Abstract: A yarn false twisting apparatus is disclosed which has a control system which is designed to insure that the machine operator will properly complete the yarn thread-up procedure, and which also effectively precludes damage to the twisting apparatus if the thread-up procedure is not properly completed. The twisting apparatus includes a pair of yarn twist imparting members having cooperating friction surfaces for engaging a running yarn, a drive whorl which is operatively connected to the twist imparting members, and a pivotally mounted control arm which is connected to the drive whorl and which is pivotable between an operative position wherein the whorl engages a drive belt, and an inoperative position wherein the whorl is disengaged from the drive belt.

Abstract: A yarn false twisting apparatus is disclosed which comprises a pair of cooperating friction discs which define a twisting zone between opposed friction surfaces thereof. One of the discs is composed of a thin flexible material, and a pressure applying member is mounted adjacent the back side of the flexible disc for biasing the disc toward the other disc locally at the twisting zone to firmly engage the yarn passing therethrough. The discs are movable with respect to the pressure applying member such that the ratio of twist insertion to yarn speed may be varied. In one illustrated embodiment, the discs are mounted so as to permit selective placement on opposite sides of the pressure applying member and reversal of their direction of rotation, and such that either S twist or Z twist may be imparted, without changing the direction or location of the yarn advance.

Abstract: A yarn false twisting apparatus is disclosed which comprises a pair of cooperating friction discs which define a twisting zone between opposed friction surfaces thereof. One of the discs is composed of a thin flexible material, and a pressure applying member is mounted adjacent the back side of the flexible disc for biasing the disc toward the other disc locally at the twisting zone to firmly engage the yarn passing therethrough. The discs are laterally movable with respect to each other, and the pressure applying member is movable in a direction perpendicular to the movement of the discs, such that the ratio of twist insertion to yarn speed may be varied.

Abstract: A yarn false twisting apparatus is disclosed which comprises a support bracket which mounts a pair of twist imparting circular discs, and drive means including a whorl rotatably mounted to the support bracket so as to be tangentially contacted by a drive belt mounted to the central frame of a twisting machine. The support bracket is mounted to the central frame for pivotal movement through 180 degrees to thereby permit selective operation in a first position wherein S twist is imparted to the yarn, and a second position wherein Z twist is imparted to the yarn. Preferably, one of the discs is composed of a thin flexible material, and a pressure applying member is mounted on the support bracket for biasing the flexible disc toward the other disc locally at the twisting zone.