Patent GB-1121942-A (GB)
Abstract: 1,121,942. Forming yarns. COMMONWEALTH SCIENTIFIC & INDUSTRIAL RESEARCH ORGANIZATION. 22 Oct., 1965 [28 Oct., 1964], No. 44875/65. Headings DID, D1F and D1W. [Also in Division F2] Apparatus for imparting in a yarn alternate zones of opposite twist comprises a pair of forwardly moving surfaces e.g. the surfaces of rubber covered rollers 7, 8, arranged to form a nip and forward the yarn, the surfaces also being reciprocated out of phase and transverse to the yarn to impart the alternating twist. In the roller pair 7, 8 of Fig. 1 the rollers are reciprocated along their axes. In Fig. 1, a pair of strands are passed through drafting apparatus 6 through the forwarding and twisting rollers 7, 8 and then brought together at a guide 9 whereafter the strands twist themselves together before being wound up on a package 10. More than two strands may be passed through the apparatus. Guide 9 is separated from the twisting point by a distance less than the length of a twist zone. The amplitude of the reciprocation is not less than 0.6 x the twist zone length and at least 80 x the twisted strand diameter. The forwarding speed of rollers 7, 8 is preferably equal to that of the preceding drawing rollers. The separation of rollers 7, 8 is preferably not more than half the diameter of the untwisted strand. An example is given with specific dimensions. Guide 9 may be replaced by a guide such as described in Specification 1,015,291 to provide an extended path of one of the yarn components. Roller driving and reciprocating In Fig. 2, not shown, rollers (7, 8) are slidably keyed on driven shafts and are reciprocated therealong by yokes moved by belts, bands or chains (19, 20) driven by an oscillating crank driven wheel 21. Alternatively the roller shafts may reciprocate through the drive gears keyed thereon or the rollers may be moved on hollow shafts by lugs projecting through slots in the shafts and reciprocated by chains. In the embodiment of Figs. 7-12, not shown, rollers (7, 8) are fixedly mounted on shafts (14, 12) mounted at each end to epicyclic gear arrangements wherefrom the rotating and reciprocatory motion is derived. Each epicyclic drive unit (30, 31) comprises, see Figs. 9-12 not shown, a fixed internal gear (35) engaged by a pinion (46) of half diameter mounted in a body portion (37) which is rotated by gear (40) to run the pinion around the internal gear. A spindle (53) is mounted on a crank (47) on the spindle (43) on pinion (46) overlying the outer rim of the pinion so that the spindle (53) is reciprocated along a diameter of internal gear (35). The shaft (11) of roller (7) is attached by a housing to spindle (53) so that roller (7) is reciprocated along its length. Mounted on crank (47) and encircling spindle (53) is a bevel gear (49) which rotates and drives roller (7) through bevel gear (57). The speed of rotation being determined by the ratio of gears (49, 57). The epicyclic devices 32<SP>1</SP>, 33<SP>1</SP> carrying the non-driven ends of the shafts being similar to devices (30, 31) but not being driven. In Figs. 21-26 not shown, there is a similar arrangement shown but the pinion is positioned outside the fixed gear and the two are connected by an intermediate gear. In Fig. 20, not shown, the roller (7) is mounted in a hollow shaft (76) carried by air bearings the shaft and roller being reciprocated and rotated by an epicyclic device. Exhaust spaces (84) are provided in the bearing to prevent air blowing along the shaft to the roller.