Abstract: The invention relates to a process for piecing on a machine for producing core spun yarns, said process comprising the following successive steps of: taking off a broken end of a core spun yarn formed from the receiving member, (for example a reel); exposing the internal core of said yarn over a pre-determined length; connecting the core thus exposed with the end of the elementary core yarn; introducing the bared core into the fiber distribution system; distributing the fibers on the core downstream of the point of join; and advancing and winding normally. The invention also relates to a device for carrying out this process.

Abstract: Method for producing a fiber spun yarn of the type in which parallelized elementary fibers are joined to a textile core, subjected to a false twist, said fibers being projected on the core, upstream of the false twist spindle.According to the invention, in the fibers projection zone, the core is guided into a channel with an open face which is situated in facing relation to the elementary fibers projection zone and the surface of which is subjected to a flow of fluid tending to exert a pulling force on the end of the fibers.

Abstract: The invention relates to a process and device for making a spun yarn of fibres comprising an internal core which consists in subjecting the yarn to form the core to a momentary false twist by means of a spindle and projecting elementary fibres onto this yarn. Such elementary fibres are projected by means of a mobile guide surface on which the fibres are delivered tangentially, the core likewise being displaced tangentially with respect to the guide surface in a direction concurrent with the direction of delivery of the fibres.

Abstract: A drive system for a drawframe for a rove drawing process in which the drawframe includes at least one pair of feed rollers, at least one pair of sleeves, at least one pair of drawing rollers, and at least one swinging arm on which one feed roller, one sleeve and one drawing roller of each pair is supported, the swinging arm being displaceable between an inoperative position and an operative position where the pair of feed rollers, pair of sleeves and pair of drawing rollers are engaged under pressure for rove drawing. The drive system includes a drive shaft and at least one displaceable friction clutch roller which is displaceable between an operative position to engage both the drive shaft and one of the feed rollers for transmitting drive from the drive shaft to the feed roller, and an inoperative position where it is disengaged from the feed roller, the friction clutch roller being displaceable into its operative position to allow progressive engagement of the drawframe at start up.

Abstract: A machine for producing self-twisting yarns has a plurality of working positions at each of which is means for feeding a yarn to be treated and means for treating the yarn, there being an operator access zone between them. The means for treating the yarn include, arranged vertically, a positive yarn delivery device, for delivering two yarns in parallel, means for imparting an alternate twist to at least one of the two yarns, and for permitting the self-twisting of the two yarns around one another, and means for winding up the yarn produced.

Abstract: A process for producing a yarn with alternate twist, which is obtained by intermittently varying the distance which the twist extends back upstream of a false twister. The variation in the distance is produced without braking the yarn and is achieved by means of a blocking device acting intermittently at a point located close to the false twister. The duration of action of the blocking device approximately corresponds to the time taken by a given point on the yarn to cover the distance from a delivery member to the false twister.

Abstract: Apparatus including two endless aprons, one operating inside the other, the top strands thereof forming a contact zone therebetween. The aprons are angled with respect to each other preferably between 130 and 150 degrees. The yarn applied through the zone is twisted upstream of the zone with respect to a variably adjustable, insertion length stop. The yarn can be heat treated, if desired, upstream or downstream of the contact zone. Alternatively, two or more yarn strands also can be false-twisted in parallel paths through the zone and joined thereafter. By changing the length of insertion of one strand with respect to the other, alternated twist is provided to the combined yarn.