Abstract: Improved yarn spinning-in process and apparatus in open-end rotor spinning units which raises the quality of the spun-in point in the yarn to a level comparable with the quality of the entire yarn length. The yarn open end is pieced on to high-quality fibers while low-grade fibers are separated from the high-quality fibers and do not participate in the spinning-in process.

Abstract: The invention relates to an apparatus for the spinning-in of yarns in an open-end rotor spinning unit. The apparatus includes a spinning-in device for returning yarn end through a take-off duct into the spinning rotor, a severing device for shortening the yarn end to a predetermined length, and a withdrawing duct which communicates with the take-off duct and which is designed, on the one hand, for holding the yarn end by the action of a vacuum which, in the contact region of the two ducts, exceeds the working vacuum in the take-off duct, and, on the other hand, for withdrawing the severed yarn end. In accordance with an essential feature of the invention, at least one air nozzle opens into the withdrawing duct which during both spinning and spinning-in processes is connected to a subatmospheric pressure source, which nozzle is designed for introducing a fresh yarn end into the take-off duct by a controlled air outflow in a particular phase of the spinning-in process.

Abstract: A heating installation equipped with a radiation- and convection floor heater for heating a room by means of a liquid heat carrier, comprising a device for heating the heat carrier, a circulation pump for circulating the heat carrier, and inflow line and return flow line for the heat carrier. The room is heated by a radiation- and convection floor heating element comprising a pipe through which flows the heat carrier. The pipe is arranged in a hollow space having a starting portion and a terminal portion. The hollow space is further provided with an inflow opening and an outflow opening. The starting portion of the hollow space communicates via the inflow opening with the heated room and the terminal portion of the hollow space communicates via the outflow opening with the heated room. The heated air in the hollow space, which flows through the heated room, is circulated by natural ventilation or forced ventilation.

Abstract: Apparatus for separating cotton type staple fibers from a fibrous sliver supplied to an open-end rotor spinning machine, said apparatus having a surface for supporting the so-called fiber beard of the sliver to be attacked by a card clothing of the combing cylinder. The dimensions and position of said support surface relative to the sliver feeding means and said card clothing are defined in dependence on the count of the sliver as well as on the gauge and staple length of the fibers to be processed. Such an optimization of the support surface dimensions and position makes it possible to attain an excellent evenness of fiber separation and consequently a good final yarn quality even with relatively low speeds of the combing cylinder, and also to reduce the risk of card clothing damage.

Abstract: A method of and an apparatus for piecing yarn in open end rotor spinning units. The returning of the yarn end into the spinning rotor for piecing is performed in two stages, in the first of which the yarn is stopped immediately upon breakage within the sucking range of the spinning rotor, and is brought immediately thereafter into a withdrawal chamber in which the yarn end is retained. In the second stage the yarn end is separated and deposited in said withdrawal chamber, and the new yarn end is introduced by further reverse motion into the spinning rotor. The apparatus has a withdrawal chamber interposed between the inlet of the withdrawing channel and a cutting mechanism. In one embodiment said chamber is connected to the withdrawing channel, opposite which there is mounted a nozzle connected to a controlled pressure air source. In another embodiment there is provided a nozzle communicating with the withdrawal chamber, said nozzle being connected to a controlled source of underpressure.

Abstract: Open-end spinning unit having two housings connected to each other, a first housing containing a spinning rotor adapted to be supplied through a supply duct with separated fibers carried by an air stream while yarn is withdrawn therefrom through a take-off duct, the second housing containing a sliver supply roller and a combing-out cylinder followed by said fiber supply duct extending through a lid inserted into the spinning rotor and forming a part of said second housing, the spinning rotor being surrounded with an air collecting space adapted to collect the air to be withdrawn from the spinning rotor. The spinning rotor turns about a vertical axis of rotation and is driven by an individual motor through the axis of which the yarn take-off duct extends in an upward direction. The lower front part of the spinning rotor extends into a cavity provided in the top part of said second housing.

Abstract: Open-end spinning unit with a spinning rotor having a lower side and an upper side. A lid is inserted into a front opening provided in said lower side, said lid being bored so as to form a fiber supply duct to convey separated fibers into the interior of said spinning rotor. A yarn take-off duct extends through said upper side of the spinning rotor and conveys the yarn via an outlet port out of the interior of the spinning rotor. A separator is secured to said lid and is designed to divide the rotor interior into a fiber supply zone and a yarn producing and take-off zone.