Patent GB-558963-A (GB)
Title: Improvements in or relating to the stretching of filaments or threads
IPC: D01F2/28
Filed: 1942-07-20
Abstract: 558,963. Stretching threads &c. JACKSON, T., and FREARSON, T. B. July 20, 1942, No. 10089. [Class 120 (iii)] [Also in Group IV] Filaments or threads are subjected to stretching in presence of a softening medium and are taken up, after stretching, by means of a twisting and winding device as fast as they are fed to it, and the tension exerted by the twisting and winding device is utilized to initiate the stretching. Stretching may be effected in a chamber containing a fluid softening agent under pressure and the threads may be supplied to this chamber through a feed chamber containing an iner fluid under pressure. The process is specially applicable to the stretching of cellulose acetate on other cellulose organic derivative threads. Where steam is used as softening medium, the wall between the feed chamber and stretching chamber is preferably of substantial thickness, and in order to facilitate initial threading up through the partition, a tunnel of substantial cross-section, closed at one or both ends by means of a plate with a small orifice, may be provided for passage of the thread. Alternatively an injector device may be provided, the thread being carried into the chamber by a jet of water or other inert fluid. The take-up device may be a ring-, flyer-, or cap-spinning device. As shown in Figs. 1 and 3, several threads 1 are taken from bobbins 50 and twisted and wound on ring-twisting spindles 2. Each spindle has a bobbin-brake 9. The stretching unit comprises input roller 10, feed chamber 11, stretching chamber 12, and output roller 13. Thread 1 passes from chamber 11 to chamber 12 through a passage 18 in partition 15, the end of the passage being closed by plate 19 which has a small hole for the thread. The partition is hollow and cooling water may be circulated through cavities 20. Water under pressure is supplied to chamber 11 through openings 23 and is directed towards the partition 15. Steam under pressure is supplied to chamber 12 through openings 21. A feed chamber and stretching chamber may be provided for each thread. The flow of steam to header 30 is controlled by the pressure in the steam header and the flow of water to header 31 is controlled by the pressure in the water header. Feed chamber 11 contains rollers 36, 37 between which the thread passes. Roller 37 is carried in slot bearings and held in contact with the lower roller by springs. The two rollers are geared together. The input roller 10 is freely mounted on shaft 43 and is driven from the same shaft 42 as is roller 36. A nip roller 46 mounted on a pivoted arm 47 engages with roller 10. Roller 36 rotates slightly faster than roller 10. Output roller 13 and nip roller 56 stretch the thread. When roller 56 is pivoted away from roller 13 the thread is engaged by guide 59 which lifts the thread clear of roller 13. A control member 61 controls brake 9 on the ring spindle 2, the nip roller 56 and guide 59, the steam and water valves 34, 35, and clutch 48 through which input roller 10 is actuated. The rods and cams attached to control member 61 are constructed so as to control the various parts of the apparatus in the desired sequence. When the operation is started, the brake 9 is released and roller 10 is set in motion, and the water and steam supplies are turned on. The thread is drawn by the tension exerted by the bobbin 8. When the requisite degree of stretch is nearly attained, the output nip roller 56 is brought into contact with the rotating roller 13 which then effects the desired stretching. Specifications 438,584, 438,587, 443,707, 443,773, 465,780, 537,962, 540,108, [all in Group IV], and 558,958 are referred to.