Patent GB-962491-A (GB)
Title: Improvements in converting continuous filament to staple fiber
Inventor: SUMNER GEORGE VIBERT
IPC: D01G1/10
Filed: 1962-05-10
Abstract: 962, 491. Stapling fibres; spinning yarns, sliver guides; twist tubes and twisting machines. SUMNER CO. Inc. May 10, 1962, No. 18001/62. Headings D1D, D1F and D1N. A twisted tow of continuous, man-made e.g. viscose rayon, ethyl cellulose, cellulose acetate, nylon, acrylic or casein, filaments is converted into staple fibre by cutting the tow continuously longitudinally down the centre so that it is completely severed into two slivers which may be condensed, drafted or spun separately and/or blended or combined with similarly converted fibres, Figs. 9 and 10 (not shown). The twist in the tow may be changed to vary the staple length and untwisted or previously twisted tow may be twisted or untwisted and then retwisted immediately prior to entering a cutter, in order to ensure uniform twist and, therefore, staple length. In the apparatus shown in Fig. 1, twisted tows 41 are each positioned by and advanced through a trumpet guide 41<SP>1</SP>, thence pass between pressure rollers 27, 28 (gears 33, 34, between which permit some vertical movement of rollers 27) and are cut by the sharp, uniform or wavy edge of a band saw 35 travelling around pulleys 36, 37. Another conversion cutter, Figs. 11 and 12, comprises a multiple assembly of circular knives 47, bearings 51, shim spacers 511, locking sleeves 51<SP>2</SP> and feed rolls 52, 52<SP>1</SP> and a complementary assembly of spacer rings 61 (defining recesses for accommodating the knives 47) feed rolls 55, 58 with axially adjustable and integral flanges 64 and 65 or adjustable flanges, Fig. 17 (not shown) on gear shafts 48 and 54: each tow is fed between rolls 73, 74, 75, which retain the even twist, guided over lease rods 76, 77, around the rim of a feed roll 78 and between plates 81, over roll 55 and is severed by knife 47. The trumpet 41<SP>1</SP>, Fig. 15, which effects untwisting and retwisting of the tow, comprises gear-connected tubes 70 (-one for each tow) having a conical entrance 70<SP>1</SP>, cylindrical portion 70<SP>2</SP>, and a rectangular mouth 70<SP>3</SP> tapering internally at 70<SP>4</SP>; each tube is adjustably rotated in a housing 70<SP>6</SP> through driving gear 71<SP>1</SP> and pinion 71. In the operation of the apparatus shown in Fig. 18, multifilament flat ribbon as supplied directly from spinnerettes is withdrawn from a box or can 91 and passes over the outside of semi-circular bar 96, through a throat 105 with the turn-table rotating at such a speed as to impart initial twist to the tow averaging the final required twist. The twisted tow passes across a V-pulley or spool 115, through one trumpet tube of a laterally adjustable assembly 89 (similar to 41<SP>1</SP> which is rotated at such a rate as to untwist and correspondingly retwist the tow. On emerging at the end 147 of the tube, the retwisted tow passes between and around rolls 149, 151, and 153, 155, and 157, 159, being cut by a circular knife just in advance of the last roller gripping point. The cut sliver then progresses to the first rolls 181 of a gill box.