Patent GB-872889-A (GB)
Title: Apparatus for producing yarns with opposed torques and yarns with opposed twists
IPC: D02G1/02
Filed: 1957-07-30
Abstract: 872,889. Apparatus for producing yarns with opposed torques or twists. FLUFLON Ltd. July 30, 1957 [July 30, 1956], No. 24050/57. Classes 120(2) and 120(3). Apparatus for producing yarns having a torque or twist in one direction in some sections of their length and a torque or twist in the opposite direction in other sections, such as are described in Specification 834,415, has means for reversing the direction of false-twist or twist applied to a running yarn. Yarns suitable for treatment may be in the form of continuous monofilaments, multifilaments or spun staple fibres which display thermoplastic properties, such as nylon, or are non-thermoplastic but have been moistened or impregnated or coated with a thermoplastic or thermosetting material or have been moistened; alternatively, yarns capable of being. cold drawn may be employed. The torque or twist may be in opposite directions over equal lengths, amounts of torque or twist in successive sections may vary, or sections of yarn may be without torque or twist, or the yarn may be without torque. When processing multi-filament or staple fibre yarns the torque may or may not be such as to cause bulking and in monofilament yarns there will be torque without bulk. Using one form of apparatus, Fig. 5, yarn from a supply P passes through a tension device 35, heater 36 and false-twist spindle 39, and is taken up on a spool S driven by a variable-speed motor 72 controlled through a rheostat 76 by a cam 78, the setting of which determines the amount of twist inserted. The false-twist spindle 39 is rotated by a variable speed motor 67 controlled by a cam 77 through a rheostat 75 and also by a reversing contactor 82 and a timing switch 83. Setting of the cam 77 determines the spindle speed and, consequently, the amount of twist per unit length imparted, and setting of the timing switch 83 determines the length of yarn having either direction of torque. A modification of this apparatus has false-twist spindles geared in pairs for treating separate yarns and cam mechanism for bringing the spindles alternately in to contact with the driving belt. A further modification has the spindles driven by individual electric motors. Another form of apparatus, Fig. 12, employs two false-twist spindles 324, 325 and two heating elements 322, 327. By means of cam-operated guides 323, 328 which move the yarn into and out of contact with the heating elements 322, 327, a torque imparted by one or other of the spindles 324, 325 is set in the yarn. Double twist spindles may be used to produce yarns having combinations of opposite twists with or without no-twist sections. A double-twist spindle 431, Fig. 14, is belt driven from a variablespeed, variable direction motor and has a tension device 435 carried on the package 430. It is stated that, by de-energizing the heater and relaxing the tension device, the twisted yarn may be caused to exhibit maximum torque in the directions opposite to the twists, whereas, by controlling the heater and/or the tension device to yarn-set, the yarn exhibits minimum torque. Specifications 803,107, 809,606 and 834,551 also are referred to.