352 on a platform 350. With the nozzle in position near the rollers, the slide is projected forwardly, for the arm to engage a pin 362 on the nozzle, by an air-cylinder 366. Sub-carriage Fig. 3. Some of the parts are mounted on a sub-carriage that follows the movements of the ring rail. Upstanding from the base 70 of the main carriage are posts 112 supporting a platform 110. The platform is suspended from posts 112 by, in the case of each post, a cable 116 over a pulley 124, its weight being counter-balanced by a spring 120. The platform is caused ot follow the movement of the ring-rail by rollers 128, 130, above and below a member 126 fixed to the rail. Traveller-threading means: means for severing and attaching the thread-end to a fresh bobbin. These means are mounted on the platform 110. the vortex nozzle 288 is moved to a position below the ring-rail so that the yarn extending from the draft rollers lies over the edge of the spinning-ring. A fork 400, Fig. 19, is advanced by an air-cylinder 406 (fig. 17 not shown) to engage the yarn and cause it to move across the outside o'f the ring. As the fork advances, a slot 394 rides past fixed guidestuds 398 on a support 390. The end of the slot is curved so that towards the end of its travel, the fork-end 400 is moved over the top of the ring towards the spindle. Air from a jet 420 is now blown against the inside of the ring blowing the traveller along until it rides over and engages the yarn. A second fork 460, 464, Fig. 23 is now lifted to engage the yarn between the traveller and nozzle, and cause it to liey as a chord across the ring. This is on the end of a two-part lever 434, 436, Fig. 22 pivoted at 432 to a panel on the platform and moved by an air-cylinder (442, Fig. 17 not shown) adjustably linked to it at 450. The yarn is severed by a moveable shear-blade on a lever 460 pivoted to the lever 436. The lever 460 has a handle 468, which, as the two-part lever is raised, engages the stop shown to move the blade against a fixed blade 464. The end thus freed is drawn and given twist in a tube 488 leading to a second vortex nozzle 486 similar to the first nozzle 288; when a bobbin is placed on the spindle, the nozzle is lowered for the yarn to be caught in a notch on the base of the bobbin as the bobbin rotates. (See Specification 21759/68) 1,189,526. Roving-severing device. In circumstances to be referred to later, it is desirable to sever the roving before it reaches the drafting-rollers. This is done by a knife 282 which can be projected by an air-cylind